text: The explosion and fire threw hot particles of the nuclear fuel and also far more dangerous fission products, radioactive isotopes such as caesium-137, iodine-131, strontium-90 and other radionuclides, into the air: the residents of the surrounding area observed the radioactive cloud on the night of the explosion.

text: The explosion and fire threw hot particles of the

entity_name: Nuclear fuel

text: nuclear fuel

text: and also far more dangerous

entity_name: Nuclear fission product

text: fission product

text: s, radioactive isotopes such as

text: and other

entity_name: Radionuclide

text: radionuclides

text: , into the air: the residents of the surrounding area observed the radioactive cloud on the night of the explosion.

text: According to Jiri Hala's textbook, the radioactivity in the fission product mixture in an atom bomb is mostly caused by short-lived isotopes such as I-131 and Ba-140. After about four months Ce-141, Zr-95/Nb-95, and Sr-89 represent the largest share of radioactive material. After two to three years, Ce-144/Pr-144, Ru-106/Rh-106, and Promethium-147 are the bulk of the radioactivity. After a few years, the radiation is dominated by strontium-90 and caesium-137, whereas in the period between 10,000 and a million years it is technetium-99 that dominates.

text: According to Jiri Hala's textbook, the radioactivity in the fission product mixture in an

entity_name: Nuclear weapon

text: atom bomb

text: is mostly caused by short-lived isotopes such as

text: and

entity_name: Barium

text: Ba

text: -140. After about four months

entity_name: Cerium

text: Ce

entity_name: Zirconium

text: Zr

entity_name: Niobium

text: Nb

text: -95, and

entity_name: Strontium

text: Sr

text: -89 represent the largest share of radioactive material. After two to three years,

text: Ce

entity_name: Praseodymium

text: Pr

entity_name: Ruthenium

text: Ru

entity_name: Rhodium

text: Rh

text: -106, and

entity_name: Isotopes of promethium

text: are the bulk of the radioactivity. After a few years, the radiation is dominated by

text: and

text: , whereas in the period between 10,000 and a million years it is

entity_name: Technetium

text: technetium

text: -99 that dominates.

method: dangnt-nlp

method: Bert-ConvKNRM

text: The U remaining after enrichment is known as depleted uranium (DU), and is considerably less radioactive than even natural uranium, though still very dense and extremely hazardous in granulated form – such granules are a natural by-product of the shearing action that makes it useful for armor-penetrating weapons and radiation shielding. At present, 95 percent of the world's stocks of depleted uranium remain in secure storage.

text: The U remaining after enrichment is known as

entity_name: Depleted uranium

text: depleted uranium

text: (DU), and is considerably less

entity_name: Radioactive decay

text: radioactive

text: than even natural uranium, though still very dense and extremely hazardous in granulated form – such granules are a natural by-product of the shearing action that makes it useful for

entity_name: Vehicle armour

text: armor

entity_name: Staballoy

text: penetrating weapons

text: and

entity_name: Radiation protection

text: radiation shielding

text: . At present, 95 percent of the world's stocks of depleted uranium remain in secure storage.

text: On Earth (and elsewhere), trace amounts of various elements continue to be produced from other elements as products of natural transmutation processes. These include some produced by cosmic rays or other nuclear reactions (see cosmogenic and nucleogenic nuclides), and others produced as decay products of long-lived primordial nuclides. For example, trace (but detectable) amounts of carbon-14 (C) are continually produced in the atmosphere by cosmic rays impacting nitrogen atoms, and argon-40 (Ar) is continually produced by the decay of primordially occurring but unstable potassium-40 (K). Also, three primordially occurring but radioactive actinides, thorium, uranium, and plutonium, decay through a series of recurrently produced but unstable radioactive elements such as radium and radon, which are transiently present in any sample of these metals or their ores or compounds. Three other radioactive elements, technetium, promethium, and neptunium, occur only incidentally in natural materials, produced as individual atoms by natural fission of the nuclei of various heavy elements or in other rare nuclear processes.

text: On Earth (and elsewhere), trace amounts of various elements continue to be produced from other elements as products of natural

entity_name: Nuclear transmutation

text: transmutation

text: processes. These include some produced by

entity_name: Cosmic ray

text: cosmic ray

text: s or other nuclear reactions (see

entity_name: Cosmogenic nuclide

text: cosmogenic

text: and

entity_name: Nucleogenic

text: nucleogenic

text: nuclides), and others produced as

entity_name: Decay product

text: decay product

text: s of long-lived

entity_name: Primordial nuclide

text: primordial nuclide

text: s. For example, trace (but detectable) amounts of

text: (C) are continually produced in the atmosphere by cosmic rays impacting

entity_name: Nitrogen

text: nitrogen

text: atoms, and argon-40 (Ar) is continually produced by the decay of primordially occurring but unstable potassium-40 (K). Also, three primordially occurring but radioactive

entity_name: Actinide

text: actinide

text: s,

entity_name: Thorium

text: thorium

entity_name: Uranium

text: uranium

text: , and

entity_name: Plutonium

text: plutonium

text: , decay through a series of recurrently produced but unstable radioactive elements such as radium and

entity_name: Radon

text: radon

text: , which are transiently present in any sample of these metals or their ores or compounds. Three other radioactive elements,

text: technetium

entity_name: Promethium

text: promethium

text: , and

entity_name: Neptunium

text: neptunium

text: , occur only incidentally in natural materials, produced as individual atoms by natural

entity_name: Nuclear fission

text: fission

text: of the

entity_name: Atomic nucleus

text: nuclei

text: of various heavy elements or in other rare nuclear processes.

method: UNH-ecn

text: Carbon has three naturally occurring isotopes. About 99% of carbon on Earth is carbon-12 (C), about 1% is carbon-13 (C), and a trace amount is carbon-14 (C). The  C and  C isotopes are stable, while C decays radioactively to nitrogen-14 (N) with a half life of 5730 years. C on Earth is produced nearly exclusively by the interaction of cosmic radiation with the upper atmosphere. A C atom is created when a thermal neutron displaces a proton in N. Minuscule amounts of C are produced by other radioactive processes, and a significant amount was released into the atmosphere during nuclear testing before the Limited Test Ban Treaty.Natural C production and hence atmospheric concentration varies only slightly over time.

text: Carbon has three naturally occurring

entity_name: Isotope

text: isotopes

text: . About 99% of carbon on Earth is

entity_name: Carbon

text: carbon

text: -12 (

text: C

text: ), about 1% is carbon-13 (

text: C

text: ), and a trace amount is carbon-14 (

text: C

text: ). The  C and  C isotopes are stable, while C decays radioactively to

text: nitrogen

text: -14 (

entity_name: Isotopes of nitrogen

text: N

text: ) with a

entity_name: Half-life

text: half life

text: of 5730 years. C on Earth is produced nearly exclusively by the interaction of cosmic radiation with the upper atmosphere. A C atom is created when a

entity_name: Neutron temperature

text: thermal neutron

text: displaces a

entity_name: Proton

text: proton

text: in N. Minuscule amounts of C are produced by other radioactive processes, and a significant amount was released into the atmosphere during nuclear testing before the

entity_name: Partial Nuclear Test Ban Treaty

text: Limited Test Ban Treaty

text: .Natural C production and hence atmospheric concentration varies only slightly over time.

text: A percentage of each group working in less contaminated areas was badged. Eventually, 18,875 film-badge dosimeters were issued to about 15% of the total work force. On the basis of this sampling, a theoretical total exposure was calculated for each person who did not have a personal badge. As expected, exposures for target ship crewmen who reboarded their ships after Baker were higher than those for support ship crews. The hulls of support ships that entered the lagoon after Baker became so radioactive that sleeping quarters were moved toward the center of each ship. Of the total mass of radioactive particles scattered by each explosion, 85% was unfissioned plutonium which produces alpha radiation not detected by film badges or Geiger counters. There was no method of detecting plutonium in a timely fashion, and participants were not monitored for ingestion of it.

text: A percentage of each group working in less contaminated areas was badged. Eventually, 18,875 film-badge

entity_name: Dosimeter

text: dosimeter

text: s were issued to about 15% of the total work force. On the basis of this sampling, a theoretical total exposure was calculated for each person who did not have a personal badge. As expected, exposures for target ship crewmen who reboarded their ships after Baker were higher than those for support ship crews. The hulls of support ships that entered the lagoon after Baker became so radioactive that sleeping quarters were moved toward the center of each ship. Of the total mass of

entity_name: Hot particle

text: radioactive particles

text: scattered by each explosion, 85% was unfissioned plutonium which produces

entity_name: Alpha decay

text: alpha radiation

text: not detected by film badges or Geiger counters. There was no method of detecting plutonium in a timely fashion, and participants were not monitored for ingestion of it.

text: Due to an anticyclone south of Japan, favorable westerly winds were dominant during most of the first week of the accident, depositing most of the radioactive material out to sea and away from population centers, with some unfavorable wind directions depositing radioactive material over Tokyo. Low-pressure area over Eastern Japan gave less favorable wind directions 21–22 March. Wind shift to north takes place Tuesday midnight. After the shift, the plume would again be pushed out to the sea for the next becoming days. Roughly similar prediction results are presented for the next 36 hours by the Finnish Meteorological Institute. In spite of winds blowing towards Tokyo during 21–22 March, he comments, "From what I've been able to gather from official reports of radioactivity releases from the Fukushima plant, Tokyo will not receive levels of radiation dangerous to human health in the coming days, should emissions continue at current levels."

text: Due to an

entity_name: Anticyclone

text: anticyclone

text: south of Japan, favorable westerly winds were dominant during most of the first week of the accident, depositing most of the radioactive material out to sea and away from population centers, with some unfavorable wind directions depositing radioactive material over Tokyo.

entity_name: Low-pressure area

text: Low-pressure area

text: over Eastern Japan gave less favorable wind directions 21–22 March. Wind shift to north takes place Tuesday midnight. After the shift, the plume would again be pushed out to the sea for the next becoming days. Roughly similar prediction results are presented for the next 36 hours by the Finnish Meteorological Institute. In spite of winds blowing towards Tokyo during 21–22 March, he comments, "From what I've been able to gather from official reports of radioactivity releases from the Fukushima plant, Tokyo will not receive levels of radiation dangerous to human health in the coming days, should emissions continue at current levels."

text: Opening a hot radiator drops the system pressure, which may cause it to boil and eject dangerously hot liquid and steam. Therefore, radiator caps often contain a mechanism that attempts to relieve the internal pressure before the cap can be fully opened.

text: The most severe nuclear accident is probably the Chernobyl disaster. In addition to conventional fatalities and acute radiation syndrome fatalities, nine children died of thyroid cancer, and it is estimated that there may be up to 4,000 excess cancer deaths among the approximately 600,000 most highly exposed people. Of the 100 million curies (4 exabecquerels) of radioactive material, the short lived radioactive isotopes such as I Chernobyl released were initially the most dangerous. Due to their short half-lives of 5 and 8 days they have now decayed, leaving the more long-lived Cs (with a half-life of 30.07 years) and Sr (with a half-life of 28.78 years) as main dangers.

text: The most severe nuclear accident is probably the

entity_name: Chernobyl disaster

text: Chernobyl disaster

text: . In addition to conventional fatalities and acute radiation syndrome fatalities, nine children died of

entity_name: Thyroid cancer

text: thyroid cancer

text: , and it is estimated that there may be up to 4,000 excess cancer deaths among the approximately 600,000 most highly exposed people. Of the 100 million

entity_name: Curie

text: curie

text: s (4

entity_name: Becquerel

text: exabecquerels

text: ) of radioactive material, the short lived radioactive isotopes such as

text: I

text: Chernobyl released were initially the most dangerous. Due to their short half-lives of 5 and 8 days they have now decayed, leaving the more long-lived

text: Cs

text: (with a half-life of 30.07 years) and

text: Sr

text: (with a half-life of 28.78 years) as main dangers.

text: The first term accounts for the source of radioactivity from the sampled air, and the second term is the loss due to the decay of that radioactivity. A convenient way to express the solution to this equation uses the scalar convolution integral, which results in

text: There is currently a total of 47,000 tonnes of high-level nuclear waste stored in the USA. Nuclear waste is approximately 94% Uranium, 1.3% Plutonium, 0.14% other Actinides, and 5.2% fission products. About 1.0% of this waste consists of long-lived isotopes Se, Zr, Te, Pd, Sn, I and Cs. Shorter lived isotopes including Sr, Sr, Ru, Sn, Cs, Cs, and Pm constitute 0.9% at one year, decreasing to 0.1% at 100 years. The remaining 3.3-4.1% consists of non-radioactive isotopes. There are technical challenges, as it is preferable to lock away the long-lived fission products, but the challenge should not be exaggerated. One tonne of waste, as described above, has measurable radioactivity of approximately 600 TBq equal to the natural radioactivity in one km of the Earth's crust, which if buried, would add only 25 parts per trillion to the total radioactivity.

text: There is currently a total of 47,000 tonnes of high-level nuclear waste stored in the USA. Nuclear waste is approximately 94% Uranium, 1.3% Plutonium, 0.14% other

text: Actinides

text: , and 5.2% fission products. About 1.0% of this waste consists of long-lived isotopes Se, Zr, Te, Pd, Sn, I and Cs. Shorter lived isotopes including Sr, Sr, Ru, Sn, Cs, Cs, and Pm constitute 0.9% at one year, decreasing to 0.1% at 100 years. The remaining 3.3-4.1% consists of non-radioactive isotopes. There are technical challenges, as it is preferable to lock away the long-lived fission products, but the challenge should not be exaggerated. One tonne of waste, as described above, has measurable radioactivity of approximately 600 T

text: Bq

text: equal to the natural radioactivity in one km of the Earth's crust, which if buried, would add only 25 parts per trillion to the total radioactivity.

text: Plutonium (Pu) is an artificial element, except for trace quantities resulting from neutron capture by uranium, and thus a standard atomic mass cannot be given. Like all artificial elements, it has no stable isotopes. It was synthesized long before being found in nature, the first isotope synthesized being Pu in 1940. Twenty plutonium radioisotopes have been characterized. The most stable are Pu-244, with a half-life of 80.8 million years, Pu-242, with a half-life of 373,300 years, and Pu-239, with a half-life of 24,110 years. All of the remaining radioactive isotopes have half-lives that are less than 7,000 years. This element also has eight meta states, though none are very stable; all meta states have half-lives of less than one second.

text: Plutonium

text: (Pu) is an

entity_name: Synthetic element

text: artificial element

text: , except for trace quantities resulting from neutron capture by uranium, and thus a standard

entity_name: Atomic mass

text: atomic mass

text: cannot be given. Like all artificial elements, it has no

entity_name: Stable isotope ratio

text: stable isotope

text: s. It was synthesized long before being found in nature, the first

text: isotope

text: synthesized being Pu in 1940. Twenty plutonium

text: radioisotope

text: s have been characterized. The most stable are

text: , with a

text: half-life

text: of 80.8 million years,

text: , with a half-life of 373,300 years, and

text: , with a half-life of 24,110 years. All of the remaining

text: radioactive

text: isotopes have half-lives that are less than 7,000 years. This element also has eight

entity_name: Nuclear isomer

text: meta state

text: s, though none are very stable; all meta states have half-lives of less than one second.

text: Iodine-131 can be "seen" by nuclear medicine imaging techniques (i.e., gamma cameras) whenever it is given for therapeutic use, since about 10% of its energy and radiation dose is via gamma radiation. However, since the other 90% of radiation (beta radiation) causes tissue damage without contributing to any ability to see or "image" the isotope, other less-damaging radioisotopes of iodine such as iodine-123 (see isotopes of iodine) are preferred in situations when only nuclear imaging is required. The isotope I-131 is still occasionally used for purely diagnostic (i.e., imaging) work, due to its low expense compared to other iodine radioisotopes. Very small medical imaging doses of I-131 have not shown any increase in thyroid cancer. The low-cost availability of I-131, in turn, is due to the relative ease of creating I-131 by neutron bombardment of natural tellurium in a nuclear reactor, then separating I-131 out by various simple methods (i.e., heating to drive off the volatile iodine). By contrast, other iodine radioisotopes are usually created by far more expensive techniques, starting with reactor radiation of expensive capsules of pressurized xenon gas.

text: Iodine-131 can be "seen" by

entity_name: Nuclear medicine

text: nuclear medicine

text: imaging techniques (i.e.,

entity_name: Gamma camera

text: gamma camera

text: s) whenever it is given for therapeutic use, since about 10% of its energy and radiation dose is via gamma radiation. However, since the other 90% of radiation (beta radiation) causes tissue damage without contributing to any ability to see or "image" the isotope, other less-damaging radioisotopes of iodine such as

text: (see

entity_name: Isotopes of iodine

text: isotopes of iodine

text: ) are preferred in situations when only nuclear imaging is required. The isotope I-131 is still occasionally used for purely diagnostic (i.e., imaging) work, due to its low expense compared to other iodine radioisotopes. Very small medical imaging doses of I-131 have not shown any increase in thyroid cancer. The low-cost availability of I-131, in turn, is due to the relative ease of creating I-131 by neutron bombardment of natural

entity_name: Tellurium

text: tellurium

text: in a nuclear reactor, then separating I-131 out by various simple methods (i.e., heating to drive off the volatile iodine). By contrast, other iodine radioisotopes are usually created by far more expensive techniques, starting with reactor radiation of expensive capsules of pressurized

entity_name: Xenon

text: xenon

text: gas.

text: On the premise that radioactive decay is truly random (rather than merely chaotic), it has been used in hardware random-number generators. Because the process is not thought to vary significantly in mechanism over time, it is also a valuable tool in estimating the absolute ages of certain materials. For geological materials, the radioisotopes and some of their decay products become trapped when a rock solidifies, and can then later be used (subject to many well-known qualifications) to estimate the date of the solidification. These include checking the results of several simultaneous processes and their products against each other, within the same sample. In a similar fashion, and also subject to qualification, the rate of formation of carbon-14 in various eras, the date of formation of organic matter within a certain period related to the isotope's half-life may be estimated, because the carbon-14 becomes trapped when the organic matter grows and incorporates the new carbon-14 from the air. Thereafter, the amount of carbon-14 in organic matter decreases according to decay processes that may also be independently cross-checked by other means (such as checking the carbon-14 in individual tree rings, for example).

text: On the premise that radioactive decay is truly

entity_name: Randomness

text: random

text: (rather than merely

entity_name: Chaos theory

text: chaotic

text: ), it has been used in

entity_name: Hardware random number generator

text: hardware random-number generator

text: s. Because the process is not thought to vary significantly in mechanism over time, it is also a valuable tool in estimating the absolute ages of certain materials. For geological materials, the radioisotopes and some of their decay products become trapped when a rock solidifies, and can then later be used (subject to many well-known qualifications) to estimate the date of the solidification. These include checking the results of several simultaneous processes and their products against each other, within the same sample. In a similar fashion, and also subject to qualification, the rate of formation of carbon-14 in various eras, the date of formation of organic matter within a certain period related to the isotope's half-life may be estimated, because the carbon-14 becomes trapped when the organic matter grows and incorporates the new carbon-14 from the air. Thereafter, the amount of carbon-14 in organic matter decreases according to decay processes that may also be independently cross-checked by other means (such as checking the carbon-14 in individual tree rings, for example).

text: Radioisotope Production Facilty capable of producing the following:

text: Though Tono-Bungay is not a science-fiction novel, radioactive decay plays a small but consequential role in it. Radioactive decay plays a much larger role in The World Set Free (1914). This book contains what is surely his biggest prophetic "hit". Scientists of the day were well aware that the natural decay of radium releases energy at a slow rate over thousands of years. The rate of release is too slow to have practical utility, but the total amount released is huge. Wells's novel revolves around an (unspecified) invention that accelerates the process of radioactive decay, producing bombs that explode with no more than the force of ordinary high explosives—but which "continue to explode" for days on end. "Nothing could have been more obvious to the people of the earlier twentieth century", he wrote, "than the rapidity with which war was becoming impossible ... [but] they did not see it until the atomic bombs burst in their fumbling hands". In 1932, the physicist and conceiver of nuclear chain reaction Leó Szilárd read The World Set Free, a book which he said made a great impression on him.

text: Though Tono-Bungay is not a science-fiction novel, radioactive decay plays a small but consequential role in it. Radioactive decay plays a much larger role in

entity_name: The World Set Free

text: The World Set Free

text: (1914). This book contains what is surely his biggest prophetic "hit". Scientists of the day were well aware that the natural decay of

entity_name: Radium

text: radium

text: releases energy at a slow rate over thousands of years. The rate of release is too slow to have practical utility, but the total amount released is huge. Wells's novel revolves around an (unspecified) invention that accelerates the process of radioactive decay, producing bombs that explode with no more than the force of ordinary high explosives—but which "continue to explode" for days on end. "Nothing could have been more obvious to the people of the earlier twentieth century", he wrote, "than the rapidity with which war was becoming impossible ... [but] they did not see it until the atomic bombs burst in their fumbling hands". In 1932, the physicist and conceiver of

entity_name: Nuclear chain reaction

text: nuclear chain reaction

entity_name: Leo Szilard

text: Leó Szilárd

text: read The World Set Free, a book which he said made a great impression on him.

text: Radon is chemically stable, but it is radioactive and does not have a stable isotope. Its most stable isotope, Rn, has a half-life of 3.8 days. Its uses are due to its radioactivity rather than its chemistry and it requires specialist handling outside of industrial gas industry norms. It can however be produced as a by-product of uraniferous ores processing. Radon is a trace naturally occurring radioactive material (NORM) encountered in the air processed in an ASU.

text: Radon is chemically stable, but it is

text: radioactive

text: and does not have a

text: stable isotope

text: . Its most stable

text: isotope

entity_name: Isotopes of radon

text: Rn

text: , has a

text: half-life

text: of 3.8 days. Its uses are due to its radioactivity rather than its chemistry and it requires specialist handling outside of industrial gas industry norms. It can however be produced as a by-product of

entity_name: Uranium ore

text: uraniferous ores

text: processing. Radon is a trace

entity_name: Naturally occurring radioactive material

text: naturally occurring radioactive material

text: (NORM) encountered in the air processed in an ASU.

text: On 16 September 2001 the French press reported slightly higher than acceptable radioactivity levels aboard Charles de Gaulle, thought to be caused by a faulty isolation element. It was later discovered that the radioactivity levels matched the design, but that the regulations concerning acceptable radioactivity levels had changed. While the United States was preparing its response to the September 11 attacks in the form of Operation Enduring Freedom, French media complained about the lack of deployable French military power. At the same time, the Defence Commission reported the maintenance of the Fleet to be substandard. In this context, Charles de Gaulle, then under repairs, was again an object of criticism, with former President Valéry Giscard d'Estaing describing it as a "half-aircraft-carrier" and requesting launching of the second carrier vessel (named PA2) in order to guarantee an availability rate of 100%.

text: On 16 September 2001 the French press reported slightly higher than acceptable radioactivity levels aboard Charles de Gaulle, thought to be caused by a faulty isolation element. It was later discovered that the radioactivity levels matched the design, but that the regulations concerning acceptable radioactivity levels had changed. While the United States was preparing its response to the

text: September 11 attacks

text: in the form of

text: Operation Enduring Freedom

text: , French media complained about the lack of deployable French military power. At the same time, the Defence Commission reported the maintenance of the Fleet to be substandard. In this context, Charles de Gaulle, then under repairs, was again an object of criticism, with former President

text: Valéry Giscard d'Estaing

text: describing it as a "half-aircraft-carrier" and requesting launching of the second carrier vessel (named PA2) in order to guarantee an availability rate of 100%.

text: A large percentage of the Earth’s uranium supply is contained in coffinite deposits, which is significant because of uranium’s uses in nuclear energy and weaponry applications.  Sedimentary deposits contain the most radioactive samples, as evidenced by the intensely radioactive coffinite found in the Colorado Plateau.   Researchers at Harvard University, the United States Geological Survey (USGS), and several other institutions attempted unsuccessfully to synthesize coffinite in the mid-1950s after its initial discovery.  In 1956, Hoekstra and Fuchs managed to create stable samples of synthetic coffinite.  All of this research was conducted for the United States Atomic Energy Commission.

text: A large percentage of the Earth’s uranium supply is contained in coffinite deposits, which is significant because of uranium’s uses in nuclear energy and weaponry applications.  Sedimentary deposits contain the most radioactive samples, as evidenced by the intensely radioactive coffinite found in the Colorado Plateau.   Researchers at

text: Harvard University

text: , the

text: United States Geological Survey

text: (USGS), and several other institutions attempted unsuccessfully to synthesize coffinite in the mid-1950s after its initial discovery.  In 1956, Hoekstra and Fuchs managed to create stable samples of synthetic coffinite.  All of this research was conducted for the

text: United States Atomic Energy Commission

text: The DoD directive makes the distinction clear that detection is harder than measurement, and the latter is necessary for MASINT. "P5.2.2.1. Nuclear radiation is not easy to detect. Radiation detection is always a multistep, highly indirect process. For example, in a scintillation detector, incident radiation excites a fluorescent material that de-excites by emitting photons of light. The light is focused onto the photocathode of a photomultiplier tube that triggers an electron avalanche. The electron shower produces an electrical pulse that activates a meter read by the operator. Not surprisingly, the quantitative relationship between the amount of radiation actually emitted and the reading on the meter is a complex function of many factors. Since those factors may only be controlled well within a laboratory, only in a laboratory setting may true measurements be made." This can be a field laboratory.

text: Nuclear accidents, because of the powerful forces involved, are often very dangerous. Historically, the first incidents involved fatal radiation exposure. Marie Curie died from aplastic anemia which resulted from her high levels of exposure. Two scientists, an American and Canadian respectively, Harry Daghlian and Louis Slotin, died after mishandling the same plutonium mass. Unlike conventional weapons, the intense light, heat, and explosive force is not the only deadly component to a nuclear weapon. Approximately half of the deaths from Hiroshima and Nagasaki died two to five years afterward from radiation exposure.

text: Nuclear accidents, because of the powerful forces involved, are often very dangerous. Historically, the first incidents involved fatal

text: radiation exposure

text: Marie Curie

text: died from

text: aplastic anemia

text: which resulted from her high levels of exposure. Two scientists, an American and Canadian respectively,

text: Harry Daghlian

text: and

text: Louis Slotin

text: , died after mishandling the

text: same plutonium mass

text: . Unlike conventional weapons, the intense light, heat, and explosive force is not the only deadly component to a nuclear weapon. Approximately half of the deaths from

entity_name: Atomic bombings of Hiroshima and Nagasaki

text: Hiroshima and Nagasaki

text: died two to five years afterward from radiation exposure.

text: The term "radiophobia" is also sometimes used in the arguments against proponents of the conservative LNT concept (Linear no-threshold response model for ionizing radiation) of radiation security proposed by the U.S. National Council on Radiation Protection and Measurements (NCRP) in 1949. The "no-threshold" position effectively assumes, from data extrapolated from the atomic bombings on Hiroshima and Nagasaki, that even negligible doses of radiation increase ones risk of cancer linearly as the exposure increases from a value of 0 up to high dose rates. This is a controversial model as the LNT model therefore suggests that radiation exposure from naturally occurring background radiation, the radiation exposure from flying at high altitudes in airplanes, as well as lying next to loved ones for extended periods and the eating of bananas, which are also weakly naturally radioactive (both mostly due to Potassium-40, a naturally occurring radioactive material required for human life) all increase one's chance of cancer.

text: The term "radiophobia" is also sometimes used in the arguments against proponents of the conservative

text: LNT concept

text: (Linear no-threshold response model for ionizing radiation) of radiation security proposed by the U.S. National Council on Radiation Protection and Measurements (NCRP) in 1949. The "no-threshold" position effectively assumes, from data extrapolated from the atomic bombings on Hiroshima and Nagasaki, that even negligible doses of radiation increase ones risk of cancer linearly as the exposure increases from a value of 0 up to high dose rates. This is a controversial model as the LNT model therefore suggests that radiation exposure from naturally occurring

text: background radiation

text: , the radiation exposure from flying at high altitudes in airplanes, as well as lying next to loved ones for extended periods and the eating of

text: bananas, which are also weakly naturally radioactive

text: (both mostly due to

text: , a

text: required

text: for human life

text: ) all increase one's chance of cancer.

text: Radiation-based Gauge: Radiation is passed from a source, through the fluid of interest, and into a scintillation detector, or counter. As the fluid density increases, the detected radiation "counts" will decrease. The source is typically the radioactive isotope cesium-137, with a half-life of about 30 years. A key advantage for this technology is that the instrument is not required to be in contact with the fluid—typically the source and detector are mounted on the outside of tanks or piping.

text: Radiation-based Gauge: Radiation is passed from a source, through the fluid of interest, and into a scintillation detector, or counter. As the fluid density increases, the detected radiation "counts" will decrease. The source is typically the radioactive isotope

text: , with a half-life of about 30 years. A key advantage for this technology is that the instrument is not required to be in contact with the fluid—typically the source and detector are mounted on the outside of tanks or piping.

text: The radioactivity present on the ground in Area 1 provides a radiologically-contaminated environment for the training of first responders. Trainees are exposed to methods of radiation detection and its health hazards. Further training takes place in other areas of NTS.

text: The radioactivity present on the ground in Area 1 provides a radiologically-contaminated environment for the training of

text: first responders

text: . Trainees are exposed to methods of radiation detection and its health hazards. Further training takes place in other areas of NTS.

text: On Tuesday, 2 August, a radiation level of 5 sieverts per hour is detected on the second floor of the turbine building in reactor 1. The radioactivity rates detected on 2 and 1 August are considered lethal for even brief human exposures, an exposure of 0.1 Sv being the normal accepted workplace exposure over 5 years and 8 Sv or 8 Gray (8Gy) being a 100% lethal dose.

text: On Tuesday, 2 August, a radiation level of 5 sieverts per hour is detected on the second floor of the turbine building in reactor 1. The radioactivity rates detected on 2 and 1 August are considered lethal for even brief human exposures, an exposure of 0.1 Sv being the normal accepted workplace exposure over 5 years and 8 Sv or 8

text: Gray

text: (8Gy) being a 100% lethal dose.

text: Radiation therapy may include photon-beam or proton-beam treatment, or fractionated external beam radiation.  Radiosurgery may be used in lieu of surgery in small tumors located away from critical structures. Fractionated external-beam radiation also can be used as primary treatment for tumors that are surgically unresectable or, for patients who are inoperable for medical reasons.

text: Radiation therapy may include photon-beam or proton-beam treatment, or

text: fractionated external beam radiation

text: .  Radiosurgery may be used in lieu of surgery in small tumors located away from critical structures. Fractionated external-beam radiation also can be used as primary treatment for tumors that are surgically unresectable or, for patients who are inoperable for medical reasons.

text: Naturally occurring samarium has a radioactivity of 128 Bq/g. It is composed of four stable isotopes: Sm, Sm, Sm and Sm, and three extremely long-lived radioisotopes, Sm (half-life t = 1.06 years), Sm (7 years) and Sm (>2 years), with Sm being the most abundant (natural abundance 26.75%). Sm is listed by various sources either as stable or radioactive isotope.

text: Naturally occurring samarium has a

text: radioactivity

text: of 128

text: Bq

text: /g. It is composed of four stable

text: isotope

text: s: Sm, Sm, Sm and Sm, and three extremely long-lived

text: radioisotope

text: s, Sm (half-life t = 1.06 years), Sm (7 years) and Sm (>2 years), with Sm being the most abundant (

text: natural abundance

text: 26.75%). Sm is listed by various sources either as stable or radioactive isotope.

text: The salt dome under the ground near Gorleben was and is intended to become a long-term storage place for all kinds of radioactive waste. On the site, the German Society for the Construction and Management of Long-Term Waste Storage Units (DBE mbH) runs what is known as a "pilot plant", which may become a long-term storage site for highly radioactive nuclear waste.

text: The

text: salt dome

text: under the ground near Gorleben was and is intended to become a long-term storage place for all kinds of radioactive waste. On the site, the German Society for the Construction and Management of Long-Term Waste Storage Units (DBE mbH) runs what is known as a "pilot plant", which may become a long-term storage site for highly radioactive nuclear waste.

text: In the late 19th century onward, the atomic theory underwent significant improvements, which shaped the further history of thorium. Thorium was first observed to be radioactive in 1898, independently, by the German chemist Gerhard Carl Schmidt and later that year, the Polish-French physicist Marie Curie. It was the second element that was found to be radioactive, after the 1896 discovery of radioactivity in uranium by Henri Becquerel. Between 1900 and 1903, Ernest Rutherford and Frederick Soddy showed how thorium decayed at a fixed rate over time into a series of other elements. This observation led to the identification of half-life as one of the outcomes of the alpha particle experiments that led to their disintegration theory of radioactivity. The biological effect of radiation was discovered in 1903; the danger presented by radioactivity to health and environment was the reason thorium was phased out of use in applications that did not explicitly use the radioactivity. Since the 1930s, it has been widely acknowledged that thorium possesses a minor threat to human organisms in large quantities.

text: In the late 19th century onward, the

text: atomic theory

text: underwent significant improvements, which shaped the further history of thorium. Thorium was first observed to be radioactive in 1898, independently, by the German chemist

text: Gerhard Carl Schmidt

text: and later that year, the Polish-French physicist

text: Marie Curie

text: . It was the second element that was found to be radioactive, after the 1896 discovery of radioactivity in uranium by

text: Henri Becquerel

text: . Between 1900 and 1903,

text: Ernest Rutherford

text: and

text: Frederick Soddy

text: showed how thorium decayed at a fixed rate over time into a series of other elements. This observation led to the identification of

text: half-life

text: as one of the outcomes of the

text: alpha particle

text: experiments that led to their disintegration theory of

text: radioactivity

text: . The biological effect of radiation was discovered in 1903; the danger presented by radioactivity to health and environment was the reason thorium was phased out of use in applications that did not explicitly use the radioactivity. Since the 1930s, it has been widely acknowledged that thorium possesses a minor threat to human organisms in large quantities.

text: The experiments included a wide array of studies, involving things like feeding radioactive food to mentally disabled children or conscientious objectors, inserting radium rods into the noses of schoolchildren, deliberately releasing radioactive chemicals over U.S. and Canadian cities, measuring the health effects of radioactive fallout from nuclear bomb tests, injecting pregnant women and babies with radioactive chemicals, and irradiating the testicles of prison inmates, amongst other things.

text: The experiments included a wide array of studies, involving things like feeding radioactive food to mentally disabled children or

text: conscientious objectors

text: , inserting

text: radium

text: rods into the noses of schoolchildren, deliberately releasing radioactive chemicals over U.S. and Canadian cities, measuring the health effects of radioactive fallout from nuclear bomb tests, injecting pregnant women and babies with radioactive chemicals, and irradiating the testicles of prison inmates, amongst other things.

text: Positron production from radioactive  decay can be considered both artificial and natural production, as the generation of the radioisotope can be natural or artificial. Perhaps the best known naturally-occurring radioisotope which produces positrons is potassium-40, a long-lived isotope of potassium which occurs as a primordial isotope of potassium. Even though a small percent of potassium (0.0117%) it is the single most abundant radioisotope in the human body. In a human body of 70 kg mass, about 4,400 nuclei of K decay per second. The activity of natural potassium is 31 Bq/g. About 0.001% of these K decays produce about 4000 natural positrons per day in the human body. These positrons soon find an electron, undergo annihilation, and produce pairs of 511 keV gamma rays, in a process similar (but much lower intensity) to that which happens during a PET scan nuclear medicine procedure.

text: Positron production from radioactive

text: decay

text: can be considered both artificial and natural production, as the generation of the radioisotope can be natural or artificial. Perhaps the best known naturally-occurring radioisotope which produces positrons is

text: , a long-lived isotope of potassium which occurs as a

text: primordial isotope

text: of potassium. Even though a small percent of potassium (0.0117%) it is the single most abundant

text: radioisotope

text: in the human body. In a human body of 70 kg mass, about 4,400 nuclei of K decay per second. The activity of natural potassium is 31

text: Bq

text: /g. About 0.001% of these K decays produce about 4000 natural positrons per day in the human body. These positrons soon find an electron, undergo annihilation, and produce pairs of 511 keV gamma rays, in a process similar (but much lower intensity) to that which happens during a

text: PET scan

text: nuclear medicine

text: procedure.

text: For fission of uranium-235, the predominant radioactive fission products include isotopes of iodine, caesium, strontium, xenon and barium. The threat becomes smaller with the passage of time. Locations where radiation fields once posed immediate mortal threats, such as much of the Chernobyl Nuclear Power Plant on day one of the accident and the ground zero sites of U.S. atomic bombings in Japan (6 hours after detonation) are now relatively safe because the radioactivity has decayed to a low level.Many of the fission products decay through very short-lived isotopes to form stable isotopes, but a considerable number of the radioisotopes have half-lives longer than a day.

text: For fission of

text: , the predominant radioactive fission products include isotopes of

text: iodine

text: caesium

text: strontium

text: xenon

text: and

text: barium

text: . The threat becomes smaller with the passage of time. Locations where radiation fields once posed immediate mortal threats, such as much of the

text: Chernobyl Nuclear Power Plant

text: on day one of the

text: accident

text: and the

text: ground zero

text: sites of

text: U.S. atomic bombings in Japan

text: (6 hours after detonation) are now relatively safe because the radioactivity has decayed to a low level.Many of the fission products decay through very short-lived isotopes to form

text: stable isotope

text: s, but a considerable number of the

text: radioisotope

text: s have

text: half-lives

text: longer than a day.

text: Radioactive water baths have been applied since 1906 in Jáchymov, Czech Republic, but even before radon discovery they were used in Bad Gastein, Austria. Radium-rich springs are also used in traditional Japanese onsen in Misasa, Tottori Prefecture. Drinking therapy is applied in Bad Brambach, Germany. Inhalation therapy is carried out in Gasteiner-Heilstollen, Austria, in Kowary, Poland and in Boulder, Montana, United States. In the United States and Europe there are several "radon spas", where people sit for minutes or hours in a high-radon atmosphere in the belief that low doses of radiation will invigorate or energize them.

text: Radioactive water baths have been applied since 1906 in

text: Jáchymov

text: Czech Republic

text: , but even before radon discovery they were used in

text: Bad Gastein

text: Austria

text: . Radium-rich springs are also used in traditional

text: Japan

text: ese

text: onsen

text: in

text: Misasa

text: Tottori Prefecture

text: . Drinking therapy is applied in

text: Bad Brambach

text: Germany

text: . Inhalation therapy is carried out in Gasteiner-Heilstollen,

text: Austria

text: , in

text: Kowary

text: Poland

text: and in

text: Boulder, Montana

text: United States

text: . In the United States and Europe there are several "radon

text: spas

text: ", where people sit for minutes or hours in a high-radon atmosphere in the belief that low doses of radiation will invigorate or energize them.

text: Chen Lu was a normal human until exposed to excessive amounts of radiation, which changed his skin coloring to an iridescent green, and allows him to manipulate radiation across the microwave spectrum. Abilities include radiation emission as heat, "hard" radiation (inflicting opponents with nausea, dizziness, and radiation poisoning), and hypnotic light. He can also absorb nuclear radiation without harm and convert it to energy for personal use such as strength enhancement or to cauterize wounds, create force fields, and emit electromagnetic radiation to deactivate machinery. He has shown the ability to leave behind "radiation pills", i.e. infusing a single individual with enough radiation to give him severe radiation poisoning and let the contamination spread in a large population. While it was briefly implied that his radioactive makeup and some further enhancements of his powers had left him radioactive and unable to have contact with unshielded people, he was retconned to have always been in full control of his abilities. Even so, during his tenure in the Dark Avengers, Norman Osborn had his original costume replaced with a customized radiation suit, hiding his oriental features and quelling every lingering fear about his radioactive makeup. Chen Lu holds a Ph. D. in nuclear physics.

text: Chen Lu was a normal human until exposed to excessive amounts of radiation, which changed his skin coloring to an

text: iridescent

text: green

text: , and allows him to manipulate radiation across the microwave spectrum. Abilities include radiation emission as heat, "hard" radiation (inflicting opponents with nausea, dizziness, and

text: radiation poisoning

text: ), and

text: hypnotic

text: light. He can also absorb nuclear radiation without harm and convert it to energy for personal use such as strength enhancement or to

text: cauterize

text: wounds, create

text: force fields

text: , and emit electromagnetic radiation to deactivate machinery. He has shown the ability to leave behind "radiation pills", i.e. infusing a single individual with enough radiation to give him severe

text: radiation poisoning

text: and let the contamination spread in a large population. While it was briefly implied that his radioactive makeup and some further enhancements of his powers had left him radioactive and unable to have contact with unshielded people, he was

text: retcon

text: ned to have always been in full control of his abilities. Even so, during his tenure in the Dark Avengers, Norman Osborn had his original costume replaced with a customized radiation suit, hiding his oriental features and quelling every lingering fear about his radioactive makeup. Chen Lu holds a Ph. D. in nuclear physics.

text: The project became controversial in 2009 when a study performed by Avner Vengosh of Duke University revealed the Disi water to be highly radioactive.  Water was tested from 37 existing wells in the aquifer, and all but one had concentrations of radioactive radium-226 and radium-228 isotopes that exceeded international standards for drinking water.  Some of the water tested exceeded standards by 2,000%. Drinking water with these isotopes has been linked to bone cancer and leukemia. Though expensive, the water could be purified of the radioactive isotopes through ion-exchange purification.

text: The project became controversial in 2009 when a study performed by Avner Vengosh of

text: Duke University

text: revealed the Disi water to be highly

text: radioactive

text: .  Water was tested from 37 existing wells in the aquifer, and all but one had concentrations of radioactive

text: and

text: isotopes that exceeded

text: international standards for drinking water

text: .  Some of the water tested exceeded standards by 2,000%. Drinking water with these isotopes has been linked to

text: bone cancer

text: and

text: leukemia

text: . Though expensive, the water could be purified of the radioactive isotopes through

text: ion-exchange purification

text: On November 18, 2007, the National Research Universal reactor, which makes medical radioisotopes, was shut down for routine maintenance.  This shutdown was voluntarily extended when AECL decided to install seismically-qualified emergency power systems (EPS) to two of the reactor's cooling pumps (in addition to the AC and DC backup power systems already in place), which had been required as part of its August 2006 operating license issued by the Canadian Nuclear Safety Commission (CNSC), whose staff had discovered that the status of the NRU facility was not in compliance with CNSC license conditions. This resulted in a worldwide shortage of radioisotopes for medical treatments because Chalk River makes the majority of the world's supply of radioisotopes, (including two-thirds of the world's technetium-99) and because AECL had not pre-arranged for an alternate supply.  On December 11, 2007, the Canadian House of Commons, acting on what the government described as "independent expert" advice, passed emergency legislation authorizing the restarting of the NRU reactor with one of the two seismic connections complete (one pump being sufficient to cool the core), and authorizing the reactor's operation for 120 days without CNSC approval.  The legislation, C-38, was passed by the Senate and received Royal Assent on December 12. Prime Minister Stephen Harper accused the "Liberal-appointed" CNSC for this shutdown which "jeopardized the health and safety of tens of thousands of Canadians".  Others viewed the actions and priorities of the Prime Minister and government in terms of protecting the eventual sale of AECL to private investors.  The government later announced plans to sell part of AECL in May 2009.

text: On November 18, 2007, the National Research Universal reactor, which makes medical radioisotopes, was shut down for routine maintenance.  This shutdown was voluntarily extended when AECL decided to install seismically-qualified emergency power systems (EPS) to two of the reactor's cooling pumps (in addition to the AC and DC backup power systems already in place), which had been required as part of its August 2006 operating license issued by the

text: Canadian Nuclear Safety Commission

text: (CNSC), whose staff had discovered that the status of the NRU facility was not in compliance with CNSC license conditions. This resulted in a worldwide shortage of radioisotopes for medical treatments because Chalk River makes the majority of the world's supply of radioisotopes, (including two-thirds of the world's

text: ) and because AECL had not pre-arranged for an alternate supply.  On December 11, 2007, the

text: Canadian House of Commons

text: , acting on what the government described as "independent expert" advice, passed emergency legislation authorizing the restarting of the NRU reactor with one of the two seismic connections complete (one pump being sufficient to cool the core), and authorizing the reactor's operation for 120 days without CNSC approval.  The legislation, C-38, was passed by the Senate and received Royal Assent on December 12. Prime Minister

text: Stephen Harper

text: accused the "Liberal-appointed" CNSC for this shutdown which "jeopardized the health and safety of tens of thousands of Canadians".  Others viewed the actions and priorities of the Prime Minister and government in terms of protecting the eventual sale of AECL to private investors.  The government later announced plans to sell part of AECL in May 2009.

text: With regards to exposure to radiation emitted by backscatter X-rays, and there are fears that people will be exposed to a "dangerous level of radiation if they get backscattered too often"  A petition by both scientists and pilots argue that the screening machines are safe. Ionizing radiation is considered a non-threshold carcinogen, but it is difficult to quantify the risk of low radiation exposures.  Active millimeter wave scanners emit radiation which is non-ionizing, does not have enough energy to directly damage DNA, and is not known to be genotoxic.

text: With regards to exposure to

text: radiation

text: emitted by backscatter X-rays, and there are fears that people will be exposed to a "dangerous level of radiation if they get backscattered too often"  A petition by both scientists and pilots argue that the screening machines are safe. Ionizing radiation is considered a non-threshold

text: carcinogen

text: , but it is difficult to quantify the risk of low radiation exposures.  Active millimeter wave scanners emit radiation which is

text: non-ionizing

text: , does not have enough energy to directly damage DNA, and is not known to be

text: genotoxic

text: An electromagnetic field very far from currents and charges (sources) is called electromagnetic radiation (EMR) since it radiates from the charges and currents in the source, and has no "feedback" effect on them, and is also not affected directly by them in the present time (rather, it is indirectly produced by a sequences of changes in fields radiating out from them in the past). EMR consists of the radiations in the electromagnetic spectrum, including radio waves, microwave, infrared, visible light, ultraviolet light, X-rays, and gamma rays. The many commercial applications of these radiations are discussed in the named and linked articles.

text: An electromagnetic field very far from currents and charges (sources) is called

text: electromagnetic radiation

text: (EMR) since it radiates from the charges and currents in the source, and has no "feedback" effect on them, and is also not affected directly by them in the present time (rather, it is indirectly produced by a sequences of changes in fields radiating out from them in the past). EMR consists of the radiations in the

text: electromagnetic spectrum

text: , including

text: radio wave

text: s,

text: microwave

text: infrared

text: visible light

text: ultraviolet light

text: X-rays

text: , and

text: gamma ray

text: s. The many commercial applications of these radiations are discussed in the named and linked articles.

text: Radiation is used to determine the composition of materials in a process called neutron activation analysis. In this process, scientists bombard a sample of a substance with particles called neutrons. Some of the atoms in the sample absorb neutrons and become radioactive. The scientists can identify the elements in the sample by studying the emitted radiation.

text: Radiation is used to determine the composition of materials in a process called

text: neutron activation analysis

text: . In this process, scientists bombard a sample of a substance with particles called

text: neutrons

text: . Some of the atoms in the sample absorb neutrons and become radioactive. The scientists can identify the elements in the sample by studying the emitted radiation.

text: A radioactive tracer, or radioactive label, is a chemical compound in which one or more atoms have been replaced by a radioisotope so by virtue of its radioactive decay it can be used to explore the mechanism of chemical reactions by tracing the path that the radioisotope follows from reactants to products. Radiolabeling is thus the radioactive form of isotopic labeling.

text: A radioactive tracer, or radioactive label, is a

text: chemical compound

text: in which one or more atoms have been replaced by a

text: radioisotope

text: so by virtue of its

text: radioactive decay

text: it can be used to explore the mechanism of chemical reactions by tracing the path that the radioisotope follows from reactants to products. Radiolabeling is thus the radioactive form of

text: isotopic labeling

text: The user must have an awareness of the types of radiation to be encountered so that the correct instrument is used. A further complication is the possible presence of "mixed radiation fields" where more than one form of radiation is present. Many instruments are sensitive to more than one type of radiation; alpha and beta, or beta and gamma, for instance, and the operator must know how to discriminate between these. The necessary skills in using a hand-held instrument are not only to manipulate the instrument, but also to interpret results of the rate of radiation exposure and the type of radiation being detected.

text: The Psyche-Magnetron, for example, was a weapon that possesses matter-shaping powers. Whosoever possessed it could conjure up anything ever devised by Kree Science. When its rays hit the user, it could create the device desired by the user and also modify the genetic structure of the body giving it super powers. The Magnetron Power Unit or Power Core was contained in a small shielded box. Unfortunately, it was extremely radioactive and, once outside of the box, it immediately changed its form to a bigger, starred polyhedron. It then emitted the same radiation emitted as the Psyche-Magnetron when it bathed a subject, but in such a high quantities as to burn, blind, and totatally annihilate the senses instantly and, sometimes, even kill the subject in a few minutes. Through its rays, the user gained greater matter-shaping powers, that, unfortunately, were very difficult to control. The radiation covered all known spectra and was strong enough to transform an area as wide as, say, Northern Florida, into a radioactive wasteland.

text: Radiation therapy may be used to treat almost every type of solid tumor, including cancers of the brain, breast, cervix, larynx, liver, lung, pancreas, prostate, skin, stomach, uterus, or soft tissue sarcomas. Radiation is also used to treat leukemia and lymphoma. Radiation dose to each site depends on a number of factors, including the radiosensitivity of each cancer type and whether there are tissues and organs nearby that may be damaged by radiation. Thus, as with every form of treatment, radiation therapy is not without its side effects.

text: Coal is a sedimentary rock formed primarily from accumulated plant matter, and it includes many inorganic minerals and elements which were deposited along with organic material during its formation.  As the rest of the Earth's crust, coal also contains low levels of uranium, thorium, and other naturally occurring radioactive isotopes whose release into the environment leads to radioactive contamination. While these substances are present as very small trace impurities, enough coal is burned that significant amounts of these substances are released. A 1,000 MW coal-burning power plant could have an uncontrolled release of as much as 5.2 metric tons per year of uranium (containing  of uranium-235) and 12.8 metric tons per year of thorium. In comparison, a 1,000 MW nuclear plant will generate about 30 metric tons of high-level radioactive solid packed waste per year. It is estimated that during 1982, US coal burning released 155 times as much uncontrolled radioactivity into the atmosphere as the Three Mile Island incident. The collective radioactivity resulting from all coal burning worldwide between 1937 and 2040 is estimated to be 2,700,000 curies or 0.101 EBq. During normal operation, the effective dose equivalent from coal plants is 100 times that from nuclear plants. Normal operation however, is a deceiving baseline for comparison: just the Chernobyl nuclear disaster released, in iodine-131 alone, an estimated 1.76 EBq . of radioactivity, a value one order of magnitude above this value for total emissions from all coal burned within a century, while the iodine-131, the major radioactive substance which comes out in accident situations, has a half life of just 8 days.

text: Coal is a sedimentary rock formed primarily from accumulated plant matter, and it includes many inorganic minerals and elements which were deposited along with organic material during its formation.  As the rest of the Earth's

text: crust

text: , coal also contains low levels of

text: uranium

text: thorium

text: , and other naturally occurring

text: radioactive isotopes

text: whose release into the environment leads to radioactive contamination. While these substances are present as very small trace impurities, enough coal is burned that significant amounts of these substances are released. A 1,000 MW coal-burning power plant could have an uncontrolled release of as much as 5.2 metric tons per year of uranium (containing  of

text: ) and 12.8 metric tons per year of thorium. In comparison, a 1,000 MW nuclear plant will generate about 30 metric tons of high-level radioactive solid packed waste per year. It is estimated that during 1982, US coal burning released 155 times as much uncontrolled radioactivity into the atmosphere as the

text: Three Mile Island incident

text: . The collective radioactivity resulting from all coal burning worldwide between 1937 and 2040 is estimated to be 2,700,000 curies or 0.101 EBq. During normal operation, the effective dose equivalent from coal plants is 100 times that from nuclear plants. Normal operation however, is a deceiving baseline for comparison: just the

text: Chernobyl nuclear disaster

text: released, in iodine-131 alone, an estimated 1.76 EBq . of radioactivity, a value one order of magnitude above this value for total emissions from all coal burned within a century, while the iodine-131, the major radioactive substance which comes out in accident situations, has a half life of just 8 days.

text: The Radioactive Incident Monitoring Network (RIMNET) is a network of 91 monitoring stations, used by the Government of the United Kingdom, which records and analyses the level of radioactivity across the United Kingdom. A reading is taken from each station every hour and an alert triggered if radiation levels for specific isotopes rise significantly above normal background radiation levels at one or more stations.

text: The Radioactive Incident Monitoring Network (RIMNET) is a network of 91 monitoring stations, used by the

text: Government of the United Kingdom

text: , which records and analyses the level of radioactivity across the United Kingdom. A reading is taken from each station every hour and an alert triggered if radiation levels for specific

text: isotope

text: s rise significantly above normal

text: background radiation

text: levels at one or more stations.

text: Tamara was used by the Radioactive Man to infect At'la'tique with a radiation plague.

text: Tamara was used by the

text: Radioactive Man

text: to infect At'la'tique with a radiation plague.

text: This particular man-made diamond being made of radioactive C-14 will also posses radioactivity. Hence, due to its own radioactive field it will generate small currents. For practical and safe use this radioactive diamond will be enclosed inside a non-radioactive man-made diamond (made from C-12).

text: If permanent brachytherapy is used, low dose radioactive sources (seeds) are left in the body after treatment - the radiation levels are very low and decrease over time. In addition, the irradiation only affects tissues within a few millimeters of the radioactive sources (i.e. the tumour being treated). As a precaution, some people receiving permanent brachytherapy may be advised to not hold any small children or be too close to pregnant women for a short time after treatment. Radiation oncologists or nurses can provide specific instructions to patients and advise for how long they need to be careful.

text: According to the opinions in the case, the plaintiff Mallinckrodt owned a patent on a device for dispensing a radioactive mist used in taking diagnostic lung X-rays, and for trapping the mist after use. Mallinckrodt sold the device to hospitals for about $40 or $50. Hospital personnel would load the device with a suitable radioactive fluid to perform a diagnostic procedure on a patient, use the device, and then discard it. Mallinckrodt labeled the devices it sold with the notice “Single use only.” Because the device itself cost approximately $10 to make but was sold for four or five times that, most of the purchase price that hospitals paid Mallinckrodt apparently represented the value of the patent (or the patented technology). This fact apparently led the defendant Medipart to go into the recycling business, in which Mallinckrodt itself had no direct interest (it chose to sell only new devices). For a $20 recycling fee, Medipart would clean one of the devices for a hospital, replace some parts, subject the device to gamma radiation to kill germs, and return it to the hospital for reuse. The district court and court of appeals opinions do not support the claim that a health or safety problem existed. However, Mallinckrodt asserted to the court that "potential adverse consequences, such as infectious disease transmission” provided the reason for its imposing the restriction against reuse.

text: An HSV1716 variant, HSV1716NTR is an oncolytic virus generated by inserting the enzyme NTR into the virus HSV1716 as a GDEPT strategy. In-vivo, administration of the prodrug CB1954 to athymic mice bearing either A431 or A2780 tumour xenografts, 48 hours after intra-tumoral injection of HSV1790, resulted in a marked reduction in tumour volumes and significantly improved survival compared to administration of virus alone. A similar approach has been taken with a variants of HSV1716 that expresses the noradrenaline transporter to deliver radioactive iodine into individual infected cancer cells, by tagging a protein that cancer cells transport. The nor-adrenaline transporter specifically transports a compound containing radioactive iodine across the cell membrane, using genes from the virus. The only cells in the body that receive a significant radiation dose are those infected and their immediate neighbours.

text: An HSV1716 variant, HSV1716NTR is an oncolytic virus generated by inserting the enzyme

text: NTR

text: into the virus HSV1716 as a

entity_section: Gene-directed enzyme prodrug therapy (GDEPT)

text: GDEPT

text: strategy. In-vivo, administration of the prodrug CB1954 to

text: athymic

text: mice bearing either A431 or A2780 tumour xenografts, 48 hours after intra-tumoral injection of HSV1790, resulted in a marked reduction in tumour volumes and significantly improved survival compared to administration of virus alone. A similar approach has been taken with a variants of HSV1716 that expresses the

text: noradrenaline transporter

text: to deliver radioactive iodine into individual infected cancer cells, by tagging a protein that cancer cells transport. The nor-adrenaline transporter specifically transports a compound containing radioactive iodine across the cell membrane, using genes from the virus. The only cells in the body that receive a significant radiation dose are those infected and their immediate neighbours.

text: Pondcrete is a mixture of cement and sludge.  Its role is to immobilize hazardous waste and, in some cases, lower-level radioactive waste, in the form of solid material.  The material was used by the United States Department of Energy and its contractor, Rockwell International, in an attempt to handle the radioactive waste from contaminated ponds in the Rocky Flats Plant for burial in Nevada desert.Portland cement is mixed with sludge to solidify into “pondcrete” blocks and placed into large, plastic lined boxes.  The sludge is taken from solar evaporation ponds which are used to remove moisture from waste materials, therefore reducing their weight.  To do this, liquid waste is poured into artificial, shallow ponds.  The waste is heated by solar radiation and any moisture is evaporated, leaving behind the waste.  These ponds contained low level radioactive process waste as well as sanitary sewage sludge and wastes, which categorize them and the Pondcrete as a mixed waste.

text: Pondcrete is a mixture of

text: cement

text: and

text: sludge

text: .  Its role is to immobilize

text: hazardous waste

text: and, in some cases, lower-level radioactive waste, in the form of solid material.  The material was used by the

text: United States Department of Energy

text: and its contractor,

text: Rockwell International

text: , in an attempt to handle the radioactive waste from contaminated ponds in the

text: Rocky Flats Plant

text: for burial in Nevada desert.

text: Portland cement

text: is mixed with

text: sludge

text: to solidify into “pondcrete” blocks and placed into large, plastic lined boxes.  The sludge is taken from solar evaporation ponds which are used to remove moisture from waste materials, therefore reducing their weight.  To do this, liquid waste is poured into artificial, shallow ponds.  The waste is heated by solar radiation and any moisture is evaporated, leaving behind the waste.  These ponds contained low level radioactive process waste as well as sanitary sewage sludge and wastes, which categorize them and the Pondcrete as a

text: mixed waste

text: Particle physics researchers like to build particle detectors under layers of dolomite to enable the detectors to detect the highest possible number of exotic particles. Because dolomite contains relatively minor quantities of radioactive materials, it can insulate against interference from cosmic rays without adding to background radiation levels.

text: Particle physics researchers like to build

text: particle detector

text: s under layers of dolomite to enable the detectors to detect the highest possible number of exotic particles. Because dolomite contains relatively minor quantities of radioactive materials, it can insulate against interference from

text: cosmic ray

text: s without adding to

text: background radiation

text: levels.

text: At 6:56 am, a plant supervisor declared a site area emergency, and less than 30 minutes later station manager Gary Miller announced a general emergency, defined as having the "potential for serious radiological consequences" to the general public. Metropolitan Edison notified the Pennsylvania Emergency Management Agency (PEMA), which in turn contacted state and local agencies, Governor Richard L. Thornburgh and lieutenant governor William Scranton III, to whom Thornburgh assigned responsibility for collecting and reporting on information about the accident. The uncertainty of operators at the plant was reflected in fragmentary, ambiguous, or contradictory statements made by Met Ed to government agencies and to the press, particularly about the possibility and severity of off-site radioactivity releases. Scranton held a press conference in which he was reassuring, yet confusing, about this possibility, stating that though there had been a "small release of radiation...no increase in normal radiation levels" had been detected. These were contradicted by another official, and by statements from Met Ed, who both claimed that no radioactivity had been released. In fact, readings from instruments at the plant and off-site detectors had detected radioactivity releases, albeit at levels that were unlikely to threaten public health as long as they were temporary, and providing that containment of the then highly contaminated reactor was maintained.

text: At 6:56 am, a plant supervisor declared a

text: site area emergency

text: , and less than 30 minutes later station manager Gary Miller announced a general emergency, defined as having the "potential for serious radiological consequences" to the general public.

text: Metropolitan Edison

text: notified the

entity_name: Pennsylvania Emergency Management Agency

text: Pennsylvania Emergency Management Agency

text: (PEMA), which in turn contacted state and local agencies,

text: Governor

text: Richard L. Thornburgh

text: and

text: lieutenant governor

text: William Scranton III

text: , to whom Thornburgh assigned responsibility for collecting and reporting on information about the accident. The uncertainty of operators at the plant was reflected in fragmentary, ambiguous, or contradictory statements made by Met Ed to government agencies and to the press, particularly about the possibility and severity of off-site radioactivity releases. Scranton held a press conference in which he was reassuring, yet confusing, about this possibility, stating that though there had been a "small release of radiation...no increase in normal radiation levels" had been detected. These were contradicted by another official, and by statements from Met Ed, who both claimed that no radioactivity had been released. In fact, readings from instruments at the plant and off-site detectors had detected radioactivity releases, albeit at levels that were unlikely to threaten public health as long as they were temporary, and providing that containment of the then highly contaminated reactor was maintained.

text: Desperate to return to full strength, he ends up establishing a reward to whoever can break open the suit. When the hired help consisting of Buzz, Hammer, and Surgeon are unable to use the Taedenite to break it open, P'andor sends them to capture Kevin. Upon his hired help capturing Kevin, P'andor tricks him into releasing him from his containment suit (the only thing limiting his powers). Revealed as a living energy being, P'andor attempts to drain the radiation out of a nuclear power plant, but also his presence in the Earth without his suit was dangerous, because he is radioactive. Kevin and Ultimate Cannonbolt are able to trap him back in his suit and turn him over to the Plumbers who deport him back to his home planet. Unfortunately, their ship is intercepted by Aggregor who blasts the Plumbers out into space and recaptures P'andor. In "Too Hot to Handle", P'andor was the only antagonist between the Andromeda Galaxy aliens.

text: A Radioisotope piezoelectric generator converts energy stored in the radioactive material directly into motion to generate electricity by the repeated deformation of a piezoelectric material. This approach creates a high-impedance source and, unlike chemical batteries, the devices will work in a very wide range of temperatures.

text: A Radioisotope piezoelectric generator converts energy stored in the

text: radioactive

text: material directly into motion to generate electricity by the repeated deformation of a

text: piezoelectric

text: material. This approach creates a high-impedance source and, unlike chemical batteries, the devices will work in a very wide range of temperatures.

text: The regulatory safe level for iodine-131 and caesium-137 in drinking water in Japan are 100 Bq/kg and 200 Bq/kg respectively. The Japanese science ministry said on 20 March that radioactive substances were detected in tap water in Tokyo, as well as Tochigi, Gunma, Chiba and Saitama prefectures. IAEA reported on 24 March that drinking water in Tokyo, Fukushima and Ibaraki had been above regulatory limits between 16 and 21 March. On 26 March, IAEA reported that the values were now within legal limits. On 23 March, Tokyo drinking water exceeded the safe level for infants, prompting the government to distribute bottled water to families with infants. Measured levels were caused by iodine-131 (I-131) and were 103, 137 and 174 Bq/l. On 24 March, iodine-131 was detected in 12 of 47 prefectures, of which the level in Tochigi was the highest at 110 Bq/kg. Caesium-137 was detected in 6 prefectures but always below 10 Bq/kg. On 25 March, tap water was reported to have reduced to 79 Bq/kg and to be safe for infants in Tokyo and Chiba but still exceeded limits in Hitachi and Tokaimura. On 27 April, "radiation in Tokyo's water supply fell to undetectable levels for the first time since 18 March."

text: The regulatory safe level for iodine-131 and caesium-137 in drinking water in Japan are 100 Bq/kg and 200 Bq/kg respectively. The Japanese science ministry said on 20 March that radioactive substances were detected in

text: tap water

text: in Tokyo, as well as

text: Tochigi

text: Gunma

text: Chiba

text: and

text: Saitama

text: prefectures. IAEA reported on 24 March that drinking water in Tokyo, Fukushima and Ibaraki had been above regulatory limits between 16 and 21 March. On 26 March, IAEA reported that the values were now within legal limits. On 23 March, Tokyo drinking water exceeded the safe level for infants, prompting the government to distribute bottled water to families with infants. Measured levels were caused by

text: (I-131) and were 103, 137 and 174 Bq/l. On 24 March, iodine-131 was detected in 12 of 47 prefectures, of which the level in Tochigi was the highest at 110 Bq/kg. Caesium-137 was detected in 6 prefectures but always below 10 Bq/kg. On 25 March, tap water was reported to have reduced to 79 Bq/kg and to be safe for infants in Tokyo and Chiba but still exceeded limits in Hitachi and Tokaimura. On 27 April, "radiation in Tokyo's water supply fell to undetectable levels for the first time since 18 March."

text: At first, it seemed as though the new radiation was similar to the then recently discovered X-rays. Further research by Becquerel, Ernest Rutherford, Paul Villard, Pierre Curie, Marie Curie, and others showed that this form of radioactivity was significantly more complicated. Rutherford was the first to realize that all such elements decay in accordance with the same mathematical exponential formula. Rutherford and his student Frederick Soddy were the first to realize that many decay processes resulted in the transmutation of one element to another. Subsequently, the radioactive displacement law of Fajans and Soddy was formulated to describe the products of alpha and beta decay.

text: At first, it seemed as though the new radiation was similar to the then recently discovered

text: X-rays

text: . Further research by Becquerel,

text: Ernest Rutherford

text: Paul Villard

text: Pierre Curie

text: Marie Curie

text: , and others showed that this form of radioactivity was significantly more complicated. Rutherford was the first to realize that all such elements decay in accordance with the same mathematical exponential formula. Rutherford and his student

text: Frederick Soddy

text: were the first to realize that many decay processes resulted in the

text: transmutation

text: of one element to another. Subsequently, the

entity_name: Radioactive displacement law of Fajans and Soddy

text: radioactive displacement law of Fajans and Soddy

text: was formulated to describe the products of

text: alpha

text: and

text: beta decay

text: Radioactive Man later released a Chinese dragon made of magic in the Federal Bank Reserve. While Captain America, Iron Man, the female Thor, and Vision fought the Chinese dragon, Spider-Man, Ms. Marvel, and Nova encounter Radioactive Man. The senior Avengers managed to destroy the dragon, but upon reuniting with their wards, they learned that they have let the Radioactive Man to escape. The young heroes explain to them that they were forced to leave the Radioactive Man alone as there was a man that needed to be rescued. The senior Avengers are proud for what the young heroes did as heroes are meant to protecting people first and foremost and welcomes them to the team.

text: Radioactive Man later released a Chinese dragon made of magic in the Federal Bank Reserve. While

text: Captain America

text: , Iron Man, the

text: female Thor

text: , and Vision fought the Chinese dragon,

text: Spider-Man

text: Ms. Marvel

text: , and

text: Nova

text: encounter Radioactive Man. The senior Avengers managed to destroy the dragon, but upon reuniting with their wards, they learned that they have let the Radioactive Man to escape. The young heroes explain to them that they were forced to leave the Radioactive Man alone as there was a man that needed to be rescued. The senior Avengers are proud for what the young heroes did as heroes are meant to protecting people first and foremost and welcomes them to the team.

text: Radioactivity is a rare property; minerals may be composed of radioactive elements. They could be a defining constituent, such as uranium in uraninite, autunite, and carnotite, or as trace impurities. In the latter case, the decay of a radioactive element damages the mineral crystal; the result, termed a radioactive halo or pleochroic halo, is observable by various techniques, such as thin-section petrography.

text: Radioactivity

text: is a rare property; minerals may be composed of radioactive elements. They could be a defining constituent, such as uranium in

text: uraninite

text: autunite

text: , and

text: carnotite

text: , or as trace impurities. In the latter case, the decay of a radioactive element damages the mineral crystal; the result, termed a radioactive halo or

text: pleochroic halo

text: , is observable by various techniques, such as thin-section petrography.

text: In the Marvel Comics universe, the Titanic Three was the team of 3 supervillains: Titanium Man, Radioactive Man and Crimson Dynamo.  While the Radioactive Man was a Chinese super-villain, the other members of the team were from the Soviet Union.  Thus the team was one of the several reflections of the Cold War in the Marvel Universe.

text: In the

text: Marvel Comics

text: universe

text: , the Titanic Three was the team of 3

text: supervillain

text: s:

text: Titanium Man

text: Radioactive Man

text: and

text: Crimson Dynamo

text: .  While the Radioactive Man was a Chinese super-villain, the other members of the team were from the Soviet Union.  Thus the team was one of the several reflections of the

text: Cold War

text: in the Marvel Universe.

text: Because denser materials absorb more radioactive emissions than lighter ones, heavy metals are useful for radiation shielding and to focus radiation beams in linear accelerators and radiotherapy applications.

text: Because denser materials absorb more radioactive emissions than lighter ones, heavy metals are useful for

text: radiation shielding

text: and to

entity_section: Neutron, X-ray, and gamma ray collimators

text: focus radiation beams

text: in

text: linear accelerator

text: s and

text: radiotherapy

text: applications.

text: All of the alkaline earth metals except magnesium and strontium have at least one naturally occurring radioisotope: beryllium-7, beryllium-10, and calcium-41 are trace radioisotopes, calcium-48 and barium-130 have very long half-lives and, thus, occur naturally, and all isotopes of radium are radioactive. Calcium-48 is the lightest nuclide to undergo double beta decay.

text: All of the alkaline earth metals except magnesium and strontium have at least one naturally occurring

text: radioisotope

text: , and

text: are

text: trace radioisotope

text: s,

text: and

text: have very long

text: half-lives

text: and, thus, occur naturally, and all

text: isotopes of radium

text: are

text: radioactive

text: . Calcium-48 is the lightest nuclide to undergo

text: double beta decay

text: The wind measurably increased the radiation levels up to 100 miles away from the disaster site. Radioactive iodine, which can lead to increased risk of thyroid cancer if absorbed into the body, was released into the air along with other fission products. To counteract the radioactive iodine the distribution of potassium iodide is used, as it prevents the absorption of the potentially dangerous radioisotopes of that element. Since Chernobyl, distributing potassium iodide to children has been a standard response when risk of radioactivity release is high.

text: During normal operation, plants have to monitor gas and liquid radioactive effluent releases.  The only type that requires continuous monitoring is radioactive noble gasses, although some require monitoring only for every discharge.  Other types of radiation must be monitored weekly or monthly according to the regulations.

text: Radioactivity was discovered in 1896 by Henri Becquerel in uranium, and subsequently observed by Marie and Pierre Curie in thorium and in the new elements polonium and radium. In 1899, Ernest Rutherford separated radioactive emissions into two types: alpha and beta (now beta minus), based on penetration of objects and ability to cause ionization. Alpha rays could be stopped by thin sheets of paper or aluminium, whereas beta rays could penetrate several millimetres of aluminium. In 1900, Paul Villard identified a still more penetrating type of radiation, which Rutherford identified as a fundamentally new type in 1903 and termed gamma rays.  Alpha, beta, and gamma are the first three letters of the Greek alphabet.

text: Radioactivity was discovered in 1896 by

text: Henri Becquerel

text: in

text: uranium

text: , and subsequently observed by

text: Marie

text: and

text: Pierre Curie

text: in

text: thorium

text: and in the new elements

text: polonium

text: and

text: radium

text: . In 1899,

text: Ernest Rutherford

text: separated radioactive emissions into two types: alpha and beta (now beta minus), based on penetration of objects and ability to cause ionization. Alpha rays could be stopped by thin sheets of paper or aluminium, whereas beta rays could penetrate several millimetres of aluminium. In 1900,

text: Paul Villard

text: identified a still more penetrating type of radiation, which Rutherford identified as a fundamentally new type in 1903 and termed

text: gamma ray

text: s.  Alpha, beta, and gamma are the first three letters of the

text: Greek alphabet

text: Exposure to ionizing radiation from radioactive materials or radiation-producing devices is also associated with the development of aplastic anemia. Marie Curie, famous for her pioneering work in the field of radioactivity, died of aplastic anemia after working unprotected with radioactive materials for a long period of time; the damaging effects of ionizing radiation were not then known.

text: Exposure to

text: ionizing radiation

text: from

text: radioactive materials

text: or radiation-producing devices is also associated with the development of aplastic anemia.

text: Marie Curie

text: , famous for her pioneering work in the field of

text: radioactivity

text: , died of aplastic anemia after working unprotected with radioactive materials for a long period of time; the damaging effects of ionizing radiation were not then known.

text: Radiation, most commonly in the form of X-Rays, is used frequently in society in order to produce positive outcomes. The primary use of radiation in healthcare is in the use of radiography for radiographic examination or procedure, and in the use of radiotherapy in the treatment of cancerous conditions. Radiophobia can be a fear which patients experience before and after either of these procedures, it is therefore the responsibility of the healthcare professional at the time, often a Radiographer or Radiation Therapist, to reassure the patients about the stochastic and deterministic effects of radiation on human physiology. Advising patients and other irradiated persons of the various radiation protection measures that are enforced, including the use of lead-rubber aprons, dosimetry and Automatic Exposure Control (AEC) is a common method of informing and reassuring radiophobia sufferers.

text: Radiation, most commonly in the form of X-Rays, is used frequently in society in order to produce positive outcomes. The primary use of radiation in healthcare is in the use of

text: radiography

text: for radiographic examination or procedure, and in the use of

text: radiotherapy

text: in the treatment of cancerous conditions. Radiophobia can be a fear which patients experience before and after either of these procedures, it is therefore the responsibility of the healthcare professional at the time, often a

text: Radiographer

text: or

text: Radiation Therapist

text: , to reassure the patients about the

text: stochastic

text: and

text: deterministic

text: effects of radiation on human physiology. Advising patients and other irradiated persons of the various

text: radiation protection

text: measures that are enforced, including the use of lead-rubber aprons,

text: dosimetry

text: and

text: Automatic Exposure Control (AEC)

text: is a common method of informing and reassuring radiophobia sufferers.

text: To detect hybridization of the probe to its target sequence, the probe is tagged (or "labeled") with a molecular marker of either radioactive or (more recently) fluorescent molecules; commonly used markers are P (a radioactive isotope of phosphorus incorporated into the phosphodiester bond in the probe DNA) or Digoxigenin, which is a non-radioactive, antibody-based marker. DNA sequences or RNA transcripts that have moderate to high sequence similarity to the probe are then detected by visualizing the hybridized probe via autoradiography or other imaging techniques. Normally, either X-ray pictures are taken of the filter, or the filter is placed under UV light. Detection of sequences with moderate or high similarity depends on how stringent the hybridization conditions were applied — high stringency, such as high hybridization temperature and low salt in hybridization buffers, permits only hybridization between nucleic acid sequences that are highly similar, whereas low stringency, such as lower temperature and high salt, allows hybridization when the sequences are less similar. Hybridization probes used in DNA microarrays refer to DNA covalently attached to an inert surface, such as coated glass slides or gene chips, to which a mobile cDNA target is hybridized.

text: To detect

text: hybridization

text: of the probe to its target sequence, the probe is tagged (or "labeled") with a

text: molecular marker

text: of either radioactive or (more recently) fluorescent molecules; commonly used markers are

text: P

text: (a

text: radioactive

text: isotope

text: of

text: phosphorus

text: incorporated into the

text: phosphodiester

text: bond in the probe DNA) or

text: Digoxigenin

text: , which is a non-radioactive,

text: antibody

text: -based marker. DNA sequences or RNA transcripts that have moderate to high sequence similarity to the probe are then detected by visualizing the hybridized probe via

text: autoradiography

text: or other imaging techniques. Normally, either X-ray pictures are taken of the filter, or the filter is placed under UV light. Detection of sequences with moderate or high similarity depends on how stringent the hybridization conditions were applied — high stringency, such as high hybridization temperature and low salt in hybridization buffers, permits only hybridization between

text: nucleic acid

text: sequences that are highly similar, whereas low stringency, such as lower temperature and high salt, allows hybridization when the sequences are less similar. Hybridization probes used in DNA

text: microarray

text: s refer to DNA covalently attached to an inert surface, such as coated glass slides or gene chips, to which a mobile cDNA target is hybridized.

text: Here is a list of radioisotopes formed by the action of cosmic rays; the list also contains the production mode of the isotope. Most cosmogenic nuclides are formed in the atmosphere, but some  are formed in situ in soil and rock exposed to cosmic rays, notably Calcium-41 in the table below.

text: Here is a list of radioisotopes formed by the action of

text: cosmic rays

text: ; the list also contains the production mode of the isotope. Most cosmogenic nuclides are formed in the atmosphere, but some  are formed in situ in soil and rock exposed to cosmic rays, notably Calcium-41 in the table below.

text: Naturally occurring europium (Eu) is composed of 2 isotopes, Eu and Eu, with Eu being the most abundant (52.2% natural abundance). While Eu is observationally stable, Eu was recently found to be unstable and to undergo alpha decay. The half-life is measured to be (4.62 ± 0.95(stat.) ± 0.68(syst.)) × 10 y which corresponds to 1 alpha decay per two minutes in every kilogram of natural europium. Besides natural radioisotope Eu, 36 artificial radioisotopes have been characterized, with the most stable being Eu with a half-life of 36.9 years, Eu with a half-life of 13.516 years, and Eu with a half-life of 8.593 years. All of the remaining radioactive isotopes have half-lives that are less than 4.7612 years, and the majority of these have half-lives that are less than 12.2 seconds. This element also has 17 meta states, with the most stable being Eu (t 12.8 hours), Eu (t 9.3116 hours) and Eu (t 96 minutes).

text: Naturally occurring

text: europium

text: (Eu) is composed of 2

text: isotope

text: s, Eu and Eu, with Eu being the most abundant (52.2%

text: natural abundance

text: ). While Eu is observationally stable, Eu was recently found to be unstable and to undergo

text: alpha decay

text: . The

text: half-life

text: is measured to be (4.62 ± 0.95(stat.) ± 0.68(syst.)) × 10 y which corresponds to 1 alpha decay per two minutes in every kilogram of natural europium. Besides natural radioisotope Eu, 36 artificial radioisotopes have been characterized, with the most stable being Eu with a

text: half-life

text: of 36.9 years, Eu with a half-life of 13.516 years, and Eu with a half-life of 8.593 years. All of the remaining

text: radioactive

text: isotopes have half-lives that are less than 4.7612 years, and the majority of these have half-lives that are less than 12.2 seconds. This element also has 17

text: meta state

text: s, with the most stable being Eu (t 12.8 hours), Eu (t 9.3116 hours) and Eu (t 96 minutes).

text: Jordan's Ministry of Water and Irrigation has stated that the radioactivity is not a problem because the water is to be diluted with an equal amount of water from other sources. This dilution would presumably halve the radioactivity of the water which, according to Vengosh's data, would not be enough to bring the water up to standards.  The Ministry of Water and Irrigation, however, has declared Vengosh's data to be inaccurate, as his study did not test water from any of the wells that will be used in the project.  As radiation varies from well to well, it is possible that the data Vengosh collected does not accurately reflect the water sources to be used in the project.

text: In 1920–1921 George de Hevesy measured self-diffusion using radioisotopes. He studied self-diffusion of radioactive isotopes of lead in liquid and solid lead.

text: In 1920–1921

text: George de Hevesy

text: measured

text: self-diffusion

text: using radioisotopes. He studied self-diffusion of radioactive isotopes of lead in liquid and solid lead.

text: Radioactive contamination is a potential danger for living organisms and results in external hazards, concerning radiation sources outside the body, and internal dangers, as a result of the incorporation of radionuclides inside the body (often by inhalation of particles or ingestion of contaminated food).

text: Radioactive contamination is a potential danger for living organisms and results in external hazards, concerning radiation sources outside the body, and internal dangers, as a result of the incorporation of radionuclides inside the body (often by

text: inhalation

text: of particles or

text: ingestion

text: of

text: contaminated food

text: Early in his life, Schrödinger experimented in the fields of electrical engineering, atmospheric electricity, and atmospheric radioactivity, but he usually worked with his former teacher Franz Exner. He also studied vibrational theory, the theory of Brownian movement, and mathematical statistics. In 1912, at the request of the editors of the Handbook of Electricity and Magnetism, Schrödinger wrote an article titled Dieelectrism. That same year, Schrödinger gave a theoretical estimate of the probable height distribution of radioactive substances, which is required to explain the observed radioactivity of the atmosphere, and in August 1913 executed several experiments in Zeehame that confirmed his theoretical estimate and those of Victor Franz Hess. For this work, Schrödinger was awarded the 1920 Haitinger Prize (Haitinger-Preis) of the Austrian Academy of Sciences. Other experimental studies conducted by the young researcher in 1914 were checking formulas for capillary pressure in gas bubbles and the study of the properties of soft beta-radiation appearing in the fall of gamma rays on the surface of metal. The last work he performed together with his friend Fritz Kohlrausch. In 1919, Schrödinger performed his last physical experiment on coherent light and subsequently focused on theoretical studies.

text: Early in his life, Schrödinger experimented in the fields of electrical engineering, atmospheric electricity, and atmospheric radioactivity, but he usually worked with his former teacher Franz Exner. He also studied vibrational theory, the theory of Brownian movement, and mathematical statistics. In 1912, at the request of the editors of the Handbook of Electricity and Magnetism, Schrödinger wrote an article titled Dieelectrism. That same year, Schrödinger gave a theoretical estimate of the probable height distribution of radioactive substances, which is required to explain the observed radioactivity of the atmosphere, and in August 1913 executed several experiments in Zeehame that confirmed his theoretical estimate and those of Victor Franz Hess. For this work, Schrödinger was awarded the 1920

text: Haitinger Prize

text: (Haitinger-Preis) of the Austrian Academy of Sciences. Other experimental studies conducted by the young researcher in 1914 were checking formulas for capillary pressure in gas bubbles and the study of the properties of soft beta-radiation appearing in the fall of gamma rays on the surface of metal. The last work he performed together with his friend Fritz Kohlrausch. In 1919, Schrödinger performed his last physical experiment on coherent light and subsequently focused on theoretical studies.

text: Because of its high solubility in water, caesium chloride is highly mobile and can even diffuse through concrete. This is a drawback for its radioactive form which urges a search for more stable radioisotope materials. Commercial sources of radioactive caesium chloride are well sealed in a double steel enclosure. However, in the Goiânia accident in Brazil, such a source containing about 93 gram of CsCl, was stolen from an abandoned hospital and forced open by two scavengers. The blue glow emitted in the dark by the radioactive caesium chloride attracted the thieves and their relatives who were unaware of the associated dangers and spread the powder. This resulted in one of the worst radiation spill accidents in which 4 people died within a month from the exposure, 20 showed signs of radiation sickness, 249 people were contaminated with radioactive caesium chloride, and about a thousand received a dose exceeding a yearly amount of background radiation. More than 110,000 people overwhelmed the local hospitals, and several city blocks had to be demolished in the cleanup operations. In the first days of the contamination, stomach disorders and nausea due to radiation sickness were experienced by several people, but only after several days one person associated the symptoms with the powder and brought a sample to the authorities.

text: Because of its high solubility in water, caesium chloride is highly mobile and can even diffuse through concrete. This is a drawback for its radioactive form which urges a search for more stable radioisotope materials. Commercial sources of radioactive caesium chloride are well sealed in a double steel enclosure. However, in the

text: Goiânia accident

text: in

text: Brazil

text: , such a source containing about 93 gram of CsCl, was stolen from an abandoned hospital and forced open by two scavengers. The blue glow emitted in the dark by the radioactive caesium chloride attracted the thieves and their relatives who were unaware of the associated dangers and spread the powder. This resulted in one of the worst radiation spill accidents in which 4 people died within a month from the exposure, 20 showed signs of

text: radiation sickness

text: , 249 people were contaminated with radioactive caesium chloride, and about a thousand received a dose exceeding a yearly amount of background radiation. More than 110,000 people overwhelmed the local hospitals, and several city blocks had to be demolished in the cleanup operations. In the first days of the contamination, stomach disorders and nausea due to radiation sickness were experienced by several people, but only after several days one person associated the symptoms with the powder and brought a sample to the authorities.

text: It is expected that some continual improvement of experimental sensitivity will allow discovery of very mild radioactivity (instability) of some isotopes that are considered to be stable today. For an example of a recent discovery, it was not until 2003 that bismuth-209 (the only naturally-occurring isotope of bismuth) was shown to be very mildly radioactive, confirming theoretical predictions from nuclear physics that bismuth-209 would decay very slowly by alpha emission.

text: It is expected that some continual improvement of experimental sensitivity will allow discovery of very mild radioactivity (instability) of some isotopes that are considered to be stable today. For an example of a recent discovery, it was not until 2003 that

text: (the only naturally-occurring isotope of bismuth) was shown to be very mildly radioactive, confirming theoretical predictions from

text: nuclear physics

text: that bismuth-209 would decay very slowly by

text: alpha emission

text: Deep borehole disposal is the concept of disposing of high-level radioactive waste from nuclear reactors in extremely deep boreholes. Deep borehole disposal seeks to place the waste as much as  beneath the surface of the Earth and relies primarily on the immense natural geological barrier to confine the waste safely and permanently so that it should never pose a threat to the environment. The Earth's crust contains 120 trillion tons of thorium and 40 trillion tons of uranium (primarily at relatively trace concentrations of parts per million each adding up over the crust's 3 * 10 ton mass), among other natural radioisotopes. Since the fraction of nuclides decaying per unit of time is inversely proportional to an isotope's half-life, the relative radioactivity of the lesser amount of human-produced radioisotopes (thousands of tons instead of trillions of tons) would diminish once the isotopes with far shorter half-lives than the bulk of natural radioisotopes decayed.

text: Deep borehole disposal

text: is the concept of disposing of high-level radioactive waste from nuclear reactors in extremely deep boreholes. Deep borehole disposal seeks to place the waste as much as  beneath the surface of the Earth and relies primarily on the immense natural geological barrier to confine the waste safely and permanently so that it should never pose a threat to the environment. The Earth's crust contains 120 trillion tons of thorium and 40 trillion tons of uranium (primarily

text: at relatively trace concentrations of parts per million each

text: adding up over the crust's 3 * 10 ton mass), among other natural radioisotopes. Since the fraction of nuclides decaying per unit of time is inversely proportional to an isotope's half-life, the relative radioactivity of the lesser amount of human-produced radioisotopes (thousands of tons instead of trillions of tons) would diminish once the isotopes with far shorter half-lives than the bulk of natural radioisotopes decayed.

text: Radioactive contamination is typically the result of a spill or accident during the production, or use of, radionuclides (radioisotopes); these have unstable nuclei which are subject to radioactive decay.

text: Radioactive contamination is typically the result of a spill or accident during the production, or use of,

text: radionuclide

text: s (radioisotopes); these have unstable nuclei which are subject to

text: radioactive decay

text: Detection of radiations is based on their interactions with matter, leading mainly to ionizations. Using a semiconductor telescope and conventional electronics to identify the C ions, the Rose and Jones's experiment was running for about six months in order to get 11 useful events.

text: However, some studies contradict the linear no-threshold model. These studies indicate that some low levels of radiation do not increase cancer risk at all, and that there may exist a threshold dosage of ionizing radiation below which exposure should be considered safe. Nonetheless the 'no safe amount' assumption is the basis of US and most national regulatory policies regarding "man-made" sources of radiation.

text: However,

text: some studies

text: contradict the linear no-threshold model. These studies indicate that some low levels of radiation do not increase cancer risk at all, and that there may exist a threshold dosage of ionizing radiation below which exposure should be considered safe. Nonetheless the 'no safe amount' assumption is the basis of US and most national regulatory policies regarding "man-made" sources of radiation.

text: Radioisotopes of hydrogen, carbon, phosphorus, sulphur, and iodine have been used extensively to trace the path of biochemical reactions. A radioactive tracer can also be used to track the distribution of a substance within a natural system such as a cell or tissue, or as a flow tracer to track fluid flow. Radioactive tracers are also used to determine the location of fractures created by hydraulic fracturing in natural gas production. Radioactive tracers form the basis of a variety of imaging systems, such as, PET scans, SPECT scans and technetium scans. Radiocarbon dating uses the naturally occurring carbon-14 isotope as an isotopic label.

text: Radioisotopes of

text: hydrogen

text: carbon

text: phosphorus

text: sulphur

text: , and

text: iodine

text: have been used extensively to trace the path of

text: biochemical reactions

text: . A radioactive tracer can also be used to track the distribution of a substance within a natural system such as a

text: cell

text: or

text: tissue

text: , or as a

text: flow tracer

text: to track

text: fluid flow

text: . Radioactive tracers are also used to determine the location of fractures created by

text: hydraulic fracturing

text: in natural gas production. Radioactive tracers form the basis of a variety of imaging systems, such as,

text: PET scan

text: s,

entity_name: Single-photon emission computed tomography

text: SPECT scan

text: s and

text: technetium scan

text: s.

text: Radiocarbon dating

text: uses the naturally occurring

text: isotope as an

text: isotopic label

text: Nihonium (Nh) is a synthetic element with atomic number 113. Being synthetic, a standard atomic mass cannot be given and like all artificial elements, it has no stable isotopes. The first isotope to be synthesized was Nh as a decay product of Mc in 2003. The first isotope to be directly synthesized was Nh in 2004. There are 6 known radioisotopes from Nh to Nh. The longest-lived isotope is Nh with a half-life of 19.6 seconds.

text: Nihonium

text: (Nh) is a

text: synthetic element

text: with atomic number 113. Being synthetic, a standard

text: atomic mass

text: cannot be given and like all artificial elements, it has no

text: stable isotope

text: s. The first

text: isotope

text: to be synthesized was Nh as a

text: decay product

text: of Mc in 2003. The first isotope to be directly synthesized was Nh in 2004. There are 6 known

text: radioisotope

text: s from Nh to Nh. The longest-lived isotope is Nh with a

text: half-life

text: of 19.6 seconds.

text: After a period of time performing as "The Rock N' Roll Chicken Heads" and "The Chicken Heads", Joe and the Chicken Heads permanently changed their name to "The Radioactive Chicken Heads" in mid-2004. According to their website, the "official" tongue-in-cheek reason behind the name change was due to "new government regulations which require all radioactive farm products to be labeled clearly".

text: In 1902, they produced a "Theory of Atomic Disintegration" to account for all their experiments. Up till then atoms were assumed to be the indestructable basis of all matter and although Curie had suggested that radioactivity was an atomic phenomenon, the idea of the atoms of radioactive substances breaking up was a radically new idea. Rutherford and Soddy demonstrated that radioactivity involved the spontaneous disintegration of atoms into other types of atoms (one element spontaneously being changed to another).

text: In 1902, they produced a "Theory of Atomic Disintegration" to account for all their experiments. Up till then atoms were assumed to be the indestructable basis of all matter and although Curie had suggested that radioactivity was an atomic phenomenon, the idea of the atoms of radioactive substances breaking up was a radically new idea. Rutherford and Soddy demonstrated that radioactivity involved the spontaneous disintegration of

text: atom

text: s into other types of atoms (one element spontaneously being changed to another).

text: Microspheres that are labeled with radioactive isotopes have been widely used since the 1960s. Radioactively labeled particles are injected into the test subject and a radiation detector measures radioactivity in tissues of interest. Application of this process is used to develop radionuclide angiography, a method of diagnosing heart problems.

text: Microspheres

text: that are labeled with

text: radioactive isotopes

text: have been widely used since the 1960s. Radioactively labeled particles are injected into the test subject and a

text: radiation detector

text: measures radioactivity in tissues of interest. Application of this process is used to develop

text: radionuclide angiography

text: , a method of diagnosing heart problems.

text: In pollution control applications, ultraviolet analyzers are used to detect emissions of nitrogen oxides, sulfur compounds, mercury and ammonia, for example in the flue gas of fossil fired power plants. Ultraviolet radiation can detect thin sheens of spilled oil on water, either by the high reflectivity of oil films at UV wavelengths, fluorescence of compounds in oil, or by absorbing of UV created by Raman scattering in water.

text: In pollution control applications, ultraviolet analyzers are used to detect emissions of nitrogen oxides, sulfur compounds, mercury and ammonia, for example in the flue gas of fossil fired power plants. Ultraviolet radiation can detect thin sheens of

text: spilled oil

text: on water, either by the high reflectivity of oil films at UV wavelengths, fluorescence of compounds in oil, or by absorbing of UV created by

text: Raman scattering

text: in water.

text: Early researchers found that an electric or magnetic field could split radioactive emissions into three types of beams. The rays were given the names alpha, beta, and gamma, in order of their ability to penetrate matter. While alpha decay was observed only in heavier elements of atomic number 52 (tellurium) and greater, the other two types of decay were produced by all of the elements. Lead, atomic number 82, is the heaviest element to have any isotopes stable (to the limit of measurement) to radioactive decay. Radioactive decay is seen in all isotopes of all elements of atomic number 83 (bismuth) or greater. Bismuth, however, is only very slightly radioactive, with a half-life greater than the age of the universe; radioisotopes with extremely long half-lives are considered effectively stable for practical purposes.

text: Early researchers found that an

text: electric

text: or

text: magnetic field

text: could split radioactive emissions into three types of beams. The rays were given the names

text: alpha

text: beta

text: , and

text: gamma

text: , in order of their ability to penetrate matter. While alpha decay was observed only in heavier elements of atomic number 52 (

text: tellurium

text: ) and greater, the other two types of decay were produced by all of the elements. Lead,

text: atomic number

text: 82, is the heaviest element to have any isotopes stable (to the limit of measurement) to radioactive decay. Radioactive decay is seen in all isotopes of all elements of atomic number 83 (

text: bismuth

text: ) or greater. Bismuth, however, is only very slightly radioactive, with a half-life greater than the age of the universe; radioisotopes with extremely long half-lives are considered effectively stable for practical purposes.

text: The Last Oracle (2008) involves an ambitious, young Russian politician's desire to use autistic savant children to develop a new world order. It is revealed that Monk did not die as understood previously in The Judas Strain, but was, for reasons central to the plot of this book, picked up by a Russian submarine and ended up in the hands of the bad guys; he is suffering from amnesia caused by experiments performed on him. Three of the savant children rescue him, and together the four escape and attempt to thwart the plot. With help from Pierce and the Gypsies, Monk and the children succeed although he still has (possibly permanent) amnesia due to the brain surgery experiments. If the plans hadn't been stopped, many world leaders would have been killed due to radiation exposure at Chernobyl, and millions of people would have died worldwide due to radiation being flooded into the world from the highly radioactive Lake Karachay.

text: The Last Oracle (2008) involves an ambitious, young Russian politician's desire to use

text: autistic

text: savant

text: children to develop a

text: new world order

text: . It is revealed that Monk did not die as understood previously in The Judas Strain, but was, for reasons central to the plot of this book, picked up by a Russian submarine and ended up in the hands of the bad guys; he is suffering from amnesia caused by experiments performed on him. Three of the savant children rescue him, and together the four escape and attempt to thwart the plot. With help from Pierce and the Gypsies, Monk and the children succeed although he still has (possibly permanent)

text: amnesia

text: due to the brain surgery experiments. If the plans hadn't been stopped, many world leaders would have been killed due to radiation exposure at

text: Chernobyl

text: , and millions of people would have died worldwide due to radiation being flooded into the world from the highly radioactive

text: Lake Karachay

text: 40 isotopes of tin have been discovered. 14 of these occur in nature. The most common is the stable isotope tin-120, followed by the stable isotope tin-118, the stable isotope tin-116, the stable isotope tin-119, the stable isotope tin-117, the primordial radioisotope tin-124, the stable isotope tin-122, the stable isotope tin-112, and the stable isotope tin-114. Tin also has four radioisotopes that occur as the result of the radioactive decay of uranium. These isotopes are tin-121, tin-123, tin-125, and tin-126.

text: isotopes of tin

text: have been discovered. 14 of these occur in nature. The most common is the stable isotope tin-120, followed by the stable isotope tin-118, the stable isotope tin-116, the stable isotope tin-119, the stable isotope tin-117, the primordial radioisotope tin-124, the stable isotope tin-122, the stable isotope tin-112, and the stable isotope tin-114. Tin also has four radioisotopes that occur as the result of the radioactive decay of uranium. These isotopes are tin-121, tin-123, tin-125, and tin-126.

text: The Earth's interior radiates heat at a rate of about 47 TW (terawatts), which is less than 0.1% of the incoming solar energy. Part of this heat loss is accounted for by the heat generated upon decay of radioactive isotopes in the Earth interior. The remaining heat loss is due to the secular cooling of the Earth, growth of the Earth’s inner core (gravitational energy and latent heat contributions), and other processes. The most important heat-producing elements are uranium (U), thorium (Th), and potassium (K). The debate about their abundances in the Earth has not concluded. Various compositional estimates exist where the total Earth’s internal radiogenic heating rate ranges from as low at ~10 TW to as high as ~30 TW. About 7 TW worth of heat-producing elements reside in the Earth's crust,  the remaining power is distributed in the Earth mantle; the amount of U, Th, and K in the Earth core is probably negligible. Radioactivity in the Earth mantle provides internal heating to power mantle convection, which is the driver of plate tectonics. The amount of mantle radioactivity and its spatial distribution—is the mantle compositionally uniform at large scale or composed of distinct reservoirs?—is of importance to geophysics.

text: The

text: Earth

text: 's interior radiates heat at a rate of about 47 TW (

text: terawatts

text: ), which is less than 0.1% of the incoming solar energy. Part of this heat loss is accounted for by the heat generated upon decay of radioactive isotopes in the Earth interior. The remaining heat loss is due to the secular cooling of the Earth, growth of the Earth’s

text: inner core

text: (gravitational energy and latent heat contributions), and other processes. The most important heat-producing elements are

text: uranium

text: (U),

text: thorium

text: (Th), and

text: potassium

text: (K). The debate about their abundances in the Earth has not concluded. Various compositional estimates exist where the total Earth’s internal radiogenic heating rate ranges from as low at ~10 TW to as high as ~30 TW. About 7 TW worth of heat-producing elements reside in the

text: Earth's crust

text: ,  the remaining power is distributed in the

text: Earth mantle

text: ; the amount of U, Th, and K in the

text: Earth core

text: is probably negligible. Radioactivity in the Earth mantle provides internal heating to power

text: mantle convection

text: , which is the driver of

text: plate tectonics

text: . The amount of mantle radioactivity and its spatial distribution—is the mantle compositionally uniform at large scale or composed of distinct reservoirs?—is of importance to geophysics.

text: More radioactivity was released in the spill than in the Three Mile Island accident that occurred four months earlier. It has been reported as the largest radioactive accident in U.S. history.

text: More radioactivity was released in the spill than in the

text: Three Mile Island accident

text: that occurred four months earlier. It has been reported as the largest

entity_name: Nuclear and radiation accidents and incidents

text: radioactive accident

text: in U.S. history.

text: 3% of the mass consists of fission products of U and Pu (also indirect products in the decay chain); these are considered radioactive waste or may be separated further for various industrial and medical uses. The fission products include every element from zinc through to the lanthanides; much of the fission yield is concentrated in two peaks, one in the second transition row (Zr, Mo, Tc, Ru, Rh, Pd, Ag) and the other later in the periodic table (I, Xe, Cs, Ba, La, Ce, Nd). Many of the fission products are either non-radioactive or only short-lived radioisotopes. But a considerable number are medium to long-lived radioisotopes such as Sr, Cs, Tc and I. Research has been conducted by several different countries into segregating the rare isotopes in fission waste including the "fission platinoids" (Ru, Rh, Pd) and silver (Ag) as a way of offsetting the cost of reprocessing; however, this is not currently being done commercially.

text: 3% of the mass consists of fission products of U and Pu (also indirect products in the

text: decay chain

text: ); these are considered

text: radioactive waste

text: or may be separated further for various industrial and medical uses. The fission products include every element from

text: zinc

text: through to the

text: lanthanide

text: s; much of the fission yield is concentrated in two peaks, one in the second transition row (

text: Zr

text: , Mo, Tc,

text: Ru

text: Rh

text: Pd

text: Ag

text: ) and the other later in the periodic table (

text: I

text: Xe

text: Cs

text: Ba

text: La

text: Ce

text: , Nd). Many of the fission products are either non-radioactive or only short-lived

text: radioisotopes

text: . But a considerable number are medium to long-lived radioisotopes such as Sr, Cs, Tc and I. Research has been conducted by several different countries into segregating the rare isotopes in fission waste including the "fission platinoids" (Ru, Rh, Pd) and silver (Ag) as a way of offsetting the cost of reprocessing; however, this is not currently being done commercially.

text: Radioactive contamination may exist on surfaces or in volumes of material or air, and specialist techniques are used to measure the levels of contamination by detection of the emitted radiation.

text: There will be three different type of storage facilities: for the spent nuclear fuel, nuclear fuel waste and radioactive waste.

text: After several years of cooling, most radioactivity is from the fission products caesium-137 and strontium-90, which are each produced in about 6% of fissions, and have half-lives of about 30 years. Other fission products with similar half-lives have much lower fission product yields, lower decay energy, and several (Sm,Eu,Cd) are also quickly destroyed by neutron capture while still in the reactor, so are not responsible for more than a tiny fraction of the radiation production at any time. Therefore, in the period from several years to several hundred years after use, radioactivity of spent fuel can be modeled simply as exponential decay of the Cs and Sr. These are sometimes known as medium-lived fission products.

text: After several years of cooling, most radioactivity is from the fission products

text: and

text: , which are each produced in about 6% of fissions, and have half-lives of about 30 years. Other fission products with similar half-lives have much lower

text: fission product yield

text: s, lower

text: decay energy

text: , and several (Sm,Eu,Cd) are also quickly destroyed by

text: neutron capture

text: while still in the reactor, so are not responsible for more than a tiny fraction of the radiation production at any time. Therefore, in the period from several years to several hundred years after use, radioactivity of spent fuel can be modeled simply as

text: exponential decay

text: of the Cs and Sr. These are sometimes known as medium-lived fission products.

text: Since 2011 Sarı has been working on creating ceramics works that take advantage of the glow properties of the radioactive uranium silicates. Sarı has been working with technology and art in parallel implementing works of art by using the techniques of uranium silicate's phosphorus effects on porcelain bodies since 2011. According to Sarı, there are two shades of red (copper red and uranium red) that are very difficult to achieve in glaze and ceramics and that a small surface of uranium red can be produced by burning uranium nitrate in high temperature. He was able to experiment with radioactive rare elements during his PhD studies in Sofia and that he was able to successfully significantly reduce alpha particle radiation from glaze and ceramics using radioactive uranium by using lead and lithium oxide layer coating which is further coated by glass layers. On 30 November 2012 Sarı held a seminar on "Uranium in Ceramic Art" at Vuzf University and also held a solo exhibition demonstrating this work with red uranium. On 27 June 2012 Sarı gave a guest lecture and held a workshop on uses of rare elements in ceramic glazes and glass bodies, cromatic glazes, Turkish blue glaze, preparation of safety floric acid bath for mat glazing at University of Applied Arts Vienna. On 15 September 2012 Sarı presented his paper with the topic "Uses of The Rare Elements into Ceramic Glazes and Glass Bodies" in the Sixth International Eskişehir Terra Cotta Symposium where he discussed the behavior within glazed ceramic/porcelain bodies of attained rare earth elements.

text: Since 2011 Sarı has been working on creating ceramics works that take advantage of the glow properties of the

text: radioactive

text: uranium

text: silicate

text: s. Sarı has been working with technology and art in parallel implementing works of art by using the techniques of uranium silicate's phosphorus effects on porcelain bodies since 2011. According to Sarı, there are two shades of red (copper red and uranium red) that are very difficult to achieve in glaze and ceramics and that a small surface of uranium red can be produced by burning uranium nitrate in high temperature. He was able to experiment with radioactive rare elements during his PhD studies in Sofia and that he was able to successfully significantly reduce

text: alpha particle

text: radiation from glaze and ceramics using radioactive uranium by using lead and lithium oxide layer coating which is further coated by glass layers. On 30 November 2012 Sarı held a seminar on "Uranium in Ceramic Art" at

text: Vuzf University

text: and also held a solo exhibition demonstrating this work with red uranium. On 27 June 2012 Sarı gave a guest lecture and held a workshop on uses of rare elements in ceramic glazes and glass bodies, cromatic glazes, Turkish blue glaze, preparation of safety floric acid bath for mat glazing at

text: University of Applied Arts Vienna

text: . On 15 September 2012 Sarı presented his paper with the topic "Uses of The Rare Elements into Ceramic Glazes and Glass Bodies" in the Sixth International Eskişehir Terra Cotta Symposium where he discussed the behavior within glazed ceramic/porcelain bodies of attained rare earth elements.

text: When Fajans worked at the laboratory of Ernest Rutherford (with Henry G. Moseley) he was researching properties of the radioactive rows. He identified the half-lives of the uranium-actinium row and thorium nuclides. He discovered the phenomenon of the electrochemical branching of the radioactive rows. Afterwards Fajans was working on the electrochemical properties of elements as a result of the radioactive changes, and he formulated the law of the radioactive shifts which was later named the radioactive displacement law of Fajans and Soddy (Frederick Soddy received the Nobel Prize in chemistry in 1921 for his isotopic research). In 1913, together with Oswald Helmuth Göhring, he discovered the radionuclide of a new element, which was later called protactinium. Fajans and Otto Hahn were the discoverers of the formula that defined the conditions of the precipitation and absorption of radioactive substances. It is very significant in the context of radiochemical methods of separating and cleaning radioactive substances found in the smallest number.

text: When Fajans worked at the laboratory of

text: Ernest Rutherford

text: (with

text: Henry G. Moseley

text: ) he was researching properties of the radioactive rows. He identified the

text: half-lives

text: of the

text: uranium

text: actinium

text: row and

text: thorium

text: nuclides. He discovered the phenomenon of the electrochemical branching of the radioactive rows. Afterwards Fajans was working on the electrochemical properties of elements as a result of the radioactive changes, and he formulated the law of the radioactive shifts which was later named the

text: Frederick Soddy

text: received the Nobel Prize in chemistry in 1921 for his isotopic research). In 1913, together with

text: Oswald Helmuth Göhring

text: , he discovered the radionuclide of a new element, which was later called

text: protactinium

text: . Fajans and

text: Otto Hahn

text: were the discoverers of the formula that defined the conditions of the precipitation and absorption of radioactive substances. It is very significant in the context of radiochemical methods of separating and cleaning radioactive substances found in the smallest number.

text: Long-lived radioactive waste from the back end of the fuel cycle is especially relevant when designing a complete waste management plan for spent nuclear fuel (SNF). When looking at long term radioactive decay, the actinides in the SNF have a significant influence due to their characteristically long half-lives. Depending on what a nuclear reactor is fueled with, the actinide composition in the SNF will be different.

text: Long-lived radioactive waste from the back end of the fuel cycle is especially relevant when designing a complete waste management plan for

text: spent nuclear fuel

text: (SNF). When looking at long term radioactive decay, the actinides in the SNF have a significant influence due to their characteristically long half-lives. Depending on what a

text: nuclear reactor

text: is fueled with, the actinide composition in the SNF will be different.

text: After the discovery of radioactivity by Henri Becquerel and Marie Curie in 1896, it was generally believed that atmospheric electricity, ionization of the air, was caused only by radiation from radioactive elements in the ground or the radioactive gases or isotopes of radon they produce. Measurements of ionization rates at increasing heights above the ground during the decade from 1900 to 1910 showed a decrease that could be explained as due to absorption of the ionizing radiation by the intervening air.

text: After the discovery of

text: radioactivity

text: by

text: Henri Becquerel

text: and

text: Marie Curie

text: in 1896, it was generally believed that atmospheric electricity,

text: ionization

text: of the

text: air

text: , was caused only by

text: radiation

text: from radioactive elements in the ground or the radioactive gases or isotopes of

text: radon

text: they produce. Measurements of ionization rates at increasing heights above the ground during the decade from 1900 to 1910 showed a decrease that could be explained as due to absorption of the ionizing radiation by the intervening air.

text: Most synthetic radioisotopes are extremely radioactive and have a short half-life. Though a health hazard, radioactive materials have many medical and industrial uses.

text: Most synthetic radioisotopes are extremely radioactive and have a short

text: half-life

text: . Though a health hazard, radioactive materials have many medical and industrial uses.

text: Neutrons are the only type of ionizing radiation that can make other objects, or material, radioactive. This process, called neutron activation, is the primary method used to produce radioactive sources for use in medical, academic, and industrial applications. Even comparatively low speed thermal neutrons cause neutron activation (in fact, they cause it more efficiently). Neutrons do not ionize atoms in the same way that charged particles such as protons and electrons do (by the excitation of an electron), because neutrons have no charge. It is through their absorption by nuclei which then become unstable that they cause ionization. Hence, neutrons are said to be "indirectly ionizing." Even neutrons without significant kinetic energy are indirectly ionizing, and are thus a significant radiation hazard.  Not all materials are capable of neutron activation; in water, for example, the most common isotopes of both types atoms present (hydrogen and oxygen) capture neutrons and become heavier but remain stable forms of those atoms.  Only the absorption of more than one neutron, a statistically rare occurrence, can activate a hydrogen atom, while oxygen requires two additional absorptions.  Thus water is only very weakly capable of activation.  The sodium in salt (as in sea water), on the other hand, need only absorb a single neutron to become Na-24, a very intense source of beta decay, with half-life of 15 hours.

text: Neutrons are the only type of ionizing radiation that can make other objects, or material, radioactive. This process, called

text: neutron activation

text: , is the primary method used to produce radioactive sources for use in medical, academic, and industrial applications. Even comparatively low speed

text: thermal neutron

text: s cause neutron activation (in fact, they cause it more efficiently). Neutrons do not ionize atoms in the same way that charged particles such as protons and electrons do (by the excitation of an electron), because neutrons have no charge. It is through their absorption by nuclei which then become unstable that they cause ionization. Hence, neutrons are said to be "indirectly ionizing." Even neutrons without significant kinetic energy are indirectly ionizing, and are thus a significant radiation hazard.  Not all materials are capable of neutron activation; in water, for example, the most common isotopes of both types atoms present (hydrogen and oxygen) capture neutrons and become heavier but remain stable forms of those atoms.  Only the absorption of more than one neutron, a statistically rare occurrence, can activate a hydrogen atom, while oxygen requires two additional absorptions.  Thus water is only very weakly capable of activation.  The sodium in salt (as in sea water), on the other hand, need only absorb a single neutron to become Na-24, a very intense source of beta decay, with half-life of 15 hours.

text: The Committee Examining Radiation Risks of Internal Emitters (CERRIE), established by the UK Government, carried out a 3-year-long independent expert review into the health risks of internal emitters (i.e., hot particles) and published its findings in 2003. The study failed to reach consensus, but the conclusion of the majority of its members was that the current ICRP risk model, despite being largely derived from studies of survivors of external radiation, adequately estimates the risk of hot particles, and that any differences between internal and external radiation are adequately accommodated by the established parameters in physiological models (relative biological effectiveness, kinetic factors); i.e., that internal radiation does not seem to be significantly more dangerous than an equal amount of externally delivered radiation. However, they noted significant levels of uncertainty regarding dose estimates for internal emitters, especially regarding less common radionuclides such as Pu and Am, and even more common ones such as Sr. Two of the twelve members disagreed with the overall findings, notably Christopher Busby who advocates controversial physico-biological mechanisms such as Second Event Theory and Photoelectric Effect Theory, by which he believes the danger of ingested particles could be greatly enhanced.

text: The

entity_name: Committee on Medical Aspects of Radiation in the Environment

text: Committee Examining Radiation Risks of Internal Emitters

text: (CERRIE), established by the UK Government, carried out a 3-year-long independent expert review into the health risks of internal emitters (i.e., hot particles) and published its findings in 2003. The study failed to reach consensus, but the conclusion of the majority of its members was that the current

entity_name: International Commission on Radiological Protection

text: ICRP

text: risk model, despite being largely derived from studies of survivors of external radiation, adequately estimates the risk of hot particles, and that any differences between internal and external radiation are adequately accommodated by the established parameters in physiological models (

text: relative biological effectiveness

text: , kinetic factors); i.e., that internal radiation does not seem to be significantly more dangerous than an equal amount of externally delivered radiation. However, they noted significant levels of uncertainty regarding dose estimates for internal emitters, especially regarding less common radionuclides such as

text: Pu

text: and

text: Am

text: , and even more common ones such as

text: Sr

text: . Two of the twelve members disagreed with the overall findings, notably

text: Christopher Busby

text: who advocates controversial physico-biological mechanisms such as

entity_section: Second Event Theory and Photoelectric Effect Controversy

text: Second Event Theory and Photoelectric Effect Theory

text: , by which he believes the danger of ingested particles could be greatly enhanced.

text: Some radioactive materials in "exclusive use" with low specific activity radioactive materials will not bear the label, however, the RADIOACTIVE placard is required.

text: Some

text: radioactive materials

text: in "exclusive use" with low

text: specific activity

text: radioactive materials will not bear the label, however, the RADIOACTIVE placard is required.

text: The discovery of the radioactivity of uranium ushered in additional scientific and practical uses of the element. The long half-life of the isotope uranium-238 (4.51 years) makes it well-suited for use in estimating the age of the earliest igneous rocks and for other types of radiometric dating, including uranium-thorium dating, uranium-lead dating and uranium-uranium dating. Uranium metal is used for X-ray targets in the making of high-energy X-rays.

text: The discovery of the radioactivity of uranium ushered in additional scientific and practical uses of the element. The long

text: half-life

text: of the isotope uranium-238 (4.51 years) makes it well-suited for use in estimating the age of the earliest

text: igneous rock

text: s and for other types of

text: radiometric dating

text: , including

text: uranium-thorium dating

text: uranium-lead dating

text: and

text: uranium-uranium dating

text: . Uranium metal is used for

text: X-ray

text: targets in the making of high-energy X-rays.

text: Einsteinium (Es) is a synthetic element, and thus a standard atomic mass cannot be given. Like all artificial elements, it has no stable isotopes. The first isotope to be discovered (in nuclear fallout from an H-bomb test) was Es in 1952. There are 19 known radioisotopes from Es to Es, and 3 nuclear isomers (Es, Es, and Es). The longest-lived isotope is Es with a half-life of 471.7 days, or around 1.293 years.

text: Einsteinium

text: (Es) is a

text: synthetic element

text: , and thus a standard

text: atomic mass

text: stable isotope

text: s. The first

text: isotope

text: to be discovered (in nuclear

text: fallout

text: from an

text: H-bomb

text: test

text: ) was Es in 1952. There are 19 known

text: radioisotope

text: s from Es to Es, and 3

text: nuclear isomer

text: s (Es, Es, and Es). The longest-lived isotope is Es with a

text: half-life

text: of 471.7 days, or around 1.293 years.

text: Radioactive substances are materials that emit radiation.

text: Radioactive substances are materials that emit

text: radiation

text: Food irradiation is the process of exposing foodstuffs to ionizing radiation. Ionizing radiation is energy that can be transmitted without direct contact (radiation) capable of freeing electrons from their atomic bonds (ionization) in the targeted food. This treatment is used to preserve food, reduce the risk of food borne illness, prevent the spread of invasive pests, and delay or eliminate sprouting or ripening. Irradiated food does not become radioactive. The radiation can be emitted by a radioactive substance or generated electrically.

text: Food irradiation is the process of exposing foodstuffs to

text: ionizing radiation

text: . Ionizing radiation is energy that can be transmitted without direct contact (

text: radiation

text: ) capable of freeing

text: electron

text: s from their atomic bonds (

text: ionization

text: ) in the targeted food. This treatment is used to

text: preserve food

text: , reduce the risk of food borne illness, prevent the spread of

text: invasive

text: pest

text: s, and delay or eliminate

text: sprouting

text: or

text: ripening

text: . Irradiated food does not become radioactive. The radiation can be emitted by a

text: radioactive

text: substance or generated electrically.

text: Elements are composed of one or more naturally occurring isotopes. The unstable (radioactive) isotopes are either primordial or postprimordial. Primordial isotopes were a product of stellar nucleosynthesis or another type of nucleosynthesis such as cosmic ray spallation, and have persisted down to the present because their rate of decay is so slow (e.g. uranium-238 and potassium-40). Post-primordial isotopes were created by cosmic ray bombardment as cosmogenic nuclides (e.g., tritium, carbon-14), or by the decay of a radioactive primordial isotope to a radioactive radiogenic nuclide daughter (e.g. uranium to radium). A few isotopes are naturally synthesized as nucleogenic nuclides, by some other natural nuclear reaction, such as when neutrons from natural nuclear fission are absorbed by another atom.

text: Elements are composed of one or more naturally occurring isotopes. The unstable (radioactive) isotopes are either

text: primordial

text: or postprimordial. Primordial isotopes were a product of

text: stellar nucleosynthesis

text: or another type of nucleosynthesis such as

text: cosmic ray spallation

text: , and have persisted down to the present because their rate of decay is so slow (e.g.

text: and

text: ). Post-primordial isotopes were created by

text: cosmic ray

text: bombardment as

text: cosmogenic nuclide

text: s (e.g.,

text: tritium

text: ), or by the decay of a radioactive primordial isotope to a radioactive

text: radiogenic nuclide

text: daughter (e.g.

text: uranium

text: to

text: radium

text: ). A few isotopes are naturally synthesized as

text: nucleogenic

text: nuclides, by some other natural

text: nuclear reaction

text: , such as when neutrons from natural

text: nuclear fission

text: are absorbed by another atom.

text: Not long after Henri Becquerel discovered radioactivity in uranium salts, Madame Curie discovered both polonium and radium as two new radioactive elements also present with uranium.The relatively high specific activity and moderate half-life of 1,600 years of Ra-226, the main radioisotope of radium found in uranium ore, made for a material which when mixed with a phosphor allowed for a glow-in-the-dark substance.

text: Not long after

text: Henri Becquerel

text: discovered

text: radioactivity

text: in uranium salts,

text: Madame Curie

text: discovered both

text: polonium

text: and

text: radium

text: as two new radioactive elements also present with uranium.The relatively high

text: specific activity

text: and moderate

text: half-life

text: of 1,600 years of

text: , the main

text: radioisotope

text: of radium found in uranium ore, made for a material which when mixed with a

text: phosphor

text: allowed for a glow-in-the-dark substance.

text: Another 30 artificial radioisotopes of tungsten have been characterized, the most stable of which are W with a half-life of 121.2 days, W with a half-life of 75.1 days, W with a half-life of 69.4 days, W with a half-life of 21.6 days, and W with a half-life of 23.72 h. All of the remaining radioactive isotopes have half-lives of less than 3 hours, and most of these have half-lives below 8 minutes. Tungsten also has 4 meta states, the most stable being W (t 6.4 minutes).

text: Another 30 artificial

text: radioisotope

text: s of tungsten have been characterized, the most stable of which are W with a half-life of 121.2 days, W with a half-life of 75.1 days, W with a half-life of 69.4 days, W with a half-life of 21.6 days, and W with a half-life of 23.72 h. All of the remaining

text: radioactive

text: isotopes have half-lives of less than 3 hours, and most of these have half-lives below 8 minutes. Tungsten also has 4

text: meta state

text: s, the most stable being W (t 6.4 minutes).

text: Ship silencing is an important part of reducing unwanted noise, which can severely limit a naval vessel's active and passive undersea warfare capability and decrease the range or probability of detection by an unfriendly vessel.  The US Navy maintains a Ship Silencing Program to address these problems. The goals of the Ship Silencing Program are a reduction of sonar self noise over the frequency range of passive capable sonar and the reduction in the ship's radiated noise to reduce detection by enemy submarines.  Self-noise is the noise generated by a ship that has an effect on its own sonar and sensors.  Radiated noise is the noise generated by a ship that has an effect on other ship's sensors, especially submarines.  The Masker-Prairie countermeasure systems are key elements in this program to reduce radiated noise and self-noise that are not reduced by controlling the sounds at their source or their transmission to the hull.

text: Radioactive  labels do not require enzyme substrates, but rather, allow the placement of medical X-ray film directly against the western blot, which develops as it is exposed to the label and creates dark regions which correspond to the protein bands of interest (see image to the right). The importance of radioactive detections methods is declining due to its hazardous radiation , because it is very expensive, health and safety risks are high, and ECL (enhanced chemiluminescence) provides a useful alternative.

text: More than a month after the first discovery of the groundwater contamination, TEPCO made a start to contain the radioactive groundwater. They assumed that the radioactivity had escaped early in the beginning of the disaster in 2011, but NRA-experts had serious doubts about their assumption. According to them, other sources could not be excluded. Numerous pipes were running everywhere on the reactor grounds to cool the reactors and decontaminate the water used, and leaks could be anywhere. This solution might easily redirect the groundwater flows, and spread the contamination even more. Besides that, TEPCO had plans for pumping groundwater. At that time the turbine-buildings of reactor nr.2 and nr.3 contained 5000 and 6000 cubic meter highly radioactive water. With wells in contact with the turbine-buildings, this could spread the radioactivity into the ground. The NRA announced that it would form a task force to find the leaks and to block the flow of the groundwater to the coastline, because the NRA suspected that the groundwater was leaking into the sea.

text: The use of radioactive tracer elements in ion uptake assays allows the calculation of km, Ki and Vmax and determines the initial change in the ion content of the cells. Mg decays by the emission of a high-energy beta or gamma particle, which can be measured using a scintillation counter. However, the radioactive half-life of Mg, the most stable of the radioactive magnesium isotopes, is only 21 hours. This severely restricts the experiments involving the nuclide. Also, since 1990, no facility has routinely produced Mg, and the price per mCi is now predicted to be approximately US$30,000. The chemical nature of Mg is such that it is closely approximated by few other cations.  However, Co, Mn and Ni have been used successfully to mimic the properties of Mg in some enzyme reactions, and radioactive forms of these elements have been employed successfully in cation transport studies. The difficulty of using metal ion replacement in the study of enzyme function is that the relationship between the enzyme activities with the replacement ion compared to the original is very difficult to ascertain.

text: On 5 January 2012 the Nambu (south) Clean Center, a waste incinerator in Kashiwa, Chiba, was taken out of production by the city council because the storage room was completely filled with 200 metric tons of radioactive ash that could not disposed of in landfills. Storage at the plant was full, with 1049 drums, and some 30 tons more were still to be taken out of the incinerator. In September 2011, the factory was closed for two months for the same reason. The Center's special advanced procedures were able to minimize the volume of the ash, but radioactive cesium was concentrated to levels above the national limit of 8.000 becquerels per kilogram for waste disposal in landfills. It was not possible to secure new storage space for the radioactive ash. Radiation levels in Kashiwa were higher than in surrounding areas, and ashes containing up to 70,800 becquerels of radioactive cesium per kilogram – higher than the national limit – were detected in the city. Other cities around Kashiwa were facing the same problem: radioactive ash was piling up. Chiba prefecture asked Abiko and Inzai to accept temporary storage at the Teganuma waste-disposal facility located at their border. But this met strong opposition from their citizens.

text: On 5 January 2012 the Nambu (south) Clean Center, a waste incinerator in

text: Kashiwa, Chiba

text: , was taken out of production by the city council because the storage room was completely filled with 200 metric tons of radioactive ash that could not disposed of in landfills. Storage at the plant was full, with 1049 drums, and some 30 tons more were still to be taken out of the incinerator. In September 2011, the factory was closed for two months for the same reason. The Center's special advanced procedures were able to minimize the volume of the ash, but radioactive cesium was concentrated to levels above the national limit of 8.000 becquerels per kilogram for waste disposal in landfills. It was not possible to secure new storage space for the radioactive ash. Radiation levels in Kashiwa were higher than in surrounding areas, and ashes containing up to 70,800 becquerels of radioactive cesium per kilogram – higher than the national limit – were detected in the city. Other cities around Kashiwa were facing the same problem: radioactive ash was piling up. Chiba prefecture asked

text: Abiko

text: and

text: Inzai

text: to accept temporary storage at the Teganuma waste-disposal facility located at their border. But this met strong opposition from their citizens.

text: Rona's methods were also used as part of the experiments conducted by the Office of Human Radiation Experiments to determine the effects of human exposure to radiation. Early in her career, she had been exposed to the dangers of radium. Rona's requests for protective gas masks were denied, as Stefan Meyer downplayed the hazards of exposure. She purchased protective gear with her own money, not believing there was no danger. When vials of radioactive material exploded and the laboratory became contaminated, Rona was convinced her mask had saved her. Gleditsch had also warned her of the dangers the year Rona was sick and living in Paris, when Joliot-Curie died, emphasizing the risk of radium-related anemia. In her 1978 book about her experiences, Rona wrote about the damage to bones, hands, and lungs of the scientists studying radioactivity. Since they wore no gloves and frequently poured substances between vials without protection, she noted that their thumbs, forefingers, and ring fingers were often damaged. The secrecy surrounding the project makes it difficult to know if any of the scientists not directly working on any project knew specifically what their contributions were being used for.

text: Rona's methods were also used as part of the experiments conducted by the

text: Office of Human Radiation Experiments

text: to determine the effects of human exposure to radiation. Early in her career, she had been exposed to the dangers of radium. Rona's requests for protective gas masks were denied, as Stefan Meyer downplayed the hazards of exposure. She purchased protective gear with her own money, not believing there was no danger. When vials of radioactive material exploded and the laboratory became contaminated, Rona was convinced her mask had saved her. Gleditsch had also warned her of the dangers the year Rona was sick and living in Paris, when Joliot-Curie died, emphasizing the risk of radium-related anemia. In her 1978 book about her experiences, Rona wrote about the damage to bones, hands, and lungs of the scientists studying radioactivity. Since they wore no gloves and frequently poured substances between vials without protection, she noted that their thumbs, forefingers, and ring fingers were often damaged. The secrecy surrounding the project makes it difficult to know if any of the scientists not directly working on any project knew specifically what their contributions were being used for.

text: A few incidents have occurred when radioactive material was disposed of improperly, shielding during transport was defective, or when it was simply abandoned or even stolen from a waste store. In the Soviet Union, waste stored in Lake Karachay was blown over the area during a dust storm after the lake had partly dried out. At Maxey Flat, a low-level radioactive waste facility located in Kentucky, containment trenches covered with dirt, instead of steel or cement, collapsed under heavy rainfall into the trenches and filled with water. The water that invaded the trenches became radioactive and had to be disposed of at the Maxey Flat facility itself. In other cases of radioactive waste accidents, lakes or ponds with radioactive waste accidentally overflowed into the rivers during exceptional storms. In Italy, several radioactive waste deposits let material flow into river water, thus contaminating water for domestic use. In France, in the summer of 2008 numerous incidents happened; in one, at the Areva plant in Tricastin, it was reported that during a draining operation, liquid containing untreated uranium overflowed out of a faulty tank and about 75 kg of the radioactive material seeped into the ground and, from there, into two rivers nearby; in another case, over 100 staff were contaminated with low doses of radiation.

text: A few incidents have occurred when radioactive material was disposed of improperly, shielding during transport was defective, or when it was simply abandoned or even stolen from a waste store. In the Soviet Union, waste stored in

text: Lake Karachay

text: was blown over the area during a

text: dust storm

text: after the lake had partly dried out. At

text: Maxey Flat

text: , a low-level radioactive waste facility located in

text: Kentucky

text: , containment trenches covered with dirt, instead of steel or cement, collapsed under heavy rainfall into the trenches and filled with water. The water that invaded the trenches became radioactive and had to be disposed of at the Maxey Flat facility itself. In other cases of radioactive waste accidents, lakes or ponds with radioactive waste accidentally overflowed into the rivers during exceptional storms. In Italy, several radioactive waste deposits let material flow into river water, thus contaminating water for domestic use. In France, in the summer of 2008 numerous incidents happened; in one, at the Areva plant in

text: Tricastin

text: , it was reported that during a draining operation, liquid containing untreated uranium overflowed out of a faulty tank and about 75 kg of the radioactive material seeped into the ground and, from there, into two rivers nearby; in another case, over 100 staff were contaminated with low doses of radiation.

text: The radiation is produced by X-ray tubes, high energy X-ray equipment or natural radioactive elements, such as radium and radon, and artificially produced radioactive isotopes of elements, such as cobalt-60 and iridium-192. Electromagnetic radiation consists of oscillating electric and magnetic fields, but is generally depicted as a single sinusoidal wave. While in the past radium and radon have both been used for radiography, they have fallen out of use as they are radiotoxic alpha radiation emitters which are expensive; iridium-192 and cobalt-60 are far better photon sources. For further details see commonly used gamma-emitting isotopes.

text: The radiation is produced by X-ray tubes, high energy X-ray equipment or natural

text: radioactive

text: elements, such as

text: radium

text: and

text: radon

text: , and artificially produced radioactive

text: isotopes

text: of elements, such as

text: and

text: . Electromagnetic radiation consists of

text: oscillating

text: electric

text: and

text: magnetic

text: fields, but is generally depicted as a single

text: sinusoidal

text: wave. While in the past

text: radium

text: and

text: radon

text: have both been used for radiography, they have fallen out of use as they are radiotoxic

text: alpha radiation

text: emitters which are expensive; iridium-192 and cobalt-60 are far better photon sources. For further details see

text: commonly used gamma-emitting isotopes

text: The danger of radiation from radioactive precipitation/"fallout" decreases with time, as radioactivity decays exponentially with time, such that for each factor of seven increase in time, the radiation is reduced by a factor of ten. Creating the following 7-10 rule-of-thumb after a typical nuclear detonation while under the conditions that all fallout that will fall on the land has done so completely and no further deposition in the area will occur - After 7 hours, the average dose rate outside is reduced by a factor of ten; after 49(7x7) hours, it is reduced by a further factor of ten (to a value of 1/100th of the initial dose rate); after two weeks the radiation from the fallout will have reduced by a factor of 1000 compared to the initial level; and after 14 weeks the average dose rate will have reduced to 1/10,000th of the initial level.

text: The danger of radiation from radioactive precipitation/"

text: fallout

text: " decreases with time, as

text: radioactivity decays

text: exponentially with time, such that for each factor of seven increase in time, the radiation is reduced by a factor of ten. Creating the following

text: 7-10 rule-of-thumb

text: after a typical nuclear detonation while under the conditions that all fallout that will fall on the land has done so completely and no further deposition in the area will occur - After 7 hours, the average

text: dose rate

text: outside is reduced by a factor of ten; after 49(7x7) hours, it is reduced by a further factor of ten (to a value of 1/100th of the initial dose rate); after two weeks the radiation from the fallout will have reduced by a factor of 1000 compared to the initial level; and after 14 weeks the average dose rate will have reduced to 1/10,000th of the initial level.

text: Thirteen years ago during a demonstration on the use of radioactive rays at a science exhibit, a spider is accidentally exposed to large amounts of radiation. In its dying moments, the arachnid bites Peter Parker. As a result, the young teenager gains amazing powers and becomes Spider-Man. However, this is not the end. Mere moments after biting Parker, the spider bites another young student named Cindy Moon. Soon after, Cindy’s abilities manifest but she is unable to control them. Some time later, Ezekiel approaches the Moon family to offer his help and guide Cindy in controlling her newfound abilities.  After six years training to use her powers, Cindy is locked up inside a facility by Ezekiel to protect her and the other “spiders” from Morlun and his family called the Inheritors.

text: Thirteen years ago during a demonstration on the use of radioactive rays at a science exhibit, a

text: spider

text: is accidentally exposed to large amounts of radiation. In its dying moments, the arachnid bites Peter Parker. As a result, the young teenager gains amazing powers and becomes

text: Spider-Man

text: . However, this is not the end. Mere moments after biting Parker, the spider bites another young student named Cindy Moon. Soon after, Cindy’s abilities manifest but she is unable to control them. Some time later,

text: Ezekiel

text: approaches the Moon family to offer his help and guide Cindy in controlling her newfound abilities.  After six years training to use her powers, Cindy is locked up inside a facility by Ezekiel to protect her and the other “spiders” from

text: Morlun

text: and his family called the Inheritors.

text: Fourteen radioisotopes have been characterized, with the most stable being O with a half-life of 122.24 s and O with a half-life of 70.606 s. All of the remaining radioactive isotopes have half-lives that are less than 27 s and the majority of these have half-lives that are less than 83 milliseconds (ms). For example, O has a half-life of 61 ms. The most common decay mode for isotopes lighter than the stable isotopes is β decay (to nitrogen) and the most common mode after is β decay (to fluorine).

text: Fourteen

text: radioisotope

text: s have been characterized, with the most stable being O with a

text: half-life

text: of 122.24 s and O with a half-life of 70.606 s. All of the remaining

text: radioactive

text: isotopes have half-lives that are less than 27 s and the majority of these have half-lives that are less than 83

text: millisecond

text: s (ms). For example, O has a half-life of 61 ms. The most common

text: decay mode

text: for isotopes lighter than the stable isotopes is

text: β decay

text: (to

text: nitrogen

text: ) and the most common mode after is

text: β decay

text: (to

text: fluorine

text: For a summary table showing the number of stable and radioactive nuclides in each category, see radionuclide. There exist twenty-nine chemical elements on Earth that are radioactive. They are those that contain thirty-four radionuclides that date before the time of formation of the solar system, and are known as primordial nuclides. Well-known examples are uranium and thorium, but also included are naturally occurring long-lived radioisotopes such as potassium-40. Another fifty or so shorter-lived radionuclides, such as radium and radon, found on Earth, are the products of decay chains that began with the primordial nuclides, or are the product of ongoing cosmogenic processes, such as the production of carbon-14 from nitrogen-14 by cosmic rays. Radionuclides may also be produced artificially in particle accelerators or nuclear reactors, resulting in 650 of these with half-lives of over an hour, and several thousand more with even shorter half-lives. See this list of nuclides for a list of these, sorted by half life.

text: For a summary table showing the number of stable and radioactive nuclides in each category, see

text: radionuclide

text: . There exist twenty-nine

text: chemical element

text: s on Earth that are radioactive. They are those that contain thirty-four radionuclides that date before the time of formation of the solar system, and are known as

text: primordial nuclide

text: s. Well-known examples are

text: uranium

text: and

text: thorium

text: , but also included are naturally occurring long-lived radioisotopes such as

text: . Another fifty or so shorter-lived radionuclides, such as

text: radium

text: and

text: radon

text: , found on Earth, are the products of

text: decay chain

text: s that began with the primordial nuclides, or are the product of ongoing

text: cosmogenic

text: processes, such as the production of

text: from

text: by

text: cosmic rays

text: . Radionuclides may also be

text: produced artificially

text: in

text: particle accelerators

text: or

text: nuclear reactors

text: , resulting in 650 of these with half-lives of over an hour, and several thousand more with even shorter half-lives. See this

text: list of nuclides

text: for a list of these, sorted by half life.

text: Neutron radiation protection relies on radiation shielding. Due to the high kinetic energy of neutrons, this radiation is considered to be the most severe and dangerous radiation to the whole body when it is exposed to external radiation sources. In comparison to conventional ionizing radiation based on photons or charged particles, neutrons are repeatedly bounced and slowed (absorbed) by light nuclei so hydrogen-rich material is more effective at shielding than iron nuclei. The light atoms serve to slow down the neutrons by elastic scattering so they can then be absorbed by nuclear reactions. However, gamma radiation is often produced in such reactions, so additional shielding has to be provided to absorb it. Care must be taken to avoid using nuclei which undergo fission or neutron capture that results in radioactive decay of nuclei that produce gamma rays.

text: Neutron

text: radiation protection

text: relies on

text: radiation shielding

text: . Due to the high kinetic energy of neutrons, this radiation is considered to be the most severe and dangerous radiation to the whole body when it is exposed to external radiation sources. In comparison to conventional ionizing radiation based on photons or charged particles, neutrons are repeatedly bounced and slowed (absorbed) by light nuclei so

text: hydrogen

text: -rich material is more effective at shielding than

text: iron

text: nuclei. The light atoms serve to slow down the neutrons by

text: elastic scattering

text: so they can then be absorbed by

text: nuclear reaction

text: s. However,

text: gamma radiation

text: is often produced in such reactions, so additional shielding has to be provided to absorb it. Care must be taken to avoid using nuclei which undergo

text: fission

text: or

text: neutron capture

text: that results in

text: radioactive decay

text: of nuclei that produce gamma rays.

text: Non-mononuclidic elements are marked with an asterisk, and the long-lived primordial radioisotope given. In two notable cases (indium and rhenium), the highest abundance naturally occurring isotope is the mildly radioactive one, and in the case of europium, nearly half of it is.

text: Non-

text: mononuclidic element

text: s are marked with an asterisk, and the long-lived

text: primordial radioisotope

text: given. In two notable cases (indium and rhenium), the highest abundance naturally occurring isotope is the mildly radioactive one, and in the case of europium, nearly half of it is.

text: Alpha particle, beta particle, and gamma ray radioactive emissions are industrially useful. Most sources of these are synthetic radioisotopes.

text: Alpha particle

text: beta particle

text: , and

text: gamma ray

text: radioactive emissions are industrially useful. Most sources of these are synthetic radioisotopes.

text: Fourteen radioisotopes have been characterized. The most stable are O with a half-life of 122.24 seconds and O with a half-life of 70.606 seconds. All of the remaining radioactive isotopes have half-lives that are less than 27 s and the majority of these have half-lives that are less than 83 milliseconds. The most common decay mode of the isotopes lighter than O is β decay to yield nitrogen, and the most common mode for the isotopes heavier than O is beta decay to yield fluorine.

text: Fourteen

text: radioisotope

text: s have been characterized. The most stable are O with a

text: half-life

text: of 122.24 seconds and O with a half-life of 70.606 seconds. All of the remaining

text: radioactive

text: isotopes have half-lives that are less than 27 s and the majority of these have half-lives that are less than 83 milliseconds. The most common

text: decay mode

text: of the isotopes lighter than O is

text: β decay

text: to yield nitrogen, and the most common mode for the isotopes heavier than O is

text: beta decay

text: to yield

text: fluorine

text: The history of nuclear cardiology began in 1927 when Dr. Herrmann Blumgart developed the first method for measuring cardiac strength by injecting subjects with a radioactive compound known as  Radium C (Bi) . The substance was injected into the venous system and traveled through the right heart into the lungs, then into the left heart and out into the arterial system where it was then detected through a Wilson chamber. The Wilson chamber represented a primitive scintillation counter which could measure radioactivity. Measured over time, this sequential acquisition of radioactivity produced what was known as "circulation time". The longer the "circulation time", the weaker the heart. Blumgart's emphasis was twofold. First, radioactive substances could be used to determine cardiac physiology (function) and should be done so with the least amount of radioactivity necessary to do so. Secondly, to accomplish this task, one needs to obtain multiple counts over time.

text: The history of

text: nuclear cardiology

text: began in 1927 when Dr. Herrmann Blumgart developed the first method for measuring cardiac strength by injecting subjects with a radioactive compound known as  Radium C (Bi) . The substance was injected into the venous system and traveled through the right heart into the lungs, then into the left heart and out into the arterial system where it was then detected through a

text: Wilson chamber

text: . The Wilson chamber represented a primitive scintillation counter which could measure

text: radioactivity

text: . Measured over time, this sequential acquisition of radioactivity produced what was known as "circulation time". The longer the "circulation time", the weaker the heart. Blumgart's emphasis was twofold. First, radioactive substances could be used to determine cardiac physiology (function) and should be done so with the least amount of radioactivity necessary to do so. Secondly, to accomplish this task, one needs to obtain multiple counts over time.

text: Before the biological effects of radiation were known, many physicians and corporations had begun marketing radioactive substances as patent medicine and radioactive quackery. Examples were radium enema treatments, and radium-containing waters to be drunk as tonics. Marie Curie spoke out against this sort of treatment, warning that the effects of radiation on the human body were not well understood. Curie later died of acute radiation syndrome, not cancer. Eben Byers, a famous American socialite, died of multiple cancers in 1932 after consuming large quantities of radium over several years; his death drew public attention to dangers of radiation. By the 1930s, after a number of cases of bone necrosis and death in enthusiasts, radium-containing medical products had nearly vanished from the market.

text: Before the biological effects of radiation were known, many physicians and corporations had begun marketing radioactive substances as

text: patent medicine

text: and

entity_name: Quackery involving radioactive substances

text: radioactive quackery

text: . Examples were radium

text: enema

text: treatments, and radium-containing waters to be drunk as tonics.

text: Marie Curie

text: spoke out against this sort of treatment, warning that the effects of radiation on the human body were not well understood. Curie later died of

text: acute radiation syndrome

text: , not cancer.

text: Eben Byers

text: , a famous American socialite, died of multiple cancers in 1932 after consuming large quantities of

text: radium

text: over several years; his death drew public attention to dangers of radiation. By the 1930s, after a number of cases of bone necrosis and death in enthusiasts, radium-containing medical products had nearly vanished from the market.

text: Nuclear decommissioning is the process whereby a nuclear power plant site is dismantled to the point that it no longer requires measures for radiation protection. The presence of radioactive material necessitates processes that are occupationally dangerous, hazardous to the natural environment, expensive, and time-intensive.

text: Nuclear decommissioning is the process whereby a

text: nuclear power plant

text: site is dismantled to the point that it no longer requires measures for radiation protection. The presence of

text: radioactive

text: material necessitates processes that are occupationally dangerous, hazardous to the natural environment, expensive, and time-intensive.

text: In December 2010 Wikileaks published cables that they alleged showed that US officials were ignoring reports of dangerously high levels of radiation  at Luiswishi mine, and implied that uranium was being separated from the ore which purportedly held only copper and cobalt.Groupe Forrest International refuted rumors of radiation or illegal trading in uranium. Forrest noted that although uranium was present in the copper and cobalt ore from the mine, it was at far too low a grade to be exploited. Forrest also said the radioactivity in the Luiswishi mine was largely lower than the European standards. DRC government officials and United Nations personnel had visited the mine and found no problems.

text: In December 2010

text: Wikileaks

text: published cables that they alleged showed that US officials were ignoring reports of dangerously high levels of radiation  at Luiswishi mine, and implied that uranium was being separated from the ore which purportedly held only copper and cobalt.Groupe Forrest International refuted rumors of radiation or illegal trading in uranium. Forrest noted that although uranium was present in the copper and cobalt ore from the mine, it was at far too low a grade to be exploited. Forrest also said the radioactivity in the Luiswishi mine was largely lower than the European standards. DRC government officials and United Nations personnel had visited the mine and found no problems.

text: The discovery of radioactivity and its associated heating properties in 1895 prompted a re-examination of the apparent age of the Earth. This had previously been estimated by its cooling rate and assumption the Earth's surface radiated like a black body. Those calculations had implied that, even if it started at red heat, the Earth would have dropped to its present temperature in a few tens of millions of years. Armed with the knowledge of a new heat source, scientists realized that the Earth would be much older, and that its core was still sufficiently hot to be liquid.

text: The discovery of

text: radioactivity

text: and its associated

text: heating

text: properties in 1895 prompted a re-examination of the apparent

text: age of the Earth

text: . This had previously been estimated by its cooling rate and assumption the Earth's surface radiated like a

text: black body

text: . Those calculations had implied that, even if it started at

text: red heat

text: , the Earth would have dropped to its present temperature in a few tens of millions of years. Armed with the knowledge of a new heat source, scientists realized that the Earth would be much older, and that its core was still sufficiently hot to be liquid.

text: In October 2011, radiation levels as high as those in the evacuation zone around Japan's Fukushima nuclear plant were detected in a Tokyo suburb. Japanese officials said the contamination was linked to the Fukushima nuclear disaster. Contamination levels "as high as those inside Fukushima's no-go zone have been detected, with officials speculating that the hotspot was created after radioactive caesium carried in rain water became concentrated because of a broken gutter".

text: Beryllium is also commonly used in some neutron sources in laboratory devices in which relatively few neutrons are needed (rather than having to use a nuclear reactor, or a particle accelerator-powered neutron generator). For this purpose, a target of beryllium-9 is bombarded with energetic alpha particles from a radioisotope such as polonium-210, radium-226, plutonium-239, or americium-241. In the nuclear reaction that occurs, a beryllium nucleus is transmuted into carbon-12, and one free neutron is emitted, traveling in about the same direction as the alpha particle was heading. Such alpha decay driven beryllium neutron sources, named "urchin" neutron initiators, were used some in early atomic bombs. Neutron sources in which beryllium is bombarded with gamma rays from a gamma decay radioisotope, are also used to produce laboratory neutrons.

text: Beryllium is also commonly used in some

text: neutron source

text: s in laboratory devices in which relatively few neutrons are needed (rather than having to use a nuclear reactor, or a

text: particle accelerator

text: -powered

text: neutron generator

text: ). For this purpose, a target of beryllium-9 is bombarded with energetic alpha particles from a

text: radioisotope

text: such as

text: polonium

text: radium

text: plutonium

text: -239, or

text: americium

text: -241. In the nuclear reaction that occurs, a beryllium nucleus is

text: transmuted

text: into carbon-12, and one free neutron is emitted, traveling in about the same direction as the alpha particle was heading. Such

text: alpha decay

text: driven beryllium neutron sources, named

text: "urchin"

text: neutron initiators, were used some in early

text: atomic bomb

text: s. Neutron sources in which beryllium is bombarded with

text: gamma ray

text: s from a

text: gamma decay

text: radioisotope, are also used to produce laboratory neutrons.

text: Curie and Joliot showed that when lighter elements such as boron and aluminium were bombarded with α-particles, there was a continuous emission of radioactive radiations, even after the α−source had been removed. They showed that the radiation was due to the emission of a particle carrying one unit positive charge with mass equal to that of an electron.

text: Curie and Joliot showed that when lighter elements such as

text: boron

text: and

text: aluminium

text: were bombarded with α-particles, there was a continuous emission of radioactive radiations, even after the α−source had been removed. They showed that the radiation was due to the emission of a particle carrying one unit positive charge with mass equal to that of an electron.

text: Long-lived radioactive waste from the back end of the fuel cycle is especially relevant when designing a complete waste management plan for SNF. When looking at long-term radioactive decay, the actinides in the SNF have a significant influence due to their characteristically long half-lives. Depending on what a nuclear reactor is fueled with, the actinide composition in the SNF will be different.

text: Long-lived radioactive waste from the back end of the fuel cycle is especially relevant when designing a complete waste management plan for SNF. When looking at long-term

text: radioactive decay

text: , the actinides in the SNF have a significant influence due to their characteristically long half-lives. Depending on what a

text: nuclear reactor

text: The radiation sources used for brachytherapy are always enclosed within a non-radioactive capsule. The sources can be delivered manually, but are more commonly delivered through a technique known as ‘afterloading’.

text: Fred Mettler commented that 20 years later: "The population remains largely unsure of what the effects of radiation actually are and retain a sense of foreboding. A number of adolescents and young adults who have been exposed to modest or small amounts of radiation feel that they are somehow fatally flawed and there is no downside to using illicit drugs or having unprotected sex. To reverse such attitudes and behaviours will likely take years although some youth groups have begun programs that have promise." In addition, disadvantaged children around Chernobyl suffer from health problems that are attributable not only to the Chernobyl accident, but also to the poor state of post-Soviet health systems.

text: Nuclear Medicine Radiographers use gamma rays produced from short-lived radioisotopes that emit radioactive tracers to investigate trauma and disease such as cancer, heart disease and brain disorders.

text: Nuclear Medicine Radiographers use

text: gamma ray

text: s produced from short-lived

text: radioisotope

text: s that emit

text: radioactive tracer

text: s to investigate trauma and disease such as cancer,

text: heart disease

text: and

text: brain disorders

text: Rasetti was one of Fermi's main colloaborators in the study of neutrons and neutron-induced radioactivity. In 1934, he participated in the discovery of the artificial radioactivity of fluorine and aluminium which would be critical in the development of the atomic bomb.

text: Rasetti was one of Fermi's main colloaborators in the study of

text: neutron

text: s and neutron-induced

text: radioactivity

text: . In 1934, he participated in the discovery of the artificial radioactivity of fluorine and aluminium which would be critical in the development of the

text: atomic bomb

text: The Earth, and all living things on it, are constantly bombarded by radiation from outside our solar system. This cosmic radiation consists of relativistic particles: positively charged nuclei (ions) from 1 amu protons (about 85% of it) to 26 amu iron nuclei and even beyond. (The high-atomic number particles are called HZE ions.) The energy of this radiation can far exceed that which humans can create, even in the largest particle accelerators (see ultra-high-energy cosmic ray). This radiation interacts in the atmosphere to create secondary radiation that rains down, including x-rays, muons, protons, antiprotons, alpha particles, pions, electrons, positrons, and neutrons.

text: The Earth, and all living things on it, are constantly bombarded by radiation from outside our solar system. This cosmic radiation consists of relativistic particles: positively charged nuclei (ions) from 1

text: amu

text: proton

text: s (about 85% of it) to 26 amu

text: iron

text: nuclei

text: and even beyond. (The high-atomic number particles are called

text: HZE ions

text: .) The energy of this radiation can far exceed that which humans can create, even in the largest

text: particle accelerator

text: s (see

text: ultra-high-energy cosmic ray

text: ). This radiation interacts in the atmosphere to create secondary radiation that rains down, including

text: x-rays

text: muon

text: s,

text: proton

text: s,

text: antiproton

text: s,

text: alpha particle

text: s,

text: pion

text: s,

text: electron

text: s,

text: positron

text: s, and

text: neutron

text: s.

text: After a radioactive isotope (Strontium-90) was found in cows milk in 1959, the concern for the environmental effects of the nuclear arms race increased exponentially. This sparked songs about the invisibility of environmental effects like radioactive isotopes. In his song "Mack the Bomb," Pete Seeger wrote a comparison between a shark and Strontium-90, explaining that the threat of a shark is at least visible, unlike radioactive isotopes.  In 1962, Malvina Reynolds also wrote a song called "What Have They Done to the Rain?", which was inspired by above-ground nuclear testing, and how it was putting Strontium-90 into the air, then into soil through rain, which is how it got into cows and their milk.

text: After a radioactive isotope (

text: ) was found in cows milk in 1959, the concern for the environmental effects of the

text: nuclear arms race

text: increased exponentially. This sparked songs about the invisibility of environmental effects like radioactive isotopes. In his song "Mack the Bomb,"

text: Pete Seeger

text: wrote a comparison between a shark and Strontium-90, explaining that the threat of a shark is at least visible, unlike radioactive isotopes.  In 1962,

text: Malvina Reynolds

text: also wrote a song called "

text: What Have They Done to the Rain?

text: ", which was inspired by above-ground nuclear testing, and how it was putting Strontium-90 into the air, then into soil through rain, which is how it got into cows and their milk.

text: ESR's National Centre for Radiation Science aims to ensure radiation science benefits New Zealand’s people, environment and industries by helping protect them from radiation and radioactive contamination, as well as promoting safe and beneficial use of radiation and radioactive materials.

text: The rotary engine places severe thermal stresses on its cases, as two sides of rotor are constantly exposed to high ignition and exhaust temperatures, while the third side inducts cool fuel/air mixture. To cope with this, and probably capitalizing on their previous experience with water cooling, Suzuki opted for a liquid-cooled engine using two separate systems. Oil is used to lubricate and cool the internals of the rotor and water-cooled the external jacketing. Oil is fed from an engine sump by a trochoid pump at around . The oil is then circulated through an oil cooler mounted across the frame and below the radiator. A pressure regulator also acts as a bypass in case of a blockage in the cooler. A centrifugal pump sends coolant around the external rotor jacketing but via an intricate path in an attempt to even out the massive thermal stresses. Liquid enters at the point of highest temperatures (ignition), passing from the right side to the left, and then makes a 180° turn, returning to the right side and passing near the exhaust port. Most of the coolant is then routed to the very large radiator that sits across the frame in front of the bike. Some of the coolant that was not directed to the radiator is now sent around the inlet port and the left side housing. Its passage is once again reversed before flowing to the radiator.   The water cooling is thermostatically controlled, and a shrouded fan on the right side of the radiator takes care of excessive temperatures, switching on at  and cutting when the temperature falls below .

text: This collaboration with founders Ralf Hütter and Florian Schneider-Esleben  led to Schult’s creating lyrics as well as graphic designs for their album covers (Ralf & Florian, Autobahn, Radioactivity, Trans Europe Express, and Computer World. and more) and creating images of the musical instruments and electronic sounds that were being crafted by the group for performances and recordings. He has created most of their sleeve designs since 1973. Together with Ralf and Florian, he has created the special world of images that Kraftwerk surround themselves with. He also co-wrote the lyrics to a number of Kraftwerk songs, including "Autobahn" (from the album of the same name), "Radio-Activity" (and all other songs on Radioactivity with lyrics), "The Hall Of Mirrors", "Trans-Europe Express", "The Model", "Computer Love", "Pocket Calculator" and "Techno Pop". For a short while around 1973, Schult also played guitar and violin in the group; this was to be short-lived, since Schult by his own admission is not quite good enough to be a professional musician, and since the group had started to develop its synth-based sound it no longer had any use for a guitarist or violinist.

text: This collaboration with founders

text: Ralf Hütter

text: and

text: Florian Schneider-Esleben

text: led to Schult’s creating lyrics as well as graphic designs for their album covers (

text: Ralf & Florian

text: Autobahn

text: , Radioactivity, Trans Europe Express, and Computer World. and more) and creating images of the musical instruments and electronic sounds that were being crafted by the group for performances and recordings. He has created most of their sleeve designs since 1973. Together with Ralf and Florian, he has created the special world of images that Kraftwerk surround themselves with. He also co-wrote the

text: lyrics

text: to a number of Kraftwerk songs, including "

text: Autobahn

text: " (from the

text: album of the same name

text: Radio-Activity

text: " (and all other songs on Radioactivity with lyrics), "The Hall Of Mirrors", "Trans-Europe Express", "

text: The Model

text: Computer Love

text: ", "Pocket Calculator" and "Techno Pop". For a short while around 1973, Schult also played guitar and violin in the group; this was to be short-lived, since Schult by his own admission is not quite good enough to be a professional musician, and since the group had started to develop its synth-based sound it no longer had any use for a guitarist or violinist.

text: Radiochemistry is the chemistry of radioactive materials, where radioactive isotopes of elements are used to study the properties and chemical reactions of non-radioactive isotopes (often within radiochemistry the absence of radioactivity leads to a substance being described as being inactive as the isotopes are stable).

text: Radiochemistry

text: is the chemistry of radioactive materials, where radioactive

text: isotope

text: s of elements are used to study the properties and

text: chemical reaction

text: s of non-radioactive isotopes (often within radiochemistry the absence of radioactivity leads to a substance being described as being inactive as the isotopes are stable).

text: The highest background radiation in an inhabited area is found in Ramsar, primarily due to the use of local naturally radioactive limestone as a building material. The 1000 most exposed residents receive an average external effective radiation dose of 6 mSv per year, (0.6 rem/yr,) six times the ICRP recommended limit for exposure to the public from artificial sources. They additionally receive a substantial internal dose from radon. Record radiation levels were found in a house where the effective dose due to ambient radiation fields was 131 mSv/a, (13.1 rem/yr) and the internal committed dose from radon was 72 mSv/a (7.2 rem/yr). This unique case is over 80 times higher than the world average natural human exposure to radiation.

text: The highest background radiation in an inhabited area is found in

text: Ramsar

text: , primarily due to the use of local naturally radioactive limestone as a building material. The 1000 most exposed residents receive an average external

text: effective radiation dose

text: of 6 mSv per year, (0.6 rem/yr,) six times the

text: ICRP

text: recommended limit for exposure to the public from artificial sources. They additionally receive a substantial internal dose from radon. Record radiation levels were found in a house where the effective dose due to ambient radiation fields was 131 mSv/a, (13.1 rem/yr) and the internal

text: committed dose

text: from

text: radon

text: was 72 mSv/a (7.2 rem/yr). This unique case is over 80 times higher than the world average natural human exposure to radiation.

text: The sources of radioactivity are not exclusive of human activity. The natural radioactivity does not come from human sources: it covers up to ¾ of the total radioactivity in the world and has its origins in the interaction of terrestrial elements with high energy cosmic rays (cosmogenic radionuclides) or in the existing materials on Earth since its formation (primordial radionuclides). In this regard, there are differences in the levels of radioactivity throughout the Earth's crust. India and mountains like the Alps are among the areas with the highest level of natural radioactivity due to their composition of rocks and sand.

text: The sources of radioactivity are not exclusive of human activity. The

text: natural radioactivity

text: does not come from human sources: it covers up to ¾ of the total radioactivity in the world and has its origins in the interaction of terrestrial elements with high energy

text: cosmic rays

text: cosmogenic radionuclides

text: ) or in the existing materials on

text: Earth

text: since its formation (

text: primordial radionuclides

text: ). In this regard, there are differences in the levels of radioactivity throughout the

text: Earth's crust

text: India

text: and mountains like the

text: Alps

text: are among the areas with the highest level of natural radioactivity due to their composition of

text: rocks

text: and

text: sand

text: Radiation burns can also occur with high power radio transmitters at any frequency where the body absorbs radio frequency energy and converts it to heat. The U.S. Federal Communications Commission (FCC) considers 50 watts to be the lowest power above which radio stations must evaluate emission safety. Frequencies considered especially dangerous occur where the human body can become resonant, at 35 MHz, 70 MHz, 80-100 MHz, 400 MHz, and 1 GHz. Exposure to microwaves of too high intensity can cause microwave burns.

text: Radiation burns can also occur with high power

text: radio transmitter

text: s at any frequency where the body absorbs radio frequency energy and converts it to heat. The U.S.

text: Federal Communications Commission

text: (FCC) considers 50 watts to be the lowest power above which radio stations must evaluate emission safety. Frequencies considered especially dangerous occur where the human body can become

text: resonant

text: , at 35 MHz, 70 MHz, 80-100 MHz, 400 MHz, and 1 GHz. Exposure to

text: microwave

text: s of too high intensity can cause

text: microwave burn

text: s.

text: Caesium chloride composed of radioisotopes such as CsCl and CsCl, is used in nuclear medicine, including treatment of cancer (brachytherapy) and diagnosis of myocardial infarction. In the production of radioactive sources, it is normal to choose a chemical form of the radioisotope which would not be readily dispersed in the environment in the event of an accident. For instance, radiothermal generators (RTGs) often use strontium titanate, which is insoluble in water. For teletherapy sources, however, the radioactive density (Ci in a given volume) needs to be very high, which is not possible with known insoluble caesium compounds. A thimble-shaped container of radioactive caesium chloride provides the active source.

text: Caesium chloride composed of

text: radioisotope

text: s such as CsCl and CsCl, is used in

text: nuclear medicine

text: , including treatment of

text: cancer

text: brachytherapy

text: ) and diagnosis of

text: myocardial infarction

text: . In the production of

text: radioactive

text: sources, it is normal to choose a chemical form of the radioisotope which would not be readily dispersed in the environment in the event of an accident. For instance, radiothermal generators (RTGs) often use

text: strontium titanate

text: , which is insoluble in water. For

text: teletherapy

text: sources, however, the radioactive density (

text: Ci

text: in a given volume) needs to be very high, which is not possible with known insoluble caesium compounds. A thimble-shaped container of radioactive caesium chloride provides the active source.

text: A Brooklyn garage band, General Malacarne, survives a radioactive event and have to battle against zombies to what they believe is the safe haven of Long Island.

text: A Brooklyn

text: garage band

text: , General Malacarne, survives a radioactive event and have to battle against zombies to what they believe is the

text: safe haven

text: of

text: Long Island

text: Only appears in "Marvel Family" #22. Prisoner 887432 is given the chance to get off execution in exchange for being a test subject for a medical experiment. He is given radioactive salt to build up immunity to radiation poisoning, like arsenic immunity. Finally he is so radioactive his clothes burn away and he wears a lead suit, finally his chains melt away. He kills the two scientists with a charge of deadly rays. He takes the remaining radioactive capsules as he needs to take one every few hours to keep his powers. At a police athletic meet at the stadium he tries to make the cops leave as he hates cops, they recognize him as an escaped killer, but their bullets melt before they hit him, he then starts burning the cops. Billy Batson is there and turns into Captain Marvel, who is immune to the radioactive rays. Radioactive Man takes another capsule, then starts fires in the stands to slow down Captain Marvel (who stamps out the flames) enough to allow him to escape. He then starts hunting cops and burning them to death. Billy reports on this, then transforms into Captain Marvel and disguises himself as a cop and waits in the neighborhood Radioactive Man has been operating in. When he tries burning him, Marvel reveals himself and puts him in jail. He takes the capsules without which his powers will die out and takes them to a hospital. But Radioactive Man had one capsule concealed in his mouth, he regains his powers and melts the bars. Police arrive at airport that day with radium for Center hospital, Radioactive Man needs more radioactive salt, but Captain Marvel stops the rays from burning the guards and captures Radioactive Man with a lead cable. Billy then says his powers wore off without a new dose, he is once again prisoner 887432, and his death sentence has been changed to life imprisonment.

text: It is generally believed that iron-56 is more common than nickel isotopes in the universe for mechanistic reasons, because its unstable progenitor nickel-56 is copiously made by staged build-up of 14 helium nuclei inside supernovas, where it has no time to decay to iron before being released into the interstellar medium in a matter of a few minutes, as the supernova explodes. However, nickel-56 then decays to cobalt-56 within a few weeks, then this radioisotope finally decays to iron-56 with a half life of about 77.3 days. The radioactive decay-powered light curve of such a process has been observed to happen in type II supernovae, such as SN 1987A. In a star, there are no good ways to create nickel-62 by alpha-addition processes, or else there would presumably be more of this highly stable nuclide in the universe.

text: It is generally believed that iron-56 is more common than nickel isotopes in the universe for mechanistic reasons, because its unstable progenitor

text: is copiously made by staged build-up of 14 helium nuclei inside supernovas, where it has no time to decay to iron before being released into the interstellar medium in a matter of a few minutes, as the supernova explodes. However, nickel-56 then decays to

text: within a few weeks, then this radioisotope finally decays to iron-56 with a half life of about 77.3 days. The radioactive decay-powered light curve of such a process has been observed to happen in

text: type II supernova

text: e, such as

text: SN 1987A

text: . In a star, there are no good ways to create nickel-62 by alpha-addition processes, or else there would presumably be more of this highly stable nuclide in the universe.

text: There followed a period of intense research into radioactivity, including the determination that the element thorium is also radioactive and the discovery of additional radioactive elements polonium and radium by Marie Skłodowska-Curie and her husband Pierre Curie.

text: There followed a period of intense research into radioactivity, including the determination that the element

text: thorium

text: is also radioactive and the discovery of additional radioactive elements

text: polonium

text: and

text: radium

text: by

text: Marie Skłodowska-Curie

text: and her husband

text: Pierre Curie

text: There are conflicting reports about what level of radioactivity can be in the water processed by Landysh; some sources state that it can only process low-level water whilst other sources state it can handle medium- and low-level water; all sources agree that it can process up 7,000 m per year. There have been questions raised about the effectiveness of the decontamination process, especially regarding the removal of caesium-137. Landysh uses a combination of filtration, ion exchange and reverse osmosis to remove radioactive material from water. After collecting and concentrating the radioactive materials, they are mixed with cement and placed in 200-litre barrels for further radioactive waste management.

text: There are conflicting reports about what level of radioactivity can be in the water processed by Landysh; some sources state that it can only process low-level water whilst other sources state it can handle medium- and low-level water; all sources agree that it can process up 7,000 m per year. There have been questions raised about the effectiveness of the decontamination process, especially regarding the removal of

text: . Landysh uses a combination of

text: filtration

text: ion exchange

text: and

text: reverse osmosis

text: to remove

text: radioactive material

text: from water. After collecting and concentrating the radioactive materials, they are mixed with

text: cement

text: and placed in 200-litre barrels for further radioactive waste management.

text: <blockquote>...a sealed source of radioactive material contained in a small volume—but not radioactively contaminated soils and bulk metals—in any one or more of the following conditions

text: Hayes was mentioned in The Simpsons episode "Radioactive Man", in which Milhouse becomes Radioactive Man's sidekick, Fallout Boy; the director of the film comments that Milhouse is "going to be big, Gabby Hayes big!"

text: Hayes was mentioned in

text: The Simpsons

text: episode "

text: Radioactive Man

text: ", in which Milhouse becomes Radioactive Man's sidekick,

entity_name: List of recurring The Simpsons characters

text: Fallout Boy

text: ; the director of the film comments that Milhouse is "going to be big, Gabby Hayes big!"

text: Potassium iodide's (KI) value as a radiation protective (thyroid blocking) agent was demonstrated at the time of the Chernobyl nuclear accident when Soviet authorities distributed it in a 30 km zone around the plant. The purpose was to protect residents from radioactive iodine, a highly carcinogenic material found in nuclear reactors which had been released by the damaged reactor. Only a limited amount of KI was available, but those who received it were protected. Later, the US Nuclear Regulatory Commission (NRC) reported, "thousands of measurements of I-131 (radioactive iodine) activity...suggest that the observed levels were lower than would have been expected had this prophylactic measure not been taken. The use of KI...was credited with permissible iodine content in 97% of the evacuees tested."

text: Positron emission tomography involves injecting a short-lived radioactive tracer isotope into the blood. When the radioisotope decays, it emits positrons which are detected by the machine sensor. The isotope is chemically incorporated into a biologically active molecule, such as glucose, which powers metabolic activity. Whenever brain activity occurs in a given area these molecules are recruited to the area. Once the concentration of the biologically active molecule, and its radioactive "dye", rises enough, the scanner can detect it. About one second elapses from when brain activity begins to when the activity is detected by the PET device. This is because it takes a certain amount of time for the dye to reach the needed concentrations can be detected.

text: Positron emission tomography involves injecting a short-lived

text: radioactive tracer

text: isotope

text: into the blood. When the radioisotope decays, it emits positrons which are detected by the machine sensor. The isotope is chemically incorporated into a biologically active molecule, such as

text: glucose

text: , which powers metabolic activity. Whenever brain activity occurs in a given area these molecules are recruited to the area. Once the concentration of the biologically active molecule, and its radioactive "dye", rises enough, the scanner can detect it. About one second elapses from when brain activity begins to when the activity is detected by the PET device. This is because it takes a certain amount of time for the dye to reach the needed concentrations can be detected.

text: The power source might be solar or possibly radioisotope based given that new liquid based compounds can generate substantial power from radioactive decay.

text: The power source might be

text: solar

text: or possibly

text: radioisotope

text: based given that new liquid based compounds can generate substantial power from radioactive decay.

text: Frederick Soddy FRS (2 September 1877 – 22 September 1956) was an English radiochemist who explained, with Ernest Rutherford, that radioactivity is due to the transmutation of elements, now known to involve nuclear reactions. He also proved the existence of isotopes of certain radioactive elements.

text: Frederick Soddy

text: FRS

text: (2 September 1877 – 22 September 1956) was an

text: English

text: radiochemist

text: who explained, with

text: Ernest Rutherford

text: , that

text: radioactivity

text: is due to the

text: transmutation

text: of

text: elements

text: , now known to involve

text: nuclear reactions

text: . He also proved the existence of

text: isotopes

text: of certain radioactive elements.

text: Alpha particles are a highly ionizing form of particle radiation. When they result from radioactive alpha decay they have low penetration depth. In this case they can be absorbed by a few centimeters of air, or by the skin. More powerful, long range alpha particles from ternary fission are three times as energetic, and penetrate proportionately farther in air. The helium nuclei that form 10-12% of cosmic rays, are also usually of much higher energy than those produced by nuclear decay processes, and when encountered in space, are thus able to traverse the human body and dense shielding. However, this type of radiation is significantly attenuated by the Earth's atmosphere, which is a radiation shield equivalent to about 10 meters of water.

text: Alpha particles are a highly ionizing form of particle radiation. When they result from radioactive alpha decay they have low penetration depth. In this case they can be

text: absorbed

text: by a few centimeters of air, or by the skin. More powerful, long range alpha particles from

text: ternary fission

text: are three times as energetic, and penetrate proportionately farther in air. The helium nuclei that form 10-12% of cosmic rays, are also usually of much higher energy than those produced by nuclear decay processes, and when encountered in space, are thus able to traverse the human body and dense shielding. However, this type of radiation is significantly attenuated by the Earth's atmosphere, which is a radiation shield equivalent to about 10 meters of water.

text: If the particles in the beam are energetic enough, induced radioactivity, production of neutrons by spalling, radiation embrittlement, and production of secondary particles can also be issues.Considerable quantities of material may be put around the beam dump, especially "downstream" of the beam dump, to serve as radiation shielding.  Also, the beam may be carefully not aimed at anything critical (such as people or particle detectors), and angled down into the earth before it hits the beam dump, so that soil serves as a radiation shield.

text: If the particles in the beam are

text: energetic

text: enough,

text: induced radioactivity

text: , production of

text: neutron

text: s by

text: spalling

text: radiation

text: embrittlement

text: , and production of secondary particles can also be issues.Considerable quantities of material may be put around the beam dump, especially "downstream" of the beam dump, to serve as

text: radiation shielding

text: .  Also, the beam may be carefully not aimed at anything critical (such as people or

text: particle detector

text: s), and angled down into the earth before it hits the beam dump, so that soil serves as a radiation shield.

text: Beta-minus (β) radiation consists of an energetic electron. It is more penetrating than alpha radiation, but less than gamma. Beta radiation from radioactive decay can be stopped with a few centimeters of plastic or a few millimeters of metal. It occurs when a neutron decays into a proton in a nucleus, releasing the beta particle and an antineutrino. Beta radiation from linac accelerators is far more energetic and penetrating than natural beta radiation. It is sometimes used therapeutically in radiotherapy to treat superficial tumors.

text: Beta-minus (β) radiation consists of an energetic

text: electron

text: . It is more penetrating than alpha radiation, but less than gamma. Beta radiation from

text: radioactive decay

text: can be stopped with a few centimeters of plastic or a few millimeters of metal. It occurs when a neutron decays into a proton in a nucleus, releasing the beta particle and an

text: antineutrino

text: . Beta radiation from

text: linac

text: accelerators is far more energetic and penetrating than natural beta radiation. It is sometimes used therapeutically in

text: radiotherapy

text: to treat superficial tumors.

text: Both the Curies experienced radium burns, both accidentally and voluntarily, and were exposed to extensive doses of radiation while conducting their research: even their clothing recorded measurable levels of radioactivity.  Had Pierre Curie not been killed as he was, it is likely that he would have eventually died of the effects of radiation, as did his wife, their daughter, Irène, and her husband, Frédéric Joliot.

text: Unlike borosilicate glass, which is amorphous, Synroc is a ceramic that incorporates the radioactive waste into its crystal structure. Naturally occurring rocks can store radioactive materials for long periods. The aim of Synroc is to imitate this by converting liquid into a crystalline structure and use to store radioactive waste. Synroc-based glass composite materials (GCM) combine the process and chemical flexibility of glass with the superior chemical durability of ceramics and can achieve higher waste loadings.

text: Unlike

text: borosilicate glass

text: , which is

text: amorphous

text: , Synroc is a

text: ceramic

text: that incorporates the radioactive waste into its

text: crystal structure

text: . Naturally occurring rocks can store radioactive materials for long periods. The aim of Synroc is to imitate this by converting liquid into a

text: crystal

text: line structure and use to store radioactive waste. Synroc-based glass composite materials (GCM) combine the process and chemical flexibility of glass with the superior chemical durability of ceramics and can achieve higher waste loadings.

text: Lyrically, the 1975 version of the song plays upon the meaning of its title, with the line "Discovered by Madame Curie (In fact, Natural radioactivity was discovered by Henri Becquerel (and independently by Silvanus Thompson); induced radioactivity by Irène Joliot-Curie, Marie Curie's daughter. Curie coined the term "radioactivity").

text: Lyrically, the 1975 version of the song plays upon the meaning of its title, with the line "Discovered by

text: Madame Curie

text: (In fact,

text: Natural radioactivity

text: was discovered by

text: Henri Becquerel

text: (and independently by

text: Silvanus Thompson

text: induced radioactivity

text: by

text: Irène Joliot-Curie

text: , Marie Curie's daughter. Curie coined the term "radioactivity").

text: Natural sources produce EM radiation across the spectrum. EM radiation with a wavelength between approximately 400 nm and 700 nm is directly detected by the human eye and perceived as visible light. Other wavelengths, especially nearby infrared (longer than 700 nm) and ultraviolet (shorter than 400 nm) are also sometimes referred to as light.

text: Natural sources produce EM radiation across the spectrum. EM radiation with a

text: wavelength

text: between approximately 400

text: nm

text: and 700 nm is directly detected by the

text: human eye

text: and perceived as visible

text: light

text: . Other wavelengths, especially nearby infrared (longer than 700 nm) and ultraviolet (shorter than 400 nm) are also sometimes referred to as light.

text: Gamma irradiation involves exposing the target material to packets of light (photons) that are highly energetic (Gamma rays). A radioactive material (radioisotopes) is used as the source for the gamma rays. Gamma irradiation is the standard because the deeper penetration of the gamma rays enables administering treatment to entire industrial pallets or totes (reducing the need for material handling) and it is significantly less expensive than using an X-ray source. Generally cobalt-60 is used as a radioactive source for gamma irradiation. Cobalt-60 is bred from cobalt-59 using neutron irradiation in specifically designed nuclear reactors. In limited applications caesium-137, a less costly alternative recovered during the processing of spent nuclear fuel, is used as a radioactive source. Insufficient quantities are available for large scale commercial use. An incident where water-soluble caesium-137 leaked into the source storage pool requiring NRC intervention has led to near elimination of this radioisotope outside of military applications.

text: Gamma irradiation involves exposing the target material to packets of light (

text: photon

text: s) that are highly energetic (

text: Gamma ray

text: s). A radioactive material (

text: radioisotope

text: s) is used as the source for the gamma rays. Gamma irradiation is the standard because the deeper penetration of the gamma rays enables administering treatment to entire industrial pallets or totes (reducing the need for material handling) and it is significantly less expensive than using an X-ray source. Generally

text: is used as a radioactive source for gamma irradiation. Cobalt-60 is bred from cobalt-59 using neutron irradiation in specifically designed nuclear reactors. In limited applications

text: , a less costly alternative recovered during the processing of

text: spent nuclear fuel

text: , is used as a radioactive source. Insufficient quantities are available for large scale commercial use. An incident where water-soluble caesium-137 leaked into the source storage pool requiring

text: NRC

text: intervention has led to near elimination of this radioisotope outside of military applications.

text: The main threat of beta radiation exposure comes from hot particles in contact with or close to the skin of a person. Also, swallowed or inhaled hot particles could cause beta burns. As it is important to avoid bringing hot particles into the shelter, one option is to remove one's outer clothing, or follow other decontamination procedures, on entry. Fallout particles will cease to be radioactive enough to cause beta burns within a few days following a nuclear explosion. The danger of gamma radiation will persist for far longer than the threat of beta burns in areas with heavy fallout exposure.

text: The main threat of

text: beta radiation

text: exposure comes from

text: hot particle

text: s in contact with or close to the skin of a person. Also, swallowed or inhaled hot particles could cause

text: beta burn

text: s. As it is important to avoid bringing hot particles into the shelter, one option is to remove one's outer clothing, or follow other

text: decontamination procedures

text: , on entry. Fallout particles will cease to be radioactive enough to cause beta burns within a few days following a nuclear explosion. The danger of gamma radiation will persist for far longer than the threat of beta burns in areas with heavy fallout exposure.

text: The nuclear reactors of K-27 were troublesome from their first criticality, but the K-27 was able to engage in test operations for about five years. On 24 May 1968, the power output of one of its reactors suddenly dropped sharply; radioactive gases were released into its engine room; and the radiation levels throughout K-27 increased dangerously – by 1.5 grays per hour. This radiation consisted mostly of gamma rays and thermal neutrons, with some alpha radiation and beta radiation in addition – generated by the released radioactive gasses such as xenon and krypton in its reactor compartment.

text: The nuclear reactors of K-27 were troublesome from their first

text: criticality

text: , but the K-27 was able to engage in test operations for about five years. On 24 May 1968, the power output of one of its reactors suddenly dropped sharply;

text: radioactive

text: gases were released into its engine room; and the

text: radiation

text: levels throughout K-27 increased dangerously – by 1.5

text: grays per hour

text: . This radiation consisted mostly of

text: gamma ray

text: s and

text: thermal neutron

text: s, with some

text: alpha radiation

text: and

text: beta radiation

text: in addition – generated by the released radioactive gasses such as

text: xenon

text: and

text: krypton

text: in its reactor compartment.

text: Nuclear electric propulsion is a field that is distinct from other space nuclear power areas, such as radioisotope systems (including radioisotope thermoelectric generators, radioisotope heater units, radioisotope piezoelectric generators & the radioisotope rocket - all of which use the heat from a static radioactive source (usually Plutonium-238) for a low level of electric or direct propulsion power), a nuclear thermal rocket (energy is used to heat the liquid hydrogen propellant), direct nuclear (fission products from a nuclear reaction directly propel the rocket), nuclear pulse propulsion (nuclear explosions propel the rocket), or space based nuclear fusion systems, either a fusion rocket, or some as-yet theoretical or unproven experimental fusion technology.

text: Nuclear electric propulsion is a field that is distinct from other space nuclear power areas, such as radioisotope systems (including

text: radioisotope thermoelectric generators

text: radioisotope heater unit

text: s,

text: radioisotope piezoelectric generator

text: s & the

text: radioisotope rocket

text: - all of which use the heat from a static radioactive source (usually

text: ) for a low level of electric or direct propulsion power), a

text: nuclear thermal rocket

text: (energy is used to heat the liquid hydrogen propellant), direct nuclear (fission products from a nuclear reaction directly propel the rocket),

text: nuclear pulse propulsion

text: (nuclear explosions propel the rocket), or space based

text: nuclear fusion

text: systems, either a

text: fusion rocket

text: , or some as-yet theoretical or unproven experimental fusion technology.

text: Woolsey's low-budget Mant! is a parody morphing of several low-budget science-fiction horror films of the 1950s (many in black & white) that fused radioactivity with mad science and mutation: In particular Tarantula (1955), wherein a scientist is injected with an atomic isotope formula with disastrous results, and in general the films Them! (1954); The Beast with a Million Eyes (1955) The Deadly Mantis (1957); The Black Scorpion (1957); The Amazing Colossal Man (1957); Monster That Challenged the World (1957); Beginning of the End (1957); War of the Colossal Beast (1958); The Fly (1958) and The Alligator People (1959). The depiction of Mant!s use of "Rumble-Rama" is a riff on William Castle's many in-theatre gimmicks ("Emergo", "Percepto", "Illusion-O", "Shock Sections" etc.), however, the only "monster movie" produced or directed by William Castle before 1970 was 1959's The Tingler, which did not use a radiation theme.  "Rumble-Rama" is also a nod to Sensurround, Universal's sound process of the 1970's. Matinee also mentions some of Woolsey's earlier "films": Island of the Flesh Eaters, The Eyes of Doctor Diablo, and The Brain Leeches (not to be confused with the real-world 1977 film of the same name).

text: Woolsey's low-budget Mant! is a parody morphing of several low-budget science-fiction horror films of the 1950s (many in black & white) that fused

text: radioactivity

text: with

text: mad science

text: and

text: mutation

text: : In particular

text: Tarantula

text: (1955), wherein a scientist is injected with an

text: atomic isotope formula

text: with disastrous results, and in general the films

text: Them!

text: The Beast with a Million Eyes

text: The Deadly Mantis

text: The Black Scorpion

text: The Amazing Colossal Man

text: Monster That Challenged the World

text: Beginning of the End

text: War of the Colossal Beast

text: The Fly

text: (1958) and

text: The Alligator People

text: (1959). The depiction of Mant!s use of "Rumble-Rama" is a riff on William Castle's many in-theatre gimmicks (

text: "Emergo", "Percepto", "Illusion-O", "Shock Sections" etc.

text: ), however, the only "monster movie" produced or directed by William Castle before 1970 was 1959's

text: The Tingler

text: , which did not use a radiation theme.  "Rumble-Rama" is also a nod to

text: Sensurround

text: , Universal's sound process of the 1970's. Matinee also mentions some of Woolsey's earlier "films": Island of the Flesh Eaters, The Eyes of Doctor Diablo, and The Brain Leeches (not to be confused with

text: the real-world 1977 film of the same name

text: All radioisotopes are unstable isotopes of elements—undergo nuclear decay and emit some form of radiation. The radiation emitted can be one of three types, called alpha, beta, or gamma radiation.

text: All radioisotopes are unstable

text: isotope

text: s of

text: elements

text: —undergo

text: nuclear decay

text: and emit some form of

text: radiation

text: . The radiation emitted can be one of three types, called

text: alpha

text: beta

text: , or

text: gamma radiation

text: Radiation can have harmful effects on solid materials as it can degrade their properties so that they are no longer mechanically sound. This is of special concern as it can greatly affect their ability to perform in nuclear reactors and is the emphasis of radiation material science, which seeks to mitigate this danger.

text: Radiation can have harmful effects on solid materials as it can degrade their properties so that they are no longer mechanically sound. This is of special concern as it can greatly affect their ability to perform in

text: nuclear reactor

text: s and is the emphasis of

text: radiation material science

text: , which seeks to mitigate this danger.

text: Ernest Rutherford and Frederick Soddy jointly  had continued their work on radioactive materials and concluded that radioactivity was due to a spontaneous transmutation of atomic elements. In radioactive decay, an element breaks down into another, lighter element, releasing alpha, beta, or gamma radiation in the process. They also determined that a particular isotope of a radioactive element decays into another element at a distinctive rate. This rate is given in terms of a "half-life", or the amount of time it takes half of a mass of that radioactive material to break down into its "decay product".

text: Ernest Rutherford

text: and

text: Frederick Soddy

text: jointly  had continued their work on radioactive materials and concluded that radioactivity was due to a spontaneous transmutation of atomic elements. In radioactive decay, an element breaks down into another, lighter element, releasing alpha, beta, or

text: gamma

text: radiation

text: in the process. They also determined that a particular isotope of a radioactive element decays into another element at a distinctive rate. This rate is given in terms of a "

text: half-life

text: ", or the amount of time it takes half of a mass of that radioactive material to break down into its "decay product".

text: After the release of her debut studio album, 1000 Fires (1995), Lords began working on her second album for Radioactive Records. However, she later left the label to focus on her acting career. "Radioactive was really good to me, but there was a lot of stuff in the mid '90s that was going on with the record industry. I was just so disgusted. I thought 'This is even worse than the film business. I wanted to grow as an artist and I felt like I was being squashed into a box. It wasn't really what I wanted to do, so I said 'Screw it', started really working on my acting career and kind of left it alone."

text: After the release of her debut studio album,

text: 1000 Fires

text: (1995), Lords began working on her second album for

text: Radioactive Records

text: . However, she later left the label to focus on her acting career. "Radioactive was really good to me, but there was a lot of stuff in the mid '90s that was going on with the record industry. I was just so disgusted. I thought 'This is even worse than the film business. I wanted to grow as an artist and I felt like I was being squashed into a box. It wasn't really what I wanted to do, so I said 'Screw it', started really working on my acting career and kind of left it alone."

text: Gary Kurfirst, who managed Talking Heads and Deborah Harry, bought the Mackenzies contract and issued their second album through his own label Radioactive, a subsidiary of MCA. After another single failed to chart, the group were persuaded to leave Radioactive by their management. The Mackenzies continued to write material; Manson was also given the opportunity to record lead vocals on a number of tracks planned for the band's third album. Although MCA had no desire to further their commitments to Goodbye Mr. Mackenzie, the label expressed interest in recording an album with Manson, and after hearing several demos, Kurfirst signed Manson to Radioactive as a solo artist, with the remaining Mackenzies performing as her backing band to circumvent the band's existing deal with MCA. Manson's contract obligated her to deliver at least one album and, at the sole option of Radioactive, up to six additional albums.

text: Gary Kurfirst

text: , who managed

text: Talking Heads

text: and

text: Deborah Harry

text: , bought the Mackenzies contract and issued their second album through his own label

text: Radioactive

text: , a subsidiary of

text: MCA

text: . After another single failed to chart, the group were persuaded to leave Radioactive by their management. The Mackenzies continued to write material; Manson was also given the opportunity to record lead vocals on a number of tracks planned for the band's third album. Although MCA had no desire to further their commitments to Goodbye Mr. Mackenzie, the label expressed interest in recording an album with Manson, and after hearing several

text: demos

text: , Kurfirst signed Manson to Radioactive as a solo artist, with the remaining Mackenzies performing as her backing band to circumvent the band's existing deal with MCA. Manson's contract obligated her to deliver at least one album and, at the sole option of Radioactive, up to six additional albums.

text: He was the leading scientist with the discovery experiments of the chemical elements darmstadtium (Ds, atomic number 110),  roentgenium (Rg, 111) and copernicium (Cn, 112). He made substantial contributions to the discovery experiments of the elements bohrium (Bh, 107), hassium (Hs, 108)  and meitnerium (Mt, 109). He participated in the discovery of the element flerovium (Fl, 114) at the Flerov Laboratory of Nuclear Reactions (FLNR) in Dubna, Russia, and his research group confirmed data measured on the synthesis of the elements flerovium and livermorium (Lv, 116) at FLNR. He identified many new isotopes located at the proton drip-line, among those the isotope Lu, the first case of radioactive emission of protons from the ground-state of a nucleus. His speciality is nuclear spectroscopy and heavy ion reactions.

text: He was the leading scientist with the discovery experiments of the chemical elements

text: darmstadtium

text: Ds

text: atomic number

text: roentgenium

text: Rg

text: , 111) and

text: copernicium

text: Cn

text: , 112). He made substantial contributions to the discovery experiments of the elements

text: bohrium

text: Bh

text: , 107),

text: hassium

text: Hs

text: , 108)  and

text: meitnerium

text: Mt

text: , 109). He participated in the discovery of the element

text: flerovium

text: Fl

text: , 114) at the

text: Flerov Laboratory of Nuclear Reactions

text: (FLNR) in

text: Dubna

text: , Russia, and his research group confirmed data measured on the synthesis of the elements flerovium and

text: livermorium

text: Lv

text: , 116) at FLNR. He identified many new isotopes located at the

text: proton drip-line

text: , among those the isotope

text: Lu

text: , the first case of radioactive emission of protons from the ground-state of a nucleus. His speciality is nuclear spectroscopy and heavy ion reactions.

text: Since the early observations the giant polytene chromosomes and its puffs were noticed in several larval tissues. Similar chromosomal structures were described in Chironomus by Balbiani, and became known as "Balbiani Rings", but the incorporation of radioactive thymidine experiments in the chromosomes of Rhynchosciara americana led to the discovery of two types of puff: a transcription-related puff, where the chromatin expands and the transcription events takes place; and an amplification-related one, where the chromatin expands and RNA transcription and DNA replication occur.

text: Since the early observations the giant polytene chromosomes and its puffs were noticed in several larval tissues. Similar chromosomal structures were described in

text: Chironomus

text: by Balbiani, and became known as "Balbiani Rings", but the incorporation of radioactive

text: thymidine

text: experiments in the chromosomes of Rhynchosciara americana led to the discovery of two types of puff: a transcription-related puff, where the chromatin expands and the transcription events takes place; and an amplification-related one, where the chromatin expands and

text: RNA transcription

text: and

text: DNA replication

text: occur.

text: Additionally, more than 4,000 tons of radioactive waste are stored at San Onofre.

text: Additionally, more than 4,000 tons of

text: radioactive waste

text: are stored at San Onofre.

text: The two forms of hypothesis testing are based on different problem formulations. The original test is analogous to a true/false question; the Neyman–Pearson test is more like multiple choice. In the view of Tukey the former produces a conclusion on the basis of only strong evidence while the latter produces a decision on the basis of available evidence. While the two tests seem quite different both mathematically and philosophically, later developments lead to the opposite claim. Consider many tiny radioactive sources. The hypotheses become 0,1,2,3... grains of radioactive sand. There is little distinction between none or some radiation (Fisher) and 0 grains of radioactive sand versus all of the alternatives (Neyman–Pearson). The major Neyman–Pearson paper of 1933 also considered composite hypotheses (ones whose distribution includes an unknown parameter). An example proved the optimality of the (Student's) t-test, "there can be no better test for the hypothesis under consideration" (p 321). Neyman–Pearson theory was proving the optimality of Fisherian methods from its inception.

text: The two forms of hypothesis testing are based on different problem formulations. The original test is analogous to a true/false question; the Neyman–Pearson test is more like multiple choice. In the view of

text: Tukey

text: the former produces a conclusion on the basis of only strong evidence while the latter produces a decision on the basis of available evidence. While the two tests seem quite different both mathematically and philosophically, later developments lead to the opposite claim. Consider many tiny radioactive sources. The hypotheses become 0,1,2,3... grains of radioactive sand. There is little distinction between none or some radiation (Fisher) and 0 grains of radioactive sand versus all of the alternatives (Neyman–Pearson). The major Neyman–Pearson paper of 1933 also considered composite hypotheses (ones whose distribution includes an unknown parameter). An example proved the optimality of the (Student's) t-test, "there can be no better test for the hypothesis under consideration" (p 321). Neyman–Pearson theory was proving the optimality of Fisherian methods from its inception.

text: The danger of radiation from fallout also decreases with time, as radioactivity decays exponentially with time, such that for each factor of seven increase in time, the radiation is reduced by a factor of ten.  For example, after 7 hours, the average dose rate is reduced by a factor of ten; after 49 hours, it is reduced by a further factor of ten (to 1/100th); after two weeks the radiation from the fallout will have reduced by a factor of 1000 compared the initial level; and after 14 weeks the average dose rate will have reduced to 1/10,000th of the initial level.

text: The danger of radiation from fallout also decreases with time, as radioactivity decays exponentially with time, such that for each factor of seven increase in time, the radiation is reduced by a factor of ten.  For example, after 7 hours, the average

text: dose rate

text: is reduced by a factor of ten; after 49 hours, it is reduced by a further factor of ten (to 1/100th); after two weeks the radiation from the fallout will have reduced by a factor of 1000 compared the initial level; and after 14 weeks the average dose rate will have reduced to 1/10,000th of the initial level.

text: It is further claimed that if radioactive isotopes such as uranium are present, the cell enables the hydrogen nuclei to fuse with these isotopes, transforming them into stable elements and thus neutralizing the radioactivity; and this would be achieved without releasing any radiation to the environment and without expending any energy. A televised demonstration on June 11, 1997, on Good Morning America was not conclusive because there was no measurement of the radioactivity of the beads after the test, thus it cannot be discarded that the beads had simply absorbed the uranium ions and become radioactive themselves. In 2002, the neutralization of radioactive isotopes has only been achieved through intense neutron bombardment in a nuclear reactor or large scale high energy particle accelerator, and at a large expense of energy.

text: It is further claimed that if

text: radioactive

text: isotope

text: s such as

text: uranium

text: are present, the cell enables the hydrogen nuclei to fuse with these isotopes, transforming them into stable

text: elements

text: and thus neutralizing the radioactivity; and this would be achieved without releasing any radiation to the environment and without expending any energy. A televised demonstration on June 11, 1997, on

text: Good Morning America

text: was not conclusive because there was no measurement of the radioactivity of the beads after the test, thus it cannot be discarded that the beads had simply absorbed the uranium ions and become radioactive themselves. In 2002, the neutralization of radioactive isotopes has only been achieved through intense neutron bombardment in a

text: nuclear reactor

text: or large scale high energy

text: particle accelerator

text: , and at a large expense of energy.

text: Apart from the stable isotopes, which make up almost all lead that exists naturally, there are trace quantities of a few radioactive isotopes. One of them is lead-210; although it has a half-life of 22.3 years, a period too short to allow any primordial lead-210 to exist, some small non-primordial quantities of it occur in nature, because lead-210 is found in the uranium series: thus, even though it constantly decays away, it is constantly regenerated by decay of its parent, polonium-214, which, while also constantly decaying, is also supplied by decay of its parent, and so on, all the way up to original uranium-238, which has been present for billions of years on Earth. Lead-210 is particularly useful for helping to identify ages of samples containing it, which is performed by measuring lead-210 to lead-206 ratios (both isotopes are present in a single decay chain). Lead-214 is also present in the decay chain of natural uranium-238, lead-212 is present in that of natural thorium-232, and lead-211 is present in that of natural uranium-235; therefore, traces of all three of these isotopes exist naturally as well. Lastly, very minute traces of lead-209 are also present from the cluster decay of radium-223, one of the daughter products of natural uranium-235. Hence, natural lead consists of not only the four stable isotopes, but also minute traces of another five short-lived radioisotopes.

text: Apart from the stable isotopes, which make up almost all lead that exists naturally, there are

text: trace quantities

text: of a few radioactive isotopes. One of them is lead-210; although it has a half-life of 22.3 years, a period too short to allow any primordial lead-210 to exist, some small non-primordial quantities of it occur in nature, because lead-210 is found in the uranium series: thus, even though it constantly decays away, it is constantly regenerated by decay of its parent, polonium-214, which, while also constantly decaying, is also supplied by decay of its parent, and so on, all the way up to original uranium-238, which has been present for billions of years on Earth. Lead-210 is particularly useful for helping to identify ages of samples containing it, which is performed by measuring lead-210 to lead-206 ratios (both isotopes are present in a single decay chain). Lead-214 is also present in the decay chain of natural uranium-238, lead-212 is present in that of natural thorium-232, and lead-211 is present in that of natural uranium-235; therefore, traces of all three of these isotopes exist naturally as well. Lastly, very minute traces of lead-209 are also present from the

text: cluster decay

text: of radium-223, one of the daughter products of natural uranium-235. Hence, natural lead consists of not only the four stable isotopes, but also minute traces of another five short-lived radioisotopes.

text: The Jordan Radioactive Storage Facility is a proposed national storage facility in Amman for Jordan's radioactive waste and nuclear materials.

text: The Jordan Radioactive Storage Facility is a proposed national storage facility in

text: Amman

text: for Jordan's radioactive waste and

text: nuclear materials

text: The Eagle finds the Steel Spider in downtown Phoenix, Arizona, as the Thunderbolts unexpectedly arrive. Ollie argues that they will try to kill him and replace him with "Some Good Government Worker". When the Thunderbolts eventually do emerge, Jason decides to ally himself with Steel Spider, shooting the team's leader, Moonstone, through the wrist with a crossbow bolt. After a prolonged fight, Sepulchre becomes involved, and the three defeat Venom, the Swordsman, Songbird, and Radioactive Man. Though the latter two wish to try to defeat them using the old team's methods, leaving Sepulchre and the Eagle, Moonstone orders that Bullseye cripple the Eagle in the same way he did Jack Flag. The issue ends with Songbird, Radioactive Man, Penance and Venom squaring up against Steel Spider, Sepulchre and Jason, in what Steel Spider describes as 'almost...a fair fight'. The Eagle ends up crippling Bullseye before making his escape.

text: The Eagle finds the Steel Spider in downtown

text: Phoenix, Arizona

text: , as the Thunderbolts unexpectedly arrive. Ollie argues that they will try to kill him and replace him with "Some Good Government Worker". When the Thunderbolts eventually do emerge, Jason decides to ally himself with Steel Spider, shooting the team's leader,

text: Moonstone

text: , through the wrist with a crossbow bolt. After a prolonged fight,

text: Sepulchre

text: becomes involved, and the three defeat

text: Venom

text: , the

text: Swordsman

text: Songbird

text: , and

text: Radioactive Man

text: . Though the latter two wish to try to defeat them using the old team's methods, leaving Sepulchre and the Eagle, Moonstone orders that

text: Bullseye

text: cripple the Eagle in the same way he did

text: Jack Flag

text: . The issue ends with Songbird, Radioactive Man,

text: Penance

text: and Venom squaring up against Steel Spider, Sepulchre and Jason, in what Steel Spider describes as 'almost...a fair fight'. The Eagle ends up crippling Bullseye before making his escape.

text: The stable isotope In is only 4.3% of naturally occurring indium. Among elements with a known stable isotope, only tellurium and rhenium similarly occur with a stable isotope in lower abundance than the long-lived radioactive isotope. Other than In, the longest-lived radioisotope is In, with a half-life of 2.8047 days. All other radioisotopes have half-lives less than a day. This element also has 47 isomers, the longest-lived being In, with a half-life of 49.51 days. All other meta-states have half-lives less than a day, most less than an hour, and many measured in milliseconds or less.

text: The stable isotope In is only 4.3% of naturally occurring indium. Among elements with a known stable isotope, only

text: tellurium

text: and

text: rhenium

text: similarly occur with a stable isotope in lower abundance than the long-lived radioactive isotope. Other than In, the longest-lived radioisotope is In, with a half-life of 2.8047 days. All other radioisotopes have half-lives less than a day. This element also has 47

text: isomers

text: , the longest-lived being In, with a half-life of 49.51 days. All other meta-states have half-lives less than a day, most less than an hour, and many measured in milliseconds or less.

text: Uranyl compounds also exhibit luminescence. The first study of the green luminescence of uranium glass, by Brewster in 1849, began extensive studies of the spectroscopy of the uranyl ion. Detailed understanding of this spectrum was obtained  130 years later. It is now well-established that the uranyl luminescence is more specifically a phosphorescence, as it is due to a transition from the lowest triplet excited state to the singlet ground state. The luminescence from KUO(SO) was involved in the discovery of radioactivity.

text: Uranyl compounds also exhibit

text: luminescence

text: . The first study of the green luminescence of

text: uranium glass

text: , by

text: Brewster

text: in 1849, began extensive studies of the spectroscopy of the uranyl ion. Detailed understanding of this spectrum was obtained  130 years later. It is now well-established that the uranyl luminescence is more specifically a

text: phosphorescence

text: , as it is due to a transition from the lowest triplet excited state to the singlet ground state. The luminescence from KUO(SO) was involved in the discovery of

text: radioactivity

text: In a reactor that has been operating for some time, the radioactive fission products will have built up to steady state concentrations such that their rate of decay is equal to their rate of formation, so that their fractional total contribution to reactor heat (via beta decay) is the same as these radioisotopic fractional contributions to the energy of fission. Under these conditions, the 6.5% of fission which appears as delayed ionizing radiation (delayed gammas and betas from radioactive fission products) contributes to the steady-state reactor heat production under power. It is this output fraction which remains when the reactor is suddenly shut down (undergoes scram). For this reason, the reactor decay heat output begins at 6.5% of the full reactor steady state fission power, once the reactor is shut down. However, within hours, due to decay of these isotopes, the decay power output is far less. See decay heat for detail.

text: In a reactor that has been operating for some time, the radioactive fission products will have built up to steady state concentrations such that their rate of decay is equal to their rate of formation, so that their fractional total contribution to reactor heat (via beta decay) is the same as these radioisotopic fractional contributions to the energy of fission. Under these conditions, the 6.5% of fission which appears as delayed ionizing radiation (delayed gammas and betas from radioactive fission products) contributes to the steady-state reactor heat production under power. It is this output fraction which remains when the reactor is suddenly shut down (undergoes

text: scram

text: ). For this reason, the reactor

text: decay heat

text: output begins at 6.5% of the full reactor steady state fission power, once the reactor is shut down. However, within hours, due to decay of these isotopes, the decay power output is far less. See

text: decay heat

text: for detail.

text: In case of a radioactive release, most plants have a system designed to remove radioactivity from the air to reduce the effects of the radioactivity release on the employees and public. This system usually consists of containment ventilation that removes radioactivity and steam from primary containment. Control room ventilation ensures that plant operators are protected. This system often consists of activated charcoal filters that remove radioactive isotopes from the air.

text: In case of a radioactive release, most plants have a system designed to remove radioactivity from the air to reduce the effects of the radioactivity release on the employees and public. This system usually consists of containment ventilation that removes radioactivity and steam from primary containment. Control room ventilation ensures that plant operators are protected. This system often consists of

text: activated charcoal

text: filters that remove radioactive isotopes from the air.

text: Medical procedures, such as diagnostic X-rays, nuclear medicine, and radiation therapy are by far the most significant source of human-made radiation exposure to the general public. Some of the major radionuclides used are I-131, Tc-99m, Co-60, Ir-192, and Cs-137. The public also is exposed to radiation from consumer products, such as tobacco (polonium-210), combustible fuels (gas, coal, etc.), televisions, luminous watches and dials (tritium), airport X-ray systems, smoke detectors (americium), electron tubes, and gas lantern mantles (thorium).

text: Medical procedures, such as diagnostic

text: X-ray

text: s,

text: nuclear medicine

text: , and

text: radiation therapy

text: are by far the most significant source of human-made radiation exposure to the general public. Some of the major

text: radionuclide

text: s used are

text: , and

text: . The public also is exposed to radiation from consumer products, such as

text: tobacco

text: polonium

text: -210), combustible fuels (gas,

text: coal

text: , etc.),

text: television

text: s, luminous

text: watch

text: es and dials (

text: tritium

text: ), airport

text: X-ray

text: systems,

text: smoke detector

text: s (

text: americium

text: ), electron tubes, and gas lantern mantles (

text: thorium

text: As chief medic Swain is often called upon to put himself at risk to help others, so the crew are surprised when he asks to be excused from a high risk mission to a radioactive Island.  But Swain is a father, and he and Sally are trying for a second child, is there a point when he has to put his own interests ahead of others?  However, when Bomber slips over an edge of a cliff and into the radioactive blast crater, Swain realises he has to put aside his fears and help her.  Unfortunately, an accident with the winch puts both their lives in danger when they fall into the contaminated water within the crater.

text: The potential complete removal of plutonium from the waste stream of the reactor reduces the concern that presently exists with spent nuclear fuel from most other reactors that arises with burying or storing their spent fuel in a geological repository, as they could possibly be used as a plutonium mine at some future date. "Despite the million-fold reduction in radiotoxicity offered by this scheme, some believe that actinide removal would offer few if any significant advantages for disposal in a geologic repository because some of the fission product nuclides of greatest concern in scenarios such as groundwater leaching actually have longer half-lives than the radioactive actinides. These concerns do not consider the plan to store such materials in insoluble Synroc, and do not measure hazards in proportion to those from natural sources such as medical x-rays, cosmic rays, or natural radioactive rocks (such as granite).  These persons are concerned with radioactive fission products such as technetium-99, iodine-129, and cesium-135 with half-lives between 213,000 and 15.7 million years" Some of which are being targeted for transmutation to belay even these comparatively low concerns, for example the IFR's positive void coefficient could be reduced to an acceptable level by adding technetium to the core, helping destroy the long-lived fission product technetium-99 by nuclear transmutation in the process. (see more Long-lived fission products)

text: The potential complete removal of plutonium from the waste stream of the reactor reduces the concern that presently exists with spent nuclear fuel from most other reactors that arises with burying or storing their spent fuel in a geological repository, as they could possibly be used as a

text: plutonium mine

text: at some future date. "Despite the million-fold reduction in radiotoxicity offered by this scheme, some believe that actinide removal would offer few if any significant advantages for disposal in a

text: geologic repository

text: because some of the

text: fission product

text: nuclide

text: s of greatest concern in scenarios such as

text: groundwater

text: leaching

text: actually have longer half-lives than the radioactive actinides. These concerns do not consider the plan to store such materials in insoluble

text: Synroc

text: , and do not measure hazards in proportion to those from natural sources such as medical x-rays, cosmic rays, or natural radioactive rocks (such as

text: granite

text: ).  These persons are concerned with radioactive fission products such as

text: , and

text: with half-lives between 213,000 and 15.7 million years" Some of which are being targeted for transmutation to belay even these comparatively low concerns, for example the IFR's

text: positive void coefficient

text: could be reduced to an acceptable level by adding technetium to the core, helping destroy the long-lived fission product

text: by

text: nuclear transmutation

text: in the process. (see more

text: Long-lived fission products

text: On 8 July 2013, TEPCO found 9,000 becquerels of cesium-134 per liter and 18,000 becquerels of cesium-137 per liter in a sample taken from a well close to the coastline. Compared with samples taken three days earlier, the levels were 90 times higher. The cause was unknown. The well is situated close to a well that was leaking highly radioactive water into the sea in April 2011. In another well, situated about 100 meters south of the first well, a sample of groundwater showed that the radioactivity had risen 18 times in 4 days; 1700 becquerels per liter strontium and other radioactive substances.  A day later the readings in the first well were 11,000 Bq/L Ce-134 and 22,000 Bq/L Ce-137, 111 times and 105 times greater than the samples of 5 July. TEPCO did not know the reasons for the higher readings, but the monitoring was to be intensified.

text: It is not known what human organs are affected by interaction with promethium; a possible candidate is the bone tissues. Sealed promethium-147 is not dangerous. However, if the packaging is damaged, then promethium becomes dangerous to the environment and humans. If radioactive contamination is found, the contaminated area should be washed with water and soap, but, even though promethium mainly affects the skin, the skin should not be abraded. If a promethium leak is found, the area should be identified as hazardous and evacuated, and emergency services must be contacted. No dangers from promethium aside from the radioactivity are known.

text: It is not known what human organs are affected by interaction with promethium; a possible candidate is the

text: bone tissue

text: s. Sealed promethium-147 is not dangerous. However, if the packaging is damaged, then promethium becomes dangerous to the environment and humans. If radioactive contamination is found, the contaminated area should be washed with water and soap, but, even though promethium mainly affects the skin, the skin should not be abraded. If a promethium leak is found, the area should be identified as hazardous and evacuated, and emergency services must be contacted. No dangers from promethium aside from the radioactivity are known.

text: As the atom came to be better understood, the nature of radioactivity became clearer. Some larger atomic nuclei are unstable, and so decay (release matter or energy) after a random interval. The three forms of radiation that Becquerel and the Curies discovered are also more fully understood. Alpha decay is when a nucleus releases an alpha particle, which is two protons and two neutrons, equivalent to a helium nucleus. Beta decay is the release of a beta particle, a high-energy electron. Gamma decay releases gamma rays, which unlike alpha and beta radiation are not matter but electromagnetic radiation of very high frequency, and therefore energy. This type of radiation is the most dangerous and most difficult to block. All three types of radiation occur naturally in certain elements.

text: As the atom came to be better understood, the nature of radioactivity became clearer. Some larger atomic nuclei are unstable, and so

text: decay

text: (release matter or energy) after a random interval. The three forms of

text: radiation

text: that Becquerel and the Curies discovered are also more fully understood.

text: Alpha decay

text: is when a nucleus releases an

text: alpha particle

text: , which is two

text: proton

text: s and two

text: neutron

text: s, equivalent to a

text: helium

text: nucleus.

text: Beta decay

text: is the release of a

text: beta particle

text: , a high-energy

text: electron

text: Gamma decay

text: releases

text: gamma rays

text: , which unlike alpha and beta radiation are not matter but

text: electromagnetic radiation

text: of very high

text: frequency

text: , and therefore

text: energy

text: . This type of radiation is the most dangerous and most difficult to block. All three types of radiation occur naturally in

entity_name: List of elements by stability of isotopes

text: certain elements

text: Mutations can occur randomly in the DNA of any organism. In order to create variety within crops, scientists can randomly induce mutations within plants. Mutagenesis uses radioactivity to induce random mutations in the hopes of stumbling upon the desired trait. Scientists can use mutating chemicals such as ethyl methanesulfonate, or radioactivity to create random mutations within the DNA. Atomic gardens are used to mutate crops. A radioactive core in located in the center of a circular garden and raised out of the ground to radiate the surrounding crops, generating mutations within a certain radius. Interestingly, mutagenesis through radiation was the process used to produce ruby red grapefruits.

text: Mutations can occur randomly in the DNA of any organism. In order to create variety within crops, scientists can randomly induce mutations within plants. Mutagenesis uses radioactivity to induce random mutations in the hopes of stumbling upon the desired trait. Scientists can use mutating chemicals such as ethyl methanesulfonate, or radioactivity to create random mutations within the DNA.

text: Atomic gardens

text: are used to mutate crops. A radioactive core in located in the center of a circular garden and raised out of the ground to radiate the surrounding crops, generating mutations within a certain radius. Interestingly, mutagenesis through radiation was the process used to produce ruby red grapefruits.

text: In response to increased concern by the public over patient radiation dose, the ASRT along with The American College of Radiology, The American Association of Physicists in Medicine and the Society for Pediatric Radiology developed and launched the Image Gently Campaign which is designed to maintain high quality imaging studies while using the lowest doses and best radiation safety practices available on pediatric patients.  This initiative has been endorsed and applied by a growing list of various Professional Medical organizations around the world and has received support and assistance from companies that manufacture equipment used in radiology.

text: In response to increased concern by the public over patient radiation dose, the ASRT along with The

text: American College of Radiology

text: , The

entity_name: American Association of Physicists in Medicine

text: American Association of Physicists in Medicine

text: and the Society for Pediatric Radiology developed and launched the Image Gently Campaign which is designed to maintain high quality imaging studies while using the lowest doses and best radiation safety practices available on pediatric patients.  This initiative has been endorsed and applied by a growing list of various Professional Medical organizations around the world and has received support and assistance from companies that manufacture equipment used in radiology.

text: Using radioactive microspheres is an older method of measuring perfusion than the more recent imaging techniques. This process involves labeling microspheres with radioactive isotopes and injecting these into the test subject. Perfusion measurements are taken by comparing the radioactivity of selected regions within the body to radioactivity of blood samples withdrawn at the time of microsphere injection.

text: Using radioactive

text: microspheres

text: is an older method of measuring perfusion than the more recent imaging techniques. This process involves labeling microspheres with

text: radioactive isotopes

text: and injecting these into the test subject. Perfusion measurements are taken by comparing the radioactivity of selected regions within the body to radioactivity of blood samples withdrawn at the time of microsphere injection.

text: The agency is still primarily responsible for the supervision of nuclear power plants, nuclear facilities, and radiation workplaces. It also strictly implement the laws for nuclear safety control, radiation protection, environmental detection, and proper administration of radioactive waste management to ensure the safety of nuclear applications, general public and investigate applications for atomic energy.

text: Within the Manhattan District, the name health physicist seems to have been derived in part from the need for secrecy (and hence a code name for radiation protection activities) and the fact that there was a group of mostly physicists working on health related problems. Thus, their activities included development of appropriate monitoring instruments, developing physical controls, administrative procedures, monitoring areas and personnel, and radioactive waste disposal—in short, the entire spectrum of modern day radiation protection problems. It was in the Manhattan District that many of the modern concepts of protection were born, including the rem unit, which took into account the biological effectiveness of the radiation, and the maximum permissible concentration (MPC) for inhaled radioactivity. Indeed, it was in the Manhattan District that modern day radiation protection effects, born in the early days of x-ray and radium, realized their maturity.

text: Within the Manhattan District, the name

text: health physicist

text: seems to have been derived in part from the need for secrecy (and hence a code name for

text: radiation protection

text: activities) and the fact that there was a group of mostly physicists working on health related problems. Thus, their activities included development of appropriate monitoring instruments, developing physical controls, administrative procedures, monitoring areas and personnel, and

text: radioactive waste

text: disposal—in short, the entire spectrum of modern day radiation protection problems. It was in the Manhattan District that many of the modern concepts of protection were born, including the

text: rem

text: unit, which took into account the biological effectiveness of the radiation, and the maximum permissible concentration (MPC) for inhaled radioactivity. Indeed, it was in the Manhattan District that modern day radiation protection effects, born in the early days of x-ray and radium, realized their maturity.

text: It is common for medium active wastes in the nuclear industry to be treated with ion exchange or other means to concentrate the radioactivity into a small volume. The much less radioactive bulk (after treatment) is often then discharged. For instance, it is possible to use a ferric hydroxide floc to remove radioactive metals from aqueous mixtures. After the radioisotopes are absorbed onto the ferric hydroxide, the resulting sludge can be placed in a metal drum before being mixed with cement to form a solid waste form. In order to get better long-term performance (mechanical stability) from such forms, they may be made from a mixture of fly ash, or blast furnace slag, and Portland cement, instead of normal concrete (made with Portland cement, gravel and sand).

text: It is common for medium active wastes in the nuclear industry to be treated with

text: ion exchange

text: or other means to concentrate the radioactivity into a small volume. The much less radioactive bulk (after treatment) is often then discharged. For instance, it is possible to use a

text: ferric

text: hydroxide

text: floc

text: to remove radioactive metals from aqueous mixtures. After the radioisotopes are absorbed onto the ferric hydroxide, the resulting sludge can be placed in a metal drum before being mixed with cement to form a solid waste form. In order to get better long-term performance (mechanical stability) from such forms, they may be made from a mixture of

text: fly ash

text: , or

text: blast furnace

text: slag

text: , and

text: Portland cement

text: , instead of normal

text: concrete

text: (made with Portland cement, gravel and sand).

text: Wednesday 19 February 2014 late in the evening a leakage was found near a storage tank with radioactive water. The water contained 230.000.000 bq/l. The water did flow over the barrier around the tank, into the grounds around it. TEPCO estimated that some 100 metric tons were lost.  After the waterflow into the tank was cut off, the leakage stopped, According to TEPCO nothing was flown into the ocean nearby. Further investigations were done after the cause of the leakage. A valve was opened by error, this caused an inflow of water to the tank. Around 2 p.m. on 19 Feb. an alarm went off, indicating that the tank was dangerously filled. This alarm was ignored, because no radioactive water was transferred to the tank. The tank, however, got overfilled, and the radioactive access water left the tank along the rain-gutter. Because all rainwater is directed outside the barriers around the tanks, the overflowing radioactive water seeped directly into the grounds. According to TEPCO all leakage was due to human error. The patrols were doubled to twice a day, and the number of workers involved was increased 6 times to 60 people. Because the leak was about 700 meters from the coastal line, TEPCO did believe that none of this water had reached the ocean.

text: In 1949, Dr. Harold E. Johns of the University of Saskatchewan sent a request to the National Research Council (NRC) of Canada asking them to produce cobalt-60 isotopes for use in a cobalt therapy unit prototype. Two cobalt-60 apparatuses were then built, one in Saskatoon in the cancer wing of the University of Saskatchewan and the other in London, Ontario. Dr. Johns collected depth-dose data at the University of Saskatchewan which would later become the world standard. The first patient to be treated with cobalt-60 radiation was treated on October 27, 1951, at Victoria Hospital in London, Ontario. In 1961 cobalt therapy was expected to replace X-ray radiotherapy. The role of the cobalt unit has partly been replaced by the linear accelerator, which can generate higher-energy radiation, and does not produce the radioactive waste that radioisotopes do with their attendant disposal problems. Cobalt treatment still has a useful role to play in certain applications and is still in widespread use worldwide, since the machinery is relatively reliable and simple to maintain compared to the modern linear accelerator.

text: In 1949, Dr.

text: Harold E. Johns

text: of the

text: University of Saskatchewan

text: sent a request to the

text: National Research Council

text: (NRC) of Canada asking them to produce cobalt-60 isotopes for use in a cobalt therapy unit prototype. Two cobalt-60 apparatuses were then built, one in

text: Saskatoon

text: in the cancer wing of the University of Saskatchewan and the other in

text: London, Ontario

text: . Dr. Johns collected depth-dose data at the University of Saskatchewan which would later become the world standard. The first patient to be treated with cobalt-60 radiation was treated on October 27, 1951, at Victoria Hospital in London, Ontario. In 1961 cobalt therapy was expected to replace X-ray radiotherapy. The role of the cobalt unit has partly been replaced by the

text: linear accelerator

text: , which can generate higher-energy radiation, and does not produce the

text: radioactive waste

text: that

text: radioisotope

text: s do with their attendant disposal problems. Cobalt treatment still has a useful role to play in certain applications and is still in widespread use worldwide, since the machinery is relatively reliable and simple to maintain compared to the modern

text: linear accelerator

text: The commonly used radioisotopes have short half lives and so do not occur in nature. They are produced by nuclear reactions. One of the most important processes is absorption of a  neutron by an atomic nucleus, in which the mass number of the element concerned increases by 1 for each neutron absorbed. For example,

text: The commonly used radioisotopes have short

text: half lives

text: and so do not occur in nature. They are produced by

text: nuclear reaction

text: s. One of the most important processes is absorption of a  neutron by an atomic nucleus, in which the mass number of the element concerned increases by 1 for each neutron absorbed. For example,

text: The Vixen experimental tests used TNT to blow up simulated nuclear warheads containing plutonium-239. In total, Vixen B scattered 22.2 kg of plutonium around the Maralinga test site known as Taranaki, in particles of widely divergent size. Plutonium is not particularly dangerous externally - it emits alpha particles which are stopped by  of air, or the dead layer of skin cells on the body, and is not a very intensive source of radiation, due to its long half-life of 24,000 years. It is most dangerous when it enters the body, in the worst case by breathing, and therefore tiny particles, often the result of such explosion testing, are the worst threat.  The extreme biological persistence of plutonium's radioactive contamination and the cancer threat posed by alpha radiation occurring internally together establish plutonium's dangers.

text: The Vixen experimental tests used TNT to blow up simulated nuclear warheads containing

text: . In total, Vixen B scattered 22.2 kg of

text: plutonium

text: around the Maralinga test site known as Taranaki, in particles of widely divergent size.

text: Plutonium is not particularly dangerous externally

text: - it emits

text: alpha particles

text: which are stopped by  of air, or the dead layer of skin cells on the body, and is not a very intensive source of radiation, due to its long

text: half-life

text: of 24,000 years. It is most dangerous when it enters the body, in the worst case by breathing, and therefore tiny particles, often the result of such explosion testing, are the worst threat.  The extreme biological persistence of plutonium's

text: radioactive contamination

text: and the cancer threat posed by alpha radiation occurring internally together establish plutonium's dangers.

text: Proportional counters in the form of large area planar detectors are used extensively to check for radioactive contamination on personnel, flat surfaces, tools and items of clothing. This is normally in the form of installed instrumentation because of the difficulties of providing portable gas supplies for hand-held devices. They are constructed with a large area detection window made from such as metallised mylar which forms one wall of the detection chamber and is part of the cathode. The anode wire is routed in a convoluted manner within the detector chamber to optimise the detection efficiency. They are normally used to detect alpha and beta particles, and can  enable discrimination between them by providing a pulse output proportional to the energy deposited in the chamber by each particle. They have a high efficiency for beta, but lower for alpha. The efficiency reduction for alpha is due to the attenuation effect of the entry window, though distance from the surface being checked also has a significant effect, and ideally a source of alpha radiation should be less than 10mm from the detector due to attenuation in air.

text: Proportional counters in the form of large area planar detectors are used extensively to check for

text: radioactive contamination

text: on personnel, flat surfaces, tools and items of clothing. This is normally in the form of installed instrumentation because of the difficulties of providing portable gas supplies for hand-held devices. They are constructed with a large area detection window made from such as metallised mylar which forms one wall of the detection chamber and is part of the cathode. The anode wire is routed in a convoluted manner within the detector chamber to optimise the detection efficiency. They are normally used to detect

text: alpha

text: and

text: beta

text: particles, and can  enable discrimination between them by providing a pulse output proportional to the energy deposited in the chamber by each particle. They have a high efficiency for beta, but lower for alpha. The efficiency reduction for alpha is due to the

text: attenuation

text: effect of the entry window, though distance from the surface being checked also has a significant effect, and ideally a source of alpha radiation should be less than 10mm from the detector due to attenuation in air.

text: Since irradiation increases with proximity to the source of radiation, and as it is impossible to distance or shield an internal source, radioactive materials inside the body can deliver much higher doses to the host organs than they normally would from outside the body. This is particularly true for alpha and beta emitters that are easily shielded by skin and clothing. Some have hypothesized that alpha's high relative biological effectiveness might be attributable to cell's tendency to absorb transuranic metals into the cellular nucleus where they would be in very close proximity to the genome, though an elevated effectiveness can also be observed for external alpha radiation in cellular studies. As in the calculations for equivalent dose and effective dose, committed dose must include corrections for the relative biological effectiveness of the radiation type and weightings for tissue sensitivity.

text: Since irradiation increases with proximity to the source of radiation, and as it is impossible to distance or shield an internal source, radioactive materials inside the body can deliver much higher doses to the host organs than they normally would from outside the body. This is particularly true for

text: alpha

text: and

text: beta

text: emitters that are easily shielded by skin and clothing. Some have hypothesized that alpha's high

text: relative biological effectiveness

text: might be attributable to cell's tendency to absorb transuranic metals into the cellular nucleus where they would be in very close proximity to the genome, though an elevated effectiveness can also be observed for external alpha radiation in cellular studies. As in the calculations for

text: equivalent dose

text: and

text: effective dose

text: , committed dose must include corrections for the relative biological effectiveness of the radiation type and weightings for tissue sensitivity.

text: Nuclear power in space is the use of nuclear power in outer space, typically either small fission systems or radioactive decay for electricity or heat. Another use is for scientific observation, as in a Mössbauer spectrometer. One common type is a radioisotope thermoelectric generator, which has been used on many space probes and on manned lunar missions, and another is small fission reactors for Earth observation satellites such as the TOPAZ nuclear reactor. A radioisotope heater unit provides heat from radioactive decay of a material and can potentially produce heat for decades.

text: Nuclear power in space is the use of

text: nuclear power

text: in

text: outer space

text: , typically either small fission systems or radioactive decay for electricity or heat. Another use is for scientific observation, as in a

text: Mössbauer spectrometer

text: . One common type is a

text: radioisotope thermoelectric generator

text: , which has been used on many space probes and on manned lunar missions, and another is small fission reactors for Earth observation satellites such as the

text: TOPAZ nuclear reactor

text: . A

text: radioisotope heater unit

text: provides heat from radioactive decay of a material and can potentially produce heat for decades.

text: The most common means of measuring the variations in a beam of radiation is by observing its effect on a photographic film. This effect is the same as that of light, and the more intense the radiation is, the more it darkens, or exposes, the film. Other methods are in use, such as the ionizing effect measured electronically, its ability to discharge an electrostatically charged plate or to cause certain chemicals to fluoresce as in fluoroscopy.

text: The most common means of measuring the variations in a beam of radiation is by observing its effect on a photographic film. This effect is the same as that of light, and the more intense the radiation is, the more it darkens, or

text: exposes

text: , the film. Other methods are in use, such as the ionizing effect measured electronically, its ability to discharge an electrostatically charged plate or to cause certain chemicals to

text: fluoresce

text: as in

text: fluoroscopy

text: All the known stable isotopes occur naturally on Earth; the other naturally occurring-isotopes are radioactive but occur on Earth due to their relatively long half-lives, or else due to other means of ongoing natural production. These include the afore-mentioned cosmogenic nuclides, the nucleogenic nuclides, and any radiogenic radioisotopes formed by ongoing decay of a primordial radioactive isotope, such as radon and radium from uranium.

text: All the known

text: stable isotopes

text: occur naturally on Earth; the other naturally occurring-isotopes are radioactive but occur on Earth due to their relatively long half-lives, or else due to other means of ongoing natural production. These include the afore-mentioned

text: cosmogenic nuclide

text: s, the

text: nucleogenic

text: nuclides, and any

text: radiogenic

text: radioisotopes formed by ongoing decay of a primordial radioactive isotope, such as

text: radon

text: and

text: radium

text: from uranium.

text: Some isotopes that are classed as stable (i.e. no radioactivity has been observed for them) are predicted to have extremely long half-lives (sometimes as high as 10 years or more). If the predicted half-life falls into an experimentally accessible range, such isotopes have a chance to move from the list of stable nuclides to the radioactive category, once their activity is observed. E.g. Bi and W were formerly classed as stable, but have been recently (2003) found to be alpha-active. However, such nuclides do not change their status as primordial when they are found to be radioactive.

text: Some isotopes that are classed as stable (i.e. no radioactivity has been observed for them) are predicted to have extremely long half-lives (sometimes as high as 10 years or more). If the predicted half-life falls into an experimentally accessible range, such isotopes have a chance to move from the list of stable nuclides to the radioactive category, once their activity is observed. E.g. Bi and W were formerly classed as stable, but have been recently (2003) found to be

text: alpha

text: -active. However, such nuclides do not change their status as primordial when they are found to be radioactive.

text: A Lucas cell can be used to measure radon gas concentrations.Radon itself is an inert gas. Its danger lies in the fact that it is radioactive and its radioactive daughters accumulate in the dust of enclosed areas. The radon daughters may lodge in the lungs and bombard them with alpha and beta radiation.

text: A Lucas cell can be used to measure

text: radon

text: gas concentrations.Radon itself is an

text: inert gas

text: . Its danger lies in the fact that it is radioactive and its radioactive daughters accumulate in the dust of enclosed areas. The radon

text: daughters

text: may lodge in the lungs and bombard them with

text: alpha

text: and

text: beta radiation

text: For northern blotting for the detection of acetylcholinesterase mRNA the nonradioactive technique was compared to a radioactive technique and found as sensitive as the radioactive one, but requires no protection against radiation and is less time consuming.

text: For northern blotting for the detection of

text: acetylcholinesterase

text: mRNA

text: the nonradioactive technique was compared to a radioactive technique and found as sensitive as the radioactive one, but requires no protection against radiation and is less time consuming.

text: Twenty-four other radioisotopes have been characterized with atomic weights ranging from 86.95 u (Ru) to 119.95 u (Ru). Most of these have half-lives that are less than five minutes, excepting Ru (half-life: 1.643 hours) and Ru (half-life: 4.44 hours).

text: Twenty-four other radioisotopes have been characterized with

text: atomic weight

text: s ranging from 86.95

text: u

text: (Ru) to 119.95 u (Ru). Most of these have half-lives that are less than five minutes, excepting Ru (half-life: 1.643 hours) and Ru (half-life: 4.44 hours).

text: Radiation-based Gauge: Radiation is passed from a source, through the fluid of interest, and into a scintillation detector, or counter. As the fluid density increases, the detected radiation "counts" will decrease. The source is typically the radioactive isotope cesium-137, with a half-life of about 30 years. A key advantage for this technology is that the instrument is not required to be in contact with the fluid – typically the source and detector are mounted on the outside of tanks or piping. .

text: , with a half-life of about 30 years. A key advantage for this technology is that the instrument is not required to be in contact with the fluid – typically the source and detector are mounted on the outside of tanks or piping. .

text: Between 1949 and 1989, over 4,000 uranium mines in the Four Corner region produced more than 225,000,000 tons of uranium ore. This activity affected a large number of Native American nations, including the Laguna, Navajo, Zuni, Southern Ute, Ute Mountain, Hopi, Acoma and other Pueblo cultures. Many of these peoples worked in the mines, mills and processing plants in New Mexico, Arizona, Utah and Colorado. These workers were not only poorly paid, they were seldom informed of dangers nor were they given appropriate protective gear. The government, mine owners, scientific, and health communities were all well aware of the hazards of working with radioactive materials at this time. Due to the Cold War demand for increasingly destructive and powerful nuclear weapons, these laborers were both exposed to and brought home large amounts of radiation in the form of dust on their clothing and skin. Epidemiologic studies of the families of these workers have shown increased incidents of radiation-induced cancers, miscarriages, cleft palates and other birth defects. The extent of these genetic effects on indigenous populations and the extent of DNA damage remains to be resolved.

text: Medical Use of Radiation: Medicine has used ionizing radiation for decades to help diagnose or treat children (and adults). There is no doubt that this imaging has saved lives. Medical imaging use has grown exponentially in the past few years, particularly the use of CAT Scans (also called CT scans). There are approximately 65 million CT scans done in the United States annually with an estimated 8 million in children. However, there is a much higher radiation dose from CT scans than from the traditional radiographs and fluoroscopy tests that radiologists perform and interpret. CT scans provide in general more information about the anatomy and diseases in the body but could be replaced for some orthopedic indications by other low dose imaging modalities like EOS. To do this, though, they may expose a person to 100 to 250 times the radiation dose compared to a chest x-ray.

text: Medical Use of Radiation: Medicine has used ionizing radiation for decades to help diagnose or treat children (and adults). There is no doubt that this imaging has saved lives. Medical imaging use has grown exponentially in the past few years, particularly the use of CAT Scans (also called CT scans). There are approximately 65 million CT scans done in the United States annually with an estimated 8 million in children. However, there is a much higher radiation dose from CT scans than from the traditional radiographs and fluoroscopy tests that radiologists perform and interpret. CT scans provide in general more information about the anatomy and diseases in the body but could be replaced for some orthopedic indications by other low dose imaging modalities like

text: EOS

text: . To do this, though, they may expose a person to 100 to 250 times the radiation dose compared to a chest x-ray.

text: His homemade reactor never came anywhere near reaching critical mass—but it ended up emitting dangerous levels of radiation, likely well over 1,000 times normal background radiation. Alarmed, Hahn began to dismantle his experiments—but in a chance encounter, police discovered his activities, which triggered a Federal Radiological Emergency Response involving the FBI and the Nuclear Regulatory Commission. On June 26, 1995 the United States Environmental Protection Agency, having designated Hahn's mother's property a Superfund hazardous materials cleanup site, dismantled the shed and its contents and buried them as low-level radioactive waste in Utah. However, his mother, fearful that she would lose her house if the full extent of the radiation were known, collected the majority of the radioactive material and threw it away in the conventional garbage, which officials did not know. Hahn refused medical evaluation for radiation exposure.

text: His homemade reactor never came anywhere near reaching critical mass—but it ended up emitting dangerous levels of radiation, likely well over 1,000 times normal

text: background radiation

text: . Alarmed, Hahn began to dismantle his experiments—but in a chance encounter, police discovered his activities, which triggered a Federal Radiological Emergency Response involving the

text: FBI

text: and the

text: Nuclear Regulatory Commission

text: . On June 26, 1995 the

entity_name: United States Environmental Protection Agency

text: United States Environmental Protection Agency

text: , having designated Hahn's mother's property a

text: Superfund

text: hazardous materials cleanup site, dismantled the shed and its contents and buried them as low-level

text: radioactive waste

text: in

text: Utah

text: . However, his mother, fearful that she would lose her house if the full extent of the radiation were known, collected the majority of the radioactive material and threw it away in the conventional garbage, which officials did not know. Hahn refused medical evaluation for

text: radiation exposure

text: Thirty radioisotopes have been characterized, with the most stable (after Th) being Th with a half-life of 75,380 years, Th with a half-life of 7,340 years, and Th with a half-life of 1.92 years. All of the remaining radioactive isotopes have half-lives that are less than thirty days and the majority of these have half-lives that are less than ten minutes. One isotope, Th, has a nuclear isomer (or metastable state) with a remarkably low excitation energy, recently measured to be 7.6 ± 0.5 eV.

text: Thirty

text: radioisotope

text: s have been characterized, with the most stable (after Th) being Th with a half-life of 75,380 years, Th with a half-life of 7,340 years, and Th with a half-life of 1.92 years. All of the remaining

text: radioactive

text: isotopes have half-lives that are less than thirty days and the majority of these have half-lives that are less than ten minutes. One isotope, Th, has a

text: nuclear isomer

text: (or metastable state) with a remarkably low excitation energy, recently measured to be 7.6 ± 0.5 eV.

text: The test does not directly assert the presence of radioactive material. A successful test asserts that the claim of no radioactive material present is unlikely given the reading (and therefore ...). The double negative (disproving the null hypothesis) of the method is confusing, but using a counter-example to disprove is standard mathematical practice. The attraction of the method is its practicality. We know (from experience) the expected range of counts with only ambient radioactivity present, so we can say that a measurement is unusually large. Statistics just formalizes the intuitive by using numbers instead of adjectives. We probably do not know the characteristics of the radioactive suitcases; We just assumethat they produce larger readings.

text: Some radioisotopes occur in nature with a half-life less than 7*10 years (carbon-14 5,730 ± 40 years, tritium 12.32 years etc.). They are synthesed all the time because of cosmic radiation. For carbon-14 this fact has practice value because it is used for radiocarbon dating.

text: Some radioisotopes occur in nature with a half-life less than 7*10 years (

text: 5,730 ± 40 years,

text: tritium

text: 12.32 years etc.). They are synthesed all the time because of cosmic radiation. For carbon-14 this fact has practice value because it is used for

text: radiocarbon dating

text: In health physics, whole-body counting refers to the measurement of radioactivity within the human body.  The technique is primarily applicable to radioactive material that emits gamma rays. Alpha particle decays can also be detected indirectly by their coincident gamma radiation. In certain circumstances, beta emitters can be measured, but with degraded sensitivity.

text: In

text: health physics

text: , whole-body counting refers to the measurement of

text: radioactivity

text: within the human body.  The technique is primarily applicable to radioactive material that emits

text: gamma

text: rays.

text: Alpha particle

text: decays can also be detected indirectly by their coincident gamma radiation. In certain circumstances,

text: beta

text: emitters can be measured, but with degraded sensitivity.

text: In a press release on 12 March at 07:00 JST, TEPCO stated, "Measurement of radioactive material (iodine-131, etc.) by monitoring car indicates increasing value compared to normal level. One of the monitoring posts is also indicating higher than normal level." Dose rates recorded on the main gate rose from 69 nGy/h (for gamma radiation, equivalent to 69 nSv/h) at 04:00 JST, 12 March, to 866 nGy/h 40 minutes later, before hitting a peak of 0.3855 mSv/h at 10:30 JST. At 13:30 JST, workers detected radioactive caesium-137 and iodine-131 near Reactor 1, which indicated some of the core's fuel had been damaged. Cooling water levels had fallen so much that parts of the nuclear fuel rods were exposed and partial melting might have occurred. Radiation levels at the site boundary exceeded the regulatory limits.

text: In a press release on 12 March at 07:00 JST, TEPCO stated, "Measurement of radioactive material (

text: , etc.) by monitoring car indicates increasing value compared to normal level. One of the monitoring posts is also indicating higher than normal level." Dose rates recorded on the main gate rose from 69

text: n

text: Gy

text: /h (for

text: gamma

text: radiation, equivalent to 69 n

text: Sv

text: /h) at 04:00 JST, 12 March, to 866 nGy/h 40 minutes later, before hitting a peak of 0.3855 mSv/h at 10:30 JST. At 13:30 JST, workers detected radioactive

text: and

text: near Reactor 1, which indicated some of the core's

entity_name: Behavior of nuclear fuel during a reactor accident

text: fuel had been damaged

text: . Cooling water levels had fallen so much that parts of the

text: nuclear fuel rods

text: were exposed and partial melting might have occurred. Radiation levels at the site boundary exceeded the regulatory limits.

text: Although radiation was discovered in late 19th century, the dangers of radioactivity and of radiation were not immediately recognized. Acute effects of radiation were first observed in the use of X-rays when Wilhelm Röntgen intentionally subjected his fingers to X-rays in 1895. He published his observations concerning the burns that developed, though he misattributed them to ozone, a free radical produced in air by X-rays. Other free radicals produced within the body are now understood to be more important. His injuries healed later.

text: Although radiation was discovered in late 19th century, the dangers of radioactivity and of radiation were not immediately recognized. Acute effects of radiation were first observed in the use of X-rays when

text: Wilhelm Röntgen

text: intentionally subjected his fingers to X-rays in 1895. He published his observations concerning the burns that developed, though he misattributed them to ozone, a

text: free radical

text: produced in air by X-rays. Other free radicals produced within the body are now understood to be more important. His injuries healed later.

text: A mast radiator (or 'radiating tower') is a radio mast or tower in which the entire structure functions as an antenna. This design, developed around 1930, is commonly used for transmitting antennas operating at low frequencies, in the VLF, LF and MF ranges, in particular those used for AM broadcasting. The metal mast is electrically connected to the transmitter. Its base is usually mounted on a nonconductive support to insulate it from the ground.  A mast radiator is a form of monopole antenna.

text: A mast radiator (or 'radiating tower') is a

text: radio mast or tower

text: in which the entire structure functions as an

text: antenna

text: . This design, developed around 1930, is commonly used for

text: transmitting

text: antennas operating at low

text: frequencies

text: , in the

text: VLF

text: LF

text: and

text: MF

text: ranges, in particular those used for AM

text: broadcasting

text: . The metal mast is electrically connected to the

text: transmitter

text: . Its base is usually mounted on a nonconductive support to insulate it from the ground.  A mast radiator is a form of

text: monopole antenna

text: In April 2010, Gundersen released a report (commissioned by several nongovernment organizations) which explored a hazard associated with the possible rusting through of the AP1000 containment structure steel liner. In the AP1000 design, the liner and the concrete are separated, and if the steel rusts through, "there is no backup containment behind it" says Gundersen. If the dome rusted through the design would expel radioactive contaminants and the plant "could deliver a dose of radiation to the public that is 10 times higher than the N.R.C. limit" according to Gundersen. Westinghouse has disputed Gundersen’s assessment. Gundersen has testified  before the Nuclear Regulatory Commission’s Advisory Committee on Reactor Safeguards saying that "if a hole appeared, the chimney effect would disperse radioactive material far and wide".

text: In April 2010, Gundersen released a report (commissioned by several nongovernment organizations) which explored a hazard associated with the possible rusting through of the AP1000 containment structure steel liner. In the AP1000 design, the liner and the concrete are separated, and if the steel rusts through, "there is no backup containment behind it" says Gundersen. If the dome rusted through the design would expel radioactive contaminants and the plant "could deliver a dose of radiation to the public that is 10 times higher than the N.R.C. limit" according to Gundersen. Westinghouse has disputed Gundersen’s assessment. Gundersen has testified  before the

text: Nuclear Regulatory Commission

text: ’s Advisory Committee on Reactor Safeguards saying that "if a hole appeared, the chimney effect would disperse radioactive material far and wide".

text: Aboveground nuclear explosions produce a characteristic mushroom cloud, which moves downwind as it reaches its stabilization height.  Dispersion of the radioactive elements causes vertical and lateral cloud movement, spreading radioactive materials over adjacent regions. While the large particles settle nearby the site of the detonation, smaller particles and gases may be dispersed around the world.  Additionally, some explosions injected radioactive material into the stratosphere, more than 10 kilometers above ground level, meaning it may float there for years before being subsequently deposited uniformly around the earth.  Global fallout is the result, which exposes everything to an elevated level of man-made background radiation.  While "downwinders" refers to those who live and work closest to the explosion site and are thus most acutely affected, there is a global effect of increased health risks due to ionizing radiation in the atmosphere.

text: Aboveground nuclear explosions produce a characteristic

text: mushroom cloud

text: , which moves downwind as it reaches its stabilization height.  Dispersion of the radioactive elements causes vertical and lateral cloud movement, spreading radioactive materials over adjacent regions. While the large particles settle nearby the site of the detonation, smaller particles and gases may be dispersed around the world.  Additionally, some explosions injected radioactive material into the

text: stratosphere

text: , more than 10 kilometers above ground level, meaning it may float there for years before being subsequently deposited uniformly around the earth.  Global fallout is the result, which exposes everything to an elevated level of man-made background radiation.  While "downwinders" refers to those who live and work closest to the explosion site and are thus most acutely affected, there is a global effect of increased health risks due to ionizing radiation in the atmosphere.

text: West Lake Landfill is an unlined mixed-waste landfill located in Bridgeton, Missouri, near St. Louis and the Mississippi River, whose contents have been shown to include radioactive waste; it is thus also an EPA Superfund cleanup site. In 1973, after having changed hands (and responsible oversight) several times, a portion of original stored radioactive material at a nearby storage facility—the material with lowest relative radioactivity, a leached barium sulfate residue originating from the Manhattan Project—was combined with topsoil to dilute the contaminated material. It was then illegally dumped at the West Lake site. Due to the discovery of the radioactive and other contaminants at the site, West Lake was proposed as a Superfund site in October 1989, and after undergoing an extensive feasibility study, it was officially listed as such a site in August 1990.

text: West Lake Landfill is an unlined mixed-waste

text: landfill

text: located in

text: Bridgeton, Missouri

text: , near

text: St. Louis

text: and the

text: Mississippi River

text: , whose contents have been shown to include radioactive waste; it is thus also an

text: EPA

text: Superfund

text: cleanup site. In 1973, after having changed hands (and responsible oversight) several times, a portion of original stored radioactive material at a nearby storage facility—the material with lowest relative radioactivity, a leached

text: barium sulfate

text: residue originating from the

text: Manhattan Project

text: —was combined with topsoil to dilute the contaminated material. It was then illegally dumped at the West Lake site. Due to the discovery of the radioactive and other contaminants at the site, West Lake was proposed as a

text: Superfund

text: site in October 1989, and after undergoing an extensive

text: feasibility study

text: , it was officially listed as such a site in August 1990.

text: Survey meters are portable radiation detection and measurement instruments used to check personnel, equipment and facilities for radioactive contamination, or to measure external or ambient ionizing radiation fields (to evaluate the direct exposure hazard). The hand-held survey meter is probably the most familiar radiation measuring device to society owing to its wide and highly visible use.

text: Survey meters are portable radiation detection and measurement instruments used to check personnel, equipment and facilities for

text: radioactive contamination

text: , or to measure external or ambient ionizing radiation fields (to evaluate the direct exposure hazard). The hand-held survey meter is probably the most familiar radiation measuring device to society owing to its wide and highly visible use.

text: Radiation is often categorized as either ionizing or non-ionizing depending on the energy of the radiated particles. Ionizing radiation carries more than 10 eV, which is enough to ionize atoms and molecules, and break chemical bonds. This is an important distinction due to the large difference in harmfulness to living organisms. A common source of ionizing radiation is radioactive materials that emit α, β, or γ radiation, consisting of helium nuclei, electrons or positrons, and photons, respectively. Other sources include X-rays from medical radiography examinations and muons, mesons, positrons, neutrons and other particles that constitute the secondary cosmic rays that are produced after primary cosmic rays interact with Earth's atmosphere.

text: Radiation is often categorized as either

text: ionizing

text: or

text: non-ionizing

text: depending on the energy of the radiated particles. Ionizing radiation carries more than 10

text: eV

text: , which is enough to

text: ionize

text: atoms and molecules, and break

text: chemical bond

text: s. This is an important distinction due to the large difference in harmfulness to living organisms. A common source of ionizing radiation is

text: radioactive

text: materials that emit α, β, or

text: γ radiation

text: , consisting of

text: helium nuclei

text: electrons

text: or

text: positrons

text: , and

text: photons

text: , respectively. Other sources include X-rays from medical

text: radiography

text: examinations and

text: muon

text: s,

text: meson

text: s,

text: positron

text: s,

text: neutron

text: s and other particles that constitute the secondary

text: cosmic ray

text: s that are produced after primary cosmic rays interact with Earth's atmosphere.

text: Citations of D.N.  Poenaru et al.  papers on heavy particle radioactivities started in 1984 after the first experimental confirmation by Rose and Jones of the 14C radioactivity of 223Ra.

text: Twenty radioisotopes have been characterized, with the most stable being Si with a half-life of 170 years, and Si with a half-life of 157.3 minutes. All of the remaining radioactive isotopes have half-lives that are less than seven seconds, and the majority of these have half-lives that are less than one tenth of a second. Silicon does not have any known nuclear isomers. Si undergoes low-energy beta decay to P and then stable S. Si may be produced by the neutron activation of natural silicon and is thus useful for quantitative analysis.

text: Twenty

text: radioisotopes

text: have been characterized, with the most stable being Si with a

text: half-life

text: of 170 years, and Si with a half-life of 157.3 minutes. All of the remaining

text: radioactive

text: isotopes have half-lives that are less than seven seconds, and the majority of these have half-lives that are less than one tenth of a second. Silicon does not have any known

text: nuclear isomer

text: s. Si undergoes low-energy

text: beta decay

text: to

text: P

text: and then stable

text: S

text: . Si may be produced by the

text: neutron activation

text: of natural silicon and is thus useful for quantitative analysis.

text: According to a report published in October 2011 by the French Institute for Radiological Protection and Nuclear Safety, between 21 March and mid-July around 2.7 × 10 Bq of caesium-137 (about 8.4 kg) entered the ocean, about 82 percent having flowed into the sea before 8 April. This emission of radioactivity into the sea represents the most important individual emission of artificial radioactivity into the sea ever observed. However, the Fukushima coast has some of the world's strongest currents and these transported the contaminated waters far into the Pacific Ocean, thus causing great dispersion of the radioactive elements. The results of measurements of both the seawater and the coastal sediments led to the supposition that the consequences of the accident, in terms of radioactivity, would be minor for marine life as of autumn 2011 (weak concentration of radioactivity in the water and limited accumulation in sediments). On the other hand, significant pollution of sea water along the coast near the nuclear plant might persist, because of the continuing arrival of radioactive material transported towards the sea by surface water running over contaminated soil. Further, some coastal areas might have less-favorable dilution or sedimentation characteristics than those observed so far. Finally, the possible presence of other persistent radioactive substances, such as strontium-90 or plutonium, has not been sufficiently studied. Recent measurements show persistent contamination of some marine species (mostly fish) caught along the coast of Fukushima district. Organisms that filter water and fish at the top of the food chain are, over time, the most sensitive to caesium pollution. It is thus justified to maintain surveillance of marine life that is fished in the coastal waters off Fukushima. Despite caesium isotopic concentration in the waters off of Japan being 10 to 1000 times above concentration prior to the accident, radiation risks are below what is generally considered harmful to marine animals and human consumers.

text: According to a report published in October 2011 by the

entity_name: Institut de radioprotection et de sûreté nucléaire

text: French Institute for Radiological Protection and Nuclear Safety

text: In 1978, NASA launched the Total Ozone Mapping Spectrometer. In 1998, anthropologist Nina Jablonski and her husband George Chaplin collected spectrometer data to measure UV radiation levels around the world, and compared it to published information on the skin colour of indigenous populations of more 50 countries. The results showed a very high correlation between UV radiation and skin colour; the weaker the sunlight was in a geographic region, the lighter the indigenous people’s skin were. Jablonski went on to prove that people living above the latitudes of 50 degrees have the highest chance of developing vitamin D deficiency. "This was one of the last barriers in the history of human settlement," Jablonski states. "Only after humans learned fishing, and therefore had access to food rich in vitamin D, could they settle regions of high latitude."People living far from the equator developed light skin to produce adequate amounts of vitamin D during winter with low levels of UV radiation. Genetic studies suggest that light-skinned humans have been selected for multiple times.

text: In 1978, NASA launched the

text: Total Ozone Mapping Spectrometer

text: . In 1998, anthropologist

text: Nina Jablonski

text: and her husband George Chaplin collected spectrometer data to measure UV radiation levels around the world, and compared it to published information on the skin colour of

text: indigenous

text: populations of more 50 countries. The results showed a very high correlation between UV radiation and skin colour; the weaker the sunlight was in a geographic region, the lighter the indigenous people’s skin were. Jablonski went on to prove that people living above the latitudes of 50 degrees have the highest chance of developing vitamin D deficiency. "This was one of the last barriers in the history of human settlement," Jablonski states. "Only after humans learned fishing, and therefore had access to food rich in vitamin D, could they settle regions of

text: high latitude

text: ."People living far from the equator developed light skin to produce adequate amounts of vitamin D during winter with low levels of UV radiation. Genetic studies suggest that light-skinned humans have been selected for multiple times.

text: Scientists have calculated that the residents of the Marshall Islands during their lifetimes will be diagnosed with an added 1.6% (with 90% uncertainty range 0.4% to 3.4%) cancers attributable to fallout-related radiation exposures. The cancers are the consequence of exposure to ionizing radiation from weapons test fallout deposited during the testing period (1948-1958) and from residual radioactive sources during the subsequent 12 y (1959-1970),

text: Scientists have calculated that the residents of the

text: Marshall Islands

text: during their lifetimes will be diagnosed with an added 1.6% (with 90% uncertainty range 0.4% to 3.4%) cancers attributable to fallout-related radiation exposures. The cancers are the consequence of exposure to ionizing radiation from weapons test fallout deposited during the testing period (1948-1958) and from residual radioactive sources during the subsequent 12 y (1959-1970),

text: Radionuclides that find their way into the environment may cause harmful effects as radioactive contamination. They can also cause damage if they are excessively used during treatment or in other ways exposed to living beings, by radiation poisoning. Potential health damage from exposure to radionuclides depends on a number of factors, and "can damage the functions of healthy tissue/organs. Radiation exposure can produce effects ranging from skin redness and hair loss, to radiation burns and acute radiation syndrome. Prolonged exposure can lead to cells being damaged and in turn lead to cancer. Signs of cancerous cells might not show up until years, or even decades, after exposure."

text: Radionuclides that find their way into the environment may cause harmful effects as

text: radioactive contamination

text: . They can also cause damage if they are excessively used during treatment or in other ways exposed to living beings, by

text: radiation poisoning

text: . Potential health damage from exposure to radionuclides depends on a number of factors, and "can damage the functions of healthy tissue/organs. Radiation exposure can produce effects ranging from skin redness and hair loss, to

text: radiation burn

text: s and

text: acute radiation syndrome

text: . Prolonged exposure can lead to cells being damaged and in turn lead to cancer. Signs of cancerous cells might not show up until years, or even decades, after exposure."

text: The CD V-700, as a true Geiger counter, is capable of measuring ambient background levels of gamma radiation and detecting the presence of beta radiation in the environment, and thus can be used to detect such common low-level radioactive artifacts as uranium-doped marbles, Fiestaware plates and radium watch faces. This differentiates them from other civil defense radiation meters such as the CD V-715, CD V-717 and CD-V-720, which are ion chamber meters that can measure gamma radiation levels far above (up to 500R/h) what the CD V-700 can (up to 50mR/h). Conversely, the ion chamber units are so insensitive to low-levels of gamma radiation that no legally exempt radiation source can make them register at all.

text: The first gamma ray source to be discovered historically was the radioactive decay process called gamma decay. In this type of decay, an excited nucleus emits a gamma ray almost immediately upon formation (it is now understood that a nuclear isomeric transition, however, can produce inhibited gamma decay with a measurable and much longer half-life). Paul Villard, a French chemist and physicist, discovered gamma radiation in 1900, while studying radiation emitted from radium. Villard knew that his described radiation was more powerful than previously described types of rays from radium, which included beta rays, first noted as "radioactivity" by Henri Becquerel in 1896, and alpha rays, discovered as a less penetrating form of radiation by Rutherford, in 1899. However, Villard did not consider naming them as a different fundamental type. Villard's radiation was recognized as being of a type fundamentally different from previously named rays, by Ernest Rutherford, who in 1903 named Villard's rays "gamma rays" by analogy with the beta and alpha rays that Rutherford had differentiated in 1899. The "rays" emitted by radioactive elements were named in order of their power to penetrate various materials, using the first three letters of the Greek alphabet: alpha rays as the least penetrating, followed by beta rays, followed by gamma rays as the most penetrating. Rutherford also noted that gamma rays were not deflected (or at least, not easily deflected) by a magnetic field, another property making them unlike alpha and beta rays.

text: The first gamma ray source to be discovered historically was the

text: radioactive decay

text: process called gamma decay. In this type of decay, an

text: excited

text: nucleus emits a gamma ray almost immediately upon formation (it is now understood that a nuclear

text: isomeric transition

text: , however, can produce inhibited gamma decay with a measurable and much longer half-life).

text: Paul Villard

text: , a French chemist and physicist, discovered gamma radiation in 1900, while studying radiation emitted from

text: radium

text: . Villard knew that his described radiation was more powerful than previously described types of rays from radium, which included

text: beta ray

text: s, first noted as "radioactivity" by

text: Henri Becquerel

text: in 1896, and

text: alpha ray

text: s, discovered as a less penetrating form of radiation by Rutherford, in 1899. However, Villard did not consider naming them as a different fundamental type. Villard's radiation was recognized as being of a type fundamentally different from previously named rays, by

text: Ernest Rutherford

text: , who in 1903 named Villard's rays "gamma rays" by analogy with the beta and alpha rays that Rutherford had differentiated in 1899. The "rays" emitted by radioactive elements were named in order of their power to penetrate various materials, using the first three letters of the Greek alphabet:

text: alpha ray

text: s as the least penetrating, followed by

text: beta ray

text: s, followed by gamma rays as the most penetrating. Rutherford also noted that gamma rays were not deflected (or at least, not easily deflected) by a magnetic field, another property making them unlike alpha and beta rays.

text: The quantitative biological effects of cosmic rays are poorly known, and are the subject of ongoing research. Several experiments, both in space and on Earth, are being carried out to evaluate the exact degree of danger. Experiments in 2007 at Brookhaven National Laboratory's NASA Space Radiation Laboratory (NSRL) suggest that  biological damage due to a given exposure is actually about half what was previously estimated: specifically, it turns out that low energy protons cause more damage than high energy ones. This is explained by the fact that slower particles have more time to interact with molecules in the body. This may be interpreted as an acceptable result for space travel as the cells affected end up with greater energy deposition and are more likely to die without proliferating into tumors. This is in contrast to the current dogma on radiation exposure to human cells which considers lower energy radiation of higher weighting factor for tumor formation.

text: The quantitative biological effects of cosmic rays are poorly known, and are the subject of ongoing research. Several experiments, both in space and on Earth, are being carried out to evaluate the exact degree of danger. Experiments in 2007 at

text: Brookhaven National Laboratory

text: 's

text: NASA Space Radiation Laboratory

text: (NSRL) suggest that  biological damage due to a given exposure is actually about half what was previously estimated: specifically, it turns out that low energy protons cause more damage than high energy ones. This is explained by the fact that slower particles have more time to interact with molecules in the body. This may be interpreted as an acceptable result for space travel as the cells affected end up with greater energy deposition and are more likely to die without proliferating into tumors. This is in contrast to the current dogma on radiation exposure to human cells which considers lower energy radiation of higher weighting factor for tumor formation.

text: The core was intended to be used in the Operation Crossroads nuclear tests, but after the criticality accident, time was needed for its radioactivity to decline. It was therefore scheduled for the third test of the series, provisionally named Charlie, but this was cancelled due to the unexpected level of radioactivity after the underwater Baker test and the inability to decontaminate the target warships.  It was later melted down and the material reused in another core.

text: The core was intended to be used in the

text: Operation Crossroads

text: nuclear tests, but after the criticality accident, time was needed for its radioactivity to decline. It was therefore scheduled for the third test of the series, provisionally named Charlie, but this was cancelled due to the unexpected level of radioactivity after the underwater Baker test and the inability to decontaminate the target warships.  It was later melted down and the material reused in another core.

text: While experimenting with the products of radioactive decay, in 1913 radiochemist Frederick Soddy discovered that there appeared to be more than one type of atom at each position on the periodic table. The term isotope was coined by Margaret Todd as a suitable name for different atoms that belong to the same element. J.J. Thomson created a technique for separating atom types through his work on ionized gases, which subsequently led to the discovery of stable isotopes.

text: While experimenting with the products of

text: radioactive decay

text: , in 1913

text: radiochemist

text: Frederick Soddy

text: discovered that there appeared to be more than one type of atom at each position on the periodic table. The term

text: isotope

text: was coined by

text: Margaret Todd

text: as a suitable name for different atoms that belong to the same element. J.J. Thomson created a technique for separating atom types through his work on ionized gases, which subsequently led to the discovery of

text: stable isotope

text: s.

text: Iodopindolol is a beta-adrenergic selective antagonist tagged by radioisotopic iodine.

text: Iodopindolol is a

text: beta-adrenergic

text: selective antagonist tagged by radioisotopic

text: iodine

text: Most commercial nuclear power plants release gaseous and liquid radiological effluents into the environment as a byproduct of the Chemical Volume Control System, which are monitored in the US by the EPA and the NRC. Civilians living within  of a nuclear power plant typically receive about 0.1 μSv per year. For comparison, the average person living at or above sea level receives at least 260 μSv from cosmic radiation.All reactors in the United States are required by law to have a containment building.  The walls of containment buildings are several feet thick and made of concrete and therefore can stop the release of any radiation emitted by the reactor into the environment. If a person is to worry about an energy source that releases large amounts of radiation into the environment, they should worry about coal-fired plants.  Hundreds of tons of uranium and thorium are contained in the ash released into the environment by coal-fired plants.   Coal-fired plants are not required to retain their radioactive wastes like nuclear power plants are but rather “expel their radioactive by-products into the environment and expose people to anywhere from one hundred to four hundred times more radiation than nuclear plants do” (Cravens 2007).  Coal-fired plants are much more hazardous to people’s health than nuclear power plants as they release much more radioactive elements into the environment.

text: Most commercial nuclear power plants release gaseous and liquid radiological effluents into the environment as a byproduct of the Chemical Volume Control System, which are monitored in the US by the EPA and the NRC. Civilians living within  of a nuclear power plant typically receive about 0.1

text: μSv

text: per year. For comparison, the average person living at or above sea level receives at least 260 μSv from

text: cosmic radiation

text: .All reactors in the United States are required by law to have a containment building.  The walls of containment buildings are several feet thick and made of concrete and therefore can stop the release of any radiation emitted by the reactor into the environment. If a person is to worry about an energy source that releases large amounts of radiation into the environment, they should worry about coal-fired plants.  Hundreds of tons of uranium and thorium are contained in the ash released into the environment by coal-fired plants.   Coal-fired plants are not required to retain their radioactive wastes like nuclear power plants are but rather “expel their radioactive by-products into the environment and expose people to anywhere from one hundred to four hundred times more radiation than nuclear plants do” (Cravens 2007).  Coal-fired plants are much more hazardous to people’s health than nuclear power plants as they release much more radioactive elements into the environment.

text: In the vicinity of each control was a compact, brick built shack called the Radiac Store, which housed approximately 20 nuclear radiation sources in the form of milled metal discs. These discs, with strengths of 0.5 röntgen, 1 röntgen, 5 röntgens and 10 röntgens, were securely stored in lead-lined containers. Discs had to be audited monthly which entailed an ROC officer physically counting the discs into the palm of their bare hands, with the results being recorded in a log book. (This task was usually achieved with a degree of haste). Discs were used to calibrate and check the stocks of radiac instruments and for simulated live-training using such instruments. In practice, Health and Safety at Work regulations introduced in the 1970s resulted in radioactive sources being rarely if ever used, and as a result they seldom left the radiac store. Discs were finally withdrawn from service and returned to Aldermaston during the mid-1980s, with the last exercise involving such live radiation sources taking place at RAF West Raynham in 1980, during the annual ROC summer training camp.

text: In the vicinity of each control was a compact, brick built shack called the Radiac Store, which housed approximately 20 nuclear radiation sources in the form of milled metal discs. These discs, with strengths of 0.5

text: röntgen

text: , 1 röntgen, 5 röntgens and 10 röntgens, were securely stored in lead-lined containers. Discs had to be audited monthly which entailed an ROC officer physically counting the discs into the palm of their bare hands, with the results being recorded in a log book. (This task was usually achieved with a degree of haste). Discs were used to calibrate and check the stocks of radiac instruments and for simulated live-training using such instruments. In practice,

text: Health and Safety at Work regulations

text: introduced in the 1970s resulted in radioactive sources being rarely if ever used, and as a result they seldom left the radiac store. Discs were finally withdrawn from service and returned to

text: Aldermaston

text: during the mid-1980s, with the last exercise involving such live radiation sources taking place at

text: RAF West Raynham

text: in 1980, during the annual ROC summer training camp.

text: Most industries are moving from film based radiography to a digital sensor based radiography much the same way that traditional photography has made this move. Since the amount of radiation emerging from the opposite side of the material can be detected and measured, variations in this amount (or intensity) of radiation are used to determine thickness or composition of material.

text: Iridium-192 (symbol Ir) is a radioactive isotope of iridium, with a half-life of 73.83 days. It decays by emitting beta (β) particles and gamma (γ) radiation. About 96% of Ir decays occur via emission of β and γ radiation, leading to Pt. Some of the β particles are captured by other Ir nuclei, which are then converted to Os. Electron capture is responsible for the remaining 4% of Ir decays.

text: Iridium-192 (symbol Ir) is a radioactive

text: isotope

text: of

text: iridium

text: , with a

text: half-life

text: of 73.83 days. It decays by emitting beta (β) particles and gamma (γ) radiation. About 96% of Ir decays occur via emission of β and γ radiation, leading to

text: Pt

text: . Some of the β particles are captured by other Ir nuclei, which are then converted to Os. Electron capture is responsible for the remaining 4% of Ir decays.

text: The security department asks Taylor, an American war planner, to observe the interrogation of a leady regarding the progress of the war. Although the robot reports that lethal radioactivity and sophisticated new Soviet weapons continue to make the surface dangerous for humans, the observers find that the leady is not radioactive. Taylor learns that this is the second such robot the security department has found; it assigns him to an expedition, wearing lead suits, to investigate the truth about surface conditions.

text: The security department asks Taylor, an American war planner, to observe the interrogation of a leady regarding the progress of the war. Although the robot reports that lethal radioactivity and sophisticated new Soviet weapons continue to make the surface dangerous for humans, the observers find that the leady is not radioactive. Taylor learns that this is the second such robot the security department has found; it assigns him to an expedition, wearing

text: lead suit

text: s, to investigate the truth about surface conditions.

text: In the fall of 1907, Sahlbom was admitted to the University of Basel. To proceed with her studies, she declined a research offer from Sjögren. Advised by Friedrich Fichter from the University of Basel, Sahlbom completed her thesis, an investigation on a capillary analysis of colloidal solutions. In 1910 Sahlbom presented the thesis at the University of Neuchâtel, and she earned a doctorate in chemical physics. In 1914, with input from Helge Backlund, Sahlbom set up a laboratory in Stockholm, where she specialized in aqueous mineralogy. A self-employed chemical analyst, Sahlbom was contracted by mineralogists and petrographers for her proficient work. In 1916 she published a second report on mineralogy and radioactivity, with 400 springs and wells analyzed. The paper confirmed that the radioactivity of mineral waters was related to geology. Overall, acid and primary rocks resulted in the most radioactive emanation; mafic and sedimentary rocks demonstrated less radioactivity.

text: In the fall of 1907, Sahlbom was admitted to the

text: University of Basel

text: . To proceed with her studies, she declined a research offer from Sjögren. Advised by

text: Friedrich Fichter

text: from the University of Basel, Sahlbom completed her thesis, an investigation on a capillary analysis of

text: colloidal

text: solutions. In 1910 Sahlbom presented the thesis at the

text: University of Neuchâtel

text: , and she earned a doctorate in

text: chemical physics

text: . In 1914, with input from Helge Backlund, Sahlbom set up a laboratory in Stockholm, where she specialized in aqueous mineralogy. A self-employed chemical analyst, Sahlbom was contracted by mineralogists and

text: petrographers

text: for her proficient work. In 1916 she published a second report on mineralogy and radioactivity, with 400 springs and wells analyzed. The paper confirmed that the radioactivity of mineral waters was related to geology. Overall, acid and primary rocks resulted in the most radioactive emanation; mafic and sedimentary rocks demonstrated less radioactivity.

text: Cobalt-60 (Co) is a synthetic radioactive isotope of cobalt, with a half-life of 5.27 years, and emits highly penetrating gamma rays. It is commonly used as a radiation source for radiotherapy and equipment sterilization in the hospital setting, and has several other industrial uses as well. The device involved in the Samut Prakan accident was a rotational Gammatron-3 teletherapy unit,  manufactured by Siemens and imported to Thailand in 1969. It was licensed for and installed at Ramathibodi Hospital in Bangkok; the radiation source involved was a replacement installed in 1981, with an initial  radioactive activity of . At the time of the accident in 2000, its activity was estimated to have decayed to .

text: (Co) is a synthetic

text: radioactive

text: isotope

text: of

text: cobalt

text: , with a

text: half-life

text: of 5.27 years, and emits highly penetrating

text: gamma ray

text: s. It is commonly used as a radiation source for

text: radiotherapy

text: and equipment sterilization in the hospital setting, and has several other industrial uses as well. The device involved in the Samut Prakan accident was a rotational Gammatron-3

text: teletherapy

text: unit,  manufactured by

text: Siemens

text: and imported to Thailand in 1969. It was licensed for and installed at

text: Ramathibodi Hospital

text: in Bangkok; the radiation source involved was a replacement installed in 1981, with an initial

text: radioactive activity

text: of . At the time of the accident in 2000, its activity was estimated to have decayed to .

text: 118 chemical elements are known to exist. All elements to element 94 are found in nature, and the remainder of the discovered elements are artificially produced, with isotopes all known to be highly radioactive with relatively short half-lives (see below). The elements in this list are ordered according to the lifetime of their most stable isotope. Of these, three elements (bismuth, thorium, and uranium) are primordial because they have half-lives long enough to still be found on the Earth, while all the others are produced either by radioactive decay or are synthesized in laboratories and nuclear reactors. Only 13 of the 38 known-but-unstable elements (assuming the total number of elements is 118) have isotopes with a half-life of at least 100 years. Every known isotope of the remaining 25 elements is highly radioactive; these are used in academic research and sometimes in industry and medicine. Some of the heavier elements in the periodic table may be revealed to have yet-undiscovered isotopes with longer lifetimes than those listed here.

text: chemical elements

text: are known to exist. All elements to element 94 are found in nature, and the remainder of the

entity_name: Timeline of chemical element discoveries

text: discovered elements

text: are artificially produced, with isotopes all known to be highly

text: radioactive

text: with relatively short half-lives (see below). The elements in this list are ordered according to the lifetime of their most stable isotope. Of these, three elements (

text: bismuth

text: thorium

text: , and

text: uranium

text: ) are primordial because they have half-lives long enough to still be found on the Earth, while all the others are produced either by

text: radioactive decay

text: or are

text: synthesized

text: in laboratories and

text: nuclear reactors

text: . Only 13 of the 38 known-but-unstable elements (assuming the total number of elements is 118) have isotopes with a half-life of at least 100 years. Every known isotope of the remaining 25 elements is highly radioactive; these are used in academic research and sometimes in industry and medicine. Some of the heavier elements in the periodic table may be revealed to have yet-undiscovered isotopes with longer lifetimes than those listed here.

text: TRIUMF’s Ion Trap for Atomic and Nuclear Science (TITAN) measures the mass of short-lived isotopes with high precision.  Radioactive isotopes from ISAC are sent to TITAN to undergo cooling, charge-breeding and trapping.  The entire process occurs in about 10 milliseconds, allowing radioactive isotopes with short half lives to be studied.

text: In 1902 Bohuslav Brauner suggested there was an element with properties intermediate between those of the known elements neodymium (60) and samarium (62); this was confirmed in 1914 by Henry Moseley who, having measured the atomic numbers of all the elements then known, found there was no element with atomic number 61. In 1926, an Italian and an American group claimed to have isolated a sample of element 61; both "discoveries" were soon proven to be false. In 1938, during a nuclear experiment conducted at Ohio State University, a few radioactive nuclides were produced that certainly were not radioisotopes of neodymium or samarium, but there was a lack of chemical proof that element 61 was produced, and the discovery was not generally recognized. Promethium was first produced and characterized at Oak Ridge National Laboratory in 1945 by the separation and analysis of the fission products of uranium fuel irradiated in a graphite reactor. The discoverers proposed the name "prometheum" (the spelling was subsequently changed), derived from Prometheus, the Titan in Greek mythology who stole fire from Mount Olympus and brought it down to humans, to symbolize "both the daring and the possible misuse of mankind's intellect." However, a sample of the metal was made only in 1963.

text: In 1902

text: Bohuslav Brauner

text: suggested there was an element with properties intermediate between those of the known elements

text: neodymium

text: (60) and

text: samarium

text: (62); this was confirmed in 1914 by

text: Henry Moseley

text: who, having measured the atomic numbers of all the elements then known, found there was no element with atomic number 61. In 1926, an Italian and an American group claimed to have isolated a sample of element 61; both "discoveries" were soon proven to be false. In 1938, during a nuclear experiment conducted at

text: Ohio State University

text: , a few radioactive nuclides were produced that certainly were not radioisotopes of neodymium or samarium, but there was a lack of chemical proof that element 61 was produced, and the discovery was not generally recognized. Promethium was first produced and characterized at

text: Oak Ridge National Laboratory

text: in 1945 by the separation and analysis of the fission products of uranium fuel irradiated in a graphite reactor. The discoverers proposed the name "prometheum" (the spelling was subsequently changed), derived from

text: Prometheus

text: , the Titan in Greek mythology who stole fire from Mount Olympus and brought it down to humans, to symbolize "both the daring and the possible misuse of mankind's intellect." However, a sample of the metal was made only in 1963.

text: In the aftermath of the accident, the investigations focused on the amounts of radioactivity released by the accident. According to the American Nuclear Society, using the official radioactivity emission figures, "The average radiation dose to people living within ten miles of the plant was eight millirem, and no more than 100 millirem to any single individual. Eight millirem is about equal to a chest X-ray, and 100 millirem is about a third of the average background level of radiation received by US residents in a year.". To put this dose into context, while the average background radiation in the US is about 360 millirem per year, the Nuclear Regulatory Commission regulates all workers' of any US nuclear power plant exposure to radiation to a total of 5000 millirem per year. Based on these low emission figures, early scientific publications on the health effects of the fallout estimated one or two additional cancer deaths in the 10-mile area around TMI.

text: In the aftermath of the accident, the investigations focused on the amounts of radioactivity released by the accident. According to the

text: American Nuclear Society

text: , using the official radioactivity emission figures, "The average radiation dose to people living within ten miles of the plant was eight

text: millirem

text: , and no more than 100 millirem to any single individual. Eight millirem is about equal to a chest

text: X-ray

text: , and 100 millirem is about a third of the average background level of radiation received by US residents in a year.". To put this dose into context, while the average background radiation in the US is about 360 millirem per year, the Nuclear Regulatory Commission regulates all workers' of any US nuclear power plant exposure to radiation to a total of 5000 millirem per year. Based on these low emission figures, early scientific publications on the health effects of the fallout estimated one or two additional cancer deaths in the 10-mile area around TMI.

text: Monazite is a rare-earth-element phosphate mineral, (Ce, La, Nd, Th, Y)PO. It appears in a small amount as an accessory mineral in many igneous, metamorphic and sedimentary rocks. Monazite minerals contain significant amounts of radioactive elements Th and U, which trigger radioactive processes. These two elements are what make this mineral suitable for radiometric dating.

text: Monazite

text: is a

text: rare-earth-element

text: phosphate mineral

text: , (Ce, La, Nd, Th, Y)PO. It appears in a small amount as an

text: accessory mineral

text: in many igneous, metamorphic and sedimentary rocks. Monazite minerals contain significant amounts of

text: radioactive

text: elements

text: Th

text: and

text: U

text: , which trigger radioactive processes. These two elements are what make this mineral suitable for

text: radiometric dating

text: If a gamma ray is emitted from a radioactive element within the human body due to radioactive decay, and its energy is sufficient to escape then it can be detected. This would be by means of either a scintillation detector or a semiconductor detector placed in close proximity to the body. Radioactive decay may give rise to gamma radiation which cannot escape the body due to being absorbed or other interaction whereby it can lose energy; so account must be taken of this in any measurement analysis.

text: If a gamma ray is emitted from a radioactive element within the human body due to

text: radioactive decay

text: , and its energy is sufficient to escape then it can be detected. This would be by means of either a

text: scintillation detector

text: or a

text: semiconductor detector

text: placed in close proximity to the body. Radioactive decay may give rise to gamma radiation which cannot escape the body due to being absorbed or other interaction whereby it can lose energy; so account must be taken of this in any measurement analysis.

text: Just because a radioisotope lands on the surface of the soil, does not mean it will enter the human food chain.  After release into the environment, radioactive materials can reach humans in a range of different routes, and the chemistry of the element usually dictates the most likely route.

text: Just because a radioisotope lands on the surface of the soil, does not mean it will enter the

text: human

text: food chain.  After release into the environment, radioactive materials can reach humans in a range of different routes, and the chemistry of the element usually dictates the most likely route.

text: No radioactivity is required or created in the process. The electron beam is generated by a device similar to the electron gun in a TV set. This device is called an accelerator. This is an example of a radiation chemistry process where the physical effects of radiation are used to process a substance.

text: No

text: radioactivity

text: is required or created in the process. The electron beam is generated by a device similar to the

text: electron gun

text: in a TV set. This device is called an accelerator. This is an example of a radiation chemistry process where the physical effects of radiation are used to process a substance.

text: According to Jiří Hála's text book, the distribution coefficient K is the ratio of the soil's radioactivity (Bq g) to that of the soil water (Bq ml). If the radioisotope is tightly bound to the minerals in the soil, then less radioactivity can be absorbed by crops and grass growing on the soil.

text: According to Jiří Hála's

text: text book

text: , the distribution coefficient K is the ratio of the soil's radioactivity (Bq g) to that of the soil water (Bq ml). If the radioisotope is tightly bound to the minerals in the soil, then less radioactivity can be absorbed by crops and

text: grass

text: growing on the soil.

text: The last portion of the EM spectrum to be discovered was associated with radioactivity. Henri Becquerel found that uranium salts caused fogging of an unexposed photographic plate through a covering paper in a manner similar to X-rays, and Marie Curie discovered that only certain elements gave off these rays of energy, soon discovering the intense radiation of radium. The radiation from pitchblende was differentiated into alpha rays (alpha particles) and beta rays (beta particles) by Ernest Rutherford through simple experimentation in 1899, but these proved to be charged particulate types of radiation. However, in 1900 the French scientist Paul Villard discovered a third neutrally charged and especially penetrating type of radiation from radium, and after he described it, Rutherford realized it must be yet a third type of radiation, which in 1903 Rutherford named gamma rays. In 1910 British physicist William Henry Bragg demonstrated that gamma rays are electromagnetic radiation, not particles, and in 1914 Rutherford and Edward Andrade measured their wavelengths, finding that they were similar to X-rays but with shorter wavelengths and higher frequency, although a 'cross-over' between X and gamma rays makes it possible to have X-rays with a higher energy (and hence shorter wavelength) than gamma rays and vice versa. The origin of the ray differentiates them, gamma rays tend to be a natural phenomena originating from the unstable nucleus of an atom and X-rays are electrically generated (and hence man-made) unless they are as a result of bremsstrahlung X-radiation caused by the interaction of fast moving particles (such as beta particles) colliding with certain materials, usually of higher atomic numbers.

text: The last portion of the EM spectrum to be discovered was associated with

text: radioactivity

text: Henri Becquerel

text: found that

text: uranium

text: salts caused fogging of an unexposed photographic plate through a covering paper in a manner similar to X-rays, and

text: Marie Curie

text: discovered that only certain elements gave off these rays of energy, soon discovering the intense radiation of

text: radium

text: . The radiation from pitchblende was differentiated into alpha rays (

text: alpha particle

text: s) and beta rays (

text: beta particle

text: s) by

text: Ernest Rutherford

text: through simple experimentation in 1899, but these proved to be charged particulate types of radiation. However, in 1900 the French scientist

text: Paul Villard

text: discovered a third neutrally charged and especially penetrating type of radiation from radium, and after he described it, Rutherford realized it must be yet a third type of radiation, which in 1903 Rutherford named

text: gamma ray

text: s. In 1910 British physicist

text: William Henry Bragg

text: demonstrated that gamma rays are electromagnetic radiation, not particles, and in 1914 Rutherford and

text: Edward Andrade

text: measured their wavelengths, finding that they were similar to X-rays but with shorter wavelengths and higher frequency, although a 'cross-over' between X and gamma rays makes it possible to have X-rays with a higher energy (and hence shorter wavelength) than gamma rays and vice versa. The origin of the ray differentiates them, gamma rays tend to be a natural phenomena originating from the unstable nucleus of an atom and X-rays are electrically generated (and hence man-made) unless they are as a result of

text: bremsstrahlung

text: X-radiation caused by the interaction of fast moving particles (such as beta particles) colliding with certain materials, usually of higher atomic numbers.

text: These levels of radioactivity pose little danger but can confuse measurement. A particular problem is encountered with naturally generated radon gas which can affect instruments which are set to detect contamination close to normal background levels and can cause false alarms. Because of this skill is required by the operator of radiological survey equipment to differentiate between background radiation and the radiation which emanates from contamination.

text: These levels of radioactivity pose little danger but can confuse measurement. A particular problem is encountered with naturally generated

text: radon

text: gas which can affect instruments which are set to detect contamination close to normal background levels and can cause false alarms. Because of this skill is required by the operator of radiological survey equipment to differentiate between

text: background radiation

text: and the radiation which emanates from contamination.

text: Her achievements included the development of the theory of radioactivity (a term that she coined), techniques for isolating radioactive isotopes, and the discovery of two elements, polonium and radium. Under her direction, the world's first studies were conducted into the treatment of neoplasms, using radioactive isotopes. She founded the Curie Institutes in Paris and in Warsaw, which remain major centres of medical research today. During World War I, she established the first military field radiological centres.

text: Her achievements included the development of the theory of radioactivity (a term that she coined), techniques for isolating radioactive

text: isotope

text: s, and the discovery of two elements,

text: polonium

text: and

text: radium

text: . Under her direction, the world's first studies were conducted into the treatment of

text: neoplasm

text: s, using radioactive isotopes. She founded the

text: Curie Institutes in Paris

text: and

text: in Warsaw

text: , which remain major centres of medical research today. During

text: World War I

text: , she established the first military field radiological centres.

text: Some weapons are designed for special purposes; a neutron bomb is a thermonuclear weapon that yields a relatively small explosion but a relatively large amount of neutron radiation; such a device could theoretically be used to cause massive casualties while leaving infrastructure mostly intact and creating a minimal amount of fallout. The detonation of any nuclear weapon is accompanied by a blast of neutron radiation. Surrounding a nuclear weapon with suitable materials (such as cobalt or gold) creates a weapon known as a salted bomb. This device can produce exceptionally large quantities of long-lived radioactive contamination. It has been conjectured that such a device could serve as a "doomsday weapon" because such a large quantity of radioactivities with half-lives of decades, lifted into the stratosphere where wind currents would distribute it around the globe, would make all life on the planet extinct.

text: Some weapons are designed for special purposes; a

text: neutron bomb

text: is a thermonuclear weapon that yields a relatively small explosion but a relatively large amount of neutron

text: radiation

text: ; such a device could theoretically be used to cause massive casualties while leaving infrastructure mostly intact and creating a minimal amount of fallout. The detonation of any nuclear weapon is accompanied by a blast of

text: neutron radiation

text: . Surrounding a nuclear weapon with suitable materials (such as

text: cobalt

text: or

text: gold

text: ) creates a weapon known as a

text: salted bomb

text: . This device can produce exceptionally large quantities of long-lived

text: radioactive contamination

text: . It has been conjectured that such a device could serve as a "doomsday weapon" because such a large quantity of radioactivities with half-lives of decades, lifted into the stratosphere where wind currents would distribute it around the globe, would make all life on the planet extinct.

text: Colloquially, radioactive materials can be described as "hot," and non-radioactive materials can be described as "cold."  There are instances in which cold iodide is administered to people in order to prevent the uptake of hot iodide by the thyroid gland.  For example, blockade of thyroid iodine uptake with potassium iodide is used in nuclear medicine scintigraphy and therapy with some radioiodinated compounds that are not targeted to the thyroid, such as iobenguane (MIBG), which used to image or treat neural tissue tumors, or iodinated fibrinogen, which is used in fibrinogen scans to investigate clotting.  These compounds contain iodine, but not in the iodide form.  However, since they may be ultimately metabolized or break down to radioactive iodide, it is common to administer non-radioactive potassium iodide to insure that metabolites of these  radiopharmaceuticals is not sequestered by thyroid gland and inadvertently administer a radiological dose to that tissue.

text: Colloquially, radioactive materials can be described as "hot," and non-radioactive materials can be described as "cold."  There are instances in which cold iodide is administered to people in order to prevent the uptake of hot iodide by the thyroid gland.  For example, blockade of thyroid iodine uptake with potassium iodide is used in

text: nuclear medicine

text: scintigraphy

text: and therapy with some radioiodinated compounds that are not targeted to the thyroid, such as

text: iobenguane

text: MIBG

text: ), which used to image or treat neural tissue tumors, or iodinated fibrinogen, which is used in

text: fibrinogen scans

text: to investigate clotting.  These compounds contain iodine, but not in the iodide form.  However, since they may be ultimately metabolized or break down to radioactive iodide, it is common to administer non-radioactive potassium iodide to insure that metabolites of these  radiopharmaceuticals is not sequestered by thyroid gland and inadvertently administer a radiological dose to that tissue.

text: Ionizing radiation is generally harmful and potentially lethal to living things but can have health benefits in radiation therapy for the treatment of cancer and thyrotoxicosis. Its most common impact is the induction of cancer with a latent period of years or decades after exposure. High doses can cause visually dramatic radiation burns, and/or rapid fatality through acute radiation syndrome. Controlled doses are used for medical imaging and radiotherapy. Some scientists suspect that low doses may have a mild hormetic effect that can improve health.

text: Ionizing radiation is generally harmful and potentially lethal to living things but can have health benefits in

text: radiation therapy

text: for the treatment of cancer and

text: thyrotoxicosis

text: . Its most common impact is the

text: induction of cancer

text: with a

text: latent period

text: of years or decades after exposure. High doses can cause visually dramatic

text: radiation burns

text: , and/or rapid fatality through

text: acute radiation syndrome

text: . Controlled doses are used for

text: medical imaging

text: and

text: radiotherapy

text: . Some scientists suspect that low doses may have a mild

text: hormetic effect

text: that can improve health.

text: In the episode "Radioactive Man", Milhouse was chosen over Bart to play Fallout Boy in the Radioactive Man movie to be filmed in Springfield. Rock band Fall Out Boy took the name of this character after, when they asked a concert audience what band name they should have, a fan shouted "Fallout Boy!"

text: In the episode "Radioactive Man", Milhouse was chosen over Bart to play Fallout Boy in the Radioactive Man movie to be filmed in Springfield.

text: Rock

text: band

text: Fall Out Boy

text: took the name of this character after, when they asked a concert audience what band name they should have, a fan shouted "Fallout Boy!"

text: Half of the park area was used as landfill in the past, and in 2005, radium (Ra), a radioactive material, was found in the sand in a depth of about 1–1.5 feet (30–40 cm). A part of this material has been removed; to the present, altogether twelve places with radioactive contamination have been found. Directly at the sources, a radiation level about 200 times higher than the natural background radiation has been measured. In August 2012 the decontamination of the park was scheduled to proceed. A section of the park is closed to the public.

text: Half of the park area was used as

text: landfill

text: in the past, and in 2005,

text: radium

text: (Ra), a

text: radioactive

text: material, was found in the sand in a depth of about 1–1.5 feet (30–40 cm). A part of this material has been removed; to the present, altogether twelve places with radioactive contamination have been found. Directly at the sources, a radiation level about 200 times higher than the natural background radiation has been measured. In August 2012 the decontamination of the park was scheduled to proceed. A section of the park is closed to the public.

text: Some common radioisotopes that decay by electron capture include:

text: In 1934 the Joliot-Curies finally made the discovery that sealed their place in scientific history. Building on the work of Marie and Pierre Curie, who had isolated naturally occurring radioactive elements, the Joliot-Curies realized the alchemist’s dream of turning one element into another: creating radioactive nitrogen from boron, radioactive isotopes of phosphorus from aluminum, and silicon from magnesium. Irradiating the natural stable isotope of aluminum with alpha particles (i.e. helium nuclei) results in an unstable isotope of phosphorus : Al + He → P + n. By then the application of radioactive materials for use in medicine was growing and this discovery allowed radioactive materials to be created quickly, cheaply, and plentifully. The Nobel Prize for chemistry in 1935 brought with it fame and recognition from the scientific community and Joliot-Curie was awarded a professorship at the Faculty of Science.

text: In 1934 the Joliot-Curies finally made the discovery that sealed their place in scientific history. Building on the work of Marie and Pierre Curie, who had isolated naturally occurring radioactive elements, the Joliot-Curies realized the alchemist’s dream of turning one element into another: creating radioactive

text: nitrogen

text: from

text: boron

text: , radioactive isotopes of

text: phosphorus

text: from

text: aluminum

text: , and

text: silicon

text: from

text: magnesium

text: . Irradiating the natural stable isotope of aluminum with

text: alpha particles

text: (i.e. helium nuclei) results in an

text: unstable isotope of phosphorus

text: : Al + He → P + n. By then the application of radioactive materials for use in medicine was growing and this discovery allowed radioactive materials to be created quickly, cheaply, and plentifully. The Nobel Prize for chemistry in 1935 brought with it fame and recognition from the scientific community and Joliot-Curie was awarded a professorship at the Faculty of Science.

text: A radionuclide identification device (RID) is a hand-held measurement instrument for the detection and identification of radioactive substances. They are used at national borders, by the police and firefighters to localize radioactive sources and determine the radioactive substances they consist of. A RID measures gamma (photon) radiation and optionally neutron radiation. These devices are sometimes named radio-isotope identifying devices (RIID) or handheld isotope identifiers.

text: A radionuclide identification device (RID) is a hand-held measurement instrument for the detection and identification of radioactive substances. They are used at national borders, by the police and firefighters to localize radioactive sources and determine the radioactive substances they consist of. A RID measures

text: gamma (photon) radiation

text: and optionally neutron radiation. These devices are sometimes named radio-isotope identifying devices (RIID) or handheld isotope identifiers.

text: In LDR brachytherapy, tiny radioactive particles the size of a grain of rice (see Figure 1) are implanted directly into the site of the tumour. These particles are known as ‘seeds’, and they can be inserted linked together as strands, or individually. Because the seeds are inserted or implanted directly into, or very close to, the tumour, they deliver high doses of radiation to the tumour without affecting the normal healthy tissues around it. This means that the procedure is less damaging than conventional radiation therapy, where the radioactive beam is delivered from outside the body and must pass through other tissues before reaching the tumour.

text: In LDR brachytherapy, tiny radioactive particles the size of a grain of rice (see

text: Figure 1

text: ) are implanted directly into the site of the

text: tumour

text: . These particles are known as ‘seeds’, and they can be inserted linked together as strands, or individually. Because the seeds are inserted or implanted directly into, or very close to, the tumour, they deliver high doses of radiation to the tumour without affecting the normal healthy tissues around it. This means that the procedure is less damaging than conventional radiation therapy, where the radioactive beam is delivered from outside the body and must pass through other tissues before reaching the tumour.

text: It includes the study of the production and use of radioactive sources for a range of processes. These include radiotherapy in medical applications; the use of radioactive tracers within industry, science and the environment; and the use of radiation to modify materials such as polymers.

text: It includes the study of the production and use of radioactive sources for a range of processes. These include

text: radiotherapy

text: in medical applications; the use of

text: radioactive tracer

text: s within industry, science and the environment; and the use of radiation to modify materials such as

text: polymer

text: s.

text: Two main approaches to reduce radiation damage are reducing the amount of energy deposited in the sensitive material (e.g. by shielding, distance from the source, or spatial orientation), or modification of the material to be less sensitive to radiation damage (e.g. by adding antioxidants, stabilizers, or choosing a more suitable material).In addition to the electronic device hardening mentioned above, some degree of protection may be obtained by shielding, usually with the interposition of high density materials (particularly lead, where space is critical, or concrete where space is available) between the radiation source and areas to be protected. For biological effects of substances such as radioactive iodine the ingestion of non-radioactive isotopes may substantially reduce the biological uptake of the radioactive form, and chelation therapy may be applied to accelerate the removal of radioactive materials formed from heavy metals from the body by natural processes.

text: Two main approaches to reduce radiation damage are reducing the amount of energy deposited in the sensitive material (e.g. by shielding, distance from the source, or spatial orientation), or modification of the material to be less sensitive to radiation damage (e.g. by adding antioxidants, stabilizers, or choosing a more suitable material).In addition to the electronic device hardening mentioned above, some degree of protection may be obtained by shielding, usually with the interposition of high density materials (particularly lead, where space is critical, or concrete where space is available) between the radiation source and areas to be protected. For biological effects of substances such as radioactive

text: iodine

text: the ingestion of non-radioactive isotopes may substantially reduce the biological uptake of the radioactive form, and

text: chelation therapy

text: may be applied to accelerate the removal of radioactive materials formed from heavy metals from the body by natural processes.

text: The suggested power source would be an Advanced Stirling Radioisotope Generator (ASRG). After separation, the probe would be powered by battery alone.

text: The suggested power source would be an

entity_name: Advanced Stirling radioisotope generator

text: Advanced Stirling Radioisotope Generator

text: (ASRG). After separation, the probe would be powered by battery alone.

text: In July 2012, it was announced that "Radioactive" would serve as the third single from Ora in the United States. In November 2012, it was confirmed that "Radioactive" would serve as the fourth single from Ora in the United Kingdom. The cover artwork for the song was revealed on 9 January 2013. It features Ora against a backdrop of colorful stars. Sia Furler and Greg Kurstin wrote the song, while Greg Kurstin was the producer.

text: In July 2012, it was announced that "Radioactive" would serve as the third single from Ora in the

text: United States

text: . In November 2012, it was confirmed that "Radioactive" would serve as the fourth single from Ora in the

text: United Kingdom

text: . The cover artwork for the song was revealed on 9 January 2013. It features Ora against a backdrop of colorful stars. Sia Furler and Greg Kurstin wrote the song, while Greg Kurstin was the producer.

text: They provide very little information on energy of detected photons, and as a result, they were criticized for their inability to distinguish gammas originating from nuclear sources from gammas originating from a large variety of benign cargo types that naturally emit radioactivity, including bananas, cat litter, granite, porcelain, stoneware, etc. Those naturally occurring radioactive materials, called NORMs account for 99% of nuisance alarms. Some radiation, like in the case of large loads of bananas is due to potassium and its rarely occurring (0.0117%) radioactive isotope potassium-40, other is due to radium or uranium that occur naturally in earth and rock, and cargo types made out of them, like cat litter or porcelain.

text: They provide very little information on energy of detected photons, and as a result, they were criticized for their inability to distinguish gammas originating from nuclear sources from gammas originating from a large variety of benign cargo types that naturally emit radioactivity, including bananas,

text: cat litter

text: granite

text: porcelain

text: stoneware

text: , etc. Those

text: s, called NORMs account for 99% of nuisance alarms. Some radiation, like in the case of large loads of bananas is due to

text: potassium

text: and its rarely occurring (0.0117%) radioactive isotope potassium-40, other is due to

text: radium

text: or

text: uranium

text: that occur naturally in earth and rock, and cargo types made out of them, like cat litter or porcelain.

text: Royston and McGill hypothesize that the creature will move through the centre of the nearby city of Inverness, to reach another source of radioactive material. Royston has some success with his anti-radiation device, which neutralizes a small container of radioactive material, but causes it to explode violently in the process. With no time left for further experiment or consideration of safety, they set up two large "scanners" on lorries, and use a canister of cobalt as bait to lure the monster from the crack where it is hidden. The idea works, but Elliott in the jeep carrying the bait barely escapes with his life when the vehicle becomes stuck in mud while leading the monster into scanner range. However, the jeep makes it to a safe distance, enough for the scanners to do their job, and the creature is neutralized and explodes a sufficient distance from the observers to avoid further injury or death. As the team approaches the crack from which the monster had emerged, however, a second, more powerful explosion occurs unexpectedly, knocking several of the team off their feet, but otherwise leaving them uninjured. Puzzled, the team continues approaching the crack, presumably to make further tests, as the film comes to an end.

text: Royston and McGill hypothesize that the creature will move through the centre of the nearby city of

text: Inverness

text: , to reach another source of radioactive material. Royston has some success with his anti-radiation device, which neutralizes a small container of radioactive material, but causes it to explode violently in the process. With no time left for further experiment or consideration of safety, they set up two large "scanners" on lorries, and use a canister of cobalt as bait to lure the monster from the crack where it is hidden. The idea works, but Elliott in the jeep carrying the bait barely escapes with his life when the vehicle becomes stuck in mud while leading the monster into scanner range. However, the jeep makes it to a safe distance, enough for the scanners to do their job, and the creature is neutralized and explodes a sufficient distance from the observers to avoid further injury or death. As the team approaches the crack from which the monster had emerged, however, a second, more powerful explosion occurs unexpectedly, knocking several of the team off their feet, but otherwise leaving them uninjured. Puzzled, the team continues approaching the crack, presumably to make further tests, as the film comes to an end.

text: Radioactive scrap metal is created when radioactive material enters the metal recycling process and contaminates scrap metal.

text: Radioactive scrap metal is created when

text: radioactive

text: material enters the metal recycling process and contaminates

text: scrap metal

text: Radiometric dating is based on the known and constant rate of decay of radioactive isotopes into their radiogenic daughter isotopes. Particular isotopes are suitable for different applications due to the type of atoms present in the mineral or other material and its approximate age. For example, techniques based on isotopes with half lives in the thousands of years, such as Carbon-14, cannot be used to date materials that have ages on the order of billions of years, as the detectable amounts of the radioactive atoms and their  decayed daughter isotopes will be too small to measure within the uncertainty of the instruments.

text: Radiometric dating is based on the known and constant rate of decay of

text: radioactive isotopes

text: into their

text: radiogenic daughter isotopes

text: . Particular isotopes are suitable for different applications due to the type of atoms present in the mineral or other material and its approximate age. For example, techniques based on isotopes with half lives in the thousands of years, such as Carbon-14, cannot be used to date materials that have ages on the order of billions of years, as the detectable amounts of the radioactive atoms and their  decayed daughter isotopes will be too small to measure within the uncertainty of the instruments.

text: Radon is formed as part of the normal radioactive decay chain of uranium and thorium. Uranium and thorium have been around since the earth was formed and their most common isotope has a very long half-life (14.05 billion years). Uranium and thorium, radium, and thus radon, will continue to occur for millions of years at about the same concentrations as they do now. As the radioactive gas of radon decays, it produces new radioactive elements called radon daughters or decay products. Radon daughters are solids and stick to surfaces such as dust particles in the air. If contaminated dust is inhaled, these particles can stick to the airways of the lung and increase the risk of developing lung cancer.

text: Radon is formed as part of the normal radioactive

text: decay chain

text: of uranium and thorium. Uranium and thorium have been around since the earth was formed and their

text: most common isotope

text: has a very long half-life (14.05 billion years). Uranium and thorium,

text: radium

text: , and thus radon, will continue to occur for millions of years at about the same concentrations as they do now. As the radioactive gas of radon decays, it produces new radioactive elements called radon daughters or decay products. Radon daughters are solids and stick to surfaces such as dust particles in the air. If contaminated dust is inhaled, these particles can stick to the airways of the lung and increase the risk of developing lung cancer.

text: Naturally occurring potassium is composed of three isotopes, of which  is radioactive. Traces of  are found in all potassium, and it is the most common radioisotope in the human body.

text: Naturally occurring potassium is composed of three

text: isotope

text: s, of which

text: is

text: radioactive

text: . Traces of  are found in all potassium, and it is the most common

text: radioisotope

text: in the human body.

text: Before the biological effects of radiation were known, many physicians and corporations had begun marketing radioactive substances as patent medicine and radioactive quackery. Examples were radium enema treatments, and radium-containing waters to be drunk as tonics. Marie Curie spoke out against this sort of treatment, warning that the effects of radiation on the human body were not well understood. Curie later died of aplastic anemia caused by radiation poisoning. Eben Byers, a famous American socialite, died of multiple cancers (but not acute radiation syndrome) in 1932 after consuming large quantities of radium over several years; his death drew public attention to dangers of radiation. By the 1930s, after a number of cases of bone necrosis and death in enthusiasts, radium-containing medical products had nearly vanished from the market.

text: patent medicine

text: and

text: radioactive quackery

text: . Examples were radium

text: enema

text: Marie Curie

text: aplastic anemia

text: caused by radiation poisoning.

text: Eben Byers

text: , a famous American socialite, died of multiple cancers (but not acute radiation syndrome) in 1932 after consuming large quantities of

text: radium

text: Naturally Occurring Radioactive Materials (NORM) and Technologically Enhanced Naturally Occurring Radioactive Materials (TENORM) consist of materials, usually industrial wastes or by-products enriched with radioactive elements found in the environment, such as uranium, thorium and potassium and any of their decay products, such as radium and radon.

text: Naturally Occurring Radioactive Materials (NORM) and Technologically Enhanced Naturally Occurring Radioactive Materials (TENORM) consist of materials, usually

text: industrial waste

text: s or by-products enriched with

text: radioactive elements

text: found in the environment, such as

text: uranium

text: thorium

text: and

text: potassium

text: and any of their decay products, such as

text: radium

text: and

text: radon

text: It is being explored as a method of immobilising uranium based radioactive waste, and rendering it safe for long term storage. Some applications in endocurietherapy, a method of radiation therapy where in radioactive microspheres are implanted directly into the treatment site and allowed to remain for an extended period of time, may also use this class of material as it would not be attacked while in situ.

text: It is being explored as a method of immobilising

text: uranium

text: based

text: radioactive waste

text: , and rendering it safe for long term storage. Some applications in

text: endocurietherapy

text: , a method of

text: radiation therapy

text: where in

text: radioactive

text: microspheres are implanted directly into the treatment site and allowed to remain for an extended period of time, may also use this class of material as it would not be attacked while

text: in situ

text: Several centers around the world have used fast neutrons for treating cancer. Due to lack of funding and support, at present only three are active in the USA.The University of Washington and the Gershenson Radiation Oncology Center operate fast neutron therapy beams and both are equipped with a Multi-Leaf Collimator (MLC) to shape the neutron beam.

text: The radioactivity in the fission product mixture is mostly caused by short lived isotopes such as Iodine-131 and Ba,  after about four months Ce, Zr/Nb and Sr take the largest share, while after about two or three years the largest share is taken by Ce/Pr, Ru/Rh and Pm. Later Sr and Cs are the main radioisotopes, being succeeded by Tc. In the case of a release of radioactivity from a power reactor or used fuel, only some elements are released; as a result, the isotopic signature of the radioactivity is very different from an open air nuclear detonation, where all the fission products are dispersed.

text: The radioactivity in the fission product mixture is mostly caused by short lived isotopes such as

text: and Ba,  after about four months Ce, Zr/Nb and Sr take the largest share, while after about two or three years the largest share is taken by Ce/Pr, Ru/Rh and Pm. Later Sr and Cs are the main radioisotopes, being succeeded by Tc. In the case of a release of radioactivity from a power reactor or used fuel, only some elements are released; as a result, the isotopic signature of the radioactivity is very different from an open air

text: nuclear detonation

text: , where all the fission products are dispersed.

text: Local residents, however, were seriously divided. Those who would like to return to their houses, were afraid, that an iterim-storage might prove to be a very permanent storage, and would make any return impossible. But others had already accepted the fact, that the radiation-levels around their former houses would be too high, and would make living there impractical for a long time. Some local residents realized that without the interim storage facility, there would no place to dispose radioactive waste at all, and the construction of the facility would create also new jobs.

text: Although this test uses radioactive materials, the total amount of radiation exposure is low. In order to decrease the radiation exposure in pregnant patients, the total radioactive dose may be decreased or the ventilation phase omitted. Computed tomography with radiocontrast can alternatively be performed, although this can result in a greater radiation dose to the patient. It has been suggested that breastfeeding should be discontinued for 24 hours following use of radiocontrast, however this is no longer considered necessary as such a limited quantity of radiocontrast gets excreted into breastmilk.

text: Although this test uses radioactive materials, the total amount of radiation exposure is low. In order to decrease the radiation exposure in pregnant patients, the total radioactive dose may be decreased or the ventilation phase omitted.

text: Computed tomography

text: with

text: radiocontrast

text: can alternatively be performed, although this can result in a greater radiation dose to the patient. It has been suggested that breastfeeding should be discontinued for 24 hours following use of radiocontrast, however this is no longer considered necessary as such a limited quantity of radiocontrast gets excreted into breastmilk.

text: Before the development of the ELISA, the only option for conducting an immunoassay was radioimmunoassay, a technique using radioactively labeled antigens or antibodies. In radioimmunoassay, the radioactivity provides the signal, which indicates whether a specific antigen or antibody is present in the sample. Radioimmunoassay was first described in a scientific paper by Rosalyn Sussman Yalow and Solomon Berson published in 1960.

text: Before the development of the ELISA, the only option for conducting an

text: immunoassay

text: was

text: radioimmunoassay

text: , a technique using

text: radioactive

text: ly labeled antigens or antibodies. In radioimmunoassay, the radioactivity provides the signal, which indicates whether a specific antigen or antibody is present in the sample. Radioimmunoassay was first described in a scientific paper by

text: Rosalyn Sussman Yalow

text: and

text: Solomon Berson

text: published in 1960.

text: Thirty-three other radioisotopes have been characterized with atomic masses ranging from Tc to Tc. Most of these have half-lives that are less than an hour; the exceptions are Tc (half-life: 2.75 hours), Tc (half-life: 4.883 hours), Tc (half-life: 20 hours), and Tc (half-life: 4.28 days).

text: Thirty-three other radioisotopes have been characterized with

text: atomic mass

text: es ranging from Tc to Tc. Most of these have half-lives that are less than an hour; the exceptions are Tc (half-life: 2.75 hours), Tc (half-life: 4.883 hours), Tc (half-life: 20 hours), and Tc (half-life: 4.28 days).

text: CERCLA identifies all radionuclides as carcinogens, although the nature of the emitted radiation (alpha, beta, gamma, or neutron and the radioactive strength), its consequent capacity to cause ionization in tissues, and the magnitude of radiation exposure, determine the potential hazard. Carcinogenicity of radiation depends on the type of radiation, type of exposure, and penetration. For example, alpha radiation has low penetration and is not a hazard outside the body, but emitters are carcinogenic when inhaled or ingested.  For example, Thorotrast, a (incidentally radioactive) suspension previously used as a contrast medium in x-ray diagnostics, is a potent human carcinogen known because of its retention within various organs and persistent emission of alpha particles.  Low-level ionizing radiation may induce irreparable DNA damage (leading to replicational and transcriptional errors needed for neoplasia or may trigger viral interactions) leading to pre-mature aging and cancer.

text: CERCLA

text: identifies all

text: radionuclide

text: s as carcinogens, although the nature of the emitted

text: radiation

text: alpha

text: beta

text: gamma

text: , or

text: neutron

text: and the radioactive strength), its consequent capacity to cause

text: ionization

text: in tissues, and the magnitude of radiation exposure, determine the potential hazard. Carcinogenicity of radiation depends on the type of radiation, type of exposure, and penetration. For example,

text: alpha radiation

text: has low penetration and is not a hazard outside the body, but emitters are carcinogenic when inhaled or ingested.  For example,

text: Thorotrast

text: , a (incidentally radioactive)

text: suspension

text: previously used as a

text: contrast

text: medium in

text: x-ray

text: diagnostics, is a potent human carcinogen known because of its retention within various

text: organs

text: and persistent emission of alpha particles.  Low-level ionizing radiation may induce irreparable DNA damage (leading to replicational and transcriptional errors needed for neoplasia or may trigger viral interactions) leading to pre-mature aging and

text: cancer

text: In contrast, afterloading involves the accurate positioning of non-radioactive applicators in the treatment site, which are subsequently loaded with the radiation sources. In manual afterloading, the source is delivered into the applicator by the operator.

text: Dynamic generators can provide power at more than 4 times the conversion efficiency of RTGs. NASA and DOE have been developing a next-generation radioisotope-fueled power source called the Stirling Radioisotope Generator (SRG) that uses free-piston Stirling engines coupled to linear alternators to convert heat to electricity. SRG prototypes demonstrated an average efficiency of 23%. Greater efficiency can be achieved by increasing the temperature ratio between the hot and cold ends of the generator. The use of non-contacting moving parts, non-degrading flexural bearings, and a lubrication-free and hermetically sealed environment have, in test units, demonstrated no appreciable degradation over years of operation. Experimental results demonstrate that an SRG could continue running for decades without maintenance. Vibration can be eliminated as a concern by implementation of dynamic balancing or use of dual-opposed piston movement. Potential applications of a Stirling radioisotope power system include exploration and science missions to deep-space, Mars, and the Moon.

text: Dynamic generators can provide power at more than 4 times the conversion efficiency of RTGs. NASA and DOE have been developing a next-generation radioisotope-fueled power source called the

text: Stirling Radioisotope Generator

text: (SRG) that uses free-piston

text: Stirling engine

text: s coupled to linear alternators to convert heat to electricity. SRG prototypes demonstrated an average efficiency of 23%. Greater efficiency can be achieved by increasing the temperature ratio between the hot and cold ends of the generator. The use of non-contacting moving parts, non-degrading

text: flexural bearings

text: , and a lubrication-free and hermetically sealed environment have, in test units, demonstrated no appreciable degradation over years of operation. Experimental results demonstrate that an SRG could continue running for decades without maintenance. Vibration can be eliminated as a concern by implementation of dynamic balancing or use of dual-opposed piston movement. Potential applications of a Stirling radioisotope power system include exploration and science missions to deep-space, Mars, and the Moon.

text: Patients often ask if they need to have special safety precautions around family and friends after receiving brachytherapy. If temporary brachytherapy is used, no radioactive sources remain in the body after treatment. Therefore, there is no radiation risk to friends or family from being in close proximity with them.

text: Zircophyllite is radioactive, but the radioactivity is barely detectable.

text: Ramsar's Talesh Mahalleh district is the most radioactive inhabited area known on Earth, due to nearby hot springs and building materials originating from them. A combined population of 2,000 residents from this district and other high radiation neighbourhoods receive an average radiation dose of 10 mGy per year, ten times more than the ICRP recommended limit for exposure to the public from artificial sources. Record levels were found in a house where the effective radiation dose due to external radiation was 131 mSv/a, and the committed dose from radon was 72 mSv/a. This unique case is over 80 times higher than the world average background radiation.

text: Ramsar's Talesh Mahalleh district is the most radioactive inhabited area known on Earth, due to nearby

text: hot spring

text: s and building materials originating from them. A combined population of 2,000 residents from this district and other high radiation neighbourhoods receive an average

text: radiation dose

text: of 10

text: mGy

text: per year, ten times more than the ICRP recommended limit for exposure to the public from artificial sources. Record levels were found in a house where the

text: effective radiation dose

text: due to external radiation was 131

text: mSv

text: /a, and the

text: committed dose

text: from

text: radon

text: was 72 mSv/a. This unique case is over 80 times higher than the world average

text: background radiation

text: Th is a radioactive isotope of thorium that can be used to date corals and determine ocean current flux. Ionium was a name given early in the study of radioactive elements to the Th isotope produced in the decay chain of U before it was realized that ionium and thorium are chemically identical. The symbol Io was used for this supposed element. (The name is still used in ionium-thorium dating.)

text: Th is a

text: radioactive

text: isotope

text: of

text: thorium

text: that can be used to date

text: coral

text: s and determine

text: ocean current

text: flux. Ionium was a name given early in the study of radioactive elements to the Th

text: isotope

text: produced in the

text: decay chain

text: of

text: U

text: before it was realized that ionium and

text: thorium

text: are chemically identical. The symbol Io was used for this supposed element. (The name is still used in

text: ionium-thorium dating

text: In radiation protection, radiation is often separated into two categories, ionizing and non-ionizing, to denote the level of danger posed to humans. Ionization is the process of removing electrons from atoms, leaving two electrically charged particles (an electron and a positively charged ion) behind. The negatively charged electrons and positively charged ions created by ionizing radiation may cause damage in living tissue. Basically, a particle is ionizing if its energy is higher than the ionization energy of a typical substance, i.e., a few eV, and interacts with electrons significantly.

text: In

text: radiation protection

text: , radiation is often separated into two categories,

text: ionizing

text: and

text: non-ionizing

text: , to denote the level of danger posed to humans.

text: Ionization

text: is the process of removing electrons from atoms, leaving two electrically charged particles (an electron and a positively charged ion) behind. The negatively charged electrons and positively charged ions created by ionizing radiation may cause damage in living tissue. Basically, a particle is ionizing if its energy is higher than the

text: ionization energy

text: of a typical substance, i.e., a few

text: eV

text: , and interacts with electrons significantly.

text: Since the fuel is contained in graphite pebbles, the volume of radioactive waste is much greater, but contains about the same radioactivity when measured in becquerels per kilowatt-hour. The waste tends to be less hazardous and simpler to handle. Current US legislation requires all waste to be safely contained, therefore pebble-bed reactors would increase existing storage problems. Defects in the production of pebbles may also cause problems. The radioactive waste must either be safely stored for many human generations, typically in a deep geological repository, reprocessed, transmuted in a different type of reactor, or disposed of by some other alternative method yet to be devised. The graphite pebbles are more difficult to reprocess due to their construction, which is not true of the fuel from other types of reactors. Proponents point out that this is a plus, as it is difficult to re-use pebble-bed reactor waste for nuclear weapons.

text: Since the fuel is contained in graphite pebbles, the volume of

text: radioactive waste

text: is much greater, but contains about the same

text: radioactivity

text: when measured in

text: becquerel

text: s per kilowatt-hour. The waste tends to be less hazardous and simpler to handle. Current US

text: legislation

text: requires all waste to be safely contained, therefore pebble-bed reactors would increase existing storage problems. Defects in the production of pebbles may also cause problems. The radioactive waste must either be safely stored for many human generations, typically in a

text: deep geological repository

text: , reprocessed,

text: transmuted

text: in a different type of reactor, or disposed of by some other alternative method yet to be devised. The graphite pebbles are more difficult to reprocess due to their construction, which is not true of the fuel from other types of reactors. Proponents point out that this is a plus, as it is difficult to re-use pebble-bed reactor waste for

text: nuclear weapons

text: Medical X-rays are a significant source of man-made radiation exposure. In 1987, they accounted for 58% of exposure from man-made sources in the United States. Since man-made sources accounted for only 18% of the total radiation exposure, most of which came from natural sources (82%), medical X-rays only accounted for 10% of total American radiation exposure; medical procedures as a whole (including nuclear medicine) accounted for 14% of total radiation exposure. By 2006, however, medical procedures in the United States were contributing much more ionizing radiation than was the case in the early 1980s. In 2006, medical exposure constituted nearly half of the total radiation exposure of the U.S. population from all sources. The increase is traceable to the growth in the use of medical imaging procedures, in particular computed tomography (CT), and to the growth in the use of nuclear medicine.

text: Medical X-rays are a significant source of man-made radiation exposure. In 1987, they accounted for 58% of exposure from man-made sources in the

text: United States

text: . Since man-made sources accounted for only 18% of the total radiation exposure, most of which came from natural sources (82%), medical X-rays only accounted for 10% of total American radiation exposure; medical procedures as a whole (including

text: nuclear medicine

text: ) accounted for 14% of total radiation exposure. By 2006, however, medical procedures in the United States were contributing much more ionizing radiation than was the case in the early 1980s. In 2006, medical exposure constituted nearly half of the total radiation exposure of the U.S. population from all sources. The increase is traceable to the growth in the use of medical imaging procedures, in particular

text: computed tomography

text: (CT), and to the growth in the use of nuclear medicine.

text: 38 isotopes of lead have been discovered. 9 of these are naturally occurring. The most common isotope is the primordial radioisotope lead-208, followed by the primordial radioisotope lead-206, the primordial radioisotope lead-207, and the primordial radioisotope lead-204. 4 isotopes of lead occur from the radioactive decay of uranium and thorium. These isotopes are lead-209, lead-210, lead-211, and lead-212.

text: isotopes of lead

text: have been discovered. 9 of these are naturally occurring. The most common isotope is the primordial radioisotope lead-208, followed by the primordial radioisotope lead-206, the primordial radioisotope lead-207, and the primordial radioisotope lead-204. 4 isotopes of lead occur from the radioactive decay of uranium and thorium. These isotopes are lead-209, lead-210, lead-211, and lead-212.

text: As these are detecting radioactive emissions, they require an extremely low radiation environment in order to work correctly. Low background counting chambers are made from low-background steel with extremely heavy radiation shielding. They are used to detect the minutest nuclear emissions.

text: As these are detecting radioactive emissions, they require an extremely low radiation environment in order to work correctly. Low background counting chambers are made from low-background steel with extremely heavy

text: radiation shielding

text: . They are used to detect the minutest nuclear emissions.

text: Several dozen radioisotopes have been characterized. , which has a half-life of 243.66 days, is the least active radioisotope, followed by  with a half-life of 46.5 hours. Zinc has 10 nuclear isomers. Zn has the longest half-life, 13.76 h. The superscript m indicates a metastable isotope. The nucleus of a metastable isotope is in an excited state and will return to the ground state by emitting a photon in the form of a gamma ray.  has three excited states and  has two. The isotopes , ,  and  each have only one excited state.

text: Several dozen

text: radioisotope

text: s have been characterized. , which has a half-life of 243.66 days, is the least active radioisotope, followed by  with a half-life of 46.5 hours. Zinc has 10

text: nuclear isomer

text: s. Zn has the longest half-life, 13.76 h. The superscript m indicates a

text: metastable

text: isotope. The nucleus of a metastable isotope is in an

text: excited state

text: and will return to the

text: ground state

text: by emitting a

text: photon

text: in the form of a

text: gamma ray

text: .  has three excited states and  has two. The isotopes , ,  and  each have only one excited state.

text: The isotope iodine-131 is easily absorbed by the thyroid. Persons exposed to releases of I-131 from any source have a higher risk for developing thyroid cancer or thyroid disease, or both. Iodine-131 has a short half-life at approximately 8 days, and therefore is an issue mostly in the first weeks after the incident. Children are more vulnerable to I-131 than adults. Increased risk for thyroid neoplasm remains elevated for at least 40 years after exposure. Potassium iodide tablets prevent iodine-131 absorption by saturating the thyroid with non-radioactive iodine. Japan's Nuclear Safety Commission recommended local authorities to instruct evacuees leaving the 20-kilometre area to ingest stable (not radioactive) iodine. CBS News reported that the number of doses of potassium iodide available to the public in Japan was inadequate to meet the perceived needs for an extensive radioactive contamination event.

text: The isotope

text: is easily absorbed by the

text: thyroid

text: . Persons exposed to releases of I-131 from any source have a higher risk for developing

text: thyroid cancer

text: or thyroid disease, or both. Iodine-131 has a short

text: half-life

text: at approximately 8 days, and therefore is an issue mostly in the first weeks after the incident. Children are more vulnerable to I-131 than adults. Increased risk for thyroid

text: neoplasm

text: remains elevated for at least 40 years after exposure.

text: Potassium iodide

text: tablets prevent iodine-131 absorption by saturating the thyroid with non-radioactive iodine. Japan's Nuclear Safety Commission recommended local authorities to instruct evacuees leaving the 20-kilometre area to ingest stable (not radioactive) iodine.

text: CBS News

text: reported that the number of doses of potassium iodide available to the public in Japan was inadequate to meet the perceived needs for an extensive radioactive contamination event.

text: Radium ( ) is a chemical element with atomic number 88, represented by the symbol Ra. Radium is an almost pure-white alkaline earth metal, but it readily oxidizes on exposure to air, becoming black in color. All isotopes of radium are highly radioactive, with the most stable isotope being radium-226, which has a half-life of 1601 years and decays into radon gas. Because of such instability, radium is luminescent, glowing a faint blue. Radium, in the form of radium chloride, was discovered by Marie Skłodowska-Curie and Pierre Curie in 1898. They extracted the radium compound from uraninite and published the discovery at the French Academy of Sciences five days later. Radium was isolated in its metallic state by Marie Curie and André-Louis Debierne through the electrolysis of radium chloride in 1910. Since its discovery, it has given names likeradium A and radium C to several isotopes of other elements that are decay products of radium-226. In nature, radium is found in uranium ores in trace amounts as small as a seventh of a gram per ton of uraninite. Radium is not necessary for living organisms, and adverse health effects are likely when it is incorporated into biochemical processes because of its radioactivity and chemical reactivity.

text: Radium ( ) is a

text: chemical element

text: with

text: atomic number

text: 88, represented by the symbol Ra. Radium is an almost pure-white

text: alkaline earth metal

text: , but it readily

text: oxidize

text: s on exposure to air, becoming black in color. All isotopes of radium are highly

text: radioactive

text: , with the most stable

text: isotope

text: being

text: , which has a

text: half-life

text: of 1601 years and

text: decays

text: into

text: radon

text: gas. Because of such instability, radium is

text: luminescent

text: , glowing a faint blue. Radium, in the form of

text: radium chloride

text: , was

text: discovered

text: by

text: Marie Skłodowska-Curie

text: and

text: Pierre Curie

text: in 1898. They extracted the radium compound from

text: uraninite

text: and published the discovery at the

text: French Academy of Sciences

text: five days later. Radium was isolated in its

text: metal

text: lic state by Marie Curie and

text: André-Louis Debierne

text: through the

text: electrolysis

text: of radium chloride in 1910. Since its discovery, it has given names like

text: radium A

text: and

text: radium C

text: to several isotopes of other elements that are

text: decay product

text: s of radium-226. In nature, radium is found in

text: uranium

text: ores in trace amounts as small as a seventh of a gram per ton of

text: uraninite

text: . Radium is not necessary for living organisms, and adverse health effects are likely when it is incorporated into biochemical processes because of its radioactivity and chemical reactivity.

text: Cherenkov radiation is widely used to facilitate the detection of small amounts and low concentrations of biomolecules. Radioactive atoms such as phosphorus-32 are readily introduced into biomolecules by enzymatic and synthetic means and subsequently may be easily detected in small quantities for the purpose of elucidating biological pathways and in characterizing the interaction of biological molecules such as affinity constants and dissociation rates.

text: Cherenkov radiation is widely used to facilitate the detection of small amounts and low concentrations of

text: biomolecule

text: s. Radioactive atoms such as phosphorus-32 are readily introduced into biomolecules by enzymatic and synthetic means and subsequently may be easily detected in small quantities for the purpose of elucidating biological pathways and in characterizing the interaction of biological molecules such as affinity constants and dissociation rates.

text: Radiation may be used to treat stage II seminoma cancers, or as adjuvant (preventative) therapy in the case of stage I seminomas, to minimize the likelihood that tiny, non-detectable tumors exist and will spread (in the inguinal and para-aortic lymph nodes).  Radiation is ineffective against and is therefore never used as a primary therapy for nonseminoma.

text: Radiation

text: may be used to treat stage II seminoma cancers, or as

text: adjuvant

text: (preventative) therapy in the case of stage I seminomas, to minimize the likelihood that tiny, non-detectable tumors exist and will spread (in the inguinal and para-aortic

text: lymph nodes

text: ).  Radiation is ineffective against and is therefore never used as a primary therapy for

text: nonseminoma

text: Vampire bats use infrared radiation to locate blood hotspots on their prey. A recent study has shown that common vampire bats tune a TRP-channel that is already heat-sensitive, TRPV1, by lowering its thermal activation threshold to about 30 °C. This is achieved through alternative splicing of TRPV1 transcripts to produce a channel with a truncated carboxy-terminal cytoplasmic domain. These splicing events occur exclusively in trigeminal ganglia, and not in dorsal root ganglia, thereby maintaining a role for TRPV1 as a detector of noxious heat in somatic afferents. The only other vertebrates capable of detecting infrared radiation are boas, pythons and pit vipers, all of which have pit organs.

text: Vampire bats use infrared radiation to locate blood hotspots on their prey. A recent study has shown that common vampire bats tune a

text: TRP-channel

text: that is already heat-sensitive, TRPV1, by lowering its thermal activation threshold to about 30 °C. This is achieved through alternative splicing of TRPV1 transcripts to produce a channel with a truncated carboxy-terminal cytoplasmic domain. These splicing events occur exclusively in trigeminal ganglia, and not in dorsal root ganglia, thereby maintaining a role for TRPV1 as a detector of noxious heat in somatic afferents. The only other

text: vertebrates

text: capable of detecting

text: infrared radiation

text: are

text: boas

text: python

text: s and

text: pit viper

text: s, all of which have pit organs.

text: The CG2 SN series of surge arrestors formerly produced by C P Clare, are advertised as being non-radioactive, and the datasheet for that series states that some members of the CG/CG2 series (75-470V) are radioactive.

text: On September 7, 2007, Armenian Energy Minister Armen Movsisyan announced that Metsamor unit-2 was to be replaced with a new nuclear power plant built on the same site at a cost of $2 billion. "The project's feasibility study is being carried out by Armenia, Russia, the US and the International Atomic Energy Agency. The old nuclear power plant is to be rebuilt within four-and-a-half years", he stated, clarifying that "many foreign countries now understand that Armenia must have a nuclear power plant."  TAEK, which had recently denied claims in Today's Zaman that its latest protest to the IAEA was made in response to the RESAI early warning system indicating "an increase in radioactive leakage in the region," stating, "None of the radioactivity analyses or RESAI station measurements done up until now have uncovered radioactivity or radiation levels above normal," confirmed that it would be involved in following related developments and taking the necessary precautions from the Turkish side.

text: On September 7, 2007, Armenian Energy Minister

text: Armen Movsisyan

text: announced that Metsamor unit-2 was to be replaced with a new nuclear power plant built on the same site at a cost of $2 billion. "The project's feasibility study is being carried out by Armenia, Russia, the US and the International Atomic Energy Agency. The old nuclear power plant is to be rebuilt within four-and-a-half years", he stated, clarifying that "many foreign countries now understand that Armenia must have a nuclear power plant."  TAEK, which had recently denied claims in

text: Today's Zaman

text: that its latest protest to the IAEA was made in response to the RESAI early warning system indicating "an increase in radioactive leakage in the region," stating, "None of the radioactivity analyses or RESAI station measurements done up until now have uncovered radioactivity or radiation levels above normal," confirmed that it would be involved in following related developments and taking the necessary precautions from the Turkish side.

text: Greenpeace has been campaigning since 1997 for the shutdown of the site, which they claim dumps "one million litres of liquid radioactive waste per day" into the ocean; "the equivalent of 50 nuclear waste barrels", claiming the radiation affects local beaches. Although official figures are to the contrary.  Greenpeace have also protested by creating roadblocks and chaining themselves to vehicles transporting materials to and from the site. However the leader of Greenpeace France, Yannick Rousselet, has since stated that they have ceased attempting to criticize the reprocessing plant on technical grounds, having succeeded at performing the process without serious spills that have been frequent at other such facilities around the world. In the past, the antinuclear movement argued that COGEMA would not succeed with reprocessing.  Eric Blanc, deputy director of the processing plant, says that although the plant does intentionally release radioactive material, the annual dose in the vicinity of the facility is less than 20 microsieverts per year, which is equivalent to the dose of solar radiation received during a single transatlantic flight, and therefore within regulation.  The AREVA NC website emphasizes that they are committed to keeping the dose below 30 microsieverts per year.

text: Greenpeace

text: has been campaigning since 1997 for the shutdown of the site, which they claim dumps "one million litres of liquid

text: radioactive waste

text: per day" into the ocean; "the equivalent of 50 nuclear waste barrels", claiming the radiation affects local beaches. Although official figures are to the contrary.  Greenpeace have also protested by creating roadblocks and chaining themselves to vehicles transporting materials to and from the site. However the leader of Greenpeace France, Yannick Rousselet, has since stated that they have ceased attempting to criticize the reprocessing plant on technical grounds, having succeeded at performing the process without serious spills that have been frequent at other such facilities around the world. In the past, the antinuclear movement argued that COGEMA would not succeed with reprocessing.  Eric Blanc, deputy director of the processing plant, says that although the plant does intentionally release radioactive material, the

text: annual

text: dose in the vicinity of the facility is less than 20

text: microsievert

text: s per year, which is equivalent to the dose of

text: solar radiation

text: received during a single

text: transatlantic

text: flight, and therefore within regulation.  The AREVA NC website emphasizes that they are committed to keeping the dose below 30 microsieverts per year.

text: Finally, there has been a widely critiqued paper published by members of the controversial Radiation and Public Health Project which attempts to ascribe the natural annual cycle of rising and falling adult and infant mortality rates in the United States to Fukushima fallout, suggesting about 14,000 have died.Those who have responded to this paper in the literature have however noted a number of errors, among them include, that this figure was based on an assumption of acute deaths from low radiation doses. There is no known mechanism for this, and more notably, "the cities under study with the lowest radiation fallout have the highest increases of death rates in the 14 weeks following Fukushima, while the Californian cities that would have received larger doses saw a decrease in death rate growth" and concluded that "innumerable factors other than radiation" were likely responsible for the major part of the variation in US mortality around the time of the nuclear disaster.

text: Finally, there has been a widely critiqued paper published by members of the controversial

text: Radiation and Public Health Project

text: which attempts to ascribe the natural annual cycle of rising and falling adult and

text: infant mortality

text: rates in the

text: United States

text: to Fukushima fallout, suggesting about 14,000 have died.Those who have responded to this paper in the literature have however noted a number of errors, among them include, that this figure was based on an assumption of acute deaths from low radiation doses. There is no known mechanism for this, and more notably, "the cities under study with the lowest radiation fallout have the highest increases of death rates in the 14 weeks following Fukushima, while the Californian cities that would have received larger doses saw a decrease in death rate growth" and concluded that "innumerable factors other than radiation" were likely responsible for the major part of the variation in US mortality around the time of the nuclear disaster.

text: Between 1949 and 1989, over 4,000 uranium mines in the Four Corners region produced more than 225,000,000 tons of uranium ore. This activity affected a large number of Native American nations, including the Laguna, Navajo, Zuni, Southern Ute, Ute Mountain, Hopi, Acoma and other Pueblo cultures. Many of these peoples worked in the mines, mills and processing plants in New Mexico, Arizona, Utah and Colorado. These workers were not only poorly paid, they were seldom informed of dangers nor were they given appropriate protective gear. The government, mine owners, scientific, and health communities were all well aware of the hazards of working with radioactive materials at this time. Due to the Cold War demand for increasingly destructive and powerful nuclear weapons, these laborers were both exposed to and brought home large amounts of radiation in the form of dust on their clothing and skin. Epidemiological studies of the families of these workers have shown increased incidents of radiation-induced cancers, miscarriages, cleft palates and other birth defects. The extent of these genetic effects on indigenous populations and the extent of DNA damage remains to be resolved. Uranium mining on the Navajo reservation continues to be a disputed issue as former Navajo mine workers and their families continue to suffer from health problems.

text: In March 2007, under the Megaport initiative, three RPMs (Radiation Portal Monitors) were already installed in Puerto Cortés by US DOE to inspect all containers with destination to USA, checking for possible dangerous radioactive threats. On 2 April 2007 the RPMs became operative.

text: In March 2007, under the Megaport initiative, three RPMs (Radiation Portal Monitors) were already installed in Puerto Cortés by

text: US DOE

text: to inspect all containers with destination to USA, checking for possible dangerous

text: radioactive

text: threats. On 2 April 2007 the RPMs became operative.

text: Sagnac was born at Périgueux and entered the École Normale Supérieure in 1889. While a lab assistant at the Sorbonne, he was one of the first in France to study X-rays, following Wilhelm Conrad Röntgen. He belonged to a group of friends and scientists that notably included Pierre  and Marie Curie, Paul Langevin, Jean Perrin, and the mathematician Émile Borel. Marie Curie says that she and her husband had traded ideas with Sagnac around the time of the discovery of radioactivity.  Sagnac died at Meudon-Bellevue.

text: Sagnac was born at

text: Périgueux

text: and entered the

text: École Normale Supérieure

text: in 1889. While a lab assistant at the

text: Sorbonne

text: , he was one of the first in France to study

text: X-rays

text: , following

text: Wilhelm Conrad Röntgen

text: . He belonged to a group of friends and scientists that notably included

text: Pierre

text: and Marie Curie,

text: Paul Langevin

text: Jean Perrin

text: , and the mathematician

text: Émile Borel

text: Marie Curie

text: says that she and her husband had traded ideas with Sagnac around the time of the discovery of radioactivity.  Sagnac died at

text: Meudon-Bellevue

text: Non-radioactive injuries from the blast itself would result from the human body being thrown and from impacts from objects. The detonation would produce intense heat that will cause burns to exposed skin and eyes. There are two general categories of nuclear radiation produced in a detonation. First, is the prompt nuclear radiation that is created from the initial explosion. This radiation may expose unprotected people to large gamma ray or neutron doses. Radioactive fallout in the form of a large dust cloud would begin within two hours after the explosion and would dissipate within minutes to weeks. The radiation from the fallout could contaminate an area for many years. The largest radiation concerns following an incident will be the radioactive material deposited on the ground, as people are evacuated from the fallout areas. These effects are likely to have significantly larger impacts on the population than internal doses. Internal doses tend to expose the body to relatively small radiation doses over a long period of time, which produces different effects than large radiation doses received during a short period of time. As the distance from ground zero increases to twelve miles, injuries due to radiation exposure will decrease, and lower level contamination, evacuation, and sheltering issues will become the major concern and distances greater than 150 miles from ground zero of a nuclear detonation, acute health concerns will not become a significant issue.

text: The Spiders and a now redeemed Karn head to Loomworld for the final battle with the Inheritors. Miguel O'Hara and Lady Spider arrive with a repaired Leopardon, now powered by radioactive isotopes. Spider-Ham disguises himself as Benjy, allowing Ben Parker to take Benjy back to his home reality. Meanwhile, Superior Spider-Man's plan to put an end the Inheritors' reign by killing the Master Weaver does stop the Inheritors, but also causes the fabric of reality to unwind.  Spider-Girl threatens to destroy the crystal that contains Solus' soul, but changes her mind after realizing that "heroes don't kill". The Inheritors are exiled to Earth-3145, where they are forced to hide in the Sims bunker to avoid death by radiation, while feeding off the radioactive spiders.

text: Naturally occurring decay heat is a significant source of the heat in the interior of the Earth.  Radioactive isotopes of uranium, thorium and potassium are the primary contributors to this decay heat, and this radioactive decay is the primary source of heat from which geothermal energy derives.

text: Naturally occurring decay heat is a significant source of the heat in the interior of the

text: Earth

text: .  Radioactive isotopes of

text: uranium

text: thorium

text: and

text: potassium

text: are the primary contributors to this decay heat, and this

text: radioactive decay

text: is the primary source of heat from which

text: geothermal energy

text: derives.

text: Gamma World is a chaotic, dangerous environment that little resembles pre-apocalyptic Earth.  The weapons unleashed during the final war were strong enough to alter coastlines, level cities, and leave large areas of land lethally radioactive.  These future weapons bathed the surviving life of Earth in unspecified forms of radiation and biochemical agents, producing widespread, permanent mutations among humans, animals, and plants.  As a result, fantastic mutations such as extra limbs, super strength, and psychic powers are relatively common.  (Random tables of such improbable mutations are a hallmark of every edition of Gamma World.)  Many animals and plants are sentient, semi-civilized species competing with surviving humans.  Both humans and non-humans have lost most knowledge of the pre-war humans, whom Gamma World's inhabitants refer to as "the Ancients".  The only group with significant knowledge of the Ancients are isolated robots and other artificial intelligences that survived the war—though these machines tend to be damaged, in ill-repair, or hostile to organic beings.

text: Gamma World is a chaotic, dangerous environment that little resembles pre-apocalyptic Earth.  The weapons unleashed during the final war were strong enough to alter coastlines, level cities, and leave large areas of land lethally radioactive.  These future weapons bathed the surviving life of Earth in unspecified forms of

text: radiation

text: and biochemical agents, producing widespread, permanent mutations among humans, animals, and plants.  As a result, fantastic mutations such as extra limbs, super strength, and psychic powers are relatively common.  (Random tables of such improbable mutations are a hallmark of every edition of Gamma World.)  Many animals and plants are sentient, semi-civilized species competing with surviving humans.  Both humans and non-humans have lost most knowledge of the pre-war humans, whom Gamma World's inhabitants refer to as "the Ancients".  The only group with significant knowledge of the Ancients are isolated robots and other artificial intelligences that survived the war—though these machines tend to be damaged, in ill-repair, or hostile to organic beings.

text: In direct transmission mode, the source extends through the base of the gauge into a predrilled hole, positioning the source at the desired depth.  The testing procedure is analogous to burying a known quantity of radioactive material at a specific depth, and then using a Geiger counter at the ground surface to measure how effectively the soil's density  blocks the penetration of gamma radiation through the soil.  As the soil's density increases, less radiation can pass through it, owing to dispersion from collisions with electrons in the soil being tested.

text: In direct transmission mode, the source extends through the base of the gauge into a predrilled hole, positioning the source at the desired depth.  The testing procedure is analogous to burying a known quantity of radioactive material at a specific depth, and then using a

text: Geiger counter

text: at the ground surface to measure how effectively the soil's density  blocks the penetration of gamma radiation through the soil.  As the soil's density increases, less radiation can pass through it, owing to dispersion from collisions with electrons in the soil being tested.

text: Radon is formed as one intermediate step in the normal radioactive decay chains through which thorium and uranium slowly decay into lead. Thorium and uranium are the two most common radioactive elements on earth; they have been around since the earth was formed. Their naturally occurring isotopes have very long half-lives, on the order of billions of years. Thorium and uranium, their decay product radium, and its decay product radon, will therefore continue to occur for tens of millions of years at almost the same concentrations as they do now. As radon itself decays, it produces other radioactive elements called radon progeny (also known as radon daughters) or decay products. Unlike the gaseous radon itself, radon daughters are solids and stick to surfaces, such as dust particles in the air. If such contaminated dust is inhaled, these particles can stick to the airways of the lung and increase the risk of developing lung cancer.

text: Radon is formed as one intermediate step in the normal radioactive

text: decay chain

text: s through which

text: thorium

text: and

text: uranium

text: slowly decay into

text: lead

text: . Thorium and uranium are the two most common radioactive elements on earth; they have been around since the earth was formed. Their naturally occurring isotopes have very long half-lives, on the order of billions of years. Thorium and uranium, their decay product

text: radium

text: , and its decay product radon, will therefore continue to occur for tens of millions of years at almost the same concentrations as they do now. As radon itself decays, it produces other radioactive elements called radon progeny (also known as radon daughters) or decay products. Unlike the gaseous radon itself, radon daughters are solids and stick to surfaces, such as dust particles in the air. If such contaminated dust is inhaled, these particles can stick to the airways of the lung and increase the risk of developing lung cancer.

text: Many radioisotopes are used as tracers in nuclear medicine, including iodine-131, phosphorus-32, and technetium-99m. Phosphorus-32 is of particular use in the identification of malignant tumours because cancerous cells have a tendency to accumulate more phosphate than normal cells. The location of the phosphorus-32 can be traced from outside the body to identify the location of potentially malignant tumors.

text: Many radioisotopes are used as tracers in

text: nuclear medicine

text: , including iodine-131, phosphorus-32, and technetium-99m. Phosphorus-32 is of particular use in the identification of malignant tumours because cancerous cells have a tendency to accumulate more phosphate than normal cells. The location of the phosphorus-32 can be traced from outside the body to identify the location of potentially malignant tumors.

text: Naturally occurring ruthenium is composed of seven stable isotopes. Additionally, 34 radioactive isotopes have been discovered. Of these radioisotopes, the most stable are Ru with a half-life of 373.59 days, Ru with a half-life of 39.26 days and Ru with a half-life of 2.9 days.

text: Naturally occurring ruthenium is composed of seven stable

text: isotope

text: s. Additionally, 34

text: radioactive isotopes

text: have been discovered. Of these

text: radioisotope

text: s, the most stable are Ru with a

text: half-life

text: of 373.59 days, Ru with a half-life of 39.26 days and Ru with a half-life of 2.9 days.

text: Radioactive tracers - Since radioactive isotopes behave, chemically, mostly like the inactive element, the behavior of a certain chemical substance can be followed by tracing the radioactivity. Examples:

text: Radioactive tracer

text: s - Since radioactive isotopes behave, chemically, mostly like the inactive element, the behavior of a certain chemical substance can be followed by tracing the radioactivity. Examples:

text: About twenty isotopes and six nuclear isomers (excited states of an isotope) of berkelium have been characterized with the mass numbers ranging from 235 to 254. All of them are radioactive. The longest half-lives are observed for Bk (1,380 years), Bk (over 300 years) and Bk (330 days); the half-lives of the other isotopes range from microseconds to several days. The isotope which is the easiest to synthesize is berkelium-249. This emits mostly soft β-particles which are inconvenient for detection. Its alpha radiation is rather weak – 1.45% with respect to the β-radiation – but is sometimes used to detect this isotope. The second important berkelium isotope, berkelium-247, is an alpha-emitter, as are most actinide isotopes.

text: About twenty isotopes and six

text: nuclear isomer

text: s (excited states of an isotope) of berkelium have been characterized with the mass numbers ranging from 235 to 254. All of them are radioactive. The longest

text: half-lives

text: are observed for Bk (1,380 years), Bk (over 300 years) and Bk (330 days); the half-lives of the other isotopes range from microseconds to several days. The isotope which is the easiest to synthesize is berkelium-249. This emits mostly soft

text: β-particles

text: which are inconvenient for detection. Its

text: alpha radiation

text: is rather weak – 1.45% with respect to the β-radiation – but is sometimes used to detect this isotope. The second important berkelium isotope, berkelium-247, is an alpha-emitter, as are most actinide isotopes.

text: In an episode (entitled "Swarm") of the 1980s cartoon, Spider-Man and His Amazing Friends, The Swarm (voiced by Al Fann) was created when alien energy from a fallen meteorite irradiated a nearby beehive, giving it sentience and the ability to use eye blasts to increase the size of bees and their hive or mutate people into bee drone hybrids. The Swarm was defeated when Spider-Man (who was immune to the mutation due to his radioactive blood), Firestar, and Iceman launched the meteorite back into space. Distancing the bees and hybrids from the meteor's radiation reversed all of The Swarm's effects.

text: In an episode (entitled "Swarm") of the 1980s cartoon,

text: Spider-Man and His Amazing Friends

text: , The Swarm (voiced by Al Fann) was created when alien energy from a fallen meteorite irradiated a nearby beehive, giving it sentience and the ability to use eye blasts to increase the size of bees and their hive or mutate people into bee drone hybrids. The Swarm was defeated when Spider-Man (who was immune to the mutation due to his radioactive blood),

text: Firestar

text: , and

text: Iceman

text: launched the meteorite back into space. Distancing the bees and hybrids from the meteor's radiation reversed all of The Swarm's effects.

text: In 1903, Crookes turned his attention to the newly discovered phenomenon of radioactivity, achieving the separation from uranium of its active transformation product, uranium-X (later established to be protactinium). Crookes observed the gradual decay of the separated transformation product, and the simultaneous reproduction of a fresh supply in the original uranium. At about the same time as this important discovery, he observed that when "p-particles", ejected from radio-active substances, impinge upon zinc sulfide, each impact is accompanied by a minute scintillation, an observation which forms the basis of one of the most useful methods in the technique of radioactivity.

text: In 1903, Crookes turned his attention to the newly discovered phenomenon of

text: radioactivity

text: , achieving the separation from

text: uranium

text: of its active transformation product, uranium-X (later established to be

text: protactinium

text: ). Crookes observed the gradual

text: decay

text: of the separated transformation product, and the simultaneous reproduction of a fresh supply in the original uranium. At about the same time as this important discovery, he observed that when "p-particles", ejected from radio-active substances, impinge upon

text: zinc sulfide

text: , each impact is accompanied by a minute scintillation, an observation which forms the basis of one of the most useful methods in the technique of radioactivity.

text: Identified by the EPA in 1980, the Welsbach/General Gas Mantle site contained soil and building materials contaminated with radioactive materials.  Radiation became prominent when the companies used thorium, a radioactive material withdrawn from monazite ore, in the production of their gas mantles.  In the late 19th century and early 20th century, Welsbach Company was located in Gloucester City, which borders Camden, and was a major producer of gas mantles until gas lights were replaced by electric lights.  The fabric of the Welsbach gas mantle was put into a solution that consisted of 99% thorium nitrate and 1% cerium nitrate in distilled water, causing it to emit a white light.  Operating from 1915 to 1940 in Camden, General Gas Mantle, or GGM, was a manufacturer of gas mantles and served as a competitor for Welsbach.  Unlike Welsbach, General Gas Mantle used only a refined, commercial thorium solution in order to produce its gas mantles.  Welsbach and General Gas Mantle went out of business in the 1940s and had no successors.

text: Identified by the

text: EPA

text: in 1980, the Welsbach/General Gas Mantle site contained soil and building materials contaminated with radioactive materials.  Radiation became prominent when the companies used

text: thorium

text: , a radioactive material withdrawn from

text: monazite

text: ore, in the production of their gas mantles.  In the late 19th century and early 20th century, Welsbach Company was located in

text: Gloucester City

text: , which borders Camden, and was a major producer of

text: gas mantle

text: s until gas lights were replaced by electric lights.  The fabric of the Welsbach gas mantle was put into a solution that consisted of 99% thorium nitrate and 1% cerium nitrate in distilled water, causing it to emit a white light.  Operating from 1915 to 1940 in Camden, General Gas Mantle, or GGM, was a manufacturer of gas mantles and served as a competitor for Welsbach.  Unlike Welsbach, General Gas Mantle used only a refined, commercial thorium solution in order to produce its gas mantles.  Welsbach and General Gas Mantle went out of business in the 1940s and had no successors.

text: The USNRC provides licensing for the entombment process, as well as providing license they research and develop programs to help decommission nuclear power plants. USNRC will continue the development of rule making for entombment. NRC will ask the company that are running power plants to set some money aside while the power plant is being run for future shut down cost. The NRC has decided that in order for nuclear entombment to be a possible, a long-term structure must be created specifically for the encasing of the radioactive waste. If the structures are not correctly built water can seep into them and come out with radioactive waste that can infect the public. The NRC itself imposes acts such as the Nuclear Waste Policy Act of 1982 and the Low-level radioactive waste policy to help regulate state governments on the procedures and precautions needed to dispose of the nuclear waste. The Nuclear Waste Policy of 1982 states that both the federal government's are responsible to provide a permanent disposal facility for high-level radioactive waste and spent nuclear fuel. As well  with the Nuclear Waste Policy Act of 1982,  which gives states the responsibility to dispose of low-level waste and provides facilities to the states that will be regulated by the NRC or by states who have agreed to follow §274 of the Atomic Energy Act.

text: The

text: USNRC

text: provides licensing for the entombment process, as well as providing license they research and develop programs to help decommission nuclear power plants. USNRC will continue the development of rule making for entombment. NRC will ask the company that are running power plants to set some money aside while the power plant is being run for future shut down cost. The NRC has decided that in order for nuclear entombment to be a possible, a long-term structure must be created specifically for the encasing of the radioactive waste. If the structures are not correctly built water can seep into them and come out with radioactive waste that can infect the public. The NRC itself imposes acts such as the

text: Nuclear Waste Policy Act of 1982

text: and the

entity_name: Low-level radioactive waste policy of the United States

text: Low-level radioactive waste policy

text: to help regulate state governments on the procedures and precautions needed to dispose of the nuclear waste. The Nuclear Waste Policy of 1982 states that both the federal government's are responsible to provide a permanent disposal facility for high-level radioactive waste and spent nuclear fuel. As well  with the Nuclear Waste Policy Act of 1982,  which gives states the responsibility to dispose of low-level waste and provides facilities to the states that will be regulated by the NRC or by states who have agreed to follow §274 of the

text: Atomic Energy Act

text: Fallout Boy also appears in a real-life comic book titled Radioactive Man, published by Bongo Comics (a comic created in part by Matt Groening, the creator of The Simpsons). In these comic books, Fallout Boy's real name is Rod Runtledge, he has a brother named Dodd. They live in Zenith City. Rod is a high school nerd living with his aunt, Aunt June. Fallout Boy was an average book worm, until one day, he was at a Radioactive demonstration, where he met up with Claude Kane. A tall piece of machinery fell towards them. Claude grabbed Rod and jumped over the rail, Claude holding onto the machine. The machine came to life, and as the ray passed through Claude, who became Radioactive Man, it hit Rod. Rod then got a pint-sized version of RM's powers and became Fallout Boy.

text: Fallout Boy also appears in a real-life comic book titled Radioactive Man, published by

text: Bongo Comics

text: (a comic created in part by

text: Matt Groening

text: , the creator of The Simpsons). In these comic books, Fallout Boy's real name is Rod Runtledge, he has a brother named Dodd. They live in Zenith City. Rod is a

text: high school

text: nerd

text: living with his aunt, Aunt June. Fallout Boy was an average book worm, until one day, he was at a Radioactive demonstration, where he met up with Claude Kane. A tall piece of machinery fell towards them. Claude grabbed Rod and jumped over the rail, Claude holding onto the machine. The machine came to life, and as the ray passed through Claude, who became Radioactive Man, it hit Rod. Rod then got a pint-sized version of RM's powers and became Fallout Boy.

text: THz-wave radar can sense gas leaks, chemicals and nuclear materials. In field tests, THz-wave radar detected chemicals at the 10-ppm level from 60 meters away. This method can be used in a fence line or aircraft mounted system that works day or night in any weather. It can locate and track chemical and radioactive plumes. THz-wave radar that can sense radioactive plumes from nuclear plants have detected plumes several kilometers away based on radiation-induced ionization effects in air.

text: The primary dangers associated with beta radiation are internal exposure from ingested fallout particles and beta burns from fallout particles no more than a few days old. Beta burns can result from contact with highly radioactive particles on bare skin; ordinary clothing separating fresh fallout particles from the skin can provide significant shielding.

text: The primary dangers associated with beta radiation are internal exposure from ingested fallout particles and beta burns from fallout particles no more than a few days old.

text: Beta burn

text: s can result from contact with highly radioactive particles on bare skin; ordinary clothing separating fresh fallout particles from the skin can provide significant shielding.

text: Clocks, watches, and instruments dating from the first half of the 20th century, often in military applications, may have been painted with radioactive luminous paint. They are usually no longer luminous; however, this is not due to radioactive decay of the radium (which has a half-life of 1600 years) but to the fluorescence of the zinc sulfide fluorescent medium being worn out by the radiation from the radium. The appearance of an often thick layer of green or yellowish brown paint in devices from this period suggests a radioactive hazard. The radiation dose from an intact device is relatively low and usually not an acute risk; but the paint is dangerous if released and inhaled or ingested.

text: The sign is commonly referred to as a radioactivity warning sign, but it is actually a warning sign of ionizing radiation. Ionizing radiation is a much broader category than radioactivity alone, as many non-radioactive sources also emit potentially dangerous levels of ionizing radiation. This includes x-ray apparatus, medical beam cannons and particle accelerators. Non-ionizing radiation can also reach potentially dangerous levels, but this warning sign is different from the trefoil ionizing radiation warning symbol.

text: The sign is commonly referred to as a

text: radioactivity

text: warning sign, but it is actually a warning sign of

text: ionizing radiation

text: . Ionizing radiation is a much broader category than radioactivity alone, as many non-radioactive sources also emit potentially dangerous levels of ionizing radiation. This includes x-ray apparatus, medical beam cannons and particle accelerators.

text: Non-ionizing radiation

text: can also reach potentially dangerous levels, but this warning sign is different from the trefoil ionizing radiation warning symbol.

text: Matter attenuates radiation in most cases, so placing any mass (e.g., lead, dirt, sandbags, vehicles) between humans and the source will reduce the radiation dose. This is not always the case, however; care should be taken when constructing shielding for a specific purpose. For example, although high atomic number materials are very effective in shielding photons, using them to shield beta particles may cause higher radiation exposure due to the production of bremsstrahlung x-rays, and hence low atomic number materials are recommended. Also, using material with a high neutron activation cross section to shield neutrons will result in the shielding material itself becoming radioactive and hence more dangerous than if it were not present.

text: Matter attenuates radiation in most cases, so placing any mass (e.g., lead, dirt, sandbags, vehicles) between humans and the source will reduce the radiation dose. This is not always the case, however; care should be taken when constructing shielding for a specific purpose. For example, although high atomic number materials are very effective in shielding

text: photon

text: s, using them to shield

text: beta particle

text: s may cause higher radiation exposure due to the production of

text: bremsstrahlung

text: x-rays, and hence low atomic number materials are recommended. Also, using material with a high

text: neutron activation

text: cross section

text: to shield neutrons will result in the shielding material itself becoming radioactive and hence more dangerous than if it were not present.

text: Americium is the only synthetic element to have found its way into the household, where the most common type of smoke detector uses Am in the form of americium dioxide as its source of ionizing radiation. This isotope is preferred over Ra because it emits 5 times more alpha particles and relatively little harmful gamma radiation. Element collector Theodore Gray mentions in his book The Elements: A Visual Exploration of Every Known Atom in the Universe "You might think that a synthetic radioactive element that follows plutonium (94)—and has a significantly shorter half-life—would be some kind of superbomb material, available only to scientists in secret laboratories. Perhaps a mad scientist is studying americium in a lair somewhere, but if you want some yourself you can simply walk into any neighborhood hardware store, supermarket, or Wal-Mart and buy some, no questions asked." He also adds "The reason is not that americium is fundamentally less dangerous than the elements around it. In fact, the commonly available isotope, Am, is significantly more radioactive than weapons-grade plutonium, and at least as toxic. No, the difference is simply that there is a useful application for americium that requires only a very tiny amount, and for which a company was prepared to go through the effort required to carve out and get a regulatory exception." The amount of americium in a typical new smoke detector is 1 microcurie (37 kBq) or 0.29 microgram. This amount declines slowly as the americium decays into neptunium-237, a different transuranic element with a much longer half-life (about 2.14 million years). With its half-life of 432.2 years, the americium in a smoke detector includes about 3% neptunium after 19 years, and about 5% after 32 years. The radiation passes through an ionization chamber, an air-filled space between two electrodes, and permits a small, constant current between the electrodes. Any smoke that enters the chamber absorbs the alpha particles, which reduces the ionization and affects this current, triggering the alarm. Compared to the alternative optical smoke detector, the ionization smoke detector is cheaper and can detect particles which are too small to produce significant light scattering; however, it is more prone to false alarms.

text: Americium is the only synthetic element to have found its way into the household, where the most common type of

text: smoke detector

text: uses Am in the form of americium dioxide as its source of

text: ionizing radiation

text: . This isotope is preferred over

text: Ra

text: because it emits 5 times more alpha particles and relatively little harmful gamma radiation. Element collector

text: Theodore Gray

text: mentions in his book The Elements: A Visual Exploration of Every Known Atom in the Universe "You might think that a synthetic radioactive element that follows plutonium (94)—and has a significantly shorter half-life—would be some kind of superbomb material, available only to scientists in secret laboratories. Perhaps a mad scientist is studying americium in a lair somewhere, but if you want some yourself you can simply walk into any neighborhood hardware store, supermarket, or Wal-Mart and buy some, no questions asked." He also adds "The reason is not that americium is fundamentally less dangerous than the elements around it. In fact, the commonly available isotope, Am, is significantly more radioactive than weapons-grade plutonium, and at least as toxic. No, the difference is simply that there is a useful application for americium that requires only a very tiny amount, and for which a company was prepared to go through the effort required to carve out and get a regulatory exception." The amount of americium in a typical new smoke detector is 1

text: microcurie

text: kBq

text: ) or 0.29

text: microgram

text: . This amount declines slowly as the americium decays into

text: neptunium

text: -237, a different transuranic element with a much longer half-life (about 2.14 million years). With its half-life of 432.2 years, the americium in a smoke detector includes about 3%

text: neptunium

text: after 19 years, and about 5% after 32 years. The radiation passes through an

text: ionization chamber

text: , an air-filled space between two

text: electrode

text: s, and permits a small, constant

text: current

text: between the electrodes. Any smoke that enters the chamber absorbs the alpha particles, which reduces the ionization and affects this current, triggering the alarm. Compared to the alternative optical smoke detector, the ionization smoke detector is cheaper and can detect particles which are too small to produce significant light scattering; however, it is more prone to

text: false alarms

text: The Waste Isolation Pilot Plant, was designed as a pilot, test study site for deep geologic storage of radioactive waste. It is managed by the U.S. Department of Energy (DOE) and currently serves as the nation's only deep geological repository for transuranic (TRU) nuclear waste generated by the military and defense industry. It is located in Southern New Mexico near the border of Texas and Mexico. It has been disposing of waste 2,150 feet underground in the ancient Permian Sea salt formation since 1999, accepting waste from 22 national atomic legacy sites. Designed to last tens thousand years, the WIPP site had its first leak of airborne radioactive materials on February 1, 2014. 140 employees working underground at the time were sheltered indoors. 13 of these tested positive for internal radioactive contamination. Internal exposure to radioactive isotopes is more serious than external exposure, as these particles lodge in the body for decades, irradiating the surrounding tissues, thus increasing the risk of future cancers and other health effects. A second leak at the plant occurred shortly after the first, releasing plutonium and other radiotoxins, causing concern for communities living near the repository. Since opening in 1999, the WIPP "pilot site" has received over 11,000 shipments of TRU waste (transuranic waste). During the February 14, 2014 leak, 22 workers were exposed to radioactive materials. Don Hancock, Director of the Nuclear Waste Safety Program for the SouthWest Research and information Center describes the theory of how nitrate salts in the "kitty litter" absorbent interacted with plutonium causing the breach of one or more 55-gallon drums stored at WIPP through a chemical reaction that caused an inflagration. Fundamental questions remain regarding the Department of Energy's clean up standards for WIPP, as there is not a "clean-up" standard or regulation for the underground site, by either the DOE oversight or the company contracted to oversee the site, Nuclear Waste Partnership. Over the past 15 years, 91,000 cubic meters of radioactive waste, and more than 171,000 containers of radioactive waste have been placed at WIPP - more than any other site in the country.

text: The discovery of radioactivity introduced another factor in the calculation. After Henri Becquerel's initial discovery in 1896, Marie and Pierre Curie discovered the radioactive elements polonium and radium in 1898; and in 1903, Pierre Curie and Albert Laborde announced that radium produces enough heat to melt its own weight in ice in less than an hour. Geologists quickly realized that this upset the assumptions underlying most calculations of the age of Earth.These had assumed that the original heat of the Earth and Sun had dissipated steadily into space, but radioactive decay meant that this heat had been continually replenished.  George Darwin and John Joly were the first to point this out, in 1903.

text: The discovery of

text: radioactivity

text: introduced another factor in the calculation. After

text: Henri Becquerel

text: 's initial discovery in 1896,

text: Marie

text: and

text: Pierre Curie

text: discovered the radioactive elements

text: polonium

text: and

text: radium

text: in 1898; and in 1903, Pierre Curie and

text: Albert Laborde

text: announced that radium produces enough heat to melt its own weight in ice in less than an hour. Geologists quickly realized that this upset the assumptions underlying most calculations of the age of Earth.These had assumed that the original heat of the Earth and Sun had dissipated steadily into space, but radioactive decay meant that this heat had been continually replenished.  George Darwin and John Joly were the first to point this out, in 1903.

text: Containment systems are designed to prevent the release of radioactive material into the environment.

text: In the fall of 1943, Alvarez returned to the United States with an offer from Robert Oppenheimer to work at Los Alamos on the Manhattan project. But Oppenheimer suggested that he first spend a few months at the University of Chicago working with Enrico Fermi before coming to Los Alamos. During these months, General Leslie Groves asked Alvarez to think of a way that the US could find out if the Germans were operating any nuclear reactors, and, if so, where they were. Alvarez suggested that an airplane could carry a system to detect the radioactive gases that a reactor produces, particularly xenon 133. The equipment did fly over Germany, but detected no radioactive xenon because the Germans had not built a reactor capable of a chain reaction. This was the first idea of monitoring fission products for intelligence gathering. It would become extremely important after the war.

text: In the fall of 1943, Alvarez returned to the United States with an offer from

text: Robert Oppenheimer

text: to work at

text: Los Alamos

text: on the

text: Manhattan project

text: . But Oppenheimer suggested that he first spend a few months at the

text: University of Chicago

text: working with

text: Enrico Fermi

text: before coming to Los Alamos. During these months, General

text: Leslie Groves

text: asked Alvarez to think of a way that the US could find out if the Germans were operating any

text: nuclear reactor

text: s, and, if so, where they were. Alvarez suggested that an airplane could carry a system to detect the radioactive gases that a reactor produces, particularly

text: xenon 133

text: . The equipment did fly over Germany, but detected no radioactive xenon because the Germans had not built a reactor capable of a chain reaction. This was the first idea of monitoring

text: fission product

text: s for

entity_name: List of intelligence gathering disciplines

text: intelligence gathering

text: . It would become extremely important after the war.

text: Cooling for the plant's steam condenser was provided by circulating water through it, drawn from the adjacent Connecticut river. This water did not come in contact with the nuclear reactor and was not radioactive.  The cooling towers were used to cool water returning from the condenser before it was discharged back into the river at times when it was too warm to comply with the environmental discharge permit. In 2007 the fourth cell of the west cooling tower collapsed, spilling some of the non-radioactive, cooling water. The collapse was an "industrial safety event," which did not threaten the integrity of the reactor or release any radiation into the environment. The NRC stated that the remaining cooling tower had enough capacity to allow the plant to operate at full output, however, until September 16, 2007 the reactor was kept at 50% power.

text: Cosmogenic nuclides (or cosmogenic isotopes) are rare isotopes created when a high-energy cosmic ray interacts with the nucleus of an in situ Solar System atom, causing nucleons (protons and neutrons) to be expelled from the atom (see cosmic ray spallation). These isotopes are produced within Earth materials such as rocks or soil, in Earth's atmosphere, and in extraterrestrial items such as meteorites.  By measuring cosmogenic isotopes, scientists are able to gain insight into a range of geological and astronomical processes.  There are both radioactive and stable cosmogenic isotopes.  Some of these radioisotopes are tritium, carbon-14 and phosphorus-32.

text: Cosmogenic nuclides (or cosmogenic isotopes) are rare

text: isotope

text: s created when a high-energy

text: cosmic ray

text: interacts with the

text: nucleus

text: of an

text: in situ

text: Solar System

text: atom

text: , causing nucleons (protons and neutrons) to be expelled from the atom (see

text: cosmic ray spallation

text: ). These isotopes are produced within Earth materials such as

text: rock

text: s or

text: soil

text: , in

text: Earth's

text: atmosphere

text: , and in extraterrestrial items such as

text: meteorite

text: s.  By measuring cosmogenic isotopes,

text: scientist

text: s are able to gain insight into a range of

text: geological

text: and

text: astronomical

text: processes.  There are both

text: radioactive

text: and

text: stable

text: cosmogenic isotopes.  Some of these radioisotopes are

text: tritium

text: and

text: These findings were consistent with studies of the effects of previous radioactivity releases. In 1945, millions of Japanese were exposed to radiation from nuclear weapons, and the effects can still be measured. Today, nearly half (44.8%) the survivors of Nagasaki studied have identifiable thyroid disease, with the American Medical Association reporting "it is remarkable that a biological effect from a single brief environmental exposure nearly 60 years in the past is still present and can be detected." This, as well as the development of thyroid cancer among residents in the North Pacific from radioactive fallout following the United States' nuclear weapons testing in the 1950s (on islands nearly 200 miles downwind of the tests) were instrumental in the decision by the FDA in 1978 to issue a request for the availability of KI for thyroid protection in the event of a release from a commercial nuclear power plant or weapons-related nuclear incident. Noting that KI's effectiveness was "virtually complete" and finding that iodine in the form of potassium iodide (KI) was substantially superior to other forms including iodate (KIO) in terms of safety, effectiveness, lack of side effects, and speed of onset, the FDA invited manufacturers to submit applications to produce and market KI.

text: These findings were consistent with studies of the effects of previous radioactivity releases. In 1945, millions of Japanese were exposed to radiation from nuclear weapons, and the effects can still be measured. Today, nearly half (44.8%) the survivors of Nagasaki studied have identifiable thyroid disease, with the American Medical Association reporting "it is remarkable that a biological effect from a single brief environmental exposure nearly 60 years in the past is still present and can be detected." This, as well as the development of thyroid cancer among residents in the North Pacific from radioactive fallout following the

text: United States' nuclear weapons testing

text: in the 1950s (on islands nearly 200 miles downwind of the tests) were instrumental in the decision by the FDA in 1978 to issue a request for the availability of KI for thyroid protection in the event of a release from a commercial nuclear power plant or weapons-related nuclear incident. Noting that KI's effectiveness was "virtually complete" and finding that iodine in the form of potassium iodide (KI) was substantially superior to other forms including

text: iodate (KIO)

text: in terms of safety, effectiveness, lack of side effects, and speed of onset, the FDA invited manufacturers to submit applications to produce and market KI.

text: The early researchers also discovered that many other chemical elements, besides uranium, have radioactive isotopes. A systematic search for the total radioactivity in uranium ores also guided Pierre and Marie Curie to isolate two new elements: polonium and radium. Except for the radioactivity of radium, the chemical similarity of radium to barium made these two elements difficult to distinguish.

text: The early researchers also discovered that many other

text: chemical element

text: s, besides uranium, have

text: radioactive isotope

text: s. A systematic search for the total radioactivity in uranium ores also guided

text: Pierre

text: and

text: Marie Curie

text: to isolate two new elements:

text: polonium

text: and

text: radium

text: . Except for the radioactivity of radium, the chemical similarity of radium to

text: barium

text: made these two elements difficult to distinguish.

text: The exposure of a human body to ionizing radiation has the same harmful effects whether the source of the radiation is a medical X-ray machine, a nuclear power plant or radiation in space. The degree of the harmful effect depends on the length of exposure and the radiation's energy density. The ever-present radiation belts extend down to the altitude of manned spacecraft such as the International Space Station (ISS) and the Space Shuttle, but the amount of exposure is within the acceptable lifetime exposure limit under normal conditions. During a major space weather event that includes an SEP burst, the flux can increase by orders of magnitude. Areas within ISS provide shielding that can keep the total dose within safe limits. For the Space Shuttle, such an event would have required immediate mission termination.

text: The exposure of a human body to

text: ionizing radiation

text: has the same

text: harmful effects

text: whether the source of the radiation is a medical

text: X-ray machine

text: , a

text: nuclear power plant

text: or radiation in space. The degree of the harmful effect depends on the length of exposure and the radiation's

text: energy density

text: . The ever-present

text: radiation belt

text: s extend down to the altitude of manned spacecraft such as the

text: International Space Station

text: (ISS) and the

text: Space Shuttle

text: , but the amount of exposure is within the

text: acceptable lifetime exposure limit

text: under normal conditions. During a major space weather event that includes an SEP burst, the flux can increase by orders of magnitude. Areas within ISS provide shielding that can keep the total dose within safe limits. For the

text: Space Shuttle

text: , such an event would have required immediate mission termination.

text: It is important to note that a vast number of processes are able to release radioactivity into the environment, for example the action of cosmic rays on the air is responsible for the formation of radioisotopes (such as C and P), the decay of Ra forms Rn which is a gas which can diffuse through rocks before entering buildings and dissolve in water and thus enter drinking water in addition human activities such as bomb tests, accidents, and normal releases from industry have resulted in the release of radioactivity.

text: It is important to note that a vast number of processes are able to release radioactivity into the environment, for example the action of

text: cosmic ray

text: s on the air is responsible for the formation of radioisotopes (such as C and P), the decay of Ra forms Rn which is a gas which can diffuse through rocks before entering buildings and dissolve in water and thus enter

text: drinking water

text: in addition human activities such as

text: bomb test

text: s, accidents, and normal releases from industry have resulted in the release of radioactivity.

text: Some isotopes are radioactive, and are therefore referred to as radioisotopes or radionuclides, whereas others have never been observed to decay radioactively and are referred to as stable isotopes or stable nuclides. For example,  is a radioactive form of carbon, whereas  and  are stable isotopes. There are about 339 naturally occurring nuclides on Earth, of which 286 are primordial nuclides, meaning that they have existed since the Solar System's formation.

text: Some isotopes are

text: radioactive

text: , and are therefore referred to as radioisotopes or

text: radionuclide

text: s, whereas others have never been observed to decay radioactively and are referred to as stable isotopes or

text: stable nuclide

text: s. For example,  is a radioactive form of carbon, whereas  and  are stable isotopes. There are about 339 naturally occurring nuclides on Earth, of which 286 are

text: primordial nuclide

text: s, meaning that they have existed since the

text: Solar System

text: 's formation.

text: 2015 - The CWIS Radiation Exposure and Risk Assessment Action Project produced the first of a series of in depth articles published in Intercontinental Cry Magazine (https://intercontinentalcry.org/fourth-world-nuclear-cloud/) disclosing the extent to which the United States, Russia, China, Britain, France, Pakistan, Israel, and India detonated nuclear bombs and create waste disposal sites that exposed 23 indigenous territories to radioactive contamination and toxic chemical risks from 1945 to 2015.

text: Up to the point where the food is processed by irradiation, the food is processed in the same way as all other food. To treat the food, they are exposed to a radioactive source, for a set period of time to achieve a desired dose. Radiation may be emitted by a radioactive substance, or by X-ray and electron beam accelerators. Special precautions are taken to ensure the food stuffs never come in contact with the radioactive substances and that the personnel and the environment are protected from exposure radiation.Irradiation treatments are typically classified by dose (high, medium, and low), but are sometimes classified by the effects of the treatment (radappertization, radicidation and radurization). Food irradiation is sometimes referred to as "cold pasteurization" or "electronic pasteurization" because ionizing the food does not heat the food to high temperatures during the process, and the effect is similar to heat pasteurization. The term "cold pasteurization" is controversial because the term may be used to disguise the fact the food has been irradiated and pasteurization and irradiation are fundamentally different processes.

text: Up to the point where the food is processed by irradiation, the food is processed in the same way as all other food. To treat the food, they are exposed to a radioactive source, for a set period of time to achieve a desired dose. Radiation may be emitted by a radioactive substance, or by X-ray and electron beam accelerators. Special precautions are taken to ensure the food stuffs never come in contact with the radioactive substances and that the personnel and the environment are protected from exposure radiation.Irradiation treatments are typically classified by dose (high, medium, and low), but are sometimes classified by the effects of the treatment (

text: radappertization

text: radicidation

text: and

text: radurization

text: ). Food irradiation is sometimes referred to as "cold pasteurization" or "electronic pasteurization" because ionizing the food does not heat the food to high temperatures during the process, and the effect is similar to heat pasteurization. The term "cold pasteurization" is controversial because the term may be used to disguise the fact the food has been irradiated and pasteurization and irradiation are fundamentally different processes.

text: Curie began her research with her parents Marie Curie and Pierre Curie studying natural radioactivity found in radioactive isotopes. Irene and her husband branched off from the Curie's to further research with turning stable isotopes into radioactive isotopes via alpha particles.

text: Curie began her research with her parents

text: Marie Curie

text: and

text: Pierre Curie

text: studying natural radioactivity found in radioactive isotopes. Irene and her husband branched off from the Curie's to further research with turning stable isotopes into radioactive isotopes via alpha particles.

text: In nuclear science, the decay chain refers to the radioactive decay of different discrete radioactive decay products as a chained series of transformations. They are also known as "radioactive cascades". Most radioisotopes do not decay directly to a stable state, but rather undergo a series of decays until eventually a stable isotope is reached.

text: In

text: nuclear science

text: , the decay chain refers to the

text: radioactive decay

text: of different discrete radioactive

text: decay product

text: s as a chained series of transformations. They are also known as "radioactive cascades". Most

text: radioisotopes

text: do not decay directly to a stable state, but rather undergo a series of decays until eventually a stable

text: isotope

text: is reached.

text: The Soviet submarine K-27 was scuttled in Stepovogo Bay with its two reactors filled with spent nuclear fuel.  At a seminar in February 2012 it was revealed that the reactors on board the submarine could re-achieve criticality and explode (a buildup of heat leading to a steam explosion vice nuclear). The catalogue of waste dumped at sea by the Soviets, according to documents seen by Bellona, includes some 17,000 containers of radioactive waste, 19 ships containing radioactive waste, 14 nuclear reactors, including five that still contain spent nuclear fuel; 735 other pieces of radioactively contaminated heavy machinery, and the K-27 nuclear submarine with its two reactors loaded with nuclear fuel.

text: The

text: Soviet submarine K-27

text: was scuttled in Stepovogo Bay with its two reactors filled with spent nuclear fuel.  At a seminar in February 2012 it was revealed that the reactors on board the submarine could re-achieve

text: criticality

text: and explode (a buildup of heat leading to a steam explosion vice nuclear). The catalogue of waste dumped at sea by the Soviets, according to documents seen by Bellona, includes some 17,000 containers of radioactive waste, 19 ships containing radioactive waste, 14 nuclear reactors, including five that still contain spent nuclear fuel; 735 other pieces of radioactively contaminated heavy machinery, and the K-27 nuclear submarine with its two reactors loaded with nuclear fuel.

text: The new phenomenon of radioactivity was seized upon by the manufacturers of quack medicine (as had the discoveries of electricity and magnetism, earlier), and a number of patent medicines and treatments involving radioactivity were put forward.

text: The new phenomenon of radioactivity was seized upon by the manufacturers of

text: quack medicine

text: (as had the discoveries of

text: electricity

text: and

text: magnetism

text: , earlier), and a number of

text: patent medicine

text: s and treatments involving radioactivity were put forward.

text: The Moon has an atmosphere so tenuous as to be nearly vacuum, with a total mass of less than . The surface pressure of this small mass is around 3 × 10 atm (0.3 nPa); it varies with the lunar day. Its sources include outgassing and sputtering, a product of the bombardment of lunar soil by solar wind ions. Elements that have been detected include sodium and potassium, produced by sputtering (also found in the atmospheres of Mercury and Io); helium-4 and neon from the solar wind; and argon-40, radon-222, and polonium-210, outgassed after their creation by radioactive decay within the crust and mantle. The absence of such neutral species (atoms or molecules) as oxygen, nitrogen, carbon, hydrogen and magnesium, which are present in the regolith, is not understood. Water vapour has been detected by Chandrayaan-1 and found to vary with latitude, with a maximum at ~60–70 degrees; it is possibly generated from the sublimation of water ice in the regolith. These gases either return into the regolith due to the Moon's gravity or be lost to space, either through solar radiation pressure or, if they are ionized, by being swept away by the solar wind's magnetic field.

text: The Moon has an atmosphere so tenuous as to be nearly

text: vacuum

text: , with a total mass of less than . The surface pressure of this small mass is around 3 × 10

text: atm

text: nPa

text: ); it varies with the lunar day. Its sources include

text: outgassing

text: and

text: sputtering

text: , a product of the bombardment of lunar soil by

text: solar wind

text: ions. Elements that have been detected include

text: sodium

text: and

text: potassium

text: , produced by sputtering (also found in the atmospheres of

text: Mercury

text: and

text: Io

text: and

text: neon

text: from the solar wind; and

text: , and

text: , outgassed after their creation by

text: radioactive decay

text: within the crust and mantle. The absence of such neutral species (atoms or molecules) as

text: oxygen

text: nitrogen

text: carbon

text: hydrogen

text: and

text: magnesium

text: , which are present in the

text: regolith

text: , is not understood. Water vapour has been detected by

text: and found to vary with latitude, with a maximum at ~60–70 degrees; it is possibly generated from the

text: sublimation

text: of water ice in the regolith. These gases either return into the regolith due to the Moon's gravity or be lost to space, either through solar radiation pressure or, if they are ionized, by being swept away by the solar wind's magnetic field.

text: Radioactive steam will vent into the atmosphere due to the water eventually evaporating. The spent fuel will eventually set fire to the building, and the steam pressure will cause the storage facilities to explode, causing a (non nuclear) explosion, emitting radiation not only in the immediate area of the plant but around the globe due to winds.  The resulting nuclear disasters spread fallout over large areas. This is repeated dozens of times as shutdown nuclear plants and spent fuel houses explode.  Radioactive clouds cross the skies and rain carries the radiation to the ground. Most plants and small animals within the affected zones die. Larger animals (like deer) flee to unaffected regions, not because they notice the radiation, but because of the lack of food.

text: Radioactive steam will vent into the atmosphere due to the water eventually evaporating. The spent fuel will eventually set fire to the building, and the

text: steam

text: pressure will cause the storage facilities to explode, causing a (non nuclear) explosion, emitting radiation not only in the immediate area of the plant but around the globe due to winds.  The resulting

text: nuclear disaster

text: s spread fallout over large areas. This is repeated dozens of times as shutdown nuclear plants and spent fuel houses explode.

text: Radioactive cloud

text: s cross the skies and

text: rain

text: carries the

text: radiation

text: to the ground. Most plants and small animals within the affected zones die. Larger animals (like

text: deer

text: ) flee to unaffected regions, not because they notice the radiation, but because of the lack of food.

text: The natural radioisotope of calcium, calcium-48, makes up about 0.1874% of natural calcium, and, thus, natural calcium is weakly radioactive. Barium-130 makes up approximately 0.1062% of natural barium, and, thus, barium is weakly radioactive, as well.

text: Also in the USA, Regulatory Guide 1.21, Measuring, Evaluating, and Reporting Radioactivity in Solid Wastes and Releases of Radioactive Materials in Liquid and Gaseous Effluents from Light-Water-Cooled Nuclear Power Plants is highly relevant to this CPAM application.

text: As a part of the Run series, he is shown being turned into a cyborg with an enhanced physique, partial body armor and a series of flame-spewing nozzles implanted in his chest, belly, face, mouth and hands. He further enhances his body by an experimental radioactive infusion process: as a result he gains a metahuman body composed of molten material, able to increase his mass and density at will and radiate high temperature radiations. In this new form he's shown to be unable, whether due to a physical limitation or simply because he is incapable of thinking that way, to reduce his increased mass, becoming in a short while a behemoth so heavy and dense that he loses the ability to move.

text: As a part of the Run series, he is shown being turned into a

text: cyborg

text: with an enhanced physique, partial body armor and a series of flame-spewing nozzles implanted in his chest, belly, face, mouth and hands. He further enhances his body by an experimental radioactive infusion process: as a result he gains a

text: metahuman

text: body composed of molten material, able to increase his mass and density at will and radiate high temperature radiations. In this new form he's shown to be unable, whether due to a physical limitation or simply because he is incapable of thinking that way, to reduce his increased mass, becoming in a short while a behemoth so heavy and dense that he loses the ability to move.

text: Based in Tokyo, the JRIA's goal is to disseminate the technologies associated with radioisotope and radiation use and promote their safe handling. Its major activities include academic activities, supplying radioisotopes, labeled compounds and radiopharmaceuticals, and collecting and treating radioactive wastes.

text: Based in

text: Tokyo

text: , the JRIA's goal is to disseminate the technologies associated with radioisotope and radiation use and promote their safe handling. Its major activities include academic activities, supplying radioisotopes, labeled compounds and radiopharmaceuticals, and collecting and treating radioactive wastes.

text: Other UFO researchers point out that high-energy ionizing radiation of the kind that can cause damage to human beings (e.g. gamma radiation) does not induce radioactivity in objects, and would not have left behind any residual radioactivity in the area.

text: Note especially that Niépce mentions "Edmond Becquerel", the father of Henri Becquerel, who would later be credited with the discovery of radioactivity.  Indeed, in 1868, Edmond Becquerel published a book, La lumière:  ses causes et ses effets (Light:  its causes and its effects), in which he mentioned Niépce's findings; specifically, that objects that were coated with uranium nitrate could expose photographic plates in the dark.<ref>On the controversy about whether Henri Becquerel knew about Niépce de Saint-Victor's earlier discovery of radioactivity in uranium, see:

text: As discussed above, only 80 elements have any stable isotopes, and 26 of these have only one stable isotope. Thus, about two-thirds of stable elements occur naturally on Earth in multiple stable isotopes, with the largest number of stable isotopes for an element being ten, for tin (). There are about 94 elements found naturally on Earth (up to plutonium inclusive), though some are detected only in very tiny amounts, such as plutonium-244. Scientists estimate that the elements that occur naturally on Earth (some only as radioisotopes) occur as 339 isotopes (nuclides) in total. Only 254 of these naturally occurring isotopes are stable in the sense of never having been observed to decay as of the present time. An additional 35 primordial nuclides (to a total of 289 primordial nuclides), are radioactive with known half-lives, but have half-lives longer than 80 million years, allowing them to exist from the beginning of the Solar System. See list of nuclides for details.

text: As discussed above, only 80 elements have any stable isotopes, and 26 of these have only one stable isotope. Thus, about two-thirds of stable elements occur naturally on Earth in multiple stable isotopes, with the largest number of stable isotopes for an element being ten, for

text: tin

text: (). There are about 94 elements found naturally on Earth (up to

text: plutonium

text: inclusive), though some are detected only in very tiny amounts, such as

text: . Scientists estimate that the elements that occur naturally on Earth (some only as radioisotopes) occur as 339 isotopes (

text: nuclide

text: s) in total. Only 254 of these naturally occurring isotopes are stable in the sense of never having been observed to decay as of the present time. An additional 35

text: primordial nuclide

text: s (to a total of 289 primordial nuclides), are radioactive with known half-lives, but have half-lives longer than 80 million years, allowing them to exist from the beginning of the Solar System. See

text: list of nuclides

text: for details.

text: In practice, however, a nuclear meltdown is often part of a larger chain of disasters (although there have been so few meltdowns in the history of nuclear power that there is not a large pool of statistical information from which to draw a credible conclusion as to what "often" happens in such circumstances). For example, in the Chernobyl accident, by the time the core melted, there had already been a large steam explosion and graphite fire and major release of radioactive contamination (as with almost all Soviet reactors, there was no containment structure at Chernobyl).Also, before a possible meltdown occurs, pressure can already be rising in the reactor, and to prevent a meltdown by restoring the cooling of the core, operators are allowed to reduce the pressure in the reactor by releasing (radioactive) steam into the environment. This enables them to inject additional cooling water into the reactor again.

text: In practice, however, a nuclear meltdown is often part of a larger chain of disasters (although there have been so few meltdowns in the history of nuclear power that there is not a large pool of statistical information from which to draw a credible conclusion as to what "often" happens in such circumstances). For example, in the Chernobyl accident, by the time the core melted, there had already been a large steam explosion and graphite fire and major release of radioactive contamination (as with almost all

text: Soviet

text: reactors, there was no

text: containment structure

text: at Chernobyl).Also, before a possible meltdown occurs, pressure can already be rising in the reactor, and to prevent a meltdown by restoring the cooling of the core, operators are allowed to reduce the pressure in the reactor by releasing (radioactive) steam into the environment. This enables them to inject additional cooling water into the reactor again.

text: Prior to the widespread use of fluorescence in the past three decades radioactivity was the most common label.

text: Prior to the widespread use of

text: fluorescence

text: in the past three decades radioactivity was the most common label.

text: In as early as 1929, it was decided that Sizoo act as professor at the newly established Faculty of Mathematics and Physics.  Despite his young age he was the only candidate who met the scientific requirements, the right beliefs, and had agreed to the task. Sizoo promoted the then emerging field of radioactivity, partly because there were no other laboratories in the Netherlands exploring this area depth.  His own research focused on natural radioactive substances.

text: In as early as 1929, it was decided that Sizoo act as professor at the newly established Faculty of Mathematics and Physics.  Despite his young age he was the only candidate who met the scientific requirements, the right beliefs, and had agreed to the task. Sizoo promoted the then emerging field of

text: radioactivity

text: , partly because there were no other laboratories in the

text: Netherlands

text: exploring this area depth.  His own research focused on natural

text: radioactive

text: substances.

text: Radiation is a carcinogen and causes numerous effects on living organisms and systems. The environmental impacts of nuclear power plant disasters such as the Chernobyl disaster, the Fukushima Daiichi nuclear disaster and the Three Mile Island accident, among others, persist indefinitely, though several other factors contributed to these events including improper management of fail safe systems and natural disasters putting uncommon stress on the generators. The radioactive decay rate of particles varies greatly, dependent upon the nuclear properties of a particular isotope. Radioactive Plutonium-244 has a half-life of 80.8 million years, which indicates the time duration required for half of a given sample to decay, though very little plutonium-244 is produced in the nuclear fuel cycle and lower half-life materials have lower activity thus giving off less dangerous radiation.

text: Radiation is a

text: carcinogen

text: and causes numerous effects on living organisms and systems. The environmental impacts of nuclear power plant disasters such as the

text: Chernobyl disaster

text: , the

text: Fukushima Daiichi nuclear disaster

text: and the

text: Three Mile Island accident

text: , among others, persist indefinitely, though several other factors contributed to these events including improper management of fail safe systems and natural disasters putting uncommon stress on the generators. The radioactive decay rate of particles varies greatly, dependent upon the nuclear properties of a particular isotope. Radioactive

text: has a half-life of 80.8 million years, which indicates the time duration required for half of a given sample to decay, though very little plutonium-244 is produced in the nuclear fuel cycle and lower half-life materials have lower activity thus giving off less dangerous radiation.

text: Radioactive isotope labeling experiments provide a powerful tool for determining the structure of organic molecules. By systematically decomposing the 2-norbornyl cation and analyzing the amount of radioactive isotope in each decomposition product, researchers were able to show further evidence for the non-classical picture of delocalized bonding (see Figure 9). Proponents of the non-classical picture would expect 50% of the generated CO in the decomposition in Figure 9 to contain C, while proponents of the classical picture would expect more of the generated CO to be radioactive due to the short-lived nature of the cation. 40% of the carbon dioxide produced via decomposition has been observed to be radioactive, suggesting that the non-classical picture is more correct.

text: His second film, Radioactive Dreams, was awarded the Golden Raven at the 5th Brussels International Fantastic Film Festival in 1987. "Radioactive Dreams" recently screened at Exhumed Films' 2013 eX Fest.

text: His second film,

text: Radioactive Dreams

text: , was awarded the Golden Raven at the 5th

entity_name: Brussels International Fantastic Film Festival

text: Brussels International Fantastic Film Festival

text: in 1987. "Radioactive Dreams" recently screened at

text: Exhumed Films

text: ' 2013 eX Fest.

text: Radioactive material is found throughout nature. Detectable amounts occur naturally in soil, rocks, water, air, and vegetation, from which it is inhaled and ingested into the body. In addition to this internal exposure, humans also receive external exposure from radioactive materials that remain outside the body and from cosmic radiation from space. The worldwide average natural dose to humans is about 2.4 millisievert (mSv) per year. This is four times the worldwide average artificial radiation exposure, which in 2008 amounted to about 0.6 mSv per year. In some rich countries, like the US and Japan, artificial exposure is, on average, greater than the natural exposure, due to greater access to medical imaging. In Europe, average natural background exposure by country ranges from under 2 mSv annually in the United Kingdom to more than 7 mSv annually for some groups of people in Finland.

text: Radioactive material is found throughout nature. Detectable amounts occur naturally in

text: soil

text: , rocks, water, air, and vegetation, from which it is inhaled and ingested into the body. In addition to this internal exposure, humans also receive external exposure from radioactive materials that remain outside the body and from cosmic radiation from space. The worldwide average natural

text: dose

text: to humans is about 2.4

text: millisievert

text: (mSv) per year. This is four times the worldwide average artificial radiation exposure, which in 2008 amounted to about 0.6 mSv per year. In some rich countries, like the US and Japan, artificial exposure is, on average, greater than the natural exposure, due to greater access to

text: medical imaging

text: . In Europe, average natural background exposure by country ranges from under 2 mSv annually in the United Kingdom to more than 7 mSv annually for some groups of people in Finland.

text: Radiation levels in Tokyo on 15 March were at one point measured at 0.809 μSv/hour although they were later reported to be at "about twice the normal level". Later, on 15 March 2011, Edano reported that radiation levels were lower and the average radiation dose rate over the whole day was 0.109 μSv/h. The wind direction on 15 March dispersed radioactivity away from the land and back over the Pacific Ocean. On 16 March, the Japanese radiation warning system, SPEEDI, indicated high levels of radioactivity would spread further than 30 km from the plant, but Japanese authorities did not relay the information to citizens because "the location or the amount of radioactive leakage was not specified at the time." From 17 March, IAEA received regular updates on radiation from 46 cities and indicated that they had remained stable and were "well below levels which are dangerous to human health". In hourly measurements of these cities until 20 March, no significant changes were reported.

text: Radiation levels in Tokyo on 15 March were at one point measured at 0.809 μ

text: Sv

text: /hour although they were later reported to be at "about twice the normal level". Later, on 15 March 2011, Edano reported that radiation levels were lower and the average radiation dose rate over the whole day was 0.109 μSv/h. The wind direction on 15 March dispersed radioactivity away from the land and back over the Pacific Ocean. On 16 March, the Japanese radiation warning system, SPEEDI, indicated high levels of radioactivity would spread further than 30 km from the plant, but Japanese authorities did not relay the information to citizens because "the location or the amount of radioactive leakage was not specified at the time." From 17 March, IAEA received regular updates on radiation from 46 cities and indicated that they had remained stable and were "well below levels which are dangerous to human health". In hourly measurements of these cities until 20 March, no significant changes were reported.

text: Auger therapy (AT) is a form of radiation therapy for the treatment of cancer which relies on a large number of low-energy electrons (emitted by the Auger effect) to damage cancer cells, rather than the high-energy radiation used in traditional radiation therapy. Similar to other forms of radiation therapy, Auger therapy relies on radiation-induced damage to cancer cells (particularly DNA damage) to arrest cell division, stop tumor growth and metastasis and kill cancerous cells. It differs from other types of radiation therapy in that electrons emitted via the Auger effect (Auger electrons) are released in large numbers with low kinetic energy. Because of their low energy, these electrons damage cells over a very short range: less than the size of a single cell, on the order of nanometers. This very short-range delivery of energy permits highly targeted therapies, since the radiation-emitting nuclide is required to be inside the cell to cause damage to its nucleus. However, this is a technical challenge; Auger therapeutics must enter their cellular targets to be most effective. Auger therapeutics are small molecules, capable of entering cells of interest and binding to specific sub-cellular components, which contain one (or more) heavy atoms capable of emitting Auger electrons by radioactive decay or external excitation.

text: Auger therapy (AT) is a form of

text: radiation therapy

text: for the treatment of

text: cancer

text: which relies on a large number of low-energy

text: electron

text: s (emitted by the

text: Auger effect

text: ) to damage cancer cells, rather than the high-energy

text: radiation

text: used in traditional radiation therapy. Similar to other forms of radiation therapy, Auger therapy relies on radiation-induced damage to cancer

text: cells

text: (particularly

text: DNA

text: damage) to arrest

text: cell division

text: , stop

text: tumor

text: growth and

text: metastasis

text: and kill cancerous cells. It differs from other types of radiation therapy in that electrons emitted via the Auger effect (Auger electrons) are released in large numbers with low

text: kinetic energy

text: . Because of their low energy, these electrons damage cells over a very short range: less than the size of a single cell, on the order of

text: nanometers

text: . This very short-range delivery of energy permits highly targeted therapies, since the radiation-emitting

text: nuclide

text: is required to be inside the cell to cause damage to its

text: nucleus

text: . However, this is a technical challenge; Auger therapeutics must enter their cellular targets to be most effective. Auger therapeutics are small molecules, capable of entering cells of interest and binding to specific sub-cellular components, which contain one (or more) heavy atoms capable of emitting Auger electrons by radioactive decay or external excitation.

text: Despite thorium's radioactivity, the element has remained in use for a long time for applications not exploiting the effect as no suitable alternatives could be found. While a 1981 study estimated that a dose from using a thorium mantle every weekend would be safe for a person,  this was not the case for people manufacturing the mantles (and thus contacting many) as well as soils around some factory sites. A major shift occurred as late as in the 1990s, when most of these applications that do not depend on thorium's radioactivity declined quickly due to safety and environmental concerns as suitable safer replacements have been found. Due to concerns, some manufacturers have switched to other materials, such as yttrium, although these are usually either more expensive or less efficient. Other manufacturers continue to make thorium mantles, but moved their factories to developing countries. As recently as 2007, some companies continued to manufacture and sell thorium mantles without giving adequate information about their radioactivity, with some even fraudulently claiming them to be non-radioactive while in reality using large quantities of thorium, up to 259 milligrams per mantle.

text: Despite thorium's radioactivity, the element has remained in use for a long time for applications not exploiting the effect as no suitable alternatives could be found. While a 1981 study estimated that a dose from using a thorium mantle every weekend would be safe for a person,  this was not the case for people manufacturing the mantles (and thus contacting many) as well as soils around some factory sites. A major shift occurred as late as in the 1990s, when most of these applications that do not depend on thorium's radioactivity declined quickly due to safety and environmental concerns as suitable safer replacements have been found. Due to concerns, some manufacturers have switched to other materials, such as yttrium, although these are usually either more expensive or less efficient. Other manufacturers continue to make thorium mantles, but moved their factories to

text: developing countries

text: . As recently as 2007, some companies continued to manufacture and sell thorium mantles without giving adequate information about their radioactivity, with some even fraudulently claiming them to be non-radioactive while in reality using large quantities of thorium, up to 259 milligrams per mantle.

text: Disintegrations per minute (dpm) and disintegrations per second (dps) are measures of the activity of the source of radioactivity. The SI unit of radioactivity, the becquerel (Bq), is equivalent to one disintegration per second. This unit should not be confused with cps, which is the number of counts received by an instrument from the source. One dps (one dpm) is the number of atoms that have decayed in one second (one minute), not the number of atoms that have been measured as decayed.

text: Disintegrations per minute (dpm) and disintegrations per second (dps) are measures of the activity of the source of radioactivity. The SI unit of radioactivity, the

text: becquerel

text: (Bq), is equivalent to one disintegration per second. This unit should not be confused with cps, which is the number of counts received by an instrument from the source. One dps (one dpm) is the number of atoms that have decayed in one second (one minute), not the number of atoms that have been measured as decayed.

text: All objects emit electromagnetic radiation of a wavelength dependent on the object’s temperature.  The frequency of the radiation is inversely proportional to the temperature.  In infrared thermography, the radiation is detected and measured with infrared imagers (radiometers).  The imagers contain an infrared detector that converts the emitting radiation into electrical signals that are displayed on a color or black & white computer display monitor.

text: All objects emit

text: electromagnetic radiation

text: of a

text: wavelength

text: dependent on the object’s temperature.  The frequency of the radiation is inversely proportional to the temperature.  In

text: infrared thermography

text: , the radiation is detected and measured with infrared imagers (radiometers).  The imagers contain an infrared detector that converts the emitting radiation into

text: electrical

text: signals that are displayed on a color or black & white computer display monitor.

text: At different times after the accident, different isotopes were responsible for the majority of the external dose. The remaining quantity of any radioisotope, and therefore the activity of that isotope, after 7 decay half-lives have passed, is less than 1% of its initial magnitude, and it continues to reduce beyond 0.78% after 7 half-lives to 0.098% remaining after 10 half-lives have passed and so on. (Some radionuclides have decay products that are likewise radioactive, which is not accounted for here.) The release of radioisotopes from the nuclear fuel was largely controlled by their boiling points, and the majority of the radioactivity present in the core was retained in the reactor.

text: At different times after the accident, different

text: isotope

text: s were responsible for the majority of the external dose. The remaining quantity of any radioisotope, and therefore the activity of that isotope, after 7 decay

text: half-lives

text: have passed, is less than 1% of its initial magnitude, and it continues to reduce beyond 0.78% after 7 half-lives to 0.098% remaining after 10 half-lives have passed and so on. (Some radionuclides have decay products that are likewise radioactive, which is not accounted for here.) The release of radioisotopes from the nuclear fuel was largely controlled by their

text: boiling point

text: s, and the majority of the

text: radioactivity

text: present in the core was retained in the reactor.

text: On 11 October 2006, Reuters reported that higher than normal levels of radiation were detected in snails and other wildlife in the region, indicating there may still be dangerous amounts of radioactive material underground. The discovery occurred during an investigation being carried out by Spain's energy research agency CIEMAT and the U.S. Department of Energy. The U.S. and Spain agreed to share the cost of the initial investigation.

text: On 11 October 2006,

text: Reuters

text: reported that higher than normal levels of radiation were detected in snails and other wildlife in the region, indicating there may still be dangerous amounts of radioactive material underground. The discovery occurred during an investigation being carried out by Spain's energy research agency

text: CIEMAT

text: and the

text: U.S. Department of Energy

text: . The U.S. and Spain agreed to share the cost of the initial investigation.

text: The light curves for type Ia are mostly very uniform, with a consistent maximum absolute magnitude and a relatively steep decline in luminosity.  Their optical energy output is driven by radioactive decay of nickel-56 (half life 6 days), which then decays to radioactive cobalt-56 (half life 77 days). These radioisotopes from material ejected in the explosion excite surrounding material to incandescence. Studies of cosmology today rely on Ni radioactivity providing the energy for the optical brightness of supernovae of Type Ia, which are the "standard candles" of cosmology but whose diagnostic 847keV and 1238keV gamma rays were first detected only in 2014. The initial phases of the light curve decline steeply as the effective size of the photosphere decreases and trapped electromagnetic radiation is depleted.  The light curve continues to decline in the B band while it may show a small shoulder in the visual at about 40 days, but this is only a hint of a secondary maximum that occurs in the infra-red as certain ionised heavy elements recombine to produce infra-red radiation and the ejecta become transparent to it. The visual light curve continues to decline at a rate slightly greater than the decay rate of the radioactive cobalt (which has the longer half life and controls the later curve), because the ejected material becomes more diffuse and less able to convert the high energy radiation into visual radiation.  After several months, the light curve changes its decline rate again as positron emission becomes dominant from the remaining cobalt-56, although this portion of the light curve has been little-studied.

text: The light curves for type Ia are mostly very uniform, with a consistent maximum absolute magnitude and a relatively steep decline in luminosity.  Their optical energy output is driven by radioactive decay of nickel-56 (half life 6 days), which then decays to radioactive cobalt-56 (half life 77 days). These radioisotopes from material ejected in the explosion excite surrounding material to incandescence. Studies of cosmology today rely on

text: Ni

text: radioactivity providing the energy for the optical brightness of supernovae of Type Ia, which are the "standard candles" of cosmology but whose diagnostic 847keV and 1238keV gamma rays were first detected only in 2014. The initial phases of the light curve decline steeply as the effective size of the photosphere decreases and trapped electromagnetic radiation is depleted.  The light curve continues to decline in the B band while it may show a small shoulder in the visual at about 40 days, but this is only a hint of a secondary maximum that occurs in the infra-red as certain ionised heavy elements recombine to produce infra-red radiation and the ejecta become transparent to it. The visual light curve continues to decline at a rate slightly greater than the decay rate of the radioactive cobalt (which has the longer half life and controls the later curve), because the ejected material becomes more diffuse and less able to convert the high energy radiation into visual radiation.  After several months, the light curve changes its decline rate again as

text: positron emission

text: becomes dominant from the remaining cobalt-56, although this portion of the light curve has been little-studied.

text: Radiochemistry is the chemistry of radioactive materials, where radioactive isotopes of elements are used to study the properties and chemical reactions of non-radioactive isotopes (often within radiochemistry the absence of radioactivity leads to a substance being described as being inactive as the isotopes are stable). Much of radiochemistry deals with the use of radioactivity to study ordinary chemical reactions. This is very different from radiation chemistry where the radiation levels are kept too low to influence the chemistry.

text: Radiochemistry is the

text: chemistry

text: of

text: radioactive

text: materials, where radioactive

text: isotope

text: chemical reaction

text: s of non-radioactive isotopes (often within radiochemistry the absence of radioactivity leads to a substance being described as being inactive as the isotopes are stable). Much of radiochemistry deals with the use of

text: radioactivity

text: to study ordinary

text: chemical reaction

text: s. This is very different from

text: radiation chemistry

text: where the radiation levels are kept too low to influence the chemistry.

text: Despite the different techniques used for non-radioactive assays, they require that ligands exhibit similar binding characteristics to its radioactive equivalent. Thus, results in both non-radioactive and radioactive assays will remain consistent.  One of the largest differences between radioactive and non-radioactive ligand assays are in regards of dangers to human health. Radioactive assays are harmful in that they produce radioactive waste; whereas, non-radioactive ligand assays utilize a different method to avoid producing toxic waste. These methods include, but are not limited to, fluorescence polarization (FP), fluorescence resonance energy transfer (FRET), and surface plasmon resonance (SPR). In order to measure process of ligand-receptor binding, most non-radioactive methods require that labeling avoids interfering with molecular interactions.

text: Despite the different techniques used for non-radioactive assays, they require that ligands exhibit similar binding characteristics to its radioactive equivalent. Thus, results in both non-radioactive and radioactive assays will remain consistent.  One of the largest differences between radioactive and non-radioactive ligand assays are in regards of dangers to human health. Radioactive assays are harmful in that they produce radioactive waste; whereas, non-radioactive ligand assays utilize a different method to avoid producing toxic waste. These methods include, but are not limited to, fluorescence polarization (FP),

text: fluorescence resonance energy transfer

text: (FRET), and

text: surface plasmon resonance

text: (SPR). In order to measure process of ligand-receptor binding, most non-radioactive methods require that labeling avoids interfering with molecular interactions.

text: Other themes in the book include the dangers of nuclear power and radioactive fallout, as evidenced by the physical transformations of the townspeople which resemble the effects of radiation exposure, of unchecked technological advancement, and of the corrupting influence of power.

text: The General Purpose Heat Source is a U.S. DOE-designed radioactive heat source for Radioisotope Thermoelectric Generators (RTG) or Stirling radioisotope generators (SRG). It is meant for space applications and is packaged as a stackable module.

text: The General Purpose Heat Source is a

text: U.S. DOE

text: -designed radioactive heat source for

text: Radioisotope Thermoelectric Generator

text: s (RTG) or

text: Stirling radioisotope generator

text: s (SRG). It is meant for space applications and is packaged as a stackable module.

text: Nordström died in December 1923, at the age of 42, from pernicious anemia. The illness was perhaps caused by exposure to radioactive substances. Nordström was known to be interested in radioactivity, and a firm adherent to the then-widespread misconception that radioactivity was beneficial for one's health. Among his publications there is one from 1913 regarding the measurement of the radioactive emancipation power of different springs and ground waters in Finland. Nordström was known for experimenting with radioactive substances and for enjoying the Finnish sauna tradition using water from a spring rich in radium.

text: Nordström died in December 1923, at the age of 42, from

text: pernicious anemia

text: . The illness was perhaps caused by exposure to

text: radioactive

text: substances. Nordström was known to be interested in radioactivity, and a firm adherent to the then-widespread misconception that radioactivity was beneficial for one's health. Among his publications there is one from 1913 regarding the measurement of the radioactive emancipation power of different springs and ground waters in Finland. Nordström was known for experimenting with radioactive substances and for enjoying the

text: Finnish sauna

text: tradition using water from a spring rich in

text: radium

text: Radioisotopes can be transformed directly through changes in valence state by acting as acceptors or by acting as cofactors to enzymes. They can also be transformed indirectly by reducing and oxidizing agents produced by microorganisms that cause changes in pH or redox potential. Other processes include precipitation and complexation of surfactants, or chelating agents that bind to radioactive elements. Human intervention, on the other hand, can improve these processes through genetic engineering and omics, or by injection of microorganisms or nutrients into the treatment area.

text: Radioisotopes can be transformed directly through changes in

text: valence state

text: by acting as

text: acceptors

text: or by acting as

text: cofactors

text: to

text: enzymes

text: . They can also be transformed indirectly by

text: reducing

text: and

text: oxidizing agents

text: produced by microorganisms that cause changes in

text: pH

text: or

text: redox potential

text: . Other processes include

text: precipitation

text: and complexation of

text: surfactants,

text: or

text: chelating agents

text: that bind to radioactive elements. Human intervention, on the other hand, can improve these processes through

text: genetic engineering

text: and

text: omics

text: , or by injection of microorganisms or

text: nutrients

text: into the treatment area.

text: The device worked a long time at a much lower level that its nominal capacity. Testing started at Friday 17 June. This test was halted only 5 hours later, due to a sharp rise in radiation levels around equipment for adsorbing radioactive caesium. On 21 June TEPCO resumed testing of the system in full operation. The trial was halted shortly after the beginning because one pump automatically halted. An incorrect setting of some valve was found to be the cause later. On 22 June another incorrectly opened valve caused disruption in the ongoing test. It was found out that part of the contaminated water passed through only one of the system's three adsorbent chambers because of the faulty valve setting. The amount of highly contaminated water was growing 400 tons a day at that moment, as fresh water was used to cool the reactors.

text: The device worked a long time at a much lower level that its nominal capacity. Testing started at Friday 17 June. This test was halted only 5 hours later, due to a sharp rise in radiation levels around equipment for

text: adsorbing

text: radioactive caesium. On 21 June TEPCO resumed testing of the system in full operation. The trial was halted shortly after the beginning because one pump automatically halted. An incorrect setting of some

text: valve

text: was found to be the cause later. On 22 June another incorrectly opened valve caused disruption in the ongoing test. It was found out that part of the contaminated water passed through only one of the system's three adsorbent chambers because of the faulty valve setting. The amount of highly contaminated water was growing 400 tons a day at that moment, as fresh water was used to cool the reactors.

text: There are 33 known isotopes of krypton (Kr) with atomic mass numbers from 69 through 101. Naturally occurring krypton is made of six stable isotopes, two of which might theoretically be slightly radioactive, plus traces of radioisotopes that are produced by cosmic rays in the atmosphere.

text: There are 33 known

text: isotope

text: s of

text: krypton

text: (Kr) with

text: atomic mass number

text: s from 69 through 101. Naturally occurring krypton is made of six

text: stable isotope

text: s, two of which might theoretically be slightly

text: radioactive

text: , plus traces of

text: radioisotopes

text: that are produced by

text: cosmic rays

text: in the

text: atmosphere

text: R-flurbiprofen– r-tPA– R101933– R115777– radiation fibrosis– radiation oncologist– radiation physicist– radiation surgery– radiation therapist– radiation therapy– radical cystectomy– radical lymph node dissection– radical mastectomy– radical perineal prostatectomy– radical prostatectomy– radical retropubic prostatectomy– radioactive drug– radioactive iodine– radioactive palladium– radioactive seed– radiofrequency ablation– radiographer– radioimmunoguided surgery– radioimmunotherapy– radioisotope– radiolabeled– radiologic exam– radionuclide scanning– radiopharmaceutical– radiosensitization– radiosensitizer– radiosurgery– radiotherapy– raloxifene– raltitrexed– randomized clinical trial– ranpirnase– rapamycin– rapid hormone cycling– rapid-onset opioid– ras gene– rasburicase– rattlesnake root– ravuconazole– rebeccamycin– recombinant tissue plasminogen activator– reconstructive surgeon– reconstructive surgery– recurrent cancer– Red blood cell– Reed–Sternberg cell– reflux– refractory cancer– regional cancer– regional chemotherapy– regional enteritis– regional lymph node– regional lymph node dissection– rehabilitation specialist– relative survival rate– relaxation technique– remission induction therapy– remote brachytherapy– renal cell cancer– renal collecting tubule– renal glomerulus– renal tubular acidosis– retinoblastoma– retinoid– retinol– retinyl palmitate– retroperitoneal– retropubic prostatectomy– retrospective cohort study– retrospective study– retroviral vector– retrovirus– RevM10 gene– rhabdoid tumor– rhabdomyosarcoma– rhizoxin– ribavirin– ribonucleotide reductase inhibitor– rifampin– risedronate– ritonavir– rituximab– RK-0202– RMP-7– RNA– Ro 31-7453– Ro 50-3821– rofecoxib– rosiglitazone– RPI.4610– RPR 109881A– RSR13– RSV

text: R-flurbiprofen

text: r-tPA

text: radiation fibrosis

text: radiation oncologist

text: radiation physicist

text: radiation surgery

text: radiation therapist

text: radiation therapy

text: radical cystectomy

text: radical lymph node dissection

text: radical mastectomy

text: radical perineal prostatectomy

text: radical prostatectomy

text: radical retropubic prostatectomy

text: radioactive drug

text: radioactive iodine

text: radioactive palladium

text: radioactive seed

text: radiofrequency ablation

text: radiographer

text: radioimmunoguided surgery

text: radioimmunotherapy

text: radioisotope

text: radiolabeled

text: radiologic exam

text: radionuclide scanning

text: radiopharmaceutical

text: radiosensitization

text: radiosensitizer

text: radiosurgery

text: radiotherapy

text: raloxifene

text: raltitrexed

text: randomized clinical trial

text: ranpirnase

text: rapamycin

text: rapid hormone cycling

text: rapid-onset opioid

text: ras gene

text: rasburicase

text: rattlesnake root

text: ravuconazole

text: rebeccamycin

text: recombinant tissue plasminogen activator

text: reconstructive surgeon

text: reconstructive surgery

text: recurrent cancer

text: Red blood cell

text: Reed–Sternberg cell

text: reflux

text: refractory cancer

text: regional cancer

text: regional chemotherapy

text: regional enteritis

text: regional lymph node

text: regional lymph node dissection

text: rehabilitation specialist

text: relative survival rate

text: relaxation technique

text: remission induction therapy

text: remote brachytherapy

text: renal cell cancer

text: renal collecting tubule

text: renal glomerulus

text: renal tubular acidosis

text: retinoblastoma

text: retinoid

text: retinol

text: retinyl palmitate

text: retroperitoneal

text: retropubic prostatectomy

text: retrospective cohort study

text: retrospective study

text: retroviral vector

text: retrovirus

text: RevM10 gene

text: rhabdoid tumor

text: rhabdomyosarcoma

text: rhizoxin

text: ribavirin

text: ribonucleotide reductase inhibitor

text: rifampin

text: risedronate

text: ritonavir

text: rituximab

text: RNA

text: Ro 31-7453

text: Ro 50-3821

text: rofecoxib

text: rosiglitazone

text: RPR 109881A

text: RSV

text: On 12 February 2013, a  section of the roof of the turbine-building, adjacent to the sarcophagus, collapsed. At first it was assumed that the roof collapsed because of the weight of snow on it. However the amount of snow was not exceptional, and the report of a Ukrainian fact-finding panel concluded that the part collapse of the turbine-building was the result of sloppy repair work and aging of the structure. The report mentioned the possibility that the repaired part of the turbine-building added a larger strain on the total structure than expected, and the braces in the roof were damaged by corrosion and sloppy welding. Experts such as Valentin Kupny, former deputy director of the nuclear plant, did warn that the complex was on the verge of a collapse, leaving the building in an extremely dangerous condition. A proposed reinforcement in 2005 was cancelled by a superior official. After the 12 February incident, radioactivity levels were up to 19 becquerels per cubic meter of air: 12 times normal. The report assumed radioactive materials from inside the structure spread to the surroundings after the roof collapsed. All 225 workers employed by the Chernobyl complex and the French company that is building the new shelter were evacuated shortly after the collapse. According to the managers of the complex, radiation levels around the plant were at normal levels (between 5 and 6 µSv/h) and should not affect workers' health. According to Kupny the situation was underestimated by the Chernobyl nuclear complex managers, and information was kept secret.

text: The first published recognition of the cosmic microwave background (CMB) radiation as a detectable phenomenon appeared in a brief paper by Soviet astrophysicists A. G. Doroshkevich and Igor Novikov, entitled "Mean Density of Radiation in the Metagalaxy and Certain Problems in Relativistic Cosmology", in the spring of 1964.

text: The first published recognition of the

text: cosmic microwave background (CMB) radiation

text: as a detectable phenomenon appeared in a brief paper by

text: Soviet

text: astrophysicists

text: A. G. Doroshkevich

text: and

text: Igor Novikov

text: , entitled "Mean Density of Radiation in the Metagalaxy and Certain Problems in Relativistic Cosmology", in the spring of 1964.

text: Like many other releases of radioactivity into the environment, the Chernobyl release was controlled by the physical and chemical properties of the radioactive elements in the core. Particularly dangerous are the highly radioactive fission products, those with high nuclear decay rates that accumulate in the food chain, such as some of the isotopes of iodine, caesium and strontium. Iodine-131 and caesium-137 are responsible for most of the radiation exposure received by the general population.

text: Like many

text: other releases of radioactivity

text: into the environment, the Chernobyl release was controlled by the physical and chemical properties of the radioactive elements in the core. Particularly dangerous are the highly radioactive

text: fission products

text: , those with high

text: nuclear decay

text: rates that accumulate in the food chain, such as some of the isotopes of

text: iodine

text: caesium

text: and

text: strontium

text: . Iodine-131 and caesium-137 are responsible for most of the radiation exposure received by the general population.

text: Thirty radioisotopes have been characterized, with the most stable being alpha-decaying Gd (naturally occurring) with a half-life of 1.08×10 years, and Gd with a half-life of 1.79×10 years. All of the remaining radioactive isotopes have half-lives less than 74.7 years. The majority of these have half-lives less than 24.6 seconds. Gadolinium isotopes have 10 metastable isomers, with the most stable being Gd (t=110 seconds), Gd (t=85 seconds) and Gd (t=24.5 seconds).

text: Thirty radioisotopes have been characterized, with the most stable being alpha-decaying Gd (naturally occurring) with a half-life of 1.08×10 years, and Gd with a half-life of 1.79×10 years. All of the remaining radioactive isotopes have half-lives less than 74.7 years. The majority of these have half-lives less than 24.6 seconds. Gadolinium isotopes have 10 metastable

text: isomer

text: s, with the most stable being Gd (t=110 seconds), Gd (t=85 seconds) and Gd (t=24.5 seconds).

text: For comparison, the average 'background' dose of natural radiation received by a person per day, based on 2000 UNSCEAR estimate, makes BRET 6.6 μSv (660 μrem). However local exposures vary, with the yearly average in the US being around 3.6 mSv (360 mrem),<ref>Radioactivity in Nature

text: Radiation monitoring involves the measurement of radiation dose or radionuclide contamination for reasons related to the assessment or control of exposure to ionizing radiation or radioactive substances, and the interpretation of the results. The ‘measurement’ of dose often means the measurement of a dose equivalent quantity as a proxy (i.e. substitute) for a dose quantity that cannot be measured directly. Also, sampling may be involved as a preliminary step to measurement of the content of radionuclides in environmental media. The methodological and technical details of the design and operation of monitoring programmes and systems for different radionuclides, environmental media and types of facility are given in IAEA Safety Guide RS–G-1.8 and in IAEA Safety Report No. 64.

text: Radiation monitoring

text: involves the measurement of

text: radiation dose

text: or

text: radionuclide

text: contamination for reasons related to the assessment or control of exposure to

text: ionizing radiation

text: or radioactive substances, and the interpretation of the results. The ‘measurement’ of dose often means the measurement of a dose equivalent quantity as a proxy (i.e. substitute) for a dose quantity that cannot be measured directly. Also, sampling may be involved as a preliminary step to measurement of the content of radionuclides in environmental media. The methodological and technical details of the design and operation of monitoring programmes and systems for different radionuclides, environmental media and types of facility are given in

text: IAEA

text: Safety Guide RS–G-1.8 and in IAEA Safety Report No. 64.

text: Up to and after the discovery of the final component of the atomic nucleus, the neutron in 1932, most scientists did not seriously consider the possibility of elements heavier than uranium. While nuclear theory at the time did not explicitly prohibit their existence, there was little evidence to suggest that they did. However, the discovery of induced radioactivity by Irène and Frédéric Joliot-Curie in late 1933 opened up an entirely new method of researching the elements and inspired a small group of Italian scientists led by Enrico Fermi to begin a series of experiments involving neutron bombardment. Although the Joliot-Curies' experiment involved bombarding a sample of Al with alpha particles to produce the radioactive P, Fermi realized that using neutrons, which have no electrical charge, would most likely produce even better results than the positively charged alpha particles. Accordingly, in March 1934 he began systematically subjecting all of the then-known elements to neutron bombardment to determine whether others could also be induced to radioactivity.

text: Up to and after the discovery of the final component of the atomic nucleus, the

text: neutron

text: in 1932, most scientists did not seriously consider the possibility of elements heavier than uranium. While nuclear theory at the time did not explicitly prohibit their existence, there was little evidence to suggest that they did. However, the discovery of

text: induced radioactivity

text: by

text: Irène

text: and

text: Frédéric Joliot-Curie

text: in late 1933 opened up an entirely new method of researching the elements and inspired a small group of Italian scientists led by

text: Enrico Fermi

text: to begin a series of experiments involving neutron bombardment. Although the Joliot-Curies' experiment involved bombarding a sample of

text: Al

text: with

text: alpha particle

text: s to produce the radioactive

text: P

text: , Fermi realized that using neutrons, which have no electrical charge, would most likely produce even better results than the positively charged alpha particles. Accordingly, in March 1934 he began systematically subjecting all of the then-known elements to neutron bombardment to determine whether others could also be induced to radioactivity.

text: Between 21 March and mid-July, around 2.7 × 10 Bq of caesium-137 (about 8.4 kg) entered the ocean, with about 82 percent having flowed into the sea before 8 April. However, the Fukushima coast has some of the world's strongest currents and these transported the contaminated waters far into the Pacific Ocean, thus causing great dispersion of the radioactive elements. The results of measurements of both the seawater and the coastal sediments led to the supposition that the consequences of the accident, in terms of radioactivity, would be minor for marine life as of autumn 2011 (weak concentration of radioactivity in the water and limited accumulation in sediments). On the other hand, significant pollution of sea water along the coast near the nuclear plant might persist, due to the continuing arrival of radioactive material transported towards the sea by surface water running over contaminated soil. Organisms that filter water and fish at the top of the food chain are, over time, the most sensitive to caesium pollution. It is thus justified to maintain surveillance of marine life that is fished in the coastal waters off Fukushima. Despite caesium isotopic concentration in the waters off of Japan being 10 to 1000 times above concentration prior to the accident, radiation risks are below what is generally considered harmful to marine animals and human consumers.

text: In many cases members of the decay chain are far more radioactive than the original nuclide. Thus, although uranium is not dangerously radioactive when pure, some pieces of naturally occurring pitchblende are quite dangerous owing to their radium content. Similarly, thorium gas mantles are very slightly radioactive when new, but become far more radioactive after only a few months of storage.

text: In many cases members of the decay chain are far more radioactive than the original nuclide. Thus, although uranium is not dangerously radioactive when pure, some pieces of naturally occurring

text: pitchblende

text: are quite dangerous owing to their

text: radium

text: content. Similarly,

text: thorium

text: gas mantle

text: s are very slightly radioactive when new, but become far more radioactive after only a few months of storage.

text: In terms of consequences of radioactivity releases and core damage the Fukushima I nuclear accidents in 2011 were the worst experienced by the industry in addition to ranking among the worst civilian nuclear accidents, though no fatalities were caused and no serious exposure of radiation to workers occurred. The Tokaimura reprocessing plant fire in 1999 had 2 worker deaths, one more exposed to radiation levels above legal limits and over 660 others received detectable radiation doses but within permissible levels, well below the threshold to affect human health. The Mihama Nuclear Power Plant experienced a steam explosion in one of the turbine buildings in 2004 where five workers were killed and six injured.

text: In terms of consequences of radioactivity releases and core damage the

text: Fukushima I nuclear accidents

text: in 2011 were the worst experienced by the industry in addition to ranking among the worst

text: civilian nuclear accidents

text: , though no fatalities were caused and no serious exposure of radiation to workers occurred. The

text: Tokaimura

text: reprocessing plant fire in 1999 had 2 worker deaths, one more exposed to radiation levels above legal limits and over 660 others received detectable radiation doses but within permissible levels, well below the threshold to affect human health. The

text: Mihama Nuclear Power Plant

text: experienced a steam explosion in one of the turbine buildings in 2004 where five workers were killed and six injured.

text: Radon was the fifth radioactive element to be discovered, in 1899 by Ernest Rutherford and Robert B. Owens, after uranium, thorium, radium and polonium.  In 1900 Friedrich Ernst Dorn reported some experiments in which he noticed that radium compounds emanate a radioactive gas he named Radium Emanation (Ra Em). Before that, in 1899, Pierre and Marie Curie observed that the gas emitted by radium remained radioactive for a month. Later that year, Robert B. Owens and Ernest Rutherford, at McGill University in Montreal, noticed variations when trying to measure radiation from thorium oxide. Rutherford noticed that the compounds of thorium continuously emit a radioactive gas that retains the radioactive powers for several minutes, and called this gas emanation (from Latin "emanare"—to elapse and "emanatio"—expiration), and later Thorium Emanation (Th Em). In 1901, he demonstrated that the emanations are radioactive, but credited the Curies for the discovery of the element. In 1903, similar emanations were observed from actinium by André-Louis Debierne and were called Actinium Emanation (Ac Em).

text: Radon was the fifth radioactive element to be discovered, in 1899 by

text: Ernest Rutherford

text: and

text: Robert B. Owens

text: , after uranium, thorium, radium and polonium.  In 1900

text: Friedrich Ernst Dorn

text: reported some experiments in which he noticed that radium compounds emanate a radioactive gas he named Radium Emanation (Ra Em). Before that, in 1899,

text: Pierre

text: and

text: Marie Curie

text: observed that the gas emitted by radium remained radioactive for a month. Later that year, Robert B. Owens and Ernest Rutherford, at

text: McGill University

text: in

text: Montreal

text: , noticed variations when trying to measure radiation from thorium oxide. Rutherford noticed that the compounds of thorium continuously emit a radioactive gas that retains the radioactive powers for several minutes, and called this gas emanation (from Latin "emanare"—to elapse and "emanatio"—expiration), and later Thorium Emanation (Th Em). In 1901, he demonstrated that the emanations are radioactive, but credited the Curies for the discovery of the element. In 1903, similar emanations were observed from actinium by

text: André-Louis Debierne

text: and were called Actinium Emanation (Ac Em).

text: Note that there are two breaks where the unstable elements technetium (atomic number: 43) and promethium (atomic number: 61) would be. These are both extremely rare, since on Earth they are only produced through the spontaneous fission of very heavy radioactive elements (for example, uranium, thorium, or the trace amounts of plutonium that exist in uranium ores), or by the interaction of certain other elements with cosmic rays. Both of the first two of these elements have been identified spectroscopically in the atmospheres of stars, where they are produced by ongoing nucleosynthetic processes. There are also breaks where the six noble gases would be, since they are not chemically bound in the Earth's crust, and they are only generated by decay chains from radioactive elements and are therefore extremely rare there. The eight naturally occurring very rare, highly radioactive elements (polonium, astatine, francium, radium, actinium, protactinium, neptunium, and plutonium) are not included, since any of these elements that were present at the formation of the Earth have decayed away eons ago, and their quantity today is negligible and is only produced from the radioactive decay of uranium and thorium.

text: Note that there are two breaks where the unstable elements

text: technetium

text: (atomic number: 43) and

text: promethium

text: (atomic number: 61) would be. These are both extremely rare, since on Earth they are only produced through the

text: spontaneous fission

text: of very heavy

text: radioactive

text: elements (for example,

text: uranium

text: thorium

text: , or the trace amounts of

text: plutonium

text: that exist in uranium ores), or by the interaction of certain other elements with

text: cosmic ray

text: s. Both of the first two of these elements have been identified spectroscopically in the atmospheres of stars, where they are produced by ongoing nucleosynthetic processes. There are also breaks where the six

text: noble gas

text: es would be, since they are not chemically bound in the Earth's crust, and they are only generated by decay chains from radioactive elements and are therefore extremely rare there. The eight naturally occurring very rare, highly radioactive elements (

text: polonium

text: astatine

text: francium

text: radium

text: actinium

text: protactinium

text: neptunium

text: , and

text: plutonium

text: ) are not included, since any of these elements that were present at the formation of the Earth have decayed away eons ago, and their quantity today is negligible and is only produced from the

text: radioactive decay

text: of uranium and thorium.

text: There were several instances of radioactive waste leakage and contamination propagated from fires during Dow's management of the facility. In 1957 a fire burned plutonium dust in the facility and sent radioactive particles into the atmosphere.

text: There were several instances of

text: radioactive waste

text: leakage and contamination propagated from fires during Dow's management of the facility. In 1957 a fire burned

text: plutonium

text: dust in the facility and sent radioactive particles into the atmosphere.

text: From the 1960s the use of radium paint was discontinued. In many cases luminous dials were implemented with non-radioactive fluorescent materials excited by light; such devices glow in the dark after exposure to light, but the glow fades. Where long-lasting self-luminosity in darkness was required, safer radioactive promethium-147 (half-life 2.6 years) or tritium (half-life 12 years) paint was used; both continue to be used today. These had the added advantage of not degrading the phosphor over time, unlike radium. Tritium emits very low-energy beta radiation (even lower-energy than the beta radiation emitted by promethium) which cannot penetrate the skin, rather than the penetrating gamma radiation of radium and is regarded as safer.

text: From the 1960s the use of radium paint was discontinued. In many cases luminous dials were implemented with non-radioactive fluorescent materials excited by light; such devices glow in the dark after exposure to light, but the glow fades. Where long-lasting self-luminosity in darkness was required, safer radioactive

text: promethium

text: -147 (half-life 2.6 years) or

text: tritium

text: (half-life 12 years) paint was used; both continue to be used today. These had the added advantage of not degrading the phosphor over time, unlike radium. Tritium emits very low-energy

text: beta radiation

text: (even lower-energy than the beta radiation emitted by promethium) which cannot penetrate the skin, rather than the penetrating gamma radiation of radium and is regarded as safer.

text: The underlying concept for diamond battery is the unusual property of a synthetic diamond (developed by the University of Bristol) which creates a small electrical current when placed in a radioactive field.  Thus, enclosing a suitable radioactive source inside such a diamond will provide ionizing radiation to the diamond, which in turn will produce a small electrical current.  In initial prototypes, nickel-63 has been used as radioactive source for the diamond.

text: The underlying concept for diamond battery is the unusual property of a

text: synthetic diamond

text: (developed by the

text: University of Bristol

text: ) which creates a small electrical current when placed in a

text: radioactive field

text: .  Thus, enclosing a suitable

text: radioactive source

text: inside such a diamond will provide

text: ionizing radiation

text: to the diamond, which in turn will produce a small electrical current.  In initial prototypes,

text: has been used as radioactive source for the diamond.

text: By 1949, her youngest son was old enough to start prep-school and Howard joined the staff at Hammersmith, becoming part of Gray's team of scientists dedicated to studying the biological effects of ionizing radiation and to developing the use of radioactive isotopes. As a geneticist, Howard already recognized the importance of DNA, and although the double helix structure would not be discovered for a few more years, "the idea that chromosomes are made of DNA was generally agreed on." On her first day, she suggested to Stephen Pelc that radioactive phosphorous taken into the cell might be incorporated into DNA and give some information on the replication and synthesis of this important substance. They injected a mouse with Phosphorus-32 to study the rate at which the isotope incorporated into the DNA of dividing cells in the testis and the resulting autoradiographs were promising.  However, in animal cells and tissues the background radioactivity from remaining Phosphorus-32 made it impossible to obtain an autoradiograph localized down to individual chromosomes and parts of chromosomes.

text: By 1949, her youngest son was old enough to start prep-school and Howard joined the staff at Hammersmith, becoming part of

text: Gray's

text: team of scientists dedicated to studying the biological effects of ionizing radiation and to developing the use of radioactive isotopes. As a geneticist, Howard already recognized the importance of DNA, and although the

text: double helix

text: structure would not be discovered for a few more years, "the idea that chromosomes are made of DNA was generally agreed on." On her first day, she suggested to Stephen Pelc that radioactive phosphorous taken into the cell might be incorporated into

text: DNA

text: and give some information on the replication and synthesis of this important substance. They injected a mouse with

text: to study the rate at which the isotope incorporated into the DNA of dividing cells in the testis and the resulting autoradiographs were promising.  However, in animal cells and tissues the background radioactivity from remaining Phosphorus-32 made it impossible to obtain an autoradiograph localized down to individual chromosomes and parts of chromosomes.

text: The health of the inhabitants of radioactive apartment buildings in Taiwan has received prominent attention in popular treatments of radiation hormesis. In 1982, more than 20,000 tons of steel was accidentally contaminated with cobalt-60, and much of this radioactive steel was used to build apartments and exposed thousands of Taiwanese to gamma radiation levels of up to >1000 times background (average 47.7 mSv, maximum 2360 mSv excess cumulative dose) – it was not until 1992 that the radioactive contamination was discovered. A medical study published in 2004 claimed the cancer mortality rates in the exposed population were much lower than expected. However, this initial study failed to control for age, comparing a much younger exposed population (mean age 17.2 years at initial exposure) with the much older general population of Taiwan  (mean age approx. 34 years in 2004), a serious flaw. Older people have much higher cancer rates even in the absence of excess radiation exposure. However, Chen et al. did find a lower cancer incidence with time, still the opposite of what would be expected, even with a younger population.

text: The health of the inhabitants of radioactive apartment buildings in

text: Taiwan

text: has received prominent attention in popular treatments of radiation hormesis. In 1982, more than 20,000 tons of steel was accidentally contaminated with

text: , and much of this radioactive steel was used to build apartments and exposed thousands of Taiwanese to gamma radiation levels of up to >1000 times background (average 47.7 mSv, maximum 2360 mSv excess cumulative dose) – it was not until 1992 that the radioactive contamination was discovered. A medical study published in 2004 claimed the cancer mortality rates in the exposed population were much lower than expected. However, this initial study failed to control for age, comparing a much younger exposed population (mean age 17.2 years at initial exposure) with the much older general population of Taiwan  (mean age approx. 34 years in 2004), a serious flaw. Older people have much higher cancer rates even in the absence of excess radiation exposure. However, Chen et al. did find a lower cancer incidence with time, still the opposite of what would be expected, even with a younger population.

text: Iodine-131 is another important gamma-emitting radionuclide produced as a fission product. With a short half-life of 8 days, this radioisotope is not of practical use in radioactive sources in industrial radiography or sensing. However, since iodine is a component of biological molecules such as thyroid hormones, iodine-131 is of great importance in nuclear medicine, and in medical and biological research as a radioactive tracer.

text: is another important gamma-emitting radionuclide produced as a fission product. With a short half-life of 8 days, this radioisotope is not of practical use in radioactive sources in industrial radiography or sensing. However, since iodine is a component of biological molecules such as thyroid hormones, iodine-131 is of great importance in

text: nuclear medicine

text: , and in medical and biological research as a

text: radioactive tracer

text: Following initial interest in brachytherapy in Europe and the US, its use declined in the middle of the twentieth century due to the problem of radiation exposure to operators from the manual application of the radioactive sources. However, the development of remote afterloading systems, which allow the radiation to be delivered from a shielded safe, and the use of new radioactive sources in the 1950s and 1960s, reduced the risk of unnecessary radiation exposure to the operator and patients. This, together with more recent advancements in three-dimensional imaging modalities, computerised treatment planning systems and delivery equipment has made brachytherapy a safe and effective treatment for many types of cancer today.

text: Following initial interest in brachytherapy in Europe and the US, its use declined in the middle of the twentieth century due to the problem of radiation exposure to operators from the manual application of the radioactive sources. However, the development of

text: remote afterloading systems

text: , which allow the radiation to be delivered from a shielded safe, and the use of new radioactive sources in the 1950s and 1960s, reduced the risk of unnecessary radiation exposure to the operator and patients. This, together with more recent advancements in three-dimensional imaging modalities, computerised treatment planning systems and delivery equipment has made brachytherapy a safe and effective treatment for many types of cancer today.

text: It was quickly noted after the discovery of radioactivity in 1897, that the total energy due to radioactive processes is about one million times greater than that involved in any known molecular change. However, it raised the question where this energy is coming from. After eliminating the idea of absorption and emission of some sort of Lesagian ether particles, the existence of a huge amount of latent energy, stored within matter, was proposed by Ernest Rutherford and Frederick Soddy in 1903. Rutherford also suggested that this internal energy is stored within normal matter as well. He went on to speculate in 1904:

text: It was quickly noted after the discovery of

text: radioactivity

text: in 1897, that the total energy due to radioactive processes is about one million times greater than that involved in any known molecular change. However, it raised the question where this energy is coming from. After eliminating the idea of absorption and emission of some sort of

text: Lesagian ether particles

text: , the existence of a huge amount of latent energy, stored within matter, was proposed by

text: Ernest Rutherford

text: and

text: Frederick Soddy

text: in 1903. Rutherford also suggested that this internal energy is stored within normal matter as well. He went on to speculate in 1904:

text: High-level radioactive waste management concerns how  radioactive materials created during production of nuclear power and nuclear weapons are dealt with. Radioactive waste contains a mixture of short-lived and long-lived nuclides, as well as non-radioactive nuclides. There was reported some 47,000 tonnes of high-level nuclear waste stored in the USA in 2002.

text: High-level radioactive waste management concerns how

text: radioactive

text: materials created during production of

text: nuclear power

text: and

text: nuclear weapon

text: s are dealt with. Radioactive waste contains a mixture of short-lived and long-lived nuclides, as well as non-radioactive nuclides. There was reported some 47,000 tonnes of high-level nuclear waste stored in the USA in 2002.

text: As well as linking the two series into a single future history, the present book served to address a criticism leveled against the largely radioactive Earth as depicted in Pebble in the Sky and mentioned in several other books. Though not explicitly stated, there was the clear implication the world being mostly radioactive and humans precariously surviving in the uncontaminated areas in between was the result of a nuclear war hundreds or thousands of years before the time of the plot. This would have made Pebble in the Sky part of the post-nuclear war subgenre common in the 1950s. It was, however, pointed out by critics that such an extensive use of nuclear weapons as to leave persistent and widespread radiation even after centuries would have completely destroyed all life on Earth at the moment when it took place. Therefore, in the present book Asimov provided a different origin for the future Earth's radioactivity.

text: As well as linking the two series into a single future history, the present book served to address a criticism leveled against the largely radioactive Earth as depicted in

text: Pebble in the Sky

text: and mentioned in several other books. Though not explicitly stated, there was the clear implication the world being mostly radioactive and humans precariously surviving in the uncontaminated areas in between was the result of a

text: nuclear war

text: hundreds or thousands of years before the time of the plot. This would have made Pebble in the Sky part of the post-nuclear war subgenre common in the 1950s. It was, however, pointed out by critics that such an extensive use of nuclear weapons as to leave persistent and widespread radiation even after centuries would have completely destroyed all life on Earth at the moment when it took place. Therefore, in the present book Asimov provided a different origin for the future Earth's radioactivity.

text: The discovery of nuclear fission occurred in 1938 in the buildings of Kaiser Wilhelm Society for Chemistry, today part of the Free University of Berlin, following nearly five decades of work on the science of radioactivity and the elaboration of new nuclear physics that described the components of atoms. In 1911, Ernest Rutherford proposed a model of the atom in which a very small, dense and positively charged nucleus of protons (the neutron had not yet been discovered) was surrounded by orbiting, negatively charged electrons (the Rutherford model). Niels Bohr improved upon this in 1913 by reconciling the quantum behavior of electrons (the Bohr model). Work by Henri Becquerel, Marie Curie, Pierre Curie, and Rutherford further elaborated that the nucleus, though tightly bound, could undergo different forms of radioactive decay, and thereby transmute into other elements. (For example, by alpha decay: the emission of an alpha particle—two protons and two neutrons bound together into a particle identical to a helium nucleus.)

text: The discovery of nuclear fission occurred in 1938 in the buildings of

text: Kaiser Wilhelm Society

text: for Chemistry, today part of the

text: Free University of Berlin

text: , following nearly five decades of work on the science of

text: radioactivity

text: and the elaboration of new

text: nuclear physics

text: that described the components of

text: atom

text: s. In 1911,

text: Ernest Rutherford

text: proposed a model of the atom in which a very small, dense and positively charged

text: nucleus

text: of

text: proton

text: s (the

text: neutron

text: had not yet been discovered) was surrounded by orbiting, negatively charged

text: electron

text: s (the

text: Rutherford model

text: Niels Bohr

text: improved upon this in 1913 by reconciling the quantum behavior of electrons (the

text: Bohr model

text: ). Work by

text: Henri Becquerel

text: Marie Curie

text: Pierre Curie

text: , and Rutherford further elaborated that the nucleus, though tightly bound, could undergo different forms of

text: radioactive decay

text: , and thereby

text: transmute

text: into other elements. (For example, by

text: alpha decay

text: : the emission of an

text: alpha particle

text: —two protons and two neutrons bound together into a particle identical to a

text: helium

text: nucleus.)

text: One dramatic source of man-made radioactivity is a nuclear weapons test. The glassy trinitite formed by the first atom bomb contains radioisotopes formed by neutron activation and nuclear fission.  In addition some natural radioisotopes are present.  A recent paper reports the levels of long-lived radioisotopes in the trinitite. The trinitite was formed from feldspar and quartz which were melted by the heat. Two samples of trinitite were used, the first (left-hand-side bars in the graph) was taken from between 40 and 65 meters of ground zero while the other sample was taken from further away from the ground zero point.

text: One dramatic source of man-made radioactivity is a

text: nuclear weapons

text: test. The glassy

text: trinitite

text: formed by the first atom bomb contains

text: radioisotope

text: s formed by

text: neutron activation

text: and

text: nuclear fission

text: .  In addition some natural radioisotopes are present.  A recent paper reports the levels of long-lived radioisotopes in the trinitite. The trinitite was formed from

text: feldspar

text: and

text: quartz

text: which were melted by the heat. Two samples of trinitite were used, the first (left-hand-side bars in the graph) was taken from between 40 and 65 meters of ground zero while the other sample was taken from further away from the

text: ground zero

text: point.

text: In homes, the water loop may be as simple as a single pipe that "loops" the flow through every radiator in a zone. In such a system, flow to the individual radiators cannot be modulated as all of the water is flowing through every radiator in the zone. Slightly more complicated systems use a "main" pipe that flows uninterrupted around the zone; the individual radiators tap off a small portion of the flow in the main pipe. In these systems, individual radiators can be modulated. Alternatively, a number of loops with several radiators can be installed, the flow in each loop or zone controlled by a zone valve connected to a thermostat.

text: In homes, the water loop may be as simple as a single pipe that "loops" the flow through every radiator in a zone. In such a system, flow to the individual radiators cannot be modulated as all of the water is flowing through every radiator in the zone. Slightly more complicated systems use a "main" pipe that flows uninterrupted around the zone; the individual radiators tap off a small portion of the flow in the main pipe. In these systems, individual radiators can be modulated. Alternatively, a number of loops with several radiators can be installed, the flow in each loop or zone controlled by a

text: zone valve

text: connected to a

text: thermostat

text: In the aftermath of the accident, investigations focused on the amount of radioactivity released by the accident. In total approximately  of radioactive gases, and approximately  of iodine-131 was released into the environment. According to the American Nuclear Society, using the official radioactivity emission figures, "The average radiation dose to people living within ten miles of the plant was eight millirem, and no more than 100 millirem to any single individual. Eight millirem is about equal to a chest X-ray, and 100 millirem is about a third of the average background level of radiation received by US residents in a year."

text: In the aftermath of the accident, investigations focused on the amount of radioactivity released by the accident. In total approximately  of

text: radioactive

text: gases, and approximately  of

text: was released into the environment. According to the

text: American Nuclear Society

text: millirem

text: X-ray

text: , and 100 millirem is about a third of the average background level of radiation received by US residents in a year."

text: An electron capture detector most often uses a radioactive source to generate electrons used for ionization. Some examples of radioactive isotopes used are H, Ni, Kr, and Sr. The gas in the detector chamber is ionized by the radiation particles. Nitrogen, argon and helium are common carrier gases used in the ECD. Argon and helium need to be combined with another gas, such as methane, in order to prevent immediate conversion into metastable ions. The combination will extend the lifetime of the metastable ions (10 seconds). The methane will cool the electrons during the collisions. The addition of methane will enhance the ability to form negative ions under high pressure because it will adjust the thermal energy to be similar to the energy distribution of the ions. Methane is the most common gas used because it can produce many positive ions when it collides with electrons. These positive ions will then form low energy electrons used for ionization:

text: An

text: electron capture detector

text: most often uses a

text: radioactive

text: source to generate electrons used for ionization. Some examples of radioactive

text: isotopes

text: used are H, Ni, Kr, and Sr. The gas in the detector chamber is ionized by the radiation particles. Nitrogen, argon and helium are common carrier gases used in the ECD. Argon and helium need to be combined with another gas, such as methane, in order to prevent immediate conversion into

text: metastable

text: ions. The combination will extend the lifetime of the metastable ions (10 seconds). The methane will cool the electrons during the collisions. The addition of methane will enhance the ability to form negative ions under high pressure because it will adjust the thermal energy to be similar to the energy distribution of the ions. Methane is the most common gas used because it can produce many positive ions when it collides with electrons. These positive ions will then form low energy electrons used for ionization:

text: In Radiation Protection practice, an instrument which reads a rate of detected events is normally known as a ratemeter, which was first developed by R D Robley Evans in 1939. This mode of operation provides real-time dynamic indication of the radiation rate, and the principle has found widespread application in radiation Survey meters used in Health Physics.

text: In Radiation Protection practice, an instrument which reads a rate of detected events is normally known as a ratemeter, which was first developed by R D Robley Evans in 1939. This mode of operation provides real-time dynamic indication of the radiation rate, and the principle has found widespread application in radiation

text: Survey meter

text: s used in Health Physics.

text: The source of the Keekle is to be found at Keekle Head Farm on High Park between Gilgarran and Asby. From there, the river moves gradually southwards via former open cast mine between Frizington and Whitehaven to Cleator, where it becomes subsumed by the River Ehen. The river is noted for its occasional abundance of salmon.  Radioactive Landfill is proposed at Keekle Head.  There is strong opposition to the proposal to put radioactive waste in the site of the former open cast mine from Radiation Free Lakeland and others.

text: The

text: source

text: of the Keekle is to be found at Keekle Head Farm on High Park between Gilgarran and Asby. From there, the river moves gradually southwards via former

text: open cast mine

text: between

text: Frizington

text: and

text: Whitehaven

text: to

text: Cleator

text: , where it becomes subsumed by the

text: River Ehen

text: . The river is noted for its occasional abundance of

text: salmon

text: .  Radioactive Landfill is proposed at Keekle Head.  There is strong opposition to the proposal to put radioactive waste in the site of the former open cast mine from Radiation Free Lakeland and others.

text: Radioactive water baths have been applied since 1906 in Jáchymov, Czech Republic, but even before radon discovery they were used in Bad Gastein, Austria. Radium-rich springs are also used in traditional Japanese onsen in Misasa, Tottori Prefecture. Drinking therapy is applied in Bad Brambach, Germany. Inhalation therapy is carried out in Gasteiner-Heilstollen, Austria, in Świeradów-Zdrój, Czerniawa-Zdrój, Kowary, Lądek Zdrój, Poland, in Harghita Băi, Romania, and in Boulder, United States. In the US and Europe there are several "radon spas", where people sit for minutes or hours in a high-radon atmosphere in the belief that low doses of radiation will invigorate or energize them.

text: Jáchymov

text: , Czech Republic, but even before radon discovery they were used in

text: Bad Gastein

text: , Austria. Radium-rich springs are also used in traditional Japanese

text: onsen

text: in

text: Misasa

text: Tottori Prefecture

text: . Drinking therapy is applied in

text: Bad Brambach

text: , Germany. Inhalation therapy is carried out in

text: Gasteiner-Heilstollen

text: , Austria, in

text: Świeradów-Zdrój

text: Czerniawa-Zdrój

text: Kowary

text: Lądek Zdrój

text: , Poland, in

text: Harghita Băi

text: , Romania, and in

text: Boulder

text: , United States. In the US and Europe there are several "radon

text: spas

text: Many radioactive sources are sealed, meaning they are permanently either completely contained in a capsule or firmly bonded solid to a surface. Capsules are usually made of stainless steel, titanium, platinum or another inert metal. The use of sealed sources removes almost all risk of dispersion of radioactive material into the environment due to mishandling, but the container is not intended to attenuate radiation, so further shielding is required for radiation protection. Sealed sources are used in almost all applications where the source does not need to be chemically or physically included in a liquid or gas.

text: Many radioactive sources are sealed, meaning they are permanently either completely contained in a capsule or firmly bonded solid to a surface. Capsules are usually made of

text: stainless steel

text: titanium

text: platinum

text: or another inert

text: metal

text: . The use of sealed sources removes almost all risk of

text: dispersion of radioactive material

text: into the environment due to mishandling, but the container is not intended to attenuate radiation, so further shielding is required for radiation protection. Sealed sources are used in almost all applications where the source does not need to be chemically or physically included in a liquid or gas.

text: In 1938, John Livingood and Glenn T. Seaborg discovered the radioisotope cobalt-60. This isotope was famously used at Columbia University in the 1950s to establish parity violation in radioactive beta decay.

text: In 1938, John Livingood and

text: Glenn T. Seaborg

text: discovered the radioisotope

text: . This isotope was famously used at

text: Columbia University

text: in the 1950s to establish

text: parity

text: violation in radioactive

text: beta decay

text: In nuclear physics, the following fundamental relationship governs radioactive decay: the number of radioactive atoms  in a sample of a radioactive isotope decays at a rate proportional to .  This leads to the first order linear differential equation

text: In

text: nuclear physics

text: , the following fundamental relationship governs

text: radioactive decay

text: : the number of radioactive atoms  in a sample of a radioactive

text: isotope

text: decays at a rate proportional to .  This leads to the first order linear differential equation

text: Each test released a plume of dispersed radioactive lanthanum. Three tests in 1950 are documented where the released radioactivity was tracked by a B-17 aircraft. In one case radiation was detected over a town  downwind. These tests were concurrent with the RaLa tests, and their aim was development of airborne detectors for tracking air burst nuclear tests. The size and altitude of the radioactive cloud was determined by the quantity of the explosive used. For the first 125 tests between 1944 and 1949, meteorology and fallout monitoring were rare, but between 1950-1954 closer monitoring was phased in, and was comprehensive afterwards. One cloud was reportedly tracked as far as  downwind, over Watrous, New Mexico.

text: Each test released a plume of dispersed radioactive lanthanum. Three tests in 1950 are documented where the released radioactivity was tracked by a

text: aircraft. In one case radiation was detected over a town  downwind. These tests were concurrent with the RaLa tests, and their aim was development of airborne detectors for tracking

text: air burst

text: nuclear test

text: s. The size and altitude of the radioactive cloud was determined by the quantity of the explosive used. For the first 125 tests between 1944 and 1949, meteorology and fallout monitoring were rare, but between 1950-1954 closer monitoring was phased in, and was comprehensive afterwards. One cloud was reportedly tracked as far as  downwind, over

text: Watrous

text: New Mexico

text: In July 2014, one edge of this smoldering fire was located about  away from OU-1, and had been spreading rapidly,  the proximity creating fears about what might happen if the fire reached the radioactive materials in OU-1.  Because it is a rare situation, neither the EPA nor any other agency is completely certain what would happen if the SSE reached the radioactive materials and especially if it became an open, flaming fire on the surface.

text: Since the fraction of a radioisotope's atoms decaying per unit of time is inversely proportional to its half-life, the relative radioactivity of a quantity of buried human radioactive waste would diminish over time compared to natural radioisotopes (such as the decay chain of 120 trillion tons of thorium and 40 trillion tons of uranium which are at relatively trace concentrations of parts per million each over the crust's 3 ton mass). For instance, over a timeframe of thousands of years, after the most active short half-life radioisotopes decayed, burying U.S. nuclear waste would increase the radioactivity in the top 2000 feet of rock and soil in the United States (10 million km) by ≈ 1 part in 10 million over the cumulative amount of natural radioisotopes in such a volume, although the vicinity of the site would have a far higher concentration of artificial radioisotopes underground than such an average.

text: Since the fraction of a radioisotope's atoms decaying per unit of time is inversely proportional to its half-life, the relative radioactivity of a quantity of buried human

text: radioactive waste

text: would diminish over time compared to natural radioisotopes (such as the decay chain of 120 trillion tons of thorium and 40 trillion tons of uranium which are

text: over the crust's 3 ton mass). For instance, over a timeframe of thousands of years, after the most active short half-life radioisotopes decayed, burying U.S. nuclear waste would increase the radioactivity in the top 2000 feet of rock and soil in the United States (10 million km) by

text: 1 part in 10 million over the cumulative amount of

text: natural radioisotopes

text: in such a volume, although the vicinity of the site would have a far higher concentration of artificial radioisotopes underground than such an average.

text: Radioisotope heater units normally provide about 1 watt of heat each, derived from the decay of a few grams of plutonium-238. This heat is given off continuously for several decades.

text: Radioisotope heater unit

text: s normally provide about 1

text: watt

text: of heat each, derived from the decay of a few

text: gram

text: s of plutonium-238. This heat is given off continuously for several decades.

text: As SEPA has a responsibility for protecting Scotland's environment and human health, it also has responsibility for regulating the storage, and use of, radioactive substances and the accumulation and disposal of radioactive wastes in Scotland, including functions under the Radioactive Substances Act 1993. The State of Scotland's Environment 2006 Report showed a downward trend in levels of man-made radioactivity in the environment over the last decade.

text: As SEPA has a responsibility for protecting Scotland's environment and human health, it also has responsibility for regulating the storage, and use of, radioactive substances and the accumulation and disposal of radioactive wastes in Scotland, including functions under the

text: Radioactive Substances Act 1993

text: . The State of Scotland's Environment 2006 Report showed a downward trend in levels of man-made radioactivity in the environment over the last decade.

text: CPAMs use a pump to draw air through a filter medium to collect airborne particulate matter that carries very small particles of radioactive material; the air itself is not radioactive. The particulate radioactive material might be natural, e.g., radon decay products ("progeny", e.g., Pb), or manmade, usually fission or activation products (e.g., Cs), or a combination of both. There are also "gas monitors" which pass the air through a sample chamber volume which is viewed continuously by a radiation detector. Radionuclides that occur in the gaseous form (e.g., Kr) are not collected on the CPAM filter to any appreciable extent, so that a separate monitoring system is needed to assess these nuclide concentrations in the sampled air. These gas monitors are often placed downstream of a CPAM so that any particulate matter in the sampled air is collected by the CPAM and thus will not contaminate the gas monitor's sample chamber.

text: The seventh version uses a streamlined version of D&D 4th edition mechanics. Character generation choice though was nearly fully removed. Instead of choosing a character class, a player had to roll a twenty-sided die two times and consult an accompanying character origin table. For example, a player might obtain the result "Radioactive Yeti" and gain the powers associated with the "Radioactive" and "Yeti" origins. Attributes, mutations, and skills were also randomly assigned. Two decks of cards comprising the core of a Collectible Card Game are included with the game. One deck represented random Alpha Mutations, which could be drawn to gain temporary powers, and the other contained various Omega Tech, powerful technological devices that could possibly backfire on those that used them. Some 4th edition rules enhancements for the setting include new damage types such as "Radiation", Gamma World-specific skills, and increased lethality. Despite these differences, it is possible to use characters and monsters from a D&D game in Gamma World and vice versa.

text: The seventh version uses a streamlined version of

text: D&D 4th edition

text: mechanics. Character generation choice though was nearly fully removed. Instead of choosing a character class, a player had to roll a twenty-sided die two times and consult an accompanying character origin table. For example, a player might obtain the result "Radioactive Yeti" and gain the powers associated with the "Radioactive" and "Yeti" origins. Attributes, mutations, and skills were also randomly assigned. Two decks of cards comprising the core of a

text: Collectible Card Game

text: are included with the game. One deck represented random Alpha Mutations, which could be drawn to gain temporary powers, and the other contained various Omega Tech, powerful technological devices that could possibly backfire on those that used them. Some 4th edition rules enhancements for the setting include new damage types such as "Radiation", Gamma World-specific skills, and increased lethality. Despite these differences, it is possible to use characters and monsters from a D&D game in Gamma World and vice versa.

text: Some radioactive materials have short half-lives; some have long half-lives. Uranium and thorium have long half-lives, and so persist in Earth's crust, but radioactive elements with short half-lives have generally disappeared. This suggested that it might be possible to measure the age of Earth by determining the relative proportions of radioactive materials in geological samples. In reality, radioactive elements do not always decay into nonradioactive ("stable") elements directly, instead, decaying into other radioactive elements that have their own half-lives and so on, until they reach a stable element. Such "decay series", such as the uranium-radium and thorium series, were known within a few years of the discovery of radioactivity, and provided a basis for constructing techniques of radiometric dating.

text: Some radioactive materials have short half-lives; some have long half-lives.

text: Uranium

text: and

text: thorium

text: have long half-lives, and so persist in Earth's crust, but radioactive elements with short half-lives have generally disappeared. This suggested that it might be possible to measure the age of Earth by determining the relative proportions of radioactive materials in geological samples. In reality, radioactive elements do not always decay into nonradioactive ("stable") elements directly, instead, decaying into other radioactive elements that have their own half-lives and so on, until they reach a

text: stable element

text: . Such "decay series", such as the uranium-radium and thorium series, were known within a few years of the discovery of radioactivity, and provided a basis for constructing techniques of radiometric dating.

text: Thus, at UV frequencies and higher (and probably somewhat also in the visible range), electromagnetic radiation does more damage to biological systems than simple heating predicts. This is most obvious in the "far" (or "extreme") ultraviolet. UV, with X-ray and gamma radiation, are referred to as ionizing radiation due to the ability of photons of this radiation to produce ions and free radicals in materials (including living tissue). Since such radiation can severely damage life at energy levels that produce little heating, it is considered far more dangerous (in terms of damage-produced per unit of energy, or power) than the rest of the electromagnetic spectrum.

text: Thus, at UV frequencies and higher (and probably somewhat also in the visible range), electromagnetic radiation does more damage to biological systems than simple heating predicts. This is most obvious in the "far" (or "extreme") ultraviolet. UV, with X-ray and gamma radiation, are referred to as

text: ionizing radiation

text: due to the ability of photons of this radiation to produce

text: ion

text: s and

text: free radical

text: s in materials (including living tissue). Since such radiation can severely damage life at energy levels that produce little heating, it is considered far more dangerous (in terms of damage-produced per unit of energy, or power) than the rest of the electromagnetic spectrum.

text: The radiation effects from the Fukushima Daiichi nuclear disaster are the observed and predicted effects resulting from the release of radioactive isotopes from the Fukushima Daiichi Nuclear Power Plant after the 2011 Tōhoku earthquake and tsunami. Radioactive isotopes were released from reactor containment vessels as a result of venting to reduce gaseous pressure, and the discharge of coolant water into the sea. This resulted in Japanese authorities implementing a 20 km exclusion zone around the power plant, and the continued displacement of approximately 156,000 people as of early 2013. Trace quantities of radioactive particles from the incident, including iodine-131 and caesium-134/137, have since been detected around the world.

text: The radiation effects from the

text: Fukushima Daiichi nuclear disaster

text: are the observed and predicted effects resulting from the release of radioactive isotopes from the

text: Fukushima Daiichi Nuclear Power Plant

text: after the

text: 2011 Tōhoku earthquake and tsunami

text: . Radioactive isotopes were released from reactor containment vessels as a result of venting to reduce gaseous pressure, and the discharge of coolant water into the sea. This resulted in Japanese authorities implementing a 20 km exclusion zone around the power plant, and the continued displacement of approximately 156,000 people as of early 2013. Trace quantities of radioactive particles from the incident, including

text: and

text: , have since been detected around the world.

text: By the 1970s there was increased public concern about the levels of radioactivity at the site, which was used by the local residents for recreational purposes. Surveys conducted in the 1980s found strontium-90 in the soil at Plot M, trace amounts of tritium in nearby wells, and plutonium, technetium, cesium, and uranium in the area. In 1994, the United States Department of Energy and the Argonne National Laboratory yielded to public pressure and earmarked $24.7 million and $3.4 million respectively to rehabilitate the site. As part of the clean up,  of radioactive waste was removed and sent to the Hanford Site for disposal. By 2002, the Illinois Department of Public Health had determined that the remaining materials posed no danger to public health.

text: By the 1970s there was increased public concern about the levels of radioactivity at the site, which was used by the local residents for recreational purposes. Surveys conducted in the 1980s found

text: in the soil at Plot M, trace amounts of tritium in nearby wells, and plutonium, technetium, cesium, and uranium in the area. In 1994, the

text: United States Department of Energy

text: and the Argonne National Laboratory yielded to public pressure and earmarked $24.7 million and $3.4 million respectively to rehabilitate the site. As part of the clean up,  of radioactive waste was removed and sent to the

text: Hanford Site

text: for disposal. By 2002, the

text: Illinois Department of Public Health

text: had determined that the remaining materials posed no danger to public health.

text: Following the explosion, a Li-2 airplane was put to use on a reconnaissance mission to report the movement of a radioactive cloud produced by the blast, and the most dangerous areas were explored and marked by special reconnaissance troops. After the reconnaissance was complete and the Soviet command gained enough information on the level of radiation, the army moved in. Much attention was paid to personal safety: the participants were provided with personal protective equipment, tinted glasses or lenses for gas masks and had individual radiation dosimeters. Gamma-roentgenometers measured the level of radiation exposure in the epicentre, dosimeters were used to estimate the radiation dose deposited in an individual wearing or a vehicle after the troops completed their task, and the troops received a 'chemical alert' signal if the radiation was too high. The soldiers wore gas masks, protective suits and respirators, special gloves and capes and moved around the territory in armoured personnel carriers, holding the distance of 400-600 metres from the hypocentre and avoiding the most dangerous areas of the explosion site. A relatively low level of radiation, strong wind and the extensive use of personal protective equipment allowed them to move 400-500 metres from the epicentre, whereas tanks and armoured personnel carriers could safely get even closer.

text: Following the explosion, a

text: airplane was put to use on a reconnaissance mission to report the movement of a radioactive cloud produced by the blast, and the most dangerous areas were explored and marked by special reconnaissance troops. After the reconnaissance was complete and the Soviet command gained enough information on the level of radiation, the army moved in. Much attention was paid to personal safety: the participants were provided with

text: personal protective equipment

text: , tinted glasses or lenses for

text: gas masks

text: and had individual radiation

text: dosimeter

text: s. Gamma-roentgenometers measured the level of radiation exposure in the epicentre, dosimeters were used to estimate the radiation dose deposited in an individual wearing or a vehicle after the troops completed their task, and the troops received a 'chemical alert' signal if the radiation was too high. The soldiers wore gas masks, protective suits and respirators, special gloves and capes and moved around the territory in armoured personnel carriers, holding the distance of 400-600 metres from the

text: hypocentre

text: and avoiding the most dangerous areas of the explosion site. A relatively low level of radiation, strong wind and the extensive use of personal protective equipment allowed them to move 400-500 metres from the epicentre, whereas tanks and armoured personnel carriers could safely get even closer.

text: Using this information, a plan of the optimal distribution of the radiation sources can be developed. This includes consideration of how the source carriers (applicators), which are used to deliver the radiation to the treatment site, should be placed and positioned. Applicators are non-radioactive and are typically needles or plastic catheters. The specific type of applicator used will depend on the type of cancer being treated and the characteristics of the target tumour.

text: Radioluminescence occurs when an incoming radiation particle collides with an atom or molecule, exciting an orbital electron to a higher energy level.  The particle usually comes from the radioactive decay of an atom of a radioisotope, an isotope of an element which is radioactive.  The electron then returns to its ground energy level by emitting the extra energy as a photon of light. The emitted photon is often in the ultraviolet energy range or higher and so invisible to the human eye.  Therefore, in radioluminescent light sources, the radioactive substance is mixed with a phosphor, a chemical that releases light of a particular color when struck by the particle.

text: Radioluminescence occurs when an incoming radiation particle collides with an atom or molecule, exciting an orbital electron to a higher energy level.  The particle usually comes from the

text: radioactive decay

text: of an atom of a

text: radioisotope

text: , an

text: isotope

text: of an element which is radioactive.  The electron then returns to its ground energy level by emitting the extra energy as a

text: photon

text: of light. The emitted photon is often in the

text: ultraviolet

text: energy range or higher and so invisible to the human eye.  Therefore, in radioluminescent light sources, the radioactive substance is mixed with a

text: phosphor

text: , a chemical that releases light of a particular color when struck by the particle.

text: A radiogenic nuclide is a nuclide that is produced by a process of radioactive decay. It may itself be radioactive (a radionuclide) or stable (a stable nuclide).

text: A radiogenic nuclide is a

text: nuclide

text: that is produced by a process of

text: radioactive decay

text: . It may itself be radioactive (a

text: radionuclide

text: ) or stable (a

text: stable nuclide

text: The hazards to people and the environment from radioactive contamination depend on the nature of the radioactive contaminant, the level of contamination, and the extent of the spread of contamination. Low levels of radioactive contamination pose little risk, but can still be detected by radiation instrumentation. If a survey or map is made of a contaminated area, random sampling locations may be labeled with their activity in becquerels or curies on contact. Low levels may be reported in counts per minute  using a scintillation counter.

text: The hazards to people and the environment from radioactive contamination depend on the nature of the radioactive contaminant, the level of contamination, and the extent of the spread of contamination. Low levels of radioactive contamination pose little risk, but can still be detected by radiation instrumentation. If a survey or map is made of a contaminated area, random sampling locations may be labeled with their activity in

text: becquerels

text: or

text: curies

text: on contact. Low levels may be reported in

text: counts per minute

text: using a

text: scintillation counter

text: In a report by the National Cancer Institute, released in 1997, it was determined that the nearly ninety atmospheric tests at the Nevada Test Site (NTS) left high levels of radioactive iodine-131 (5.5 exabecquerels) across a large area of the continental United States, especially in the years 1952, 1953, 1955, and 1957.  The National Cancer Institute report estimates that doses received in these years are estimated to be large enough to produce 10,000 to 75,000 additional cases of thyroid cancer in the U.S.  Another report, published by the Scientific Research Society, estimates that about 22,000 additional radiation-related cancers and 2,000 additional deaths from radiation-related leukemia are expected to occur in the United States because of external and internal radiation from both NTS and global fallout.

text: In a report by the

text: National Cancer Institute

text: , released in 1997, it was determined that the nearly ninety atmospheric tests at the Nevada Test Site (NTS) left high levels of radioactive iodine-131 (5.5 exabecquerels) across a large area of the continental United States, especially in the years 1952, 1953, 1955, and 1957.  The National Cancer Institute report estimates that doses received in these years are estimated to be large enough to produce 10,000 to 75,000 additional cases of thyroid cancer in the U.S.  Another report, published by the Scientific Research Society, estimates that about 22,000 additional radiation-related cancers and 2,000 additional deaths from radiation-related leukemia are expected to occur in the United States because of external and internal radiation from both NTS and global fallout.

text: Ra is the most stable isotope of radium and is the last isotope in the (4n + 2) decay chain of uranium-238 with a half-life of over a millennium: it makes up almost all of natural radium. Its immediate decay product is the dense radioactive noble gas radon, which is responsible for much of the danger of environmental radium. It is 2.7 million times more radioactive than the same molar amount of natural uranium (mostly uranium-238), due to its proportionally shorter half-life.

text: Ra is the most stable isotope of radium and is the last isotope in the (4n + 2) decay chain of uranium-238 with a half-life of over a millennium: it makes up almost all of natural radium. Its immediate decay product is the dense radioactive

text: noble gas

text: radon

text: , which is responsible for much of the danger of environmental radium. It is 2.7 million times more radioactive than the same

text: molar amount

text: of natural

text: uranium

text: (mostly uranium-238), due to its proportionally shorter half-life.

text: In radiation therapy, the amount of radiation applied varies depending on the type and stage of cancer being treated. For curative cases, the typical dose for a solid epithelial tumor ranges from 60 to 80 Gy, while lymphomas are treated with 20 to 40 Gy. Preventive (adjuvant) doses are typically around 45–60 Gy in 1.8–2 Gy fractions (for breast, head, and neck cancers).

text: In radiation therapy, the amount of radiation applied varies depending on the type and stage of cancer being treated. For curative cases, the typical dose for a solid

text: epithelial

text: tumor ranges from 60 to 80 Gy, while

text: lymphoma

text: s are treated with 20 to 40 Gy. Preventive (adjuvant) doses are typically around 45–60 Gy in 1.8–2 Gy fractions (for breast, head, and neck cancers).

text: Nuclear decommissioning is the process by which a nuclear power plant site is dismantled so that it will no longer require measures for radiation protection. The presence of radioactive material necessitates processes that are occupationally dangerous, and hazardous to the natural environment, expensive, and time-intensive.

text: Nuclear decommissioning is the process by which a

text: nuclear power plant

text: site is dismantled so that it will no longer require measures for radiation protection. The presence of

text: radioactive

text: material necessitates processes that are occupationally dangerous, and hazardous to the natural environment, expensive, and time-intensive.

text: At the turn of the twentieth century the theoretical underpinnings of chemistry were finally understood due to a series of remarkable discoveries that succeeded in probing and discovering the very nature of the internal structure of atoms. In 1897, J. J. Thomson of Cambridge University discovered the electron and soon after the French scientist Becquerel as well as the couple Pierre and Marie Curie investigated the phenomenon of radioactivity. In a series of pioneering scattering experiments Ernest Rutherford at the University of Manchester  discovered the internal structure of the atom and the existence of the proton, classified and explained the different types of radioactivity and successfully transmuted the first element by bombarding nitrogen with alpha particles.

text: At the turn of the twentieth century the theoretical underpinnings of chemistry were finally understood due to a series of remarkable discoveries that succeeded in probing and discovering the very nature of the internal structure of atoms. In 1897,

text: J. J. Thomson

text: of

text: Cambridge University

text: discovered the

text: electron

text: and soon after the French scientist

text: Becquerel

text: as well as the couple

text: Pierre

text: and

text: Marie Curie

text: investigated the phenomenon of

text: radioactivity

text: . In a series of pioneering scattering experiments

text: Ernest Rutherford

text: at the

text: University of Manchester

text: discovered the internal structure of the atom and the existence of the proton, classified and explained the different types of radioactivity and successfully

text: transmuted

text: the first element by bombarding

text: nitrogen

text: with

text: alpha particle

text: s.

text: Real name Gu Lao, is one of the oldest Chinese heroes. He used his solar powers to carry out the Cultural Revolution. His body is highly radioactive, so he is forced to wear special armor reverse engineered from Durlan technology. He has since become bitter and disillusioned as China abandons Mao Zedong's vision and embraces market economics. He lives like a hermit in an isolated stretch of the Gobi Desert due to the possible threat of a nuclear meltdown. Mother of Champions is immune to his radiation, and was the first person to touch him in over fifteen years.

text: Real name Gu Lao, is one of the oldest Chinese heroes. He used his solar powers to carry out the

text: Cultural Revolution

text: . His body is highly

text: radioactive

text: , so he is forced to wear special armor reverse engineered from Durlan technology. He has since become bitter and disillusioned as China abandons

text: Mao Zedong

text: 's vision and embraces market economics. He lives like a hermit in an isolated stretch of the

text: Gobi Desert

text: due to the possible threat of a nuclear meltdown. Mother of Champions is immune to his radiation, and was the first person to touch him in over fifteen years.

text: A ministerial order of January 1970 extended protection in cases of partial unemployment to home workers, while an ordinance of August 1970 fixed the conditions of health necessary for service in the merchant navy. A general provision of October 1970 determined in detail the circumstances in which the competent authority must take action on the basis of the act on the technical means of work. The requirement also stipulated the extent to which the technical standards established by national and international organisations can be regarded as “rules of the art.” In a directive of 10 November 1970, the Minister of Labour and Social Affairs recommended to the higher authorities for work protection of the "Lander" to bring in the directive published, in agreement with the Ministry of Labour, by the German Engineers' Association on the evaluation of work station noise in relation to loss of hearing, in order to improve safeguards for workers against the noises in question. In September 1971, an ordinance was published concerning dangerous working materials; safeguarding persons using these materials against the dangers involved. In August 1971, a law came into force directed at reducing atmospheric pollution from lead compounds in four-stroke engine fuels. As a safeguard against radiation, a decree on the system of authorisations for medicaments treated with ionizing radiation or containing radioactive substances, in its version of 8 August 1967, was remodelled by a new Decree of 10 May 1971 which added some radionuclides to the list of medicaments which doctors in private practice were authorized to use. A law on individual promotion of vocational training came into force in October 1971, which provided for financial grants for attendance at further general or technical teaching establishments from the second year of studies at higher technical schools, academies and higher education establishments, training centres of second degree, or certain courses of television teaching. Grants were also made in certain cases for attendance at training centres located outside the Federal Republic.

text: Explosive detection using ion mobility spectrometry (IMS) is based on velocities of ions in a uniform electric field. There are some variant to IMS such as Ion trap mobility spectrometry (ITMS) or Non-linear dependence on ion mobility (NLDM) which are based on IMS principle. The sensitivity of devices using this technology is limited to pg levels. The technology also requires the ionization of sample explosives which is accomplished by a radioactive source such as nickel-63 or americium-241. This technology is found in most commercially available explosive detectors such as the GE VaporTracer, Smith Sabre 4000 and Russian built MO-2M and MO-8. The presence of radioactive materials in these equipments cause regulatory hassles and requires special permissions at customs ports. These detectors cannot be field serviced and may pose radiation hazard to the operator if the casing of the detector cracks due to mishandling. Bi-yearly checks are mandatory on such equipment in most countries by regulating agencies to ensure that there are no radiation leaks. Disposal of these equipments is also controlled owing to the high half-life of the radioactive material used.

text: Explosive detection using

text: ion mobility spectrometry

text: (IMS) is based on velocities of ions in a uniform electric field. There are some variant to IMS such as Ion trap mobility spectrometry (ITMS) or Non-linear dependence on ion mobility (NLDM) which are based on IMS principle. The sensitivity of devices using this technology is limited to pg levels. The technology also requires the ionization of sample explosives which is accomplished by a radioactive source such as nickel-63 or americium-241. This technology is found in most commercially available explosive detectors such as the GE VaporTracer, Smith Sabre 4000 and Russian built MO-2M and MO-8. The presence of radioactive materials in these equipments cause regulatory hassles and requires special permissions at customs ports. These detectors cannot be field serviced and may pose radiation hazard to the operator if the casing of the detector cracks due to mishandling. Bi-yearly checks are mandatory on such equipment in most countries by regulating agencies to ensure that there are no radiation leaks. Disposal of these equipments is also controlled owing to the high half-life of the radioactive material used.

text: Although radiation was discovered in late 19th century, the dangers of radioactivity and of radiation were not immediately recognized. Acute effects of radiation were first observed in the use of X-rays when Wilhelm Röntgen intentionally subjected his fingers to X-rays in 1895. He published his observations concerning the burns that developed, though he attributed them to ozone rather than to X-rays. His injuries healed later.

text: Wilhelm Röntgen

text: intentionally subjected his fingers to X-rays in 1895. He published his observations concerning the burns that developed, though he attributed them to ozone rather than to X-rays. His injuries healed later.

text: In 1905 Albert Einstein formulated the idea of mass–energy equivalence. While the work on radioactivity by Becquerel and Marie Curie predates this, an explanation of the source of the energy of radioactivity would have to wait for the discovery that the nucleus itself was composed of smaller constituents, the nucleons.

text: In 1905

text: Albert Einstein

text: formulated the idea of

text: mass–energy equivalence

text: . While the work on radioactivity by

text: Becquerel

text: and

text: Marie Curie

text: predates this, an explanation of the source of the energy of radioactivity would have to wait for the discovery that the nucleus itself was composed of smaller constituents, the

text: nucleon

text: s.

text: The United States 9/11 Commission has said that nuclear power plants were potential targets originally considered for the September 11, 2001 attacks. If terrorist groups could sufficiently damage safety systems to cause a core meltdown at a nuclear power plant, and/or sufficiently damage spent fuel pools, such an attack could lead to a widespread radioactive contamination. According to a 2004 report by the U.S. Congressional Budget Office, "The human, environmental, and economic costs from a successful attack on a nuclear power plant that results in the release of substantial quantities of radioactive material to the environment could be great." An attack on a reactor’s spent fuel pool could also be serious, as these pools are less protected than the reactor core. The release of radioactivity could lead to thousands of near-term deaths and greater numbers of long-term fatalities.

text: The United States 9/11 Commission has said that nuclear power plants were potential targets originally considered for the

text: September 11, 2001

text: attacks. If terrorist groups could sufficiently damage safety systems to cause a

text: core meltdown

text: at a nuclear power plant, and/or sufficiently damage spent fuel pools, such an attack could lead to a widespread radioactive contamination. According to a 2004 report by the U.S.

text: Congressional Budget Office

text: , "The human, environmental, and economic costs from a successful attack on a nuclear power plant that results in the release of substantial quantities of radioactive material to the environment could be great." An attack on a reactor’s

text: spent fuel pool

text: could also be serious, as these pools are less protected than the reactor core. The release of radioactivity could lead to thousands of near-term deaths and greater numbers of long-term fatalities.

text: Before (and, occasionally, after) the discovery of radioactivity, uranium was primarily used in small amounts for yellow glass and pottery glazes, such as uranium glass and in Fiestaware.

text: Before (and, occasionally, after) the discovery of radioactivity, uranium was primarily used in small amounts for yellow glass and pottery glazes, such as

text: uranium glass

text: and in

text: Fiestaware

text: In 1977 at Rice University Clayton had been named Co-Investigator for the NASA-approved proposal for the OSSE spectrometer on CGRO, and in 1982 he  summarized physical expectations for several gamma-ray-line emitting young nuclei. Key to the intense supernova radioactivity had been Clayton's 1967 discovery that rapid-silicon-burning was dominated by abundances of radioactive alpha-particle nuclei (those having equal numbers of protons and neutrons). Clayton has quipped that SN explosions are "the largest nuclear accidents of all time". Supernova 1987A ejected 20,000 times the mass of the earth as pure radioactive Ni nuclei! Abundant iron of our world was demonstrated to be a daughter of radioactive nickel, the most important of the radioactive nuclei. Modern studies of supernovae are dominated by their intensely radioactive natures. Spacetime data for cosmology relies on Ni radioactivity providing the energy for the optical brightness of supernovae of Type Ia, which are the "standard candles" of cosmology but whose diagnostic 847keV and 1238keV gamma rays were first detected only in 2014, fully 47 years after Clayton's prediction of their emission by supernovae. Clayton's work earned for him NASA's 1992 Exceptional Scientific Achievement Award and in the same year the NASA Public Service Group Achievement Award for the OSSE Spectrometer on CGRO. Both the OSSE instrument and the Comptel instrument confirmed predictions. Clayton had previously attempted to establish gamma-ray-line astronomy from r process radioactive nuclei; but r-process nuclei are much less abundant in supernovae than are the nuclei fused during silicon-burning. So it was the latter that became the demonstrated source of radioactive nuclei.  Chapters 8, 11, 17 and 18 in Catch a Falling Star, whose title Clayton has said he chose as an allusion to the gravitational core collapse that triggers these supernovae.

text: In 1977 at Rice University Clayton had been named Co-Investigator for the NASA-approved proposal for the

text: OSSE

text: spectrometer on CGRO, and in 1982 he  summarized physical expectations for several gamma-ray-line emitting young nuclei. Key to the intense supernova radioactivity had been Clayton's 1967 discovery that rapid-silicon-burning was dominated by abundances of radioactive alpha-particle nuclei (those having equal numbers of protons and neutrons). Clayton has quipped that SN explosions are "the largest nuclear accidents of all time". Supernova 1987A ejected 20,000 times the mass of the earth as pure radioactive

text: Ni

text: nuclei! Abundant iron of our world was demonstrated to be a daughter of radioactive nickel, the most important of the radioactive nuclei. Modern studies of supernovae are dominated by their intensely radioactive natures. Spacetime data for cosmology relies on

text: Ni

text: radioactivity providing the energy for the optical brightness of supernovae of Type Ia, which are the "standard candles" of cosmology but whose diagnostic 847keV and 1238keV gamma rays were first detected only in 2014, fully 47 years after Clayton's prediction of their emission by supernovae. Clayton's work earned for him NASA's 1992 Exceptional Scientific Achievement Award and in the same year the NASA Public Service Group Achievement Award for the

text: OSSE

text: Spectrometer on

text: CGRO

text: . Both the

text: OSSE

text: instrument and the

text: Comptel

text: instrument confirmed predictions. Clayton had previously attempted to establish gamma-ray-line astronomy from

text: r process

text: radioactive nuclei; but r-process nuclei are much less abundant in supernovae than are the nuclei fused during silicon-burning. So it was the latter that became the demonstrated source of radioactive nuclei.  Chapters 8, 11, 17 and 18 in Catch a Falling Star, whose title Clayton has said he chose as an allusion to the gravitational core collapse that triggers these supernovae.

text: Three extended families, eventually totaling about 100 people, moved back to their home island in 1972 despite the risk. But 10 years later, a team of French scientists performed additional tests on the island and its inhabitants. They found some wells were too radioactive for use and determined that the pandanus and breadfruit were also dangerous for human consumption. Urine samples from the islanders on Bikini Atoll showed low levels of plutonium 239 and 240. As a result, the Bikini community filed a federal lawsuit seeking a complete scientific survey of Bikini and the northern Marshall Islands. Inter-departmental squabbling over responsibility for the costs delayed the work for three years. Then in May 1977 scientists found dangerously high levels of strontium-90 in the well water exceeding the U.S. maximum allowed limits. In June, the Department of Energy stated that "All living patterns involving Bikini Island exceed Federal [radiation] guidelines for thirty year population doses." Later that year scientists discovered an 11-fold increase in the caesium-137 body burdens in all of the people living on the atoll. In  May 1978 officials from the U.S. Department of the Interior described the 75% increase in radioactive caesium 137 found as "incredible".

text: Three extended families, eventually totaling about 100 people, moved back to their home island in 1972 despite the risk. But 10 years later, a team of French scientists performed additional tests on the island and its inhabitants. They found some wells were too radioactive for use and determined that the pandanus and breadfruit were also dangerous for human consumption. Urine samples from the islanders on Bikini Atoll showed low levels of plutonium 239 and 240. As a result, the Bikini community filed a federal lawsuit seeking a complete scientific survey of Bikini and the northern Marshall Islands. Inter-departmental squabbling over responsibility for the costs delayed the work for three years. Then in May 1977 scientists found dangerously high levels of

text: in the well water exceeding the U.S. maximum allowed limits. In June, the Department of Energy stated that "All living patterns involving Bikini Island exceed Federal [radiation] guidelines for thirty year population doses." Later that year scientists discovered an 11-fold increase in the

text: body burdens in all of the people living on the atoll. In  May 1978 officials from the U.S. Department of the Interior described the 75% increase in radioactive caesium 137 found as "incredible".

text: Neutron activation is the process in which neutron radiation induces radioactivity in materials, and occurs when atomic nuclei capture free neutrons, becoming heavier and entering excited states. The excited nucleus often decays immediately by emitting gamma rays, or particles such as beta particles, alpha particles, fission products and neutrons (in nuclear fission). Thus, the process of neutron capture, even after any intermediate decay, often results in the formation of an unstable activation product. Such radioactive nuclei can exhibit half-lives ranging from small fractions of a second to many years.

text: Neutron activation is the process in which

text: neutron radiation

text: induces

text: radioactivity

text: in materials, and occurs when

text: atomic nuclei

text: capture

text: free neutron

text: s, becoming heavier and entering

text: excited state

text: s. The excited nucleus often decays immediately by emitting

text: gamma rays

text: , or particles such as

text: beta particles

text: alpha particle

text: s,

text: fission products

text: and neutrons (in

text: nuclear fission

text: ). Thus, the process of

text: neutron capture

text: , even after any intermediate decay, often results in the formation of an unstable

text: activation product

text: . Such radioactive nuclei can exhibit

text: half-lives

text: ranging from small fractions of a second to many years.

text: 1968 a Soviet supplied IRT-2000 research reactor together with a number of other facilities that could be used for radioisotope production was built close to Baghdad.

text: 1968 a Soviet supplied IRT-2000 research reactor together with a number of other facilities that could be used for radioisotope production was built close to

text: Baghdad

text: William Bailey was never tried for Byers' death, although the Federal Trade Commission issued an order against his business. However this did not stop Bailey from trading in radioactive products. He later founded a new company – "Radium Institute", in New York – and marketed a radioactive belt-clip, a radioactive paperweight, and a mechanism which made water radioactive.

text: William Bailey was never tried for Byers' death, although the

text: Federal Trade Commission

text: issued an order against his business. However this did not stop Bailey from trading in radioactive products. He later founded a new company – "Radium Institute", in New York – and marketed a radioactive belt-clip, a radioactive paperweight, and a mechanism which made water radioactive.

text: RIA testing relies on the creation of two reagents. One reagent is a radioactive molecule that is the product of covalently bonding a radioactive isotope atom with a molecule of the target substance (e.g. insulin). The second reagent is an antibody which specifically chemically attaches itself to the target substance when the two are in contact. The initial radioactivity of a mixture of the two reagents is then measured. This radioactive mixture is then added to a measured quantity of fluid (e.g. blood) containing an unknown but usually very low concentration of the target substance. Because the antibodies preferentially attach to non-radioactive molecules, the proportion of radioactive target-antibody links is reduced by an amount proportional to the concentration of the target substance in the fluid. When the final radioactivity of the isolated target-antibody material is measured, the concentration of the target substance (i.e. the amount of insulin in the blood) can be calculated.

text: RIA testing relies on the creation of two reagents. One reagent is a radioactive

text: molecule

text: that is the product of

text: covalently

text: bonding

text: a

text: radioactive

text: isotope

text: atom

text: with a molecule of the target substance (e.g. insulin). The second reagent is an antibody which specifically chemically attaches itself to the target substance when the two are in contact. The initial radioactivity of a mixture of the two reagents is then measured. This radioactive mixture is then added to a measured quantity of fluid (e.g. blood) containing an unknown but usually very low concentration of the target substance. Because the antibodies preferentially attach to non-radioactive molecules, the proportion of radioactive target-antibody links is reduced by an amount proportional to the concentration of the target substance in the fluid. When the final radioactivity of the isolated target-antibody material is measured, the concentration of the target substance (i.e. the amount of insulin in the blood) can be calculated.

text: It is feared that a terrorist group could detonate a dirty bomb, a type of radiological weapon. A dirty bomb is made of any radioactive source and a conventional explosive. There would be no nuclear blast and likely no fatalities, but the radioactive material is dispersed and can cause extensive fallout depending on the material used. A foot-long stick of radioactive cobalt could be taken from a food irradiation plant and combined with ten pounds of explosives to contaminate 1,000 square kilometers and make some areas uninhabitable for decades. There are other radiological weapons called radiological exposure devices where an explosive is not necessary. A radiological weapon may be very appealing to terrorist groups as it is highly successful in instilling fear and panic among a population (particularly because of the threat of radiation poisoning) and would contaminate the immediate area for some period of time, disrupting attempts to repair the damage and subsequently inflicting significant economic losses.

text: It is feared that a terrorist group could detonate a

text: dirty bomb

text: , a type of

text: radiological weapon

text: . A dirty bomb is made of any radioactive source and a conventional explosive. There would be no nuclear blast and likely no fatalities, but the radioactive material is dispersed and can cause extensive

text: fallout

text: depending on the material used. A foot-long stick of radioactive cobalt could be taken from a food irradiation plant and combined with ten pounds of explosives to contaminate 1,000 square kilometers and make some areas uninhabitable for decades. There are other radiological weapons called radiological exposure devices where an explosive is not necessary. A radiological weapon may be very appealing to terrorist groups as it is highly successful in instilling fear and panic among a population (particularly because of the threat of

text: radiation poisoning

text: ) and would contaminate the immediate area for some period of time, disrupting attempts to repair the damage and subsequently inflicting significant economic losses.

text: Since 2011, he conducted numerous radiation field work at Fukushima as well as other locations in Japan. Earlier, he was also involved in detecting and analyzing radioactive contamination at sites in Spain, Ukraine, and the Czech Republic. In 2013, he has earned the highest grade at the radiation protection course of the Technical university at Delft, Netherlands.

text: Twenty-nine radioisotopes have been characterized, with the most stable being alpha-decaying Gd (naturally occurring) with a half-life of 1.08×10 years, and Gd with a half-life of 1.79×10 years. All of the remaining radioactive isotopes have half-lives of less than 74.7 years. The majority of these have half-lives of less than 24.6 seconds. Gadolinium isotopes have 4 metastable isomers, with the most stable being Gd (t=110 seconds), Gd (t=85 seconds) and Gd (t=24.5 seconds).

text: Twenty-nine radioisotopes have been characterized, with the most stable being alpha-decaying Gd (naturally occurring) with a half-life of 1.08×10 years, and Gd with a half-life of 1.79×10 years. All of the remaining radioactive isotopes have half-lives of less than 74.7 years. The majority of these have half-lives of less than 24.6 seconds. Gadolinium isotopes have 4 metastable

text: isomer

text: Due to the short range of absorption and inability to penetrate the outer layers of skin, alpha particles are not, in general, dangerous to life unless the source is ingested or inhaled, in which case they become extremely dangerous. Because of this high mass and strong absorption, if alpha-emitting radionuclides do enter the body (upon being inhaled, ingested, or injected, as with the use of Thorotrast for high-quality X-ray images prior to the 1950s), alpha radiation is the most destructive form of ionizing radiation. It is the most strongly ionizing, and with large enough doses can cause any or all of the symptoms of radiation poisoning. It is estimated that chromosome damage from alpha particles is anywhere from 10 to 1000 times greater than that caused by an equivalent amount of gamma or beta radiation, with the average being set at 20 times. The powerful alpha emitter polonium-210 (a milligram of Po emits as many alpha particles per second as 4.215 grams of Ra) is suspected of playing a role in lung cancer and bladder cancer related to tobacco smoking. Po was used to kill Russian dissident and ex-FSB officer Alexander V. Litvinenko in 2006.

text: Due to the short range of absorption and inability to penetrate the outer layers of skin, alpha particles are not, in general, dangerous to life unless the source is ingested or inhaled, in which case they become extremely dangerous. Because of this high mass and strong absorption, if alpha-emitting radionuclides do enter the body (upon being inhaled, ingested, or injected, as with the use of

text: Thorotrast

text: for high-quality X-ray images prior to the 1950s), alpha radiation is the most destructive form of

text: ionizing radiation

text: . It is the most strongly ionizing, and with large enough doses can cause any or all of the symptoms of

text: radiation poisoning

text: . It is estimated that

text: chromosome

text: damage from alpha particles is anywhere from 10 to 1000 times greater than that caused by an equivalent amount of gamma or beta radiation, with the average being set at 20 times. The powerful alpha emitter

text: (a milligram of Po emits as many alpha particles per second as 4.215 grams of

text: Ra

text: ) is suspected of playing a role in

text: lung cancer

text: and

text: bladder cancer

text: related to

text: tobacco smoking

text: . Po was used to kill Russian dissident and ex-

text: FSB

text: officer

text: Alexander V. Litvinenko

text: in 2006.

text: In the current M1135 Nuclear, Biological, Chemical, Reconnaissance Vehicle and previous US NBC tactical monitoring vehicle, the M93 Fox (which is derived from the German radiation detection version of the TPz Fuchs), is built around the AN/VDR2 Radioactivity, Detection, Indication, and Computation (RADIAC) set, capable of measuring beta and gamma radiation both inside and outside the vehicle. This system was first used during DESERT STORM.

text: In the current

entity_name: M1135 Nuclear, Biological, Chemical, Reconnaissance Vehicle

text: M1135 Nuclear, Biological, Chemical, Reconnaissance Vehicle

text: and previous US NBC tactical monitoring vehicle, the

text: M93 Fox

text: (which is derived from the German radiation detection version of the

text: TPz Fuchs

text: ), is built around the AN/VDR2 Radioactivity, Detection, Indication, and Computation (RADIAC) set, capable of measuring beta and gamma radiation both inside and outside the vehicle. This system was first used during

text: DESERT STORM

text: On 26 April 1986 an accident at the Chernobyl nuclear power plant in Ukraine released a radioactive cloud across half of Europe. In Italy the first reactions of the authorities tend to downplay the impact of the accident. The magazine La Nuova Ecologia and the Lega per l'Ambinte, in early May, show evidence during a press conference of the data about radiation levels detected in the country. In the following days the authorities forbid the consumption of some foods such as milk and salad. On May 10 in Rome a great popular event attended by more than 200,000 people marks the first step towards a referendum that the following year puts an end to the use of nuclear energy in Italy.

text: The term radioisotope, which in its general sense refers to any radioactive isotope (radionuclide), has historically been used to refer to all radiopharmaceuticals, and this usage remains common. Technically, however, many radiopharmaceuticals incorporate a radioactive tracer atom into a larger pharmaceutically-active molecule, which is localized in the body, after which the radionuclide tracer atom allows it to be easily detected with a gamma camera or similar gamma imaging device. An example is fludeoxyglucose in which fluorine-18 is incorporated into deoxyglucose. Some radioisotopes (for example gallium-67, gallium-68, and radioiodine) are used directly as soluble ionic salts, without further modification. This use relies on the chemical and biological properties of the radioisotope itself, to localize it within the body.

text: The term radioisotope, which in its general

text: sense

text: refers to any radioactive

text: isotope

text: radionuclide

text: ), has historically been used to refer to all radiopharmaceuticals, and this usage remains common. Technically, however, many radiopharmaceuticals incorporate a

text: radioactive tracer

text: atom into a larger pharmaceutically-active molecule, which is localized in the body, after which the radionuclide tracer atom allows it to be easily detected with a

text: gamma camera

text: or similar gamma imaging device. An example is

text: fludeoxyglucose

text: in which

text: is incorporated into

text: deoxyglucose

text: . Some radioisotopes (for example

text: , and

text: radioiodine

text: ) are used directly as soluble ionic salts, without further modification. This use relies on the chemical and biological properties of the radioisotope itself, to localize it within the body.

text: Cherenkov radiation is used to detect high-energy charged particles. In pool-type nuclear reactors, beta particles (high-energy electrons) are released as the fission products decay. The glow continues after the chain reaction stops, dimming as the shorter-lived products decay. Similarly, Cherenkov radiation can characterize the remaining radioactivity of spent fuel rods.

text: Cherenkov radiation is used to detect high-energy charged particles. In

text: pool-type nuclear reactors

text: , beta particles (high-energy electrons) are released as the

text: fission products

text: decay. The glow continues after the chain reaction stops, dimming as the shorter-lived products decay. Similarly, Cherenkov radiation can characterize the remaining

text: radioactivity

text: of spent fuel rods.

text: Induced radioactivity occurs when a previously stable material has been made radioactive by exposure to specific radiation. Most radioactivity does not induce other material to become radioactive. This Induced radioactivity was discovered by Irène Curie and F. Joliot in 1934 and received the Nobel Prize in 1935 for this discovery.  This is also known as man-made radioactivity. The phenomenon by which even light elements are made radioactive by artificial or induced methods is called artificial radioactivity.

text: Induced radioactivity occurs when a previously stable material has been made

text: radioactive

text: by exposure to specific

text: radiation

text: . Most radioactivity does not induce other material to become radioactive. This Induced radioactivity was discovered by

text: Irène Curie

text: and

text: F. Joliot

text: in 1934 and received the Nobel Prize in 1935 for this discovery.  This is also known as man-made radioactivity. The phenomenon by which even light elements are made radioactive by artificial or induced methods is called artificial radioactivity.

text: Molecule Man is trapped in a radioactive maze and must reach the escape teleport before the radiation kills him.

text: The design called for a  airplane powered by an advanced Stirling radioisotope generator that would have allowed it to fly uninterrupted for about one year. However, the National Research Council's "Decadal Survey" did not prioritize the moon Titan for exploration, and the development of the advanced Stirling radioisotope generator was suspended indefinitely.

text: The design called for a  airplane powered by an

text: advanced Stirling radioisotope generator

text: that would have allowed it to fly uninterrupted for about one year. However, the National Research Council's "Decadal Survey" did not prioritize the moon Titan for exploration, and the development of the advanced Stirling radioisotope generator was suspended indefinitely.

text: In 1972 the Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter was held and in 1975 the USSR ratified the agreement to limit the dumping of high-level radioactive wastes in the oceans. In 1983 many Convention members signed a voluntary moratorium on all dumping of radioactive wastes at sea, but the USSR did not sign and continued to dispose of low-level radioactive reactor coolant water from its nuclear submarines. Leaks and intentional releases of radioactive materials from Russian facilities in the Far East prompted Japan to offer financial aid for Russia to build facilities to treat low-level radioactive water in 1994. By 1996 a design for a floating processing facility was accepted and contracts issued to the Tomen Corporation (Japan), Babcock & Wilcox (USA) and  the Amurskiy shipyard (Russia). Landysh was built at the Amurskiy  shipyard in Komsomolsk-on-Amur, completed in 1998 and commissioned in 2000. Landysh remained at Zvezda shipyard in Bolshoy Kamen until 2011. As of May 9, 2011 discussions between Rosatom, the Russian nuclear agency, and Japan concerning the dispatch of Landysh to Japan were still ongoing. Japanese reluctance to accept Russian assistance may be linked to the Kuril Islands dispute between Russia and Japan.

text: In 1972 the

entity_name: London Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter

text: Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter

text: was held and in 1975 the

text: USSR

text: ratified the agreement to limit the dumping of high-level radioactive wastes in the oceans. In 1983 many Convention members signed a voluntary moratorium on all dumping of radioactive wastes at sea, but the USSR did not sign and continued to dispose of low-level radioactive reactor coolant water from its nuclear submarines. Leaks and intentional releases of radioactive materials from Russian facilities in the Far East prompted Japan to offer financial aid for Russia to build facilities to treat low-level radioactive water in 1994. By 1996 a design for a floating processing facility was accepted and contracts issued to the Tomen Corporation (Japan),

text: Babcock & Wilcox

text: (USA) and  the Amurskiy shipyard (Russia). Landysh was built at the Amurskiy  shipyard in

text: Komsomolsk-on-Amur

text: , completed in 1998 and commissioned in 2000. Landysh remained at

text: Zvezda shipyard

text: in

text: Bolshoy Kamen

text: until 2011. As of May 9, 2011 discussions between

text: Rosatom

text: , the Russian nuclear agency, and Japan concerning the dispatch of Landysh to Japan were still ongoing. Japanese reluctance to accept Russian assistance may be linked to the

text: Kuril Islands dispute

text: between Russia and Japan.

text: There is a debate over what should constitute an acceptable scientific and engineering foundation for proceeding with radioactive waste disposal strategies. There are those who have argued, on the basis of complex geochemical simulation models, that relinquishing control over radioactive materials to geohydrologic processes at repository closure is an acceptable risk. They maintain that so-called "natural analogues" inhibit subterranean movement of radionuclides, making disposal of radioactive wastes in stable geologic formations unnecessary. However, existing models of these processes are empirically underdetermined: due to the subterranean nature of such processes in solid geologic formations, the accuracy of computer simulation models has not been verified by empirical observation, certainly not over periods of time equivalent to the lethal half-lives of high-level radioactive waste. On the other hand, some insist deep geologic repositories in stable geologic formations are necessary. National management plans of various countries display a variety of approaches to resolving this debate.

text: This is a branch of medicine that uses radiation to provide information about the functioning of a person's specific organs or to treat disease. In most cases, the information is used by physicians to make a quick, accurate diagnosis of the patient's illness. The thyroid, bones, heart, liver and many other organs can be easily imaged, and disorders in their function revealed. In some cases radiation can be used to treat diseased organs, or tumours. Five Nobel Laureates have been intimately involved with the use of radioactive tracers in medicine.Over 10,000 hospitals worldwide use radioisotopes in medicine, and about 90% of the procedures are for diagnosis.  The most common radioisotope used in diagnosis is technetium-99, with some 30 million procedures per year, accounting for 80% of all nuclear medicine procedures worldwide.In developed countries (26% of world population) the frequency of diagnostic nuclear medicine is 1.9% per year, and the frequency of therapy with radioisotopes is about one tenth of this. In the USA there are some 18 million nuclear medicine procedures per year among 311 million people, and in Europe about 10 million among 500 million people. In Australia there are about 560,000 per year among 21 million people, 470,000 of these using reactor isotopes. The use of radiopharmaceuticals in diagnosis is growing at over 10% per year.Nuclear medicine was developed in the 1950s by physicians with an endocrine emphasis, initially using iodine-131 to diagnose and then treat thyroid disease. In recent years, specialists have also come from radiology, as dual CT/PET procedures have become established.Computed X-ray tomography (CT) scans and nuclear medicine contribute 36% of the total radiation exposure and 75% of the medical exposure to the US population, according to a US National Council on Radiation Protection & Measurements report in 2009.  The report showed that Americans’ average total yearly radiation exposure had increased from 3.6 millisievert to 6.2 mSv per year since the early 1980s, due to medical-related procedures. (Industrial radiation exposure, including that from nuclear power plants, is less than 0.1% of overall public radiation exposure.)

text: Radiation monitoring involves the measurement of radiation dose or radionuclide contamination for reasons related to the assessment or control of exposure to radiation or radioactive substances, and the interpretation of the results.

text: Like all focused energy, the beam will irradiate all matter in the targeted area, including everything beyond/behind it that is not shielded, with no possible discrimination between individuals, objects or materials. Anyone incapable of leaving the target area (e.g., physically handicapped, infants, incapacitated, trapped, etc.) would continue to receive radiation until the operator turned off the beam. Reflective materials such as aluminium cooking foil should reflect this radiation and could be used to make clothing that would be protective against this radiation.

text: Americium-241 is an alpha emitter with a half-life of 432.6 years. Alpha particle radiation, as opposed to beta (electron) and gamma (electromagnetic) radiation, is used for two additional reasons: alpha particles have high ionization, so sufficient air particles will be ionized for the current to exist, and they have low penetrative power, meaning they will be stopped, safely, by the plastic of the smoke detector or the air. About one percent of the emitted radioactive energy of Am is gamma radiation. The amount of elemental americium-241 is small enough to be exempt from the regulations applied to larger sources. It includes about 37 kBq or 1 µCi of radioactive element americium-241 (Am), corresponding to about 0.3 µg of the isotope. This provides sufficient ion current to detect smoke, while producing a very low level of radiation outside the device.

text: Americium-241 is an

text: alpha emitter

text: with a

text: half-life

text: of 432.6 years. Alpha particle radiation, as opposed to

text: beta

text: (electron) and gamma (electromagnetic) radiation, is used for two additional reasons: alpha particles have high ionization, so sufficient air particles will be ionized for the current to exist, and they have low penetrative power, meaning they will be stopped, safely, by the plastic of the smoke detector or the air. About one percent of the emitted radioactive energy of Am is

text: gamma radiation

text: . The amount of elemental americium-241 is small enough to be exempt from the regulations applied to larger sources. It includes about 37

text: kBq

text: or 1

text: µCi

text: of radioactive element americium-241 (Am), corresponding to about 0.3 µg of the isotope. This provides sufficient ion current to detect smoke, while producing a very low level of radiation outside the device.

text: The other iodine radioisotopes have much shorter half-lives, no longer than days. Some of them have medical applications involving the thyroid gland, where the iodine that enters the body is stored and concentrated. Iodine-123 has a half-life of thirteen hours and decays by electron capture to tellurium-123, emitting gamma radiation; it is used in nuclear medicine imaging, including single photon emission computed tomography (SPECT) and X-ray computed tomography (X-Ray CT) scans. Iodine-125 has a half-life of fifty-nine days, decaying by electron capture to tellurium-125 and emitting low-energy gamma radiation; the second-longest-lived iodine radioisotope, it has uses in biological assays, nuclear medicine imaging and in radiation therapy as brachytherapy to treat a number of conditions, including prostate cancer, uveal melanomas, and brain tumours. Finally, iodine-131, with a half-life of eight days, beta decays to an excited state of stable xenon-131 that then converts to the ground state by emitting gamma radiation. It is a common fission product and thus is present in high levels in radioactive fallout. It may then be absorbed through contaminated food, and will also accumulate in the thyroid. As it decays, it may cause damage to the thyroid. The primary risk from exposure to high levels of iodine-131 is the chance occurrence of radiogenic thyroid cancer in later life. Other risks include the possibility of non-cancerous growths and thyroiditis. The usual means of protection against the negative effects of iodine-131 is by saturating the thyroid gland with stable iodine-127 in the form of potassium iodide tablets, taken daily for optimal prophylaxis. However, iodine-131 may also be used for medicinal purposes in radiation therapy for this very reason, when tissue destruction is desired after iodine uptake by the tissue. Iodine-131 is also used as a radioactive tracer.

text: The other iodine radioisotopes have much shorter half-lives, no longer than days. Some of them have medical applications involving the

text: thyroid gland

text: , where the iodine that enters the body is stored and concentrated.

text: has a half-life of thirteen hours and decays by

text: electron capture

text: to

text: , emitting

text: gamma radiation

text: ; it is used in

text: nuclear medicine

text: imaging, including

text: single photon emission computed tomography

text: (SPECT) and

text: X-ray computed tomography

text: (X-Ray CT) scans.

text: has a half-life of fifty-nine days, decaying by electron capture to

text: and emitting low-energy gamma radiation; the second-longest-lived iodine radioisotope, it has uses in

text: biological assay

text: s,

text: nuclear medicine

text: imaging and in

text: radiation therapy

text: as

text: brachytherapy

text: to treat a number of conditions, including

text: prostate cancer

text: uveal melanoma

text: s, and

text: brain tumour

text: s. Finally,

text: , with a half-life of eight days, beta decays to an excited state of stable

text: that then converts to the ground state by emitting gamma radiation. It is a common

text: fission product

text: and thus is present in high levels in radioactive

text: fallout

text: . It may then be absorbed through contaminated food, and will also accumulate in the thyroid. As it decays, it may cause damage to the thyroid. The primary risk from exposure to high levels of iodine-131 is the chance occurrence of

text: radiogenic

text: thyroid cancer

text: in later life. Other risks include the possibility of non-cancerous growths and

text: thyroiditis

text: . The usual means of protection against the negative effects of iodine-131 is by saturating the thyroid gland with stable iodine-127 in the form of

text: potassium iodide

text: tablets, taken daily for optimal prophylaxis. However, iodine-131 may also be used for medicinal purposes in

text: radiation therapy

text: for this very reason, when tissue destruction is desired after iodine uptake by the tissue. Iodine-131 is also used as a

text: radioactive tracer

text: The additional radioactivity in the biosphere caused by human activity due to the releases of man-made radioactivity and of Naturally Occurring Radioactive Materials (NORM) can be divided into several classes.

text: Radiation flux is a measure of the amount of radiation received by an object from a given source. This can be any type of radiation, including electromagnetic, sound, and particles from a radioactive source.

text: Radiation flux is a measure of the amount of

text: radiation

text: received by an object from a given source. This can be any type of radiation, including electromagnetic, sound, and particles from a

text: radioactive

text: source.

text: Ionising radiation occurs naturally but can also be artificially created.  Generally people can be exposed to radiation externally from radioactive material or internally by inhaling or ingesting radioactive substances.  Exposure to electromagnetic rays such as x-rays and gamma rays can, depending on the time exposed, cause sterility, genetic defects, premature ageing and death.

text: Ionising radiation

text: occurs naturally but can also be artificially created.  Generally people can be exposed to radiation externally from radioactive material or internally by inhaling or ingesting radioactive substances.  Exposure to electromagnetic rays such as x-rays and gamma rays can, depending on the time exposed, cause sterility, genetic defects, premature ageing and death.

text: Because some radioactivity is present everywhere (i.e., background radiation), the spectrum should be analyzed when no source is present. The background radiation must then be subtracted from the actual measurement. Lead absorbers can be placed around the measurement apparatus to reduce background radiation.

text: Because some radioactivity is present everywhere (i.e.,

text: background radiation

text: ), the spectrum should be analyzed when no source is present. The background radiation must then be subtracted from the actual measurement.

text: Lead

text: absorbers can be placed around the measurement apparatus to reduce background radiation.

text: Jiří Hála's textbook states that soils vary greatly in their ability to bind radioisotopes, the clay particles and humic acids can alter the distribution of the isotopes between the soil water and the soil.  The distribution coefficient K is the ratio of the soil's radioactivity (Bq g) to that of the soil water (Bq ml).  If the radioactivity is tightly bonded to by the minerals in the soil then less radioactivity can be absorbed by crops and grass growing in the soil.

text: Jiří Hála's

text: textbook

text: states that soils vary greatly in their ability to bind radioisotopes, the

text: clay

text: particles and

text: humic acid

text: s can alter the distribution of the isotopes between the soil water and the soil.  The distribution coefficient K is the ratio of the soil's radioactivity (Bq g) to that of the soil water (Bq ml).  If the radioactivity is tightly bonded to by the minerals in the soil then less radioactivity can be absorbed by crops and

text: grass

text: growing in the soil.

text: The neutron radiation serves to transmute the surrounding matter, often rendering it radioactive. When added to the dust of radioactive material released by the bomb itself, a large amount of radioactive material is released into the environment. This form of radioactive contamination is known as nuclear fallout and poses the primary risk of exposure to ionizing radiation for a large nuclear weapon.

text: The neutron radiation serves to transmute the surrounding matter, often rendering it

text: radioactive

text: . When added to the dust of radioactive material released by the bomb itself, a large amount of radioactive material is released into the environment. This form of

text: radioactive contamination

text: is known as

text: nuclear fallout

text: and poses the primary risk of exposure to ionizing radiation for a large nuclear weapon.

text: Actually, the radioactive system is like a digital 'clock', while the geological processes can be like replacing a battery. When a new battery is inserted, this 'clock' starts counting from 00:00. This process is what we call the age resetting mechanism.

text: The 1991 Final Report of the Nuclear Shipyard Worker Study (NSWS) analyzed the effects of radiation exposure in the U.S. to three cohort groups: 27,872 high-dose nuclear workers, 10348 low-dose nuclear workers, and a control group of 32,510 shipyard workers not exposed to radiation. Dose reconstruction for occupational radiation exposure used by the U.S. Department of Labor assumes that the probability of cancer is "at least as likely as not" rendering it complex for workers to claim compensation via The Act.

text: In IRMA, the antibodies are labeled with radioisotopes which are used to bind antigens present in the specimen. When a positive sample is added to the tubes, radioactively labeled (labeled with I125 or I131 radioisotopes) antibodies bind to the free epitopes of antigens and form an antigen-antibody complex. Unbound labeled antibodies are removed by a second reaction with a solid phase antigen. The amount of radioactive remaining in the solution is direct function of the antigen concentration.

text: It is safe to say that it might be possible to stop a loss-of-coolant event prior to core damage occurring, but that any core damage incidents will probably assure massive release of radioactive materials. Further, dangerous power fluctuations are natural to the design.

text: On 31 March, TEPCO reported that it had measured radioactivity in the plant-site groundwater which was 10,000 times the government limit. The company did not think that this radioactivity had spread to drinking water. NISA questioned the radioactivity measurement and TEPCO is re-evaluating it. Some debris around the plant has been found to be highly radioactive, including a concrete fragment emanating 900 mSv/h.

text: In a radioactive ion source, a small piece of radioactive material, for instance Ni or Am, is used to ionize a gas. This is used in ionization smoke detectors and ion mobility spectrometers.

text: In a radioactive ion source, a small piece of radioactive material, for instance

text: Ni

text: or

text: Am

text: , is used to ionize a gas. This is used in ionization

text: smoke detector

text: s and

text: ion mobility spectrometer

text: s.

text: Radio-Activity opens with the accelerating pulse of the minute long intro "Geiger Counter", which is meant to simulate the sounds made by a Geiger counter as it approaches radioactive objects. "Geiger Counter" then segues into the title track "Radioactivity". The song refers both to radioactivity, the process by which the nucleus of an unstable atom loses energy by emitting radiation, and the act of listening to recorded sounds and the radio (with the line 'Tune into the melody'). It is followed by a song about the radio (specifically, shortwave radio), entitled "Radioland". "Radioland" links into a tone that quickly increases in pitch which kicks off the fast-tempoed "Airwaves", which is a song about a modern communication. "Airwaves" segues into a 38 second long "Intermission", which then goes into "News". "News" features simulated radio recordings of German-language news about radioactivity.

text: Radio-Activity opens with the accelerating pulse of the minute long intro "Geiger Counter", which is meant to simulate the sounds made by a

text: Geiger counter

text: as it approaches radioactive objects. "Geiger Counter" then segues into the title track "

text: Radioactivity

text: ". The song refers both to

text: radioactivity

text: , the process by which the

text: nucleus

text: of an unstable

text: atom

text: loses energy by emitting radiation, and the act of listening to recorded sounds and the radio (with the line 'Tune into the melody'). It is followed by a song about the radio (specifically,

text: shortwave radio

text: ), entitled "Radioland". "Radioland" links into a tone that quickly increases in pitch which kicks off the fast-tempoed "Airwaves", which is a song about a modern communication. "Airwaves" segues into a 38 second long "Intermission", which then goes into "News". "News" features simulated radio recordings of German-language news about radioactivity.

text: Exposure to radioactive substances can produce radiation poisoning, an unrelated phenomenon.

text: Exposure to radioactive substances can produce

text: radiation poisoning

text: , an unrelated phenomenon.

text: Microwave exposure at low-power levels below the Specific absorption rate set by government regulatory bodies are considered harmless non-ionizing radiation and have no effect on the human body.  However, levels above the Specific absorption rate set by the U.S. Federal Communications Commission are considered potentially harmful (see Mobile phone radiation and health).

text: Microwave exposure at low-power levels below the

text: Specific absorption rate

text: set by government regulatory bodies are considered harmless non-ionizing radiation and have no effect on the human body.  However, levels above the Specific absorption rate set by the U.S.

text: Federal Communications Commission

text: are considered potentially harmful (see

text: Mobile phone radiation and health

text: The background rate for natural radiation varies considerably with location, being as low as 1.5 mSv/a (1.5 mSv per year) in some areas and over 100 mSv/a in others. The highest level of purely natural radiation recorded on the Earth's surface is 90 µGy/h (0.8 Gy/a) on a Brazilian black beach composed of monazite. The highest background radiation in an inhabited area is found in Ramsar, primarily due to naturally radioactive limestone used as a building material. Some 2000 of the most exposed residents receive an average radiation dose of 10 mGy per year, (1 rad/yr) ten times more than the ICRP recommended limit for exposure to the public from artificial sources. Record levels were found in a house where the effective radiation dose due to external radiation was 135 mSv/a, (13.5 rem/yr) and the committed dose from radon was 640 mSv/a (64.0 rem/yr). This unique case is over 200 times higher than the world average background radiation. Despite the high levels of background radiation that the residence of Ramsar receive there is no compelling evidence that they experience a greater health risks. The ICRP recommendations are conservative limits and may represent an over representation of the actual health risk. Generally radiation safety organization recommend the most conservative limits assuming it is best to error on the side of caution. This level of caution is appropriate but should not be used to create fear about background radiation danger. Radiation danger from background radiation may be a serious threat but is more likely a small overall risk compared to all other factors in the environment.

text: The background rate for natural radiation varies considerably with location, being as low as 1.5 mSv/a (1.5 mSv per year) in some areas and over 100 mSv/a in others. The highest level of purely natural radiation recorded on the Earth's surface is 90 µGy/h (0.8 Gy/a) on a Brazilian black beach composed of

text: monazite

text: . The highest background radiation in an inhabited area is found in

text: Ramsar

text: , primarily due to naturally radioactive limestone used as a building material. Some 2000 of the most exposed residents receive an average

text: radiation dose

text: of 10

text: mGy

text: per year, (1

text: rad

text: /yr) ten times more than the ICRP recommended limit for exposure to the public from artificial sources. Record levels were found in a house where the

text: effective radiation dose

text: due to external radiation was 135 mSv/a, (13.5 rem/yr) and the

text: committed dose

text: from

text: radon

text: was 640 mSv/a (64.0 rem/yr). This unique case is over 200 times higher than the world average background radiation. Despite the high levels of background radiation that the residence of Ramsar receive there is no compelling evidence that they experience a greater health risks. The ICRP recommendations are conservative limits and may represent an over representation of the actual health risk. Generally radiation safety organization recommend the most conservative limits assuming it is best to error on the side of caution. This level of caution is appropriate but should not be used to create fear about background radiation danger. Radiation danger from background radiation may be a serious threat but is more likely a small overall risk compared to all other factors in the environment.

text: Many historians consider the discovery of artificially produced radionuclides by Frédéric Joliot-Curie and Irène Joliot-Curie in 1934 as the most significant milestone in nuclear medicine. In February 1934, they reported the first artificial production of radioactive material in the journal Nature, after discovering radioactivity in aluminum foil that was irradiated with a polonium preparation. Their work built upon earlier discoveries by Wilhelm Konrad Roentgen for X-ray, Henri Becquerel for radioactive uranium salts, and Marie Curie (mother of Irène Curie) for radioactive thorium, polonium and coining the term "radioactivity." Taro Takemi studied the application of nuclear physics to medicine in the 1930s. The history of nuclear medicine will not be complete without mentioning these early pioneers.

text: Many historians consider the discovery of artificially produced radionuclides by

text: Frédéric Joliot-Curie

text: and

text: Irène Joliot-Curie

text: in 1934 as the most significant milestone in nuclear medicine. In February 1934, they reported the first artificial production of radioactive material in the journal

text: Nature

text: , after discovering radioactivity in aluminum foil that was irradiated with a polonium preparation. Their work built upon earlier discoveries by

text: Wilhelm Konrad Roentgen

text: for X-ray,

text: Henri Becquerel

text: for radioactive uranium salts, and

text: Marie Curie

text: (mother of Irène Curie) for radioactive thorium, polonium and coining the term "radioactivity."

text: Taro Takemi

text: studied the application of

text: nuclear physics

text: to medicine in the 1930s. The history of nuclear medicine will not be complete without mentioning these early pioneers.

text: Environmental radioactivity is produced by radioactive materials in the human environment.  While some radioisotopes, such as strontium-90 (Sr) and technetium-99 (Tc), are only found on Earth as a result of human activity, and some, like potassium-40 (K), are only present due to natural processes, a few isotopes, e.g. tritium (H), result from both natural processes and human activities. The concentration and location of some natural isotopes, particularly uranium-238 (U), can be affected by human activity.

text: Environmental

text: radioactivity

text: is produced by radioactive materials in the

text: human

text: environment

text: .  While some

text: radioisotopes

text: , such as

text: (Sr) and

text: (Tc), are only found on

text: Earth

text: as a result of human activity, and some, like

text: (K), are only present due to natural processes, a few isotopes, e.g.

text: tritium

text: (H), result from both natural processes and human activities. The concentration and location of some natural isotopes, particularly

text: (U), can be affected by human activity.

text: There are three ways a radiographer will ensure they are not exposed to higher than required levels of radiation, time, distance, shielding. The less time that a person is exposed to radiation the lower their dose will be. The further a person is from a radioactive source the lower the level of radiation they receive, this is largely due to the inverse square law. Lastly the more a radioactive source is shielded by either better or greater amounts of shielding the lower the levels of radiation that will escape from the testing area. The most commonly used shielding materials in use are sand, lead (sheets or shot), steel, spent (non-radioactive uranium) tungsten and in suitable situations water.

text: Ionizing radiation has many industrial, military, and medical uses. Its usefulness must be balanced with its hazards, a compromise that has shifted over time. For example, at one time, assistants in shoe shops used X-rays to check a child's shoe size, but this practice was halted when the risks of ionizing radiation were better understood.

text: Ionizing radiation has many industrial, military, and medical uses. Its usefulness must be balanced with its hazards, a compromise that has shifted over time. For example, at one time, assistants in shoe shops

text: used X-rays to check a child's shoe size

text: , but this practice was halted when the risks of ionizing radiation were better understood.

text: The NRPA is responsible for: overseeing the use of radioactive substances and fissile material, coordinating contingency plans against nuclear accidents and radioactive fallout, monitoring natural and artificial radiation in the environment and at the workplace, increasing our knowledge of the occurrence as well as monitoring risk and effects of radiation. It has regional offices in Tromsø and Sør-Varanger and is divided into three sections:

text: The NRPA is responsible for: overseeing the use of radioactive substances and fissile material, coordinating contingency plans against nuclear accidents and radioactive fallout, monitoring natural and artificial radiation in the environment and at the workplace, increasing our knowledge of the occurrence as well as monitoring risk and effects of radiation. It has regional offices in

text: Tromsø

text: and

text: Sør-Varanger

text: and is divided into three sections:

text: Although testing at the well sites that supply Aqaba reveals high radioactivity, testing performed using water from the tap in Aqaba shows the water to be safe.  There is no confirmed explanation for this phenomenon, although it is hypothesized that the depth of the wells (the ones that supply Aqaba are relatively shallow) may play a role as the radiation varies greatly at shallow depths.In May, 2011, the President of the Jordanian Geologists Association Bahjat Al Adwan stated that the radiation is present in the water in the form of Radon, and thus dissipates harmlessly when the water is exposed to air on the surface.  This explanation has not been confirmed scientifically,  however.

text: Although testing at the

text: well sites

text: that supply Aqaba reveals high radioactivity, testing performed using water from the tap in Aqaba shows the water to be safe.  There is no confirmed explanation for this phenomenon, although it is hypothesized that the depth of the wells (the ones that supply Aqaba are relatively shallow) may play a role as the radiation varies greatly at shallow depths.In May, 2011, the President of the Jordanian Geologists Association Bahjat Al Adwan stated that the radiation is present in the water in the form of Radon, and thus dissipates harmlessly when the water is exposed to air on the surface.  This explanation has not been confirmed scientifically,  however.

text: The countries involved — listed in order of total contributions measured in TBq (TBq=10 Becquerel) — were the USSR, the UK, Switzerland, the US, Belgium, France, the Netherlands, Japan, Sweden, Russia, New Zealand, Germany, Italy and South Korea. Together, they dumped a total of 85,100 TBq (85.1x10Bq) of radioactive waste at over 100 ocean sites, as measured in initial radioactivity at the time of dump.

text: The countries involved — listed in order of total contributions measured in TBq (TBq=10

text: Becquerel

text: ) — were the USSR, the UK, Switzerland, the US, Belgium, France, the Netherlands, Japan, Sweden, Russia, New Zealand, Germany, Italy and South Korea. Together, they dumped a total of 85,100 TBq (85.1x10Bq) of radioactive waste at over 100 ocean sites, as measured in initial radioactivity at the time of dump.

text: Being within the intended Containment differentiates radioactive material from radioactive contamination. When radioactive materials are concentrated to a detectable level outside a containment, the area affected is generally referred to as "contaminated".

text: Ore concentrate was transferred to refineries in New South Wales and Victoria. Radium had reached a price of ₤13,000 per gram in 1911, and in the same year, at a cost of ₤15,000 the company built a refinery at Hunter's Hill in New South Wales to produce radium compounds. 350 milligrams of radium bromide (RaBr) and 150 kg of uranium were produced. The radium bromide was used for research in the emerging fields of radiation and radioactivity and some of the Hunter's Hill radium was sold to pioneering nuclear researchers Ernest Rutherford and Marie Curie.

text: Ore concentrate was transferred to refineries in

text: New South Wales

text: and

text: Victoria

text: . Radium had reached a price of ₤13,000 per gram in 1911, and in the same year, at a cost of ₤15,000 the company built a refinery at

text: Hunter's Hill

text: in

text: New South Wales

text: to produce radium compounds. 350 milligrams of

text: radium bromide

text: (RaBr) and 150 kg of

text: uranium

text: were produced. The radium bromide was used for research in the emerging fields of

text: radiation

text: and

text: radioactivity

text: and some of the Hunter's Hill radium was sold to pioneering nuclear researchers

text: Ernest Rutherford

text: and

text: Marie Curie

text: At an annual food safety exhibition in Tokyo held on 26 to 28 October 2011 machines were shown that could measure radiation: on conveyor belts food and other objects could be proofed by a radiation sensor, and the outcome could be read within 12 seconds. In this way a large number of objects could be checked in a very short time. Despite the huge price: 56,000 dollars, farmers, beef processors and restaurant chains showed great interest. Smaller devices to check food for radioactivity were shown, testing food placed in beakers. These could be used by smaller firms or even in households. The lowest cost of these small machines was still around 9,000 dollars.

text: In 1981, the EPA began investigating the area where the companies once operated for radioactive materials.  Five areas were identified as having abnormally high levels of gamma radiation, including the locations of both companies and three primarily residential areas.  In 1993, a sixth area was identified.  Radioactive materials were identified at 100 properties located near the companies' former facilities in Camden and Gloucester City, as well as the company locations themselves.  In 1996, due to the levels of contamination in the areas, the Welsbach and General Gas Mantle site was added to the National Priorities List, which consists of areas in the United States that are or could become contaminated with dangerous substances.  The EPA demolished the General Gas Mantle building in late 2000 and only one building remains at the former Welsbach site.  Since it was declared a Superfund site, the EPA has removed over 350,000 tons of contaminated materials from the Welsbach/General Gas Mantle site.

text: In 1981, the EPA began investigating the area where the companies once operated for radioactive materials.  Five areas were identified as having abnormally high levels of gamma radiation, including the locations of both companies and three primarily residential areas.  In 1993, a sixth area was identified.  Radioactive materials were identified at 100 properties located near the companies' former facilities in Camden and Gloucester City, as well as the company locations themselves.  In 1996, due to the levels of contamination in the areas, the Welsbach and General Gas Mantle site was added to the

text: National Priorities List

text: , which consists of areas in the United States that are or could become contaminated with dangerous substances.  The EPA demolished the General Gas Mantle building in late 2000 and only one building remains at the former Welsbach site.  Since it was declared a Superfund site, the EPA has removed over 350,000 tons of contaminated materials from the Welsbach/General Gas Mantle site.

text: In 1946 Canadian Manhattan Project physicist Louis Slotin performed a risky experiment known as "tickling the dragon's tail" which involved two hemispheres of neutron-reflective beryllium being brought together around a plutonium core to bring it to criticality. Against operating procedures, the hemispheres were separated only by a screwdriver. The screwdriver slipped and set off a chain reaction criticality accident filling the room with harmful radiation and a flash of blue light (caused by excited, ionized air particles returning to their unexcited states). Slotin reflexively separated the hemispheres in reaction to the heat flash and blue light, preventing further irradiation of several co-workers present in the room. However, Slotin absorbed a lethal dose of the radiation and died nine days later. The infamous plutonium mass used in the experiment was referred to as the demon core.

text: In 1946 Canadian

text: Manhattan Project

text: physicist

text: Louis Slotin

text: performed a risky experiment known as

text: "tickling the dragon's tail"

text: which involved two hemispheres of

text: neutron-reflective

text: beryllium

text: being brought together around a

text: plutonium core

text: to bring it to criticality. Against operating procedures, the hemispheres were separated only by a screwdriver. The screwdriver slipped and set off a chain reaction

text: criticality accident

text: filling the room with harmful radiation and a flash of blue light (caused by excited, ionized air particles returning to their unexcited states). Slotin reflexively separated the hemispheres in reaction to the heat flash and blue light, preventing further irradiation of several co-workers present in the room. However, Slotin absorbed a lethal dose of the radiation and died nine days later. The infamous plutonium mass used in the experiment was referred to as the

text: demon core

text: The Sudbury Neutrino Observatory (SNO) in Sudbury, Ontario used 1,000 tonnes of heavy water on loan from Atomic Energy of Canada Limited. The neutrino detector is  underground in a mine, to shield it from muons produced by cosmic rays. SNO was built to answer the question of whether or not electron-type neutrinos produced by fusion in the Sun (the only type the Sun should be producing directly, according to theory) might be able to turn into other types of neutrinos on the way to Earth. SNO detects the Cherenkov radiation in the water from high-energy electrons produced from electron-type neutrinos as they undergo charged current (CC) interactions with neutrons in deuterium, turning them into protons and electrons (however, only the electrons are fast enough to produce Cherenkov radiation for detection). SNO also detects neutrino↔electron scattering (ES) events, where the neutrino transfers energy to the electron, which then proceeds to generate Cherenkov radiation distinguishable from that produced by CC events. The first of these two reactions is produced only by electron-type neutrinos, while the second can be caused by all of the neutrino flavors. The use of deuterium is critical to the SNO function, because all three "flavours" (types) of neutrinos may be detected in a third type of reaction as well, neutrino-disintegration, in which a neutrino of any type (electron, muon, or tau) scatters from a deuterium nucleus (deuteron), transferring enough energy to break up the loosely bound deuteron into a free neutron and proton via a neutral current (NC) interaction. This event is detected when the free neutron is absorbed by Cl present from NaCl deliberately dissolved in the heavy water, causing emission of characteristic capture gamma rays. Thus, in this experiment, heavy water not only provides the transparent medium necessary to produce and visualize Cherenkov radiation, but it also provides deuterium to detect exotic mu type (μ) and tau (τ) neutrinos, as well as a non-absorbent moderator medium to preserve free neutrons from this reaction, until they can be absorbed by an easily detected neutron-activated isotope.

text: The

text: Sudbury Neutrino Observatory

text: (SNO) in

text: Sudbury

text: Ontario

text: used 1,000 tonnes of heavy water on loan from

text: Atomic Energy of Canada Limited

text: . The

text: neutrino detector

text: is  underground in a mine, to shield it from

text: muon

text: s produced by

text: cosmic ray

text: s. SNO was built to answer the question of whether or not electron-type

text: neutrino

text: s produced by fusion in the

text: Sun

text: (the only type the Sun should be producing directly, according to theory) might be able to turn into other types of neutrinos on the way to Earth. SNO detects the

text: Cherenkov radiation

text: in the water from high-energy electrons produced from electron-type

text: neutrino

text: s as they undergo charged current (CC) interactions with

text: neutron

text: s in

text: deuterium

text: , turning them into protons and electrons (however, only the electrons are fast enough to produce Cherenkov radiation for detection). SNO also detects neutrino↔electron scattering (ES) events, where the neutrino transfers energy to the electron, which then proceeds to generate Cherenkov radiation distinguishable from that produced by CC events. The first of these two reactions is produced only by electron-type neutrinos, while the second can be caused by all of the neutrino flavors. The use of deuterium is critical to the SNO function, because all three "flavours" (types) of neutrinos may be detected in a third type of reaction as well, neutrino-disintegration, in which a neutrino of any type (electron, muon, or tau) scatters from a deuterium nucleus (

text: deuteron

text: ), transferring enough energy to break up the loosely bound deuteron into a free

text: neutron

text: and

text: proton

text: via a neutral current (NC) interaction. This event is detected when the free neutron is absorbed by Cl present from NaCl deliberately dissolved in the heavy water, causing emission of characteristic capture gamma rays. Thus, in this experiment, heavy water not only provides the transparent medium necessary to produce and visualize Cherenkov radiation, but it also provides deuterium to detect exotic mu type (μ) and tau (τ) neutrinos, as well as a non-absorbent moderator medium to preserve free neutrons from this reaction, until they can be absorbed by an easily detected neutron-activated isotope.

text: Section 811 prohibits anyone, knowingly, unlawfully, and with intent to cause death, serious bodily injury, or substantial damage to property or the environment, from: (1) possessing radioactive material or making or possessing a nuclear explosive device or a radioactive material dispersal or radiation-emitting device; (2) using radioactive material or a device, using, damaging, or interfering with the operation of a nuclear facility in a manner that causes or increases the risk of the release of radioactive material, or causing radioactive contamination or exposure to radiation; or (3) threatening, attempting, or conspiring to commit such an offense. Sets forth: (1) the circumstances in which the United States can exercise jurisdiction over such offenses, and (2) exceptions applicable to activities of the armed forces.

text: Studies of the "radioactivity", that soon revealed the phenomenon of radioactive decay, provided another argument against considering chemical elements as fundamental nature's elements. Despite these discoveries, the term atom stuck to Dalton's (chemical) atoms and now denotes the smallest particle of a chemical element, not something really indivisible.

text: Studies of the "radioactivity", that soon revealed the phenomenon of

text: radioactive decay

text: , provided another argument against considering

text: chemical element

text: s as fundamental nature's elements. Despite these discoveries, the term atom stuck to Dalton's (chemical) atoms and now denotes the smallest particle of a chemical element, not something really indivisible.

text: Detectors can be divided into two major categories: imaging detectors (such as photographic plates and X-ray film (photographic film), now mostly replaced by various digitizing devices like image plates or flat panel detectors) and dose measurement devices (such as ionization chambers, Geiger counters, and dosimeters used to measure the local radiation exposure, dose, and/or dose rate, for example, for verifying that radiation protection equipment and procedures are effective on an ongoing basis).

text: Detectors can be divided into two major categories: imaging detectors (such as

text: photographic plate

text: s and X-ray film (

text: photographic film

text: ), now mostly replaced by various

text: digitizing

text: devices like

text: image plate

text: s or

text: flat panel detector

text: s) and dose measurement devices (such as

text: ionization chamber

text: s,

text: Geiger counter

text: s, and

text: dosimeter

text: s used to measure the local

text: radiation exposure

text: dose

text: , and/or dose rate, for example, for verifying that

text: radiation protection

text: equipment and procedures are effective on an ongoing basis).

text: The conditions inside certain types of nuclear reactors with high neutron flux can cause induced radioactivity. The components in those reactors may become highly radioactive from the radiation to which they are exposed. Induced radioactivity increases the amount of nuclear waste that must eventually be disposed, but it is not referred to as radioactive contamination unless it is uncontrolled.

text: The conditions inside certain types of

text: nuclear reactor

text: s with high

text: neutron flux

text: can cause induced radioactivity. The components in those reactors may become highly radioactive from the radiation to which they are exposed. Induced radioactivity increases the amount of

text: nuclear waste

text: that must eventually be disposed, but it is not referred to as

text: radioactive contamination

text: unless it is uncontrolled.

text: The advanced Stirling radioisotope generator (ASRG) is a radioisotope power system under development at NASA's Glenn Research Center. It uses a Stirling power conversion technology to convert radioactive-decay heat into electricity for use on spacecraft. The energy conversion process used by an ASRG is about four times more efficient than in previous radioisotope systems to produce a similar amount of power, and allows it to use about one quarter of the plutonium-238 as other similar generators.

text: The advanced Stirling radioisotope generator (ASRG) is a

text: radioisotope

text: power system under development at NASA's

text: Glenn Research Center

text: . It uses a

text: Stirling

text: power conversion technology to convert radioactive-decay heat into electricity for use on

text: spacecraft

text: . The energy conversion process used by an ASRG is about four times more efficient than in previous radioisotope systems to produce a similar amount of power, and allows it to use about one quarter of the

text: as other similar generators.

text: Bismuth (Bi) has no stable isotopes, but does have one very long-lived isotope; thus, the relative atomic mass can be given as 208.9803987(16). Although bismuth-209 is now known to be unstable, it has classically been considered to be a "stable" isotope because it has a half-life of over 1.9×10 years, which is more than a billion (1000 million) times the age of the universe. Besides Bi, the most stable bismuth radioisotopes are Bi with a half-life of 3.04 million years, Bi with a half-life of 368,000 years and Bi, with a half-life of 32.9 years, none of which occur in nature. All other isotopes have half-lives under 1 year, most under a day. Of naturally occurring radioisotopes, the most stable is radiogenic Bi with a half-life of 5.012 days.

text: Bismuth

text: (Bi) has no

text: stable

text: isotope

text: s, but does have one very long-lived isotope; thus, the

text: relative atomic mass

text: can be given as 208.9803987(16). Although

text: is now known to be unstable, it has classically been considered to be a "stable" isotope because it has a

text: half-life

text: of over 1.9×10 years, which is more than a billion (1000 million) times the age of the universe. Besides Bi, the most stable bismuth

text: radioisotopes

text: are Bi with a half-life of 3.04 million years, Bi with a half-life of 368,000 years and Bi, with a half-life of 32.9 years, none of which occur in nature. All other isotopes have half-lives under 1 year, most under a day. Of naturally occurring radioisotopes, the most stable is

text: radiogenic

text: Bi with a half-life of 5.012 days.

text: Radiation is also used to treat diseases in radiation therapy.

text: Radiation is also used to treat diseases in

text: radiation therapy

text: There was also some concern about the luminescent dial that glowed green in the dark. This effect came from a small glass tube of tritium gas, which gave off beta radiation, which in turn energized light-producing phosphors and made the dial fluoresce. Although the radioactivity was equivalent only to that given off by a wristwatch it was felt wise to withdraw this facility as public concern over radioactivity grew.

text: When the conjugates include a radioisotope see radioimmunotherapy.When the conjugates include a toxin see immunotoxin.

text: When the conjugates include a

text: radioisotope

text: see

text: radioimmunotherapy

text: .When the conjugates include a

text: toxin

text: see

text: immunotoxin

text: The Earth and all living things on it are constantly bombarded by radiation from outer space. This radiation primarily consists of positively charged ions from protons to iron and larger nuclei derived sources outside our solar system. This radiation interacts with atoms in the atmosphere to create an air shower of secondary radiation, including X-rays, muons, protons, alpha particles, pions, electrons, and neutrons. The immediate dose from cosmic radiation is largely from muons, neutrons, and electrons, and this dose varies in different parts of the world based largely on the geomagnetic field and altitude. For example, the city of Denver in the United States (at 1650 meters elevation) receives a cosmic ray dose roughly twice that of a location at sea level. This radiation is much more intense in the upper troposphere, around 10 km altitude, and is thus of particular concern for airline crews and frequent passengers, who spend many hours per year in this environment. During their flights airline crews typically get an extra dose on the order of 2.2 mSv (220 mrem) per year.

text: The Earth and all living things on it are constantly bombarded by radiation from outer space. This radiation primarily consists of positively charged ions from

text: proton

text: s to

text: iron

text: and larger

text: nuclei

text: derived sources outside our

text: solar system

text: . This radiation interacts with atoms in the atmosphere to create an

text: air shower

text: of secondary radiation, including

text: X-ray

text: s,

text: muon

text: s,

text: proton

text: s,

text: alpha particle

text: s,

text: pion

text: s,

text: electron

text: s, and

text: neutron

text: s. The immediate dose from cosmic radiation is largely from muons, neutrons, and electrons, and this dose varies in different parts of the world based largely on the

text: geomagnetic field

text: and altitude. For example, the city of

text: Denver

text: in the United States (at 1650 meters elevation) receives a cosmic ray dose roughly twice that of a location at sea level. This radiation is much more intense in the upper

text: troposphere

text: , around 10 km altitude, and is thus of particular concern for

text: airline

text: crews and frequent passengers, who spend many hours per year in this environment. During their flights airline crews typically get an extra dose on the order of 2.2 mSv (220 mrem) per year.

text: The DACS machines used cheque-like tokens (which were guillotined to the size of a normal cheque inside the machine) which had been impregnated with a radioactive compound of carbon-14, which was detected and matched against the personal identification number (PIN) entered on a keypad. The short-range beta emission from carbon-14 could be easily detected, and he determined that the radiation hazard was acceptable as "you would have to eat 136,000 such cheques for it to have any effect on you". A proposed PIN length of 6 digits was rejected and 4 digits chosen instead, because it was the longest string of numbers that his wife could remember.

text: The DACS machines used cheque-like tokens (which were guillotined to the size of a normal cheque inside the machine) which had been impregnated with a radioactive compound of

text: , which was detected and matched against the

text: personal identification number

text: (PIN) entered on a keypad. The short-range beta emission from carbon-14 could be easily detected, and he determined that the radiation hazard was acceptable as "you would have to eat 136,000 such cheques for it to have any effect on you". A proposed PIN length of 6 digits was rejected and 4 digits chosen instead, because it was the longest string of numbers that his wife could remember.

text: On January 15, 1994, President Bill Clinton formed the Advisory Committee on Human Radiation Experiments (ACHRE), chaired by Ruth Faden, Ph.D., MPH of the Johns Hopkins Berman Institute of Bioethics. One of the primary motivating factors behind his decision to create ACHRE was action taken by his newly appointed Secretary of Energy, Hazel O’Leary, J.D. One of her first actions on taking the reins of the Department of Energy was to announce a new openness policy for the Department. The policy led almost immediately to the release of over 1.6 million pages of classified records. The records made clear that since the 1940s the Atomic Energy Commission had been sponsoring tests on the effects of radiation on the human body. American citizens who had checked into hospitals for a variety of ailments were secretly injected with varying amounts of plutonium and other radioactive materials without their knowledge.  Ebb Cade was an unwilling participant in medical experiments that involved injection of 4.7 micrograms of Plutonium on 10 April 1945 at Oak Ridge, Tennessee. This experiment was under the supervision of Harold Hodge. Most patients thought it was "just another injection," but the secret studies left enough radioactive material in many of the patients' bodies to induce life-threatening conditions.  Such experiments were not limited to hospital patients, but included other populations such as those set out above, e.g., orphans fed irradiated milk, children injected with radioactive materials, prisoners in Washington and Oregon state prisons. Much of the experimentation was carried out in order to assess how the human body metabolizes radioactive materials, information that could be used by the Departments of Energy and Defense in Cold War defense/attack planning.

text: On January 15, 1994, President

text: Bill Clinton

text: formed the

entity_name: Advisory Committee on Human Radiation Experiments

text: Advisory Committee on Human Radiation Experiments

text: (ACHRE), chaired by Ruth Faden, Ph.D., MPH of the Johns Hopkins Berman Institute of Bioethics. One of the primary motivating factors behind his decision to create ACHRE was action taken by his newly appointed Secretary of Energy, Hazel O’Leary, J.D. One of her first actions on taking the reins of the Department of Energy was to announce a new openness policy for the Department. The policy led almost immediately to the release of over 1.6 million pages of classified records. The records made clear that since the 1940s the Atomic Energy Commission had been sponsoring tests on the effects of radiation on the human body. American citizens who had checked into hospitals for a variety of ailments were secretly injected with varying amounts of plutonium and other radioactive materials without their knowledge.

text: Ebb Cade

text: was an unwilling participant in medical experiments that involved injection of 4.7 micrograms of

text: Plutonium

text: on 10 April 1945 at

text: Oak Ridge, Tennessee

text: . This experiment was under the supervision of

text: Harold Hodge

text: . Most patients thought it was "just another injection," but the secret studies left enough radioactive material in many of the patients' bodies to induce life-threatening conditions.  Such experiments were not limited to hospital patients, but included other populations such as those set out above, e.g., orphans fed irradiated milk, children injected with radioactive materials, prisoners in Washington and Oregon state prisons. Much of the experimentation was carried out in order to assess how the human body metabolizes radioactive materials, information that could be used by the Departments of Energy and Defense in

text: Cold War

text: defense/attack planning.

text: Radioactive waste treatment is the treatment and containment of radioactive waste.

text: Radioactive waste treatment

text: is the treatment and containment of radioactive waste.

text: A small number of CD V-700s was modified by the addition of a much larger end-window probe to detect alpha radiation in addition to betas and gammas and which operated at considerably lower voltages, resulting to changes in the high voltage electronics. These units were redesignated as the CDV-700M and were issued on the basis of six units per state emergency management agency. Their primarily intended use was for detecting and cleaning up low-level radioactive contamination in state RADEF calibration labs, though they could be used to detect alpha radiation in the field if needed.

text: A small number of CD V-700s was modified by the addition of a much larger end-window probe to detect

text: alpha radiation

text: in addition to betas and gammas and which operated at considerably lower voltages, resulting to changes in the high voltage electronics. These units were redesignated as the CDV-700M and were issued on the basis of six units per state emergency management agency. Their primarily intended use was for detecting and cleaning up low-level radioactive contamination in state RADEF calibration labs, though they could be used to detect alpha radiation in the field if needed.

text: Forsmark Nuclear Power Plant is a nuclear power plant in Forsmark, Sweden, and also the site of the Swedish Final repository for radioactive operational waste. It is operated by a subsidiary of Vattenfall.

text: Forsmark Nuclear Power Plant is a

text: nuclear power plant

text: in

text: Forsmark

text: Sweden

text: , and also the site of the Swedish Final repository for radioactive operational waste. It is operated by a subsidiary of

text: Vattenfall

text: The common historical unit for radioactivity, the curie, is based on the radioactivity of Ra.

text: The common historical unit for radioactivity, the

text: curie

text: , is based on the radioactivity of Ra.

text: Shortly after the accident, firefighters arrived to try to extinguish the fires. First on the scene was a Chernobyl Power Station firefighter brigade under the command of Lieutenant Volodymyr Pravik, who died on 9 May 1986 of acute radiation sickness. They were not told how dangerously radioactive the smoke and the debris were, and may not even have known that the accident was anything more than a regular electrical fire: "We didn't know it was the reactor. No one had told us."

text: Shortly after the accident, firefighters arrived to try to extinguish the fires. First on the scene was a Chernobyl Power Station firefighter brigade under the command of Lieutenant

text: Volodymyr Pravik

text: , who died on 9 May 1986 of

text: acute radiation sickness

text: . They were not told how dangerously radioactive the smoke and the debris were, and may not even have known that the accident was anything more than a regular

text: electrical fire

text: : "We didn't know it was the reactor. No one had told us."

text: Irradiation with X-rays or gamma rays, electromagnetic radiation rather than particles, does not make materials radioactive. Irradiation with particles may make materials radioactive, depending upon the type of particles and their energy, and the type of target material: neutrons and very high-energy particles can make materials radioactive, but have good penetration, whereas lower energy particles (other than neutrons) cannot make materials radioactive, but have poorer penetration.

text: Irradiation

text: with X-rays or gamma rays, electromagnetic radiation rather than

text: particles

text: , does not make materials

text: radioactive

text: . Irradiation with particles may make materials radioactive, depending upon the type of particles and their energy, and the type of target material: neutrons and very high-energy particles can make materials radioactive, but have good penetration, whereas lower energy particles (other than neutrons) cannot make materials radioactive, but have poorer penetration.

text: In November 1964 the sail failure of fuel pins was detected during the scheduled repair in Severodvinsk and it was decided to refuel both reactors. On 7 February 1965 the ejection of radioactive steam took place during the lift of a reactor cover. Crewmembers were evacuated from the reactor compartment, the reactor cover was lowered down and naval staff was informed about the accident. Arrived naval specialists came to the wrong conclusion that deterioration of radiation environment was only a result of emission of high-active reactor water and they allowed to continue refueling. On 12 February 1965 the ejection of radioactive steam took place again during the second lift of the reactor cover because of inaccurate following operational instruction, crewmembers overwatched the procedure were evacuated from the reactor compartment and the reactor cover was lowered down. The uncontrolled reactor with unclear position of its cover remained unwatched during 4 hours when a fire occurred. The attempts to extinguish the fire in the reactor compartment with the use of fresh water and CO fire extinguishers were not successful so shipyard fire fighting vehicles filled the reactor compartment with 250 tons of outside water. About 150 tons of that radioactive water spread over another submarine compartments through burnt-out sealings and deteriorated the radiation environment in a work area significantly, 7 men were exposed to radiation. The only possible decision was to remove the contaminated reactor compartment and to install a new one. The operation wasn't done till August 1968.

text: In November 1964 the sail failure of fuel pins was detected during the scheduled repair in

text: Severodvinsk

text: Supernova radioactivity dominates light curves and the chemistry of dust condensation is also dominated by radioactivity. Dust is usually either carbon or oxides depending on which is more abundant, but Compton electrons dissociate the CO molecule in about one month. The new chemical astronomy of supernova solids depends on the supernova radioactivity:

text: Congress assigned responsibility to the U.S. Department of Energy (DOE) to site, construct, operate, and close a repository for the disposal of spent nuclear fuel and high-level radioactive waste. The U.S. Environmental Protection Agency (EPA) was directed to set public health and safety standards for releases of radioactive materials from a repository, and the U.S. Nuclear Regulatory Commission (NRC) was required to promulgate regulations governing construction, operation, and closure of a repository. Generators and owners of spent nuclear fuel and high-level radioactive waste were required to pay the costs of disposal of such radioactive materials. The waste program, which was expected to cost billions of dollars, would be funded through a fee paid by electric utilities on nuclear-generated electricity. An Office of Civilian Radioactive Waste Management was established in the U.S. Department of Energy (DOE) to implement the Act.

text: Congress

text: assigned responsibility to the

text: U.S. Department of Energy

text: (DOE) to site, construct, operate, and close a repository for the disposal of spent nuclear fuel and high-level radioactive waste. The

text: U.S. Environmental Protection Agency

text: (EPA) was directed to set public health and safety standards for releases of radioactive materials from a repository, and the

text: U.S. Nuclear Regulatory Commission

text: (NRC) was required to promulgate regulations governing construction, operation, and closure of a repository. Generators and owners of spent nuclear fuel and high-level radioactive waste were required to pay the costs of disposal of such radioactive materials. The waste program, which was expected to cost billions of dollars, would be funded through a fee paid by electric utilities on nuclear-generated electricity. An Office of Civilian Radioactive Waste Management was established in the U.S. Department of Energy (DOE) to implement the Act.

text: For example, in considering radiation safety , background radiation is defined by the International Atomic Energy Agency as "Dose or dose rate (or an observed measure related to the dose or dose rate) attributable to all sources other than the one(s) specified. So a distinction is made between sources of dose which are incidentally in a location, which are defined here as being "background", and the dose due to a specified source. This is important where radiation measurements are taken of a specified radiation source, and the incidental background may affect this measurement. An example would be detection of radioactive contamination in a gamma ray background, which could increase the total reading above that expected from the contamination alone.

text: For example, in considering

text: radiation safety

text: , background radiation is defined by the

text: International Atomic Energy Agency

text: as "Dose or dose rate (or an observed measure related to the dose or dose rate) attributable to all sources other than the one(s) specified. So a distinction is made between sources of dose which are incidentally in a location, which are defined here as being "background", and the dose due to a specified source. This is important where radiation measurements are taken of a specified radiation source, and the incidental background may affect this measurement. An example would be detection of radioactive contamination in a gamma ray background, which could increase the total reading above that expected from the contamination alone.

text: Passive millimeter wave scanners, like the SPO-7, which is not commonly found at airports, only detect naturally available radiation and do not emit any radiation for imaging.

text: In 1901, Rutherford and Frederick Soddy showed that alpha and beta radioactivity involves the transmutation of atoms into atoms of other chemical elements. In 1913, after the products of more radioactive decays were known, Soddy and Kazimierz Fajans independently proposed their radioactive displacement law, which states that beta (i.e., ) emission from one element produces another element one place to the right in the periodic table, while alpha emission produces an element two places to the left.

text: In 1901, Rutherford and

text: Frederick Soddy

text: showed that alpha and beta radioactivity involves the

text: transmutation

text: of atoms into atoms of other chemical elements. In 1913, after the products of more radioactive decays were known, Soddy and

text: Kazimierz Fajans

text: independently proposed their

text: radioactive displacement law

text: , which states that beta (i.e., ) emission from one element produces another element one place to the right in the

text: periodic table

text: , while alpha emission produces an element two places to the left.

text: The time it takes for a single parent atom to decay to an atom of its daughter isotope can vary widely, not only for different parent-daughter chains, but also for identical pairings of parent and daughter isotopes. While the decay of a single atom occurs spontaneously, the decay of an initial population of identical atoms over time t, follows a decaying exponential distribution, e, where λ is called a decay constant. Because of this exponential nature, one of the properties of an isotope is its half-life, the time by which half of an initial number of identical parent radioisotopes have decayed to their daughters. Half-lives have been determined in laboratories for thousands of radioisotopes (or, radionuclides). These can range from nearly instantaneous to as much as 10 years or more.

text: The time it takes for a single parent atom to decay to an atom of its daughter isotope can vary widely, not only for different parent-daughter chains, but also for identical pairings of parent and daughter isotopes. While the decay of a single atom occurs spontaneously, the decay of an initial population of identical atoms over time t, follows a decaying exponential distribution, e, where λ is called a

text: decay constant

text: . Because of this exponential nature, one of the properties of an isotope is its

text: half-life

text: , the time by which half of an initial number of identical parent radioisotopes have decayed to their daughters. Half-lives have been determined in laboratories for thousands of radioisotopes (or, radionuclides). These can range from nearly instantaneous to as much as 10 years or more.

text: The full impact of radiation exposure was hidden for many years by Soviet authorities. The general consensus of health studies conducted at the site since it was closed is that radioactive fallout from nuclear testing had a direct impact on the health of about 200,000 local residents. Specifically, scientists have linked higher rates of different types of cancer to post-irradiation effects.  Likewise, several studies have explored the correlation between radiation exposure and thyroid abnormalities.

text: In 1930  Rutherford, Chadwick and Ellis published together a classic monograph Radiations from Radioactive Substances.

text: In the years that followed, radioactivity was extensively investigated, notably by the husband and wife team of Pierre Curie and Marie Curie and by Ernest Rutherford and his collaborators. By the turn of the century physicists had also discovered three types of radiation emanating from atoms, which they named alpha, beta, and gamma radiation. Experiments by Otto Hahn in 1911 and by James Chadwick in 1914 discovered that the beta decay spectrum was continuous rather than discrete. That is, electrons were ejected from the atom with a continuous range of energies, rather than the discrete amounts of energy that were observed in gamma and alpha decays. This was a problem for nuclear physics at the time, because it seemed to indicate that energy was not conserved in these decays.

text: In the years that followed,

text: radioactivity

text: was extensively investigated, notably by the husband and wife team of

text: Pierre Curie

text: and

text: Marie Curie

text: and by

text: Ernest Rutherford

text: and his collaborators. By the turn of the century physicists had also discovered three types of

text: radiation

text: emanating from atoms, which they named

text: alpha

text: beta

text: , and

text: gamma

text: radiation. Experiments by

text: Otto Hahn

text: in 1911 and by

text: James Chadwick

text: in 1914 discovered that the beta decay

text: spectrum

text: was continuous rather than discrete. That is, electrons were ejected from the atom with a continuous range of energies, rather than the discrete amounts of energy that were observed in gamma and alpha decays. This was a problem for nuclear physics at the time, because it seemed to indicate that

text: energy was not conserved

text: in these decays.

text: The introduction of the radioactive marker can either take place in vivo or in vitro.In the in vivo method, stannous (tin) ions are injected into the patient's bloodstream. A subsequent intravenous injection of the radioactive substance, technetium-99m-pertechnetate, labels the red blood cells in vivo. With an administered activity of about 800 MBq, the effective radiation dose is about 8 mSv to 12 mSv.In the in vitro method, some of the patient's blood is drawn and the stannous ions (in the form of stannous chloride) are injected into the drawn blood. The technetium is subsequently added to the mixture as in the in vivo method.In both cases, the stannous chloride reduces the technetium ion and prevents it from leaking out of the red blood cells during the procedure.The in vivo technique is more convenient for the majority of patients since it is less time-consuming and less costly and more than 80 percent of the injected radionuclide usually binds to red blood cells with this approach. Red blood cell binding of the radioactive tracer is generally more efficient with the in vitro labeling, and it is preferred in patients with indwelling intravenous catheters to decrease the adherence of Tc-99m to the catheter wall and increase the efficiency of blood pool labeling.

text: The introduction of the radioactive marker can either take place

text: in vivo

text: or

text: in vitro

text: .In the in vivo method, stannous (

text: tin

text: ) ions are injected into the patient's bloodstream. A subsequent intravenous injection of the

text: radioactive

text: substance,

text: technetium

text: pertechnetate

text: , labels the red blood cells

text: in vivo

text: . With an administered activity of about 800

text: MBq

text: , the

text: effective radiation dose

text: is about 8

text: mSv

text: to 12 mSv.In the in vitro method, some of the patient's blood is drawn and the stannous ions (in the form of

text: stannous chloride

text: ) are injected into the drawn blood. The technetium is subsequently added to the mixture as in the in vivo method.In both cases, the stannous chloride reduces the technetium ion and prevents it from leaking out of the red blood cells during the procedure.The in vivo technique is more convenient for the majority of patients since it is less time-consuming and less costly and more than 80 percent of the injected radionuclide usually binds to red blood cells with this approach. Red blood cell binding of the radioactive tracer is generally more efficient with the in vitro labeling, and it is preferred in patients with indwelling intravenous catheters to decrease the adherence of Tc-99m to the catheter wall and increase the efficiency of blood pool labeling.

text: The environmental impact of nuclear power results from the nuclear fuel cycle processes including mining, processing, transporting and storing fuel and radioactive fuel waste. Released radioisotopes pose a health danger to human populations, animals and plants as radioactive particles enter organisms through various transmission routes.

text: The environmental impact of

text: nuclear power

text: results from the

text: nuclear fuel cycle

text: processes including mining, processing, transporting and storing fuel and

text: radioactive

text: fuel waste. Released

text: radioisotopes

text: pose a health danger to human populations, animals and plants as radioactive particles enter organisms through various transmission routes.

text: Following his retirement in 1962, the American Medical Association continued to repeat Brucer's warning that "over-emphasis on radiation hazard could easily cause us to curtail the use of roentgen rays in medicine, in which case medicine as we now know it would disappear. It might cause us to curtain the use of roentgen rays in dentistry. It could cause us to stop radiation therapy and diagnosis with radioactive isotopes... the neglect of these things would be even more dangerous than under-emphasis of radiation safety."

text: Following his retirement in 1962, the

text: American Medical Association

text: continued to repeat Brucer's warning that "over-emphasis on radiation hazard could easily cause us to curtail the use of roentgen rays in medicine, in which case medicine as we now know it would disappear. It might cause us to curtain the use of roentgen rays in dentistry. It could cause us to stop radiation therapy and diagnosis with radioactive isotopes... the neglect of these things would be even more dangerous than under-emphasis of radiation safety."

text: The dangers of radioactivity and radiation were not immediately recognized. The discovery of x‑rays in 1895 led to widespread experimentation by scientists, physicians, and inventors. Many people began recounting stories of burns, hair loss and worse in technical journals as early as 1896. In February of that year, Professor Daniel and Dr. Dudley of Vanderbilt University performed an experiment involving x-raying Dudley's head that resulted in his hair loss. A report by Dr. H.D. Hawks, a graduate of Columbia College, of his suffering severe hand and chest burns in an x-ray demonstration, was the first of many other reports in Electrical Review.

text: The dangers of radioactivity and radiation were not immediately recognized. The discovery of x‑rays in 1895 led to widespread experimentation by scientists, physicians, and inventors. Many people began recounting stories of burns, hair loss and worse in technical journals as early as 1896. In February of that year, Professor Daniel and Dr. Dudley of

text: Vanderbilt University

text: performed an experiment involving x-raying Dudley's head that resulted in his hair loss. A report by Dr. H.D. Hawks, a graduate of Columbia College, of his suffering severe hand and chest burns in an x-ray demonstration, was the first of many other reports in Electrical Review.

text: 1. 200 hours of classroom training in basic radioisotope handling techniques specifically applicable to the use of unsealed sources is required. The training should consist of lectures and laboratory sessions in the following areas:

text: Since radioactivity was discovered around the turn of the 20th century, the main application of radioluminescence has been in radioluminescent paint, used on watch and compass dials, gunsights, aircraft flight instrument faces, and other instruments, to allow them to be seen in the dark.  Radioluminescent paint consists of a mixture of a chemical containing a radioisotope with a radioluminescent chemical (phosphor).  The continuous radioactive decay of the isotope's atoms releases radiation particles which strike the molecules of the phosphor, causing them to give off light.  The constant bombardment by radioactive particles causes the chemical breakdown of many types of phosphor, so radioluminescent paints lose some of their luminosity over their working life.

text: Since radioactivity was discovered around the turn of the 20th century, the main application of radioluminescence has been in

text: radioluminescent paint

text: , used on

text: watch

text: and

text: compass

text: dials,

text: gunsight

text: s,

text: aircraft flight instrument

text: faces, and other instruments, to allow them to be seen in the dark.  Radioluminescent paint consists of a mixture of a chemical containing a

text: radioisotope

text: with a radioluminescent chemical (

text: phosphor

text: ).  The continuous

text: radioactive decay

text: of the isotope's atoms releases radiation particles which strike the molecules of the phosphor, causing them to give off light.  The constant bombardment by radioactive particles causes the chemical breakdown of many types of phosphor, so radioluminescent paints lose some of their luminosity over their working life.

text: Radioactive isotopes can also be used as a light source, to provide an illuminated reticle for low-light condition aiming. In sights like the SUSAT or Elcan C79 Optical Sight tritium-illuminated reticles are used for low-light condition aiming. Trijicon Corporation uses tritium in their combat and hunting-grade firearm optics, including the ACOG. The (radioactive) tritium light source has to be replaced every 8–12 years, since it gradually loses its brightness due to radioactive decay.

text: Radioactive isotopes

text: can also be used as a light source, to provide an illuminated reticle for low-light condition aiming. In sights like the

text: SUSAT

text: or

text: Elcan

text: C79 Optical Sight

text: tritium

text: -illuminated reticles are used for low-light condition aiming.

text: Trijicon

text: Corporation uses tritium in their combat and hunting-grade firearm optics, including the

text: ACOG

text: . The (radioactive) tritium light source has to be replaced every 8–12 years, since it gradually loses its brightness due to

text: radioactive decay

text: The plate source is in common use for the calibration of radioactive contamination instruments. This has a known amount of radioactive material fixed to its surface, such as an alpha and/or beta emitter, to allow the calibration of large area radiation detectors used for contamination surveys and personnel monitoring. Such measurements are typically counts per unit time received by the detector, such as counts per minute or counts per second.

text: The plate source is in common use for the

text: calibration

text: of radioactive contamination instruments. This has a known amount of radioactive material fixed to its surface, such as an alpha and/or beta emitter, to allow the calibration of large area radiation detectors used for contamination surveys and personnel monitoring. Such measurements are typically counts per unit time received by the detector, such as

text: counts per minute

text: or counts per second.

text: In Energoland, there are more than thirty objects, applications, and interactive expositions. Edutainment (blending education and entertainment) at Mochovce offers information on energy, electricity generation, global warming, and carbon burden. In addition, visitors learn about the energy mix, electricity grid dispatching, or about the radiation around us. The exposition also focuses on power industry, not only with respect to safety and radioactive waste but also dealing with the fuel cycle, nanowolrd of atoms, and Cherenkov radiation. Some of the specialities include the 3D cinema with its own movie Energy Odyssey, a model of emission-free motorcycle, interactive LED floor or thermal mirror, and mobile application using augmented reality, "Energoland", downloadable from Google Play or AppStore. Through the Energy Map, various facts and statistics can be searched which are directly shown in the map of the world with the highlighted countries.Energoland also wants its visitors to make their own opinion of the electricity generation and its sources. Therefore it does not provide information only about nuclear energy but it also brings knowledge about other sources: water, sun, wind, geothermal energy, or fossil fuels.

text: Radioactive waste is waste that contains radioactive material. Radioactive waste is usually a by-product of nuclear power generation and other applications of nuclear fission or nuclear technology, such as research and medicine. Radioactive waste is hazardous to most forms of life and the environment, and is regulated by government agencies in order to protect human health and the environment.

text: Radioactive waste is

text: waste

text: that contains

text: radioactive

text: material. Radioactive waste is usually a

text: by-product

text: of

text: nuclear power

text: generation and other applications of

text: nuclear fission

text: or

text: nuclear technology

text: , such as

text: research

text: and

text: medicine

text: . Radioactive waste is

text: hazardous

text: to most forms of life and the environment, and is

text: regulated

text: by government agencies in order to protect human health and the environment.

text: Radioactivity naturally decays over time, so radioactive waste has to be isolated and confined in appropriate disposal facilities for a sufficient period until it no longer poses a threat. The time radioactive waste must be stored for depends on the type of waste and radioactive isotopes. It can range from a few days for highly radioactive isotopes to millions of years for slightly radioactive ones. Current major approaches to managing radioactive waste have been segregation and storage for short-lived waste, near-surface disposal for low and some intermediate level waste, and deep burial or partitioning / transmutation for the high-level waste.

text: Radioactivity naturally decays over time, so radioactive waste has to be isolated and confined in appropriate disposal facilities for a sufficient period until it no longer poses a threat. The time radioactive waste must be stored for depends on the type of waste and radioactive isotopes. It can range from a few days for highly radioactive isotopes to millions of years for slightly radioactive ones. Current major approaches to managing radioactive waste have been segregation and storage for short-lived waste, near-surface disposal for low and some intermediate level waste, and

text: deep burial

text: or

text: partitioning / transmutation

text: for the high-level waste.

text: Small amounts of radioactive iodine were found in the breast milk of women living east of Tokyo. However, the levels were below the safety limits for tap water consumption by infants. Regulatory limits for infants in Japan are several levels of magnitude beneath what is known to potentially affect human health. Radiation protection standards in Japan are currently stricter than international recommendations and the standards of most other states, including those in North America and Europe . By Nov 2012, no radioactivity was detected in Fukushimas mothers breast milk. 100% of samples contained no detectable amount of radioactivity.

text: Small amounts of radioactive

text: iodine

text: were found in the

text: breast milk

text: of women living east of Tokyo. However, the levels were below the safety limits for tap water consumption by infants. Regulatory limits for infants in Japan are several levels of magnitude beneath what is known to potentially affect human health. Radiation protection standards in Japan are currently stricter than international recommendations and the standards of most other states, including those in North America and Europe . By Nov 2012, no radioactivity was detected in Fukushimas mothers breast milk. 100% of samples contained no detectable amount of radioactivity.

text: Substances containing natural radioactivity are known as NORM. After human processing that exposes or concentrates this natural radioactivity (such as mining bringing coal to the surface or burning it to produce concentrated ash), it becomes technologically enhanced naturally occurring radioactive material (TENORM). A lot of this waste is alpha particle-emitting matter from the decay chains of uranium and thorium. The main source of radiation in the human body is potassium-40 (K), typically 17 milligrams in the body at a time and 0.4 milligrams/day intake. Most rocks, due to their components, have a low level of radioactivity. Usually ranging from 1 millisievert (mSv) to 13 mSv annually depending on location, average radiation exposure from natural radioisotopes is 2.0 mSv per person a year worldwide. This makes up the majority of typical total dosage (with mean annual exposure from other sources amounting to 0.6 mSv from medical tests averaged over the whole populace, 0.4 mSv from cosmic rays, 0.005 mSv from the legacy of past atmospheric nuclear testing, 0.005 mSv occupational exposure, 0.002 mSv from the Chernobyl disaster, and 0.0002 mSv from the nuclear fuel cycle).

text: Substances containing natural radioactivity are known as

text: NORM

text: . After human processing that exposes or concentrates this natural radioactivity (such as mining bringing coal to the surface or burning it to produce concentrated ash), it becomes technologically enhanced naturally occurring radioactive material (TENORM). A lot of this waste is

text: alpha particle

text: -emitting matter from the decay chains of

text: uranium

text: and

text: thorium

text: . The main source of radiation in the human body is

text: potassium

text: -40 (

text: K

text: ), typically 17 milligrams in the body at a time and 0.4 milligrams/day intake. Most rocks, due to their components, have a low level of radioactivity. Usually ranging from 1

text: millisievert

text: (mSv) to 13 mSv annually depending on location, average radiation exposure from natural radioisotopes is 2.0 mSv per person a year worldwide. This makes up the majority of typical total dosage (with mean annual exposure from other sources amounting to 0.6 mSv from medical tests averaged over the whole populace, 0.4 mSv from

text: cosmic ray

text: s, 0.005 mSv from the legacy of past atmospheric nuclear testing, 0.005 mSv occupational exposure, 0.002 mSv from the

text: Chernobyl disaster

text: , and 0.0002 mSv from the nuclear fuel cycle).

text: Radiation therapy is commonly applied to the cancerous tumor because of its ability to control cell growth. Ionizing radiation works by damaging the DNA of cancerous tissue leading to cellular death.  To spare normal tissues (such as skin or organs which radiation must pass through to treat the tumor), shaped radiation beams are aimed from several angles of exposure to intersect at the tumor, providing a much larger absorbed dose there than in the surrounding, healthy tissue. Besides the tumour itself, the radiation fields may also include the draining lymph nodes if they are clinically or radiologically involved with tumor, or if there is thought to be a risk of subclinical malignant spread. It is necessary to include a margin of normal tissue around the tumor to allow for uncertainties in daily set-up and internal tumor motion. These uncertainties can be caused by internal movement (for example, respiration and bladder filling) and movement of external skin marks relative to the tumor position.

text: Radiation therapy is commonly applied to the cancerous tumor because of its ability to control cell growth. Ionizing radiation works by damaging the

text: DNA

text: of cancerous tissue leading to

text: cellular death

text: .  To spare normal tissues (such as skin or organs which radiation must pass through to treat the tumor), shaped radiation beams are aimed from several angles of exposure to intersect at the tumor, providing a much larger

text: absorbed dose

text: there than in the surrounding, healthy tissue. Besides the tumour itself, the radiation fields may also include the draining lymph nodes if they are clinically or radiologically involved with tumor, or if there is thought to be a risk of subclinical malignant spread. It is necessary to include a margin of normal tissue around the tumor to allow for uncertainties in daily set-up and internal tumor motion. These uncertainties can be caused by internal movement (for example, respiration and bladder filling) and movement of external skin marks relative to the tumor position.

text: In 1896, Henri Becquerel found that rays emanating from certain minerals penetrated black paper and caused fogging of an unexposed photographic plate. His doctoral student Marie Curie discovered that only certain chemical elements gave off these rays of energy. She named this behavior radioactivity.

text: In 1896,

text: Henri Becquerel

text: found that rays emanating from certain minerals penetrated black paper and caused fogging of an unexposed photographic plate. His doctoral student

text: Marie Curie

text: discovered that only certain chemical elements gave off these rays of energy. She named this behavior

text: radioactivity

text: Terrorist attacks such as those executed by al-Qaeda on New York City and Washington, D.C. on September 11, 2001 and in London on July 7, 2005 have prompted fears that extremist groups might use radioactive dirty bombs in further attacks in the United States and elsewhere.In March 2007, undercover investigators from the Government Accountability Office set up a false company and obtained a license from the Nuclear Regulatory Commission that would have allowed them to buy the radioactive materials needed for a dirty bomb. According to the GAO report, NRC officials did not visit the company or attempt to personally interview its executives. Instead, within 28 days, the NRC mailed the license to the West Virginia postal box. Upon receipt of the license, GAO officials were able to easily modify its stipulations, and remove a limit on the amount of radioactive material they could buy. A spokesman for the NRC said that the agency considered the radioactive devices a "lower-level threat"; a bomb built with the materials could have contaminated an area about the length of a city block, but would not have presented an immediate health hazard.

text: Terrorist attacks such as those executed by

text: al-Qaeda

text: on

text: New York City

text: and

text: Washington, D.C.

text: on

text: September 11, 2001

text: and in

text: London

text: on

text: July 7, 2005

text: have prompted fears that extremist groups might use radioactive

text: dirty bomb

text: s in further attacks in the United States and elsewhere.In March 2007, undercover investigators from the

text: Government Accountability Office

text: set up a false company and obtained a license from the Nuclear Regulatory Commission that would have allowed them to buy the radioactive materials needed for a dirty bomb. According to the GAO report, NRC officials did not visit the company or attempt to personally interview its executives. Instead, within 28 days, the NRC mailed the license to the West Virginia postal box. Upon receipt of the license, GAO officials were able to easily modify its stipulations, and remove a limit on the amount of radioactive material they could buy. A spokesman for the NRC said that the agency considered the radioactive devices a "lower-level threat"; a bomb built with the materials could have contaminated an area about the length of a city block, but would not have presented an immediate health hazard.

text: Radium was discovered by Marie Sklodowska-Curie and her husband Pierre Curie on 21 December 1898, in a uraninite sample. While studying the mineral earlier, the Curies removed uranium from it and found that the remaining material was still radioactive. They separated out an element similar to bismuth from pitchblende in July 1898, that turned out to be polonium. They then separated out a radioactive mixture consisting mostly of two components: compounds of barium, which gave a brilliant green flame color, and unknown radioactive compounds which gave carmine spectral lines that had never been documented before. The Curies found the radioactive compounds to be very similar to the barium compounds, except that they were more insoluble. This made it possible for the Curies to separate out the radioactive compounds and discover a new element in them. The Curies announced their discovery to the French Academy of Sciences on 26 December 1898. The naming of radium dates to about 1899, from the French word radium, formed in Modern Latin from radius (ray): this was in recognition of radium's power of emitting energy in the form of rays.

text: Radium was

text: discovered

text: by

text: Marie Sklodowska-Curie

text: and her husband

text: Pierre Curie

text: on 21 December 1898, in a

text: uraninite

text: sample. While studying the mineral earlier, the Curies removed uranium from it and found that the remaining material was still radioactive. They separated out an element similar to

text: bismuth

text: from pitchblende in July 1898, that turned out to be

text: polonium

text: . They then separated out a radioactive mixture consisting mostly of two components: compounds of

text: barium

text: , which gave a brilliant green flame color, and unknown radioactive compounds which gave

text: carmine

text: spectral line

text: s that had never been documented before. The Curies found the radioactive compounds to be very similar to the barium compounds, except that they were more insoluble. This made it possible for the Curies to separate out the radioactive compounds and discover a new element in them. The Curies announced their discovery to the

text: French Academy of Sciences

text: on 26 December 1898. The naming of radium dates to about 1899, from the French word radium, formed in Modern Latin from radius (ray): this was in recognition of radium's power of emitting energy in the form of rays.

text: During the 1970s there was growing concern that the combined conventional forces of the  Soviet Union and the Warsaw Pact could overwhelm the forces of NATO.  It seemed unthinkable to respond to a Soviet/Warsaw Pact incursion into Western Europe with strategic nuclear weapons, inviting a catastrophic exchange.  Thus, technologies were developed to greatly reduce collateral damage while being effective against advancing conventional military forces.  Some of these were  low-yield neutron bombs, which were lethal to tank crews, especially with tanks massed in tight formation, while producing relatively little blast, thermal radiation, or radioactive fallout.  Other technologies were so-called “suppressed radiation devices,” which produced mostly blast with little radioactivity, making them much like conventional explosives, but with much more energy.

text: During the 1970s there was growing concern that the combined conventional forces of the

text: Soviet Union and the Warsaw Pact

text: could overwhelm the forces of

text: NATO

text: .  It seemed unthinkable to respond to a Soviet/Warsaw Pact incursion into Western Europe with

text: strategic nuclear weapon

text: s, inviting a catastrophic exchange.  Thus, technologies were developed to greatly reduce collateral damage while being effective against advancing conventional military forces.  Some of these were

text: low-yield neutron bombs

text: , which were lethal to tank crews, especially with tanks massed in tight formation, while producing relatively little blast, thermal radiation, or radioactive fallout.  Other technologies were so-called “suppressed radiation devices,” which produced mostly blast with little radioactivity, making them much like conventional explosives, but with much more energy.

text: Nuclear diving is similar to HAZMAT diving; the difference is the exposure to radiation instead of a water borne contaminant. To this end, different precautions are required for nuclear diving, mainly, equipment which will not absorb radioactive contamination and pose a disposal problem after several dives. Moreover, exhaustive briefing of the group or diver for the specific environment he is going to work, depth, water temperature and potential radioactive sources.Heat stress can also be a danger for the diver, in which case a cold water suit may be used: the cold water suit is a special canvas coverall which floods the outside of the diver's drysuit with chilled water, countering the dangerously high ambient water temperature. A dosimeter is used to ensure that the diver does not receive a dangerous dose of radiation during the dive, assisting in calculating the maximum length of the dive. In addition the dosimeter can also be used to find radiation hot spots, which can indicate areas in need of repair.

text: Nuclear diving is similar to HAZMAT diving; the difference is the exposure to

text: radiation

text: instead of a water borne contaminant. To this end, different precautions are required for nuclear diving, mainly, equipment which will not absorb radioactive contamination and pose a disposal problem after several dives. Moreover, exhaustive briefing of the group or diver for the specific environment he is going to work, depth, water temperature and potential radioactive sources.Heat stress can also be a danger for the diver, in which case a cold water suit may be used: the cold water suit is a special canvas coverall which floods the outside of the diver's drysuit with chilled water, countering the dangerously high ambient water temperature. A

text: dosimeter

text: is used to ensure that the diver does not receive a dangerous dose of radiation during the dive, assisting in calculating the maximum length of the dive. In addition the dosimeter can also be used to find radiation hot spots, which can indicate areas in need of repair.

text: Contamination may occur from radioactive gases, liquids or particles. For example, if a radionuclide used in nuclear medicine is spilled (accidentally or, as in the case of the Goiânia accident, through ignorance), the material could be spread by people as they walk around. Radioactive contamination may also be an inevitable result of certain processes, such as the release of radioactive xenon in nuclear fuel reprocessing. In cases that radioactive material cannot be contained, it may be diluted to safe concentrations. For a discussion of environmental contamination by alpha emitters please see actinides in the environment.

text: Contamination may occur from radioactive gases, liquids or particles. For example, if a radionuclide used in

text: nuclear medicine

text: is spilled (accidentally or, as in the case of the

text: Goiânia accident

text: , through ignorance), the material could be spread by people as they walk around. Radioactive contamination may also be an inevitable result of certain processes, such as the release of radioactive

text: xenon

text: in

text: nuclear fuel reprocessing

text: . In cases that radioactive material cannot be contained, it may be diluted to safe concentrations. For a discussion of environmental contamination by

text: alpha

text: emitters please see

text: actinides in the environment

text: Allanite contains up to 20% rare earth elements and is a valuable source of them. The inclusion of thorium and other radioactive elements in allanite results in some interesting phenomena. Allanite often has a pleochroic halo of radiation damage in the minerals immediately adjacent. Also highly radioactive grains of allanite often have their structure disrupted or are metamict. The age of allanite grains that have not been destroyed by radiation can be determined using different techniques.

text: Allanite contains up to 20% rare earth elements and is a valuable source of them. The inclusion of

text: thorium

text: and other radioactive elements in allanite results in some interesting phenomena. Allanite often has a

text: pleochroic halo

text: of radiation damage in the minerals immediately adjacent. Also highly radioactive grains of allanite often have their structure disrupted or are

text: metamict

text: . The age of allanite grains that have not been destroyed by radiation can be determined using different techniques.

text: Abundant radioactivity is widely regarded as Clayton's most important discovery for astronomy because it controls the late appearance of supernovae.  Quasiequilibrium demanded that even the mountain-like abundance peak at iron was synthesized as radioactive nickel parents Ni and Ni in the supernovae explosions rather than as iron directly as Hoyle and Fowler maintained. This discovery intensified Clayton's long and productive focus with radioactive isotopes ejected from supernovae, leading to his predictions of both gamma-ray line astronomy and of radioactive supernova grains condensed from hot supernova gases. Experimental confirmation two decades later of both predictions spurred those new fields of astronomy and brought Clayton high honors. At Rice University a prolific 1970-74 with colleagues W. David Arnett, Stanford E. Woosley and W.Michael Howard explored other explosive nucleosynthesis caused by the radially outgoing supernova shock wave. Leadership of nucleosynthesis seems to have shifted by 1975 to Rice University.

text: Abundant radioactivity is widely regarded as Clayton's most important discovery for astronomy because it controls the late appearance of supernovae.  Quasiequilibrium demanded that even the mountain-like abundance peak at iron was synthesized as radioactive nickel parents

text: Ni

text: and

text: Ni

text: in the supernovae explosions rather than as iron directly as Hoyle and Fowler maintained. This discovery intensified Clayton's long and productive focus with radioactive isotopes ejected from supernovae, leading to his predictions of both gamma-ray line astronomy and of radioactive supernova grains condensed from hot supernova gases. Experimental confirmation two decades later of both predictions spurred those new fields of astronomy and brought Clayton high honors. At Rice University a prolific 1970-74 with colleagues W. David Arnett, Stanford E. Woosley and W.Michael Howard explored other explosive nucleosynthesis caused by the radially outgoing supernova shock wave. Leadership of nucleosynthesis seems to have shifted by 1975 to Rice University.

text: Specific radioactivity a is defined as radioactivity per unit mass of the radionuclide:

text: In snakes that can detect infrared radiation, such as pythons and pit vipers, the initial neural input is through the trigeminal nerve instead of the optic tract. The rest of the processing is similar to that of the visual sense and, thus, involves the optic tectum.

text: In

text: snake

text: s that can detect

text: infrared radiation

text: , such as

text: python

text: s and

text: pit viper

text: s, the initial neural input is through the

text: trigeminal nerve

text: instead of the

text: optic tract

text: . The rest of the processing is similar to that of the visual sense and, thus, involves the optic tectum.

text: Quackery involving radioactive substances is quackery that improperly promotes radioactivity as a therapy for illnesses. Unlike  radiotherapy, which is the scientifically sound use of radiation for the destruction of cells (usually cancer cells), quackery involving radioactive substances pseudoscientifically promotes radiation as healthful and healing for cells and tissues. It was most popular during the early 20th century, after the discovery in 1896 of radioactive decay. The practice has widely declined, but is still actively practiced by some.

text: Quackery involving radioactive substances is

text: quackery

text: that improperly promotes

text: radioactivity

text: as a

text: therapy

text: for illnesses. Unlike

text: radiotherapy

text: , which is the

text: scientifically

text: sound use of

text: radiation

text: for the destruction of

text: cells

text: (usually

text: cancer

text: cells), quackery involving radioactive substances

text: pseudoscientifically

text: promotes radiation as healthful and healing for cells and

text: tissues

text: . It was most popular during the early 20th century, after the discovery in 1896 of

text: radioactive decay

text: . The practice has widely declined, but is still actively practiced by some.

text: Henri Becquerel discovered radioactivity by using uranium in 1896. Becquerel made the discovery in Paris by leaving a sample of a uranium salt, KUO(SO) (potassium uranyl sulfate), on top of an unexposed photographic plate in a drawer and noting that the plate had become "fogged". He determined that a form of invisible light or rays emitted by uranium had exposed the plate.

text: Henri Becquerel

text: discovered

text: radioactivity

text: by using uranium in 1896. Becquerel made the discovery in Paris by leaving a sample of a uranium salt, KUO(SO) (potassium uranyl sulfate), on top of an unexposed

text: photographic plate

text: in a drawer and noting that the plate had become "fogged". He determined that a form of invisible light or rays emitted by uranium had exposed the plate.

text: On 18 December 2011, a worker discovered some 230 cubic meters of radioactive water in a 54 meters long tunnel under the waste-water processing plant. The water-level varied from half a meter to 3 meters deep. Radiation levels measured 3 millisievert per hour, just a fraction of the radiation-level of the highly contaminated water that was stored above this tunnel. This level of radiation is marginal and not dangerous. TEPCO investigated the source of the water and found that most likely, some water had flowed into the tunnel from the storage above and had been diluted afterwards by incoming groundwater. According to TEPCO, this tunnel had no connection to the sea. The discovery did, however, raise questions about the inspections and management-capabilities of TEPCO because it failed to notice the water in the tunnel after the water-treatment facility was completed.

text: Tin (Sn) is the element with the greatest number of stable isotopes (ten; three of them are potentially radioactive but have not been observed to decay), which is probably related to the fact that 50 is a "magic number" of protons. 29 additional unstable isotopes are known, including the "doubly magic" tin-100 (Sn) (discovered in 1994) and tin-132 (Sn). The longest-lived radioisotope is Sn, with a half-life of 230,000 years. The other 28 radioisotopes have half-lives less than a year.

text: Tin

text: (Sn) is the element with

text: the greatest number of stable isotopes

text: (ten; three of them are potentially radioactive but have not been observed to decay), which is probably related to the fact that 50 is a "

text: magic number

text: " of protons. 29 additional unstable isotopes are known, including the "

text: doubly magic

text: " tin-100 (Sn) (discovered in 1994) and tin-132 (Sn). The longest-lived radioisotope is Sn, with a half-life of 230,000 years. The other 28 radioisotopes have half-lives less than a year.

text: On the 16th of March, 2009, a leak of radioactive gases from Pelindaba was reported by NECSA. Abnormal levels of gamma radiation associated with xenon and krypton gases were detected, causing an emergency to be declared. Members of staff were evacuated.

text: This element was the first one discovered by the Curies while they were investigating the cause of pitchblende radioactivity. Pitchblende, after removal of the radioactive elements uranium and thorium, was more radioactive than the uranium and thorium combined. This spurred the Curies to search for additional radioactive elements. They first separated out polonium from pitchblende in July 1898, and five months later, also isolated radium.

text: This element was the first one discovered by the Curies while they were investigating the cause of

text: pitchblende

text: radioactivity

text: . Pitchblende, after removal of the radioactive elements

text: uranium

text: and

text: thorium

text: , was more radioactive than the uranium and thorium combined. This spurred the Curies to search for additional radioactive elements. They first separated out polonium from pitchblende in July 1898, and five months later, also isolated

text: radium

text: Radioactive contamination can create a hot zone, as occupants are in danger of being exposed to radiation.

text: Radioactive contamination

text: can create a hot zone, as occupants are in danger of being exposed to radiation.

text: In 1896, Henri Becquerel discovered radioactivity.  It was only a little over a quarter of a century (1925) until the first radioactive tracer study in animals was performed by George de Hevesy, and the next year (1926) the first diagnostic tracer study in humans was performed by Herman Blumgart and Otto Yens.

text: In 1896,

text: Henri Becquerel

text: discovered

text: radioactivity

text: .  It was only a little over a quarter of a century (1925) until the first radioactive tracer study in animals was performed by

text: George de Hevesy

text: , and the next year (1926) the first diagnostic tracer study in

text: humans

text: was performed by Herman Blumgart and Otto Yens.

text: One of the goals of this test was to study the physical characteristics of the crater and the surrounding area pre- and post-detonation associated with Project 1.4. A camera was mounted to a RB-50 aircraft and the resultant crater was mapped using photogrammetry. Measurements were taken from 500 feet (152 meters) down to ground zero for both pre- and post detonation. Survey measurements of the Cactus test could not be made until the resultant radiation amounts had lowered to safer levels. Along with photogrammetric radial measurements, Airblast measurements were also recorded near surface zero for Cactus in accordance with Project 1.7. Similar to Project 1.8, Project 1.9 sought to determine transmission of blast pressure through the ground soil. Forty-three drums were buried at varying depths 600 feet (183 meters) from ground zero of the Cactus detonation. Individuals from the Air Force Ballistic Missile Division – TRW Space Technologies Laboratory sought to the Shock Spectra Studies of Project 1.12. Measurement gauges were located between 625 and 965 feet (191 to 294 meters) from the blast site. Fallout measurements and samples were taken by aircraft in the aftermath of the detonation, as part of Project 2.8. These surveys were designed in part to determine the impact of specific radionuclides to overall nuclear fallout. Samples were taken early post-blast using a new rocket sampler, the UCRL, which were then followed by B-57D and WB-50 aircraft. Between four and twenty-four hours post-detonation, the WB-50 collected several samples at 1,000 feet (305 meters) in altitude. Project 3.2 involved structural tests of corrugated steel arches. One of these arches was placed 980 feet (299 meters) away from the Cactus blast site. Eight days after the test, a crew of 13 men were allowed near the surface zero in order to extract the arch. The extraction took around twelve hours, and the radioactivity levels reached a maximum at 0.420 R/h during this time. Project 5.2 sought to determine the effects of the blast on two A4D-1 aircraft, both in thermal radiation and pressure. Nine film badges were placed throughout each aircraft in order to measure radiation. The Gamma dosimeter worn by the pilot in aircraft 827 indicated a neutron exposure level of 0.105 rem. There is not information available for the dosimeter worn by the pilot in aircraft 831. Radiation recorded by six of the nine film badges ranged from 0.49-1.74R. Information from the remaining three film badges, located at the Pilot’s right leg, left sleeve, and left vest is not available. The pilot’s exposures were both greater than 3R.  Project 5.3 was very similar to 5.2, focusing on the effects of the blast on the structure of two test FJ-4 aircraft. Radiation from film badges on aircraft 467 ranged from 0.52-3.71 R, and 1.23-5.06 R for aircraft number 310. In Project 6.4, the Army Signal Research and Development Laboratory (SRDL) investigated the electromagnetic pulses post-detonation, utilizing two instruments, one at Wotho (roughly 240 nautical miles from Enewetak) and one at Kusaie (around 440 nautical miles from Enewetak). Though Cactus is mentioned in Project 6.5, whose goal was to study the radar echoes from the fireball, it is not clear what destroyers were involved if any. Destroyers for the Teak, Fir and Yucca tests are explicitly stated. Project 6.6, the lasts of the projects that involved the Cactus test, sought to measure the physical properties of the stabilized radioactive cloud following the blast.

text: One of the goals of this test was to study the physical characteristics of the crater and the surrounding area pre- and post-detonation associated with Project 1.4. A camera was mounted to a RB-50 aircraft and the resultant crater was mapped using photogrammetry. Measurements were taken from 500 feet (152 meters) down to ground zero for both pre- and post detonation. Survey measurements of the Cactus test could not be made until the resultant radiation amounts had lowered to safer levels. Along with photogrammetric radial measurements, Airblast measurements were also recorded near surface zero for Cactus in accordance with Project 1.7. Similar to Project 1.8, Project 1.9 sought to determine transmission of blast pressure through the ground soil. Forty-three drums were buried at varying depths 600 feet (183 meters) from ground zero of the Cactus detonation. Individuals from the

text: Air Force Ballistic Missile Division

text: – TRW Space Technologies Laboratory sought to the Shock Spectra Studies of Project 1.12. Measurement gauges were located between 625 and 965 feet (191 to 294 meters) from the blast site. Fallout measurements and samples were taken by aircraft in the aftermath of the detonation, as part of Project 2.8. These surveys were designed in part to determine the impact of specific radionuclides to overall nuclear fallout. Samples were taken early post-blast using a new rocket sampler, the

text: UCRL

text: , which were then followed by B-57D and

text: aircraft. Between four and twenty-four hours post-detonation, the WB-50 collected several samples at 1,000 feet (305 meters) in altitude. Project 3.2 involved structural tests of corrugated steel arches. One of these arches was placed 980 feet (299 meters) away from the Cactus blast site. Eight days after the test, a crew of 13 men were allowed near the surface zero in order to extract the arch. The extraction took around twelve hours, and the radioactivity levels reached a maximum at 0.420 R/h during this time. Project 5.2 sought to determine the effects of the blast on two A4D-1 aircraft, both in thermal radiation and pressure. Nine film badges were placed throughout each aircraft in order to measure radiation. The Gamma

text: dosimeter

text: worn by the pilot in aircraft 827 indicated a neutron exposure level of 0.105 rem. There is not information available for the dosimeter worn by the pilot in aircraft 831. Radiation recorded by six of the nine film badges ranged from 0.49-1.74R. Information from the remaining three film badges, located at the Pilot’s right leg, left sleeve, and left vest is not available. The pilot’s exposures were both greater than 3R.  Project 5.3 was very similar to 5.2, focusing on the effects of the blast on the structure of two test

text: aircraft. Radiation from film badges on aircraft 467 ranged from 0.52-3.71 R, and 1.23-5.06 R for aircraft number 310. In Project 6.4, the Army Signal Research and Development Laboratory (SRDL) investigated the

text: electromagnetic

text: pulses post-detonation, utilizing two instruments, one at

text: Wotho

text: (roughly 240 nautical miles from Enewetak) and one at Kusaie (around 440 nautical miles from Enewetak). Though Cactus is mentioned in Project 6.5, whose goal was to study the radar echoes from the fireball, it is not clear what destroyers were involved if any. Destroyers for the Teak, Fir and Yucca tests are explicitly stated. Project 6.6, the lasts of the projects that involved the Cactus test, sought to measure the physical properties of the stabilized radioactive cloud following the blast.

text: Journal of Environmental Radioactivity is a monthly peer-reviewed scientific journal on environmental radioactivity and radioecology. It was established in 1984 and is published by Elsevier. Its editor-in-chief is Stephen C. Sheppard (ECOMatters Inc.) and is an affiliated journal of the International Union of Radioecology.

text: Journal of Environmental Radioactivity is a monthly

text: peer-reviewed

text: scientific journal

text: on

text: environmental radioactivity

text: and

text: radioecology

text: . It was established in 1984 and is published by

text: Elsevier

text: . Its

text: editor-in-chief

text: is Stephen C. Sheppard (ECOMatters Inc.) and is an affiliated journal of the

text: International Union of Radioecology

text: Scavenging of abandoned radioactive material has been the cause of several other cases of radiation exposure, mostly in developing nations, which may have less regulation of dangerous substances (and sometimes less general education about radioactivity and its hazards) and a market for scavenged goods and scrap metal. The scavengers and those who buy the material are almost always unaware that the material is radioactive and it is selected for its aesthetics or scrap value. Irresponsibility on the part of the radioactive material's owners, usually a hospital, university or military, and the absence of regulation concerning radioactive waste, or a lack of enforcement of such regulations, have been significant factors in radiation exposures. For an example of an accident involving radioactive scrap originating from a hospital see the Goiânia accident.

text: Scavenging of abandoned radioactive material has been the cause of several other cases of

text: radiation exposure

text: , mostly in

text: developing nation

text: s, which may have less regulation of dangerous substances (and sometimes less general education about radioactivity and its hazards) and a market for scavenged goods and scrap metal. The scavengers and those who buy the material are almost always unaware that the material is radioactive and it is selected for its

text: aesthetics

text: or scrap value. Irresponsibility on the part of the radioactive material's owners, usually a hospital, university or military, and the absence of regulation concerning radioactive waste, or a lack of enforcement of such regulations, have been significant factors in radiation exposures. For an example of an accident involving radioactive scrap originating from a hospital see the

text: Goiânia accident

text: It was reported that radioactive iodine was detected in the tap water in Fukushima, Tochigi, Gunma, Tokyo, Chiba, Saitama, and Niigata, and radioactive cesium in the tap water in Fukushima, Tochigi and Gunma. Radioactive cesium, iodine, and strontium were also detected in the soil in some places in Fukushima. There may be a need to replace the contaminated soil. Many radioactive hotspots were found outside the evacuation zone, including Tokyo. Food products were also found contaminated by radioactive matter in several places in Japan. On 5 April 2011, the government of the Ibaraki Prefecture banned the fishing of sand lance after discovering that this species was contaminated by radioactive cesium above legal limits. As late as July 2013 slightly elevated levels of radioactivity were found in beef on sale at Tokyo markets. No death or morbidity has so far been reported as a result of the radioactive emissions.

text: It was reported that radioactive iodine was detected in the tap water in Fukushima, Tochigi, Gunma, Tokyo, Chiba, Saitama, and Niigata, and radioactive cesium in the tap water in Fukushima, Tochigi and Gunma. Radioactive cesium, iodine, and strontium were also detected in the soil in some places in Fukushima. There may be a need to replace the contaminated soil. Many radioactive hotspots were found outside the evacuation zone, including Tokyo. Food products were also found contaminated by radioactive matter in several places in Japan. On 5 April 2011, the government of the

text: Ibaraki Prefecture

text: banned the fishing of

text: sand lance

text: after discovering that this species was contaminated by radioactive

text: cesium

text: above legal limits. As late as July 2013 slightly elevated levels of radioactivity were found in beef on sale at Tokyo markets. No death or morbidity has so far been reported as a result of the radioactive emissions.

text: Both cpm and cps are the rate of detection events registered by the measuring instrument, not the rate of emission from the source of radiation. For radioactive decay measurements it must not be confused with disintegrations per unit time (dpm), which represents the rate of atomic disintegration events at the source of the radiation.

text: Both cpm and cps are the rate of detection events registered by the measuring instrument, not the rate of emission from the source of radiation. For

text: radioactive decay

text: measurements it must not be confused with disintegrations per unit time (dpm), which represents the rate of atomic disintegration events at the source of the radiation.

text: Some radioactive fission products can be converted into shorter-lived radioisotopes by transmutation. Transmutation of all fission products with half-life greater than one year is studied in Grenoble, with varying results.

text: An independent study revealed the water to be radioactive and potentially dangerous to drink, initially surrounding the project with controversy. Jordan's Ministry of Water and Irrigation has stated that the radioactivity is not a problem because the water is to be diluted with an equal amount of water from other sources, although it remains disputed if this would be enough to bring the water up to standards. The Ministry said the independent study was inaccurate, as it did not test water from any of the wells that will be used in the project. The President of the Jordanian Geologists Association Bahjat Al Adwan stated that the radiation is present in the water in the form of Radon, and thus dissipates harmlessly when the water is exposed to air on the surface.

text: An independent study revealed the water to be

text: radioactive

text: and potentially dangerous to drink, initially surrounding the project with controversy. Jordan's Ministry of Water and Irrigation has stated that the radioactivity is not a problem because the water is to be diluted with an equal amount of water from other sources, although it remains disputed if this would be enough to bring the water up to standards. The Ministry said the independent study was inaccurate, as it did not test water from any of the wells that will be used in the project. The President of the Jordanian Geologists Association Bahjat Al Adwan stated that the radiation is present in the water in the form of Radon, and thus dissipates harmlessly when the water is exposed to air on the surface.

text: Issues entirely separate from the question of the sustainability of nuclear fuel, relate to the use of nuclear fuel and the high-level radioactive waste the nuclear industry generates that if not properly contained, is highly hazardous to people and wildlife. Radiocontaminants in the environment can enter the food chain and become bioaccumulated. Internal or external exposure can cause mutagenic DNA breakage producing teratogenic generational birth defects, cancers and other damage.  The United Nations (UNSCEAR) estimated in 2008 that average annual human radiation exposure includes 0.01 millisievert (mSv) from the legacy of past atmospheric nuclear testing plus the Chernobyl disaster and the nuclear fuel cycle, along with 2.0 mSv from natural radioisotopes and 0.4 mSv from cosmic rays; all exposures vary by location.  natural uranium radioisotopes in nuclear waste and naturally in the ground emits radiation for the prolonged period of 4.5 billion years or more, and storage has risks of containment. The storage of waste, health implications and dangers of radioactive fuel continue to be a topic of debate, resulting in a controversial and unresolved industry.

text: Issues entirely separate from the question of the sustainability of nuclear fuel, relate to the use of nuclear fuel and the high-level radioactive waste the nuclear industry generates that if not properly contained, is

text: highly hazardous

text: to people and wildlife. Radiocontaminants in the environment can enter the

text: food chain

text: and become

text: bioaccumulated

text: . Internal or external exposure can cause

text: mutagenic

text: DNA

text: breakage producing

text: teratogenic

text: generational

text: birth defect

text: s,

text: cancer

text: s and other damage.  The United Nations (

entity_name: United Nations Scientific Committee on the Effects of Atomic Radiation

text: UNSCEAR

text: ) estimated in 2008 that average annual human radiation exposure includes 0.01

text: millisievert

text: (mSv) from the legacy of past atmospheric nuclear testing plus the

text: Chernobyl disaster

text: and the nuclear fuel cycle, along with 2.0 mSv from natural radioisotopes and 0.4 mSv from

text: cosmic ray

text: s; all exposures

text: vary by location

text: .  natural uranium

text: radioisotopes

text: in

text: nuclear waste

text: and naturally in the ground emits radiation for the prolonged period of 4.5 billion years or more, and storage has

text: risks of containment

text: . The storage of waste, health implications and dangers of radioactive fuel continue to be a topic of debate, resulting in a

text: controversial and unresolved industry

text: The three main divisions of radiation therapy are external beam radiation therapy or teletherapy, brachytherapy or sealed source radiation therapy, and systemic radioisotope therapy or unsealed source radiotherapy. The differences relate to the position of the radiation source; external is outside the body, brachytherapy uses sealed radioactive sources placed precisely in the area under treatment, and systemic radioisotopes are given by infusion or oral ingestion. Brachytherapy can use temporary or permanent placement of radioactive sources. The temporary sources are usually placed by a technique called afterloading. In afterloading a hollow tube or applicator is placed surgically in the organ to be treated, and the sources are loaded into the applicator after the applicator is implanted. This minimizes radiation exposure to health care personnel. Particle therapy is a special case of external beam radiation therapy where the particles are protons or heavier ions. Intraoperative radiation therapy or IORT is a special type of radiation therapy that is delivered immediately after surgical removal of the cancer. This method has been employed in breast cancer (TARGeted Introperative radiation therapy or TARGIT), brain tumors and rectal cancers.

text: The three main divisions of radiation therapy are

text: external beam radiation therapy

text: or teletherapy, brachytherapy or sealed source radiation therapy, and systemic radioisotope therapy or unsealed source radiotherapy. The differences relate to the position of the radiation source; external is outside the body, brachytherapy uses sealed radioactive sources placed precisely in the area under treatment, and systemic radioisotopes are given by infusion or oral ingestion. Brachytherapy can use temporary or permanent placement of radioactive sources. The temporary sources are usually placed by a technique called afterloading. In afterloading a hollow tube or applicator is placed surgically in the organ to be treated, and the sources are loaded into the applicator after the applicator is implanted. This minimizes radiation exposure to health care personnel.

text: Particle therapy

text: is a special case of external beam radiation therapy where the particles are

text: protons

text: or heavier

text: ions

text: . Intraoperative radiation therapy or

text: IORT

text: is a special type of radiation therapy that is delivered immediately after surgical removal of the cancer. This method has been employed in breast cancer (TARGeted Introperative radiation therapy or

text: TARGIT

text: ), brain tumors and rectal cancers.

text: Roscoe L. Koontz (December 16, 1922 – May 17, 1997) was an American Health Physicist. Trained as one of the first health physicists through the first Atomic Energy Health Physics Fellowship Training Program at the University of Rochester, Koontz contributed to the development of practices, instrumentation, and techniques to protect people from ionizing radiation. His early research focused on problems of neutron dosimetry, toxicology of uranium, plutonium, and fission products. Most of his career was spent at Atomics International where his key achievements included designing a pinhole gamma ray camera, developing techniques for measuring absolute thermal neutron flux using radioactive indium foils, and helping design and fabricate equipment to automate air and water sampling equipment and radiation activity measuring devices.

text: Roscoe L. Koontz (December 16, 1922 – May 17, 1997) was an American

text: Health Physicist

text: . Trained as one of the first health physicists through the first

text: Atomic Energy Health Physics Fellowship Training Program

text: at the

text: University of Rochester

text: , Koontz contributed to the development of practices, instrumentation, and techniques to protect people from

text: ionizing radiation

text: . His early research focused on problems of neutron

text: dosimetry

text: , toxicology of

text: uranium

text: plutonium

text: , and

text: fission products

text: . Most of his career was spent at

text: Atomics International

text: where his key achievements included designing a pinhole

text: gamma ray

text: camera, developing techniques for measuring absolute thermal

text: neutron flux

text: using radioactive indium foils, and helping design and fabricate equipment to automate air and water sampling equipment and

text: radiation

text: activity measuring devices.

text: A trace radioisotope is a radioisotope that occurs naturally in trace amounts (i.e., extremely small). Generally speaking, trace radioisotopes have half-lives that are short in comparison to the age of the Earth, since primordial nuclides tend to occur in larger than trace amounts. Trace radioisotopes are therefore present only because they are continually produced on Earth by natural processes. Natural processes which produce trace radioisotopes include cosmic ray bombardment of stable nuclides, ordinary alpha and beta decay of the long-lived heavy nuclides, thorium-232, uranium-238, and uranium-235, spontaneous fission of uranium-238, and nuclear transmutation reactions induced by natural radioactivity, such as the production of plutonium-239 and uranium-236 from neutron capture by natural uranium.

text: A trace radioisotope is a

text: radioisotope

text: that occurs naturally in trace amounts (i.e., extremely small). Generally speaking, trace radioisotopes have

text: half-lives

text: that are short in comparison to the

text: age of the Earth

text: , since

text: primordial nuclide

text: s tend to occur in larger than trace amounts. Trace radioisotopes are therefore present only because they are continually produced on Earth by natural processes. Natural processes which produce trace radioisotopes include

text: cosmic ray

text: bombardment of stable nuclides, ordinary

text: alpha

text: and

text: beta decay

text: of the long-lived heavy nuclides,

text: , and

text: spontaneous fission

text: of

text: , and

text: nuclear transmutation

text: reactions induced by

text: natural radioactivity

text: , such as the production of

text: and

text: from

text: neutron capture

text: by

text: natural uranium

text: The research reactor suffered on 24 October 2016 1:45 pm a small leakage of radioactive Iodine. No health risk or danger to the environment outside the facility was expected by the NRPA-authority. The reactor was already shut down at the time for routine maintenance. On 25 October the Norwegian Institute for Energy Technology (IFE), announced that the leak had been contained.  No injuries were reported. The personnel at the plant had suffered only a small dosage of radiation.

text: High levels of contamination may pose major risks to people and the environment. People can be exposed to potentially lethal radiation levels, both externally and internally, from the spread of contamination following an accident (or a deliberate initiation) involving large quantities of radioactive material. The biological effects of external exposure to radioactive contamination are generally the same as those from an external radiation source not involving radioactive materials, such as x-ray machines, and are dependent on the absorbed dose.

text: High levels of contamination may pose major risks to people and the environment. People can be exposed to potentially lethal radiation levels, both externally and internally, from the spread of contamination following an

text: accident

text: (or a

text: deliberate initiation

text: ) involving large quantities of radioactive material. The

text: biological effects of external exposure

text: to radioactive contamination are generally the same as those from an external radiation source not involving radioactive materials, such as

text: x-ray

text: machines, and are dependent on the

text: absorbed dose

text: It is noticeable that at the higher speeds the flat plate and square cell types show much higher figure of merit than the other two types, although at a speed of 20 miles per hour the type with spiral vanes would perhaps be better than any of the others. The figures of merit as drawn apply only to radiators mounted in ‘unobstructed’ positions, such that the flow of air through and around them is practicably unaffected by other parts of the aircraft. For use in such positions at high speeds, every form of turbulence device known to this bureau is detrimental to the general performance of the radiator. On the other hand, if the radiator is to be used in such a position as the nose of the fuselage, the airflow through it at best is low, and an increase in airflow is accompanied by an increase in head resistance of the combination of fuselage and radiator. In this case, heat must be transmitted as rapidly as possible to the small amount of air that does flow through, and it may be profitable to use turbulence devices. It is possible that the rate of heat transfer for the whole radiator may be increased, while added air resistance of the core may actually reduce the head resistance of the fuselage and radiator.

text: Nuklo is the son of Robert Frank and Madeline Joyce, also known as the Whizzer and Miss America. He was born in the fictional town of Mount Athena, New York (where Project Pegasus is also located). The two retired from their careers as costumed crimefighters several years after the end of World War II, married, revealed their identities to the government, and took jobs at one of the nation’s first nuclear power plants. When a radiation experiment went awry, the Franks rushed into a high radiation area to manually activate the damping rods that were malfunctioning and were exposed to massive amounts of radiation. Madeline Frank was pregnant at the time and when she gave birth eight months later, her son proved to be a mutant who emitted toxic radiation levels. (Apparently, due to their own superhuman powers, the Franks were immune to the deleterious effects of excessive radiation.) The Franks were persuaded by the government to place their infant son in a special capsule which would retard his aging process while draining him of excess radioactivity.

text: Nuklo is the son of Robert Frank and Madeline Joyce, also known as the

text: Whizzer

text: and

text: Miss America

text: . He was born in the fictional town of Mount Athena, New York (where

text: Project Pegasus

text: is also located). The two retired from their careers as costumed crimefighters several years after the end of World War II, married, revealed their identities to the government, and took jobs at one of the nation’s first nuclear power plants. When a radiation experiment went awry, the Franks rushed into a high radiation area to manually activate the damping rods that were malfunctioning and were exposed to massive amounts of radiation. Madeline Frank was pregnant at the time and when she gave birth eight months later, her son proved to be a mutant who emitted toxic radiation levels. (Apparently, due to their own superhuman powers, the Franks were immune to the deleterious effects of excessive radiation.) The Franks were persuaded by the government to place their infant son in a special capsule which would retard his aging process while draining him of excess radioactivity.

text: At least 27 radioisotopes have also been synthesized ranging in atomic mass from 58 to 89. The most stable of these is Ge, decaying by electron capture with a half-life of 270.95 d. It decays to the medically useful positron-emitting isotope Ga. (See gallium-68 generator for notes on the source of this isotope, and its medical use). The least stable known germanium isotope is Ge with a half-life of 30 ms.

text: At least 27

text: radioisotope

text: s have also been synthesized ranging in atomic mass from 58 to 89. The most stable of these is Ge, decaying by

text: electron capture

text: with a half-life of 270.95 d. It decays to the medically useful positron-emitting isotope Ga. (See

text: gallium-68 generator

text: for notes on the source of this isotope, and its medical use). The least stable known germanium isotope is Ge with a half-life of 30 ms.

text: Radiation in space usually comes from three main sources: (i) the Van Allen radiation belts; (ii) solar proton events and solar energetic particles; and (iii) galactic cosmic rays. For long duration missions, the high doses of radiation can damage electronic components and solar cells. A major concern is also radiation-induced "single-event effects" such as single event upset. Manned missions usually avoid the radiation belts and the international space station is at an altitude well below the most severe regions of the radiation belts. During solar energetic events (solar flares and coronal mass ejections) particles can be accelerated to very high energies and can reach the Earth in times as short as 30 minutes (but usually take some hours). These particles are mainly protons and heavier ions that can cause radiation damage, disruption to logic circuits and even hazards to astronauts. Manned missions to return to the Moon or to travel to Mars will have to deal with the major problems presented by solar particle events to radiation safety, in addition to the important contribution to doses from the low-level background cosmic rays. In near-Earth orbits, the Earth's geomagnetic field screens spacecraft from a large part of these hazards - a process called geomagnetic shielding.Space debris and meteoroids can impact spacecraft at high speeds, causing mechanical or electrical damage.  The average speed of space debris is 10 km/s  while the average speed of meteoroids is much greater.  For example, the meteoroids associated with the Perseid meteor shower travel at an average speed of 58 km/s.  Mechanical damage from debris impacts have been studied through space missions including LDEF, which had over 20,000 documented impacts through its 5.7 year mission.  Electrical anomalies associated with impact events include ESA's Olympus spacecraft, which lost attitude control during the 1993 Perseid meteor shower.  A similar event occurred with the Landsat 5 spacecraft during the 2009 Perseid meteor shower.

text: Radiation in space usually comes from three main sources: (i) the

text: Van Allen radiation belts

text: ; (ii)

text: solar proton event

text: s and

text: solar energetic particle

text: s; and (iii) galactic

text: cosmic rays

text: . For long duration missions, the high doses of radiation can damage electronic components and solar cells. A major concern is also radiation-induced "single-event effects" such as

text: single event upset

text: . Manned missions usually avoid the radiation belts and the

text: international space station

text: is at an altitude well below the most severe regions of the radiation belts. During solar energetic events (

text: solar flares

text: and

text: coronal mass ejections

text: ) particles can be accelerated to very high energies and can reach the Earth in times as short as 30 minutes (but usually take some hours). These particles are mainly protons and heavier ions that can cause radiation damage, disruption to logic circuits and even hazards to astronauts. Manned missions to return to the Moon or to travel to Mars will have to deal with the major problems presented by solar particle events to radiation safety, in addition to the important contribution to doses from the low-level background

text: cosmic rays

text: . In near-Earth orbits, the Earth's

text: geomagnetic field

text: screens spacecraft from a large part of these hazards - a process called

text: geomagnetic shielding

text: .Space debris and meteoroids can impact spacecraft at high speeds, causing mechanical or electrical damage.  The average speed of space debris is 10 km/s  while the average speed of meteoroids is much greater.  For example, the meteoroids associated with the

text: Perseid meteor shower

text: travel at an average speed of 58 km/s.  Mechanical damage from debris impacts have been studied through space missions including

text: LDEF

text: , which had over 20,000 documented impacts through its 5.7 year mission.  Electrical anomalies associated with impact events include

text: ESA

text: 's Olympus spacecraft, which lost attitude control during the 1993 Perseid meteor shower.  A similar event occurred with the

text: Landsat 5

text: spacecraft during the 2009 Perseid meteor shower.

text: Restriction Landmark Genomic Scanning (or RLGS) is a genome analysis method that allows for rapid simultaneous visualization of thousands of landmarks, or restriction sites. Using a combination of restriction enzymes some of which are specific to DNA modifications, the technique can be used to visualize differences in methylation levels across the genome of a given organism. RLGS employs direct labeling of DNA, which is first cut by a specific series of restriction enzymes, and then labeled by a radioactive isotope (usually phosphorus-32). A two-dimensional electrophoresis process is then employed, yielding high-resolution results. The radioactive second-dimension gel is then allowed to expose a large sheet of film. The radiation produced by the radioactive labeling will cause the film to be exposed wherever the restriction fragments have migrated during electrophoresis. The film is then developed, yielding a visual representation of the results in the form of an autoradiograph. The same combination of restriction enzymes will produce the same pattern of 'spots' from samples from the same organisms, but different patterns for different types of organism. For example, human and mouse DNA will produce distinctly different patterns when treated with the same combination of enzymes. These finished auto-rads can be examined against each other, revealing any changes in gene expression that lead to visual differences in the film. Each autoradiograph contains thousands of spots, each corresponding to a labeled DNA restriction landmark.

text: Restriction Landmark Genomic Scanning (or RLGS) is a

text: genome

text: analysis method that allows for rapid simultaneous visualization of thousands of landmarks, or

text: restriction sites

text: . Using a combination of

text: restriction enzyme

text: s some of which are specific to

text: DNA modifications

text: , the technique can be used to visualize differences in

text: methylation

text: levels across the

text: genome

text: of a given organism. RLGS employs direct labeling of

text: DNA

text: , which is first cut by a specific series of restriction enzymes, and then labeled by a

text: radioactive

text: isotope

text: (usually

text: ). A

text: two-dimensional

text: electrophoresis

text: process is then employed, yielding high-resolution results. The radioactive second-dimension gel is then allowed to expose a large sheet of

text: film

text: . The radiation produced by the radioactive labeling will cause the film to be exposed wherever the restriction fragments have migrated during electrophoresis. The film is then developed, yielding a visual representation of the results in the form of an

text: autoradiograph

text: . The same combination of restriction enzymes will produce the same pattern of 'spots' from samples from the same organisms, but different patterns for different types of organism. For example, human and mouse DNA will produce distinctly different patterns when treated with the same combination of enzymes. These finished auto-rads can be examined against each other, revealing any changes in gene expression that lead to visual differences in the film. Each autoradiograph contains thousands of spots, each corresponding to a labeled DNA restriction landmark.

text: The intermediate stages each emit the same amount of radioactivity as the original radioisotope (though not the same energy). When equilibrium is achieved, a granddaughter isotope is present in direct proportion to its half-life; but since its activity is inversely proportional to its half-life, each nuclide in the decay chain finally contributes as much radioactivity as the head of the chain, though not the same energy. For example, uranium-238 is weakly radioactive, but pitchblende, a uranium ore, is 13 times more radioactive than the pure uranium metal of the same amount because of the radium and other daughter isotopes it contains. Not only are unstable radium isotopes significant radioactivity emitters, but as the next stage in the decay chain they also generate radon, a heavy, inert, naturally occurring radioactive gas. Rock containing thorium and/or uranium (such as some granites) emits radon gas that can accumulate in enclosed places such as basements or underground mines. Radon exposure is considered the leading cause of lung cancer in non-smokers.

text: The intermediate stages each emit the same amount of radioactivity as the original radioisotope (though not the same energy). When equilibrium is achieved, a granddaughter isotope is present in direct proportion to its half-life; but since its activity is inversely proportional to its half-life, each nuclide in the decay chain finally contributes as much radioactivity as the head of the chain, though not the same energy. For example, uranium-238 is weakly radioactive, but

text: pitchblende

text: , a uranium ore, is 13 times more radioactive than the pure uranium metal of the same amount because of the

text: radium

text: and other daughter isotopes it contains. Not only are unstable radium isotopes significant radioactivity emitters, but as the next stage in the decay chain they also generate

text: radon

text: , a heavy, inert, naturally occurring radioactive gas. Rock containing thorium and/or uranium (such as some granites) emits radon gas that can accumulate in enclosed places such as basements or underground mines. Radon exposure is considered the leading cause of

text: lung cancer

text: in non-smokers.

text: Radioactive beams of specific isotopes are widely used in the fields of experimental physics, biology and materials science. The production and formation of these radioactive atoms into an ionic beam for study is an entire field of research carried out at many laboratories throughout the world. The first isotope separator was developed at the Copenhagen Cyclotron by Bohr and co-workers using the principle of electromagnetic separation. Today, there are many laboratories around the world which supply beams of radioactive ions for use. Arguably the principal Isotope Separator On-Line (ISOL) is ISOLDE at CERN, which is a joint European facility spread across the Franco-Swiss border near the city of Geneva. This laboratory uses mainly proton spallation of uranium carbide targets to produce a wide range of radioactive fission fragments that are not found naturally on earth. During spallation (bombardment with high energy protons), a uranium carbide target is heated to several thousand degrees so that radioactive atoms produced in the nuclear reaction are released. Once out of the target, the vapour of radioactive atoms travels to an ionizer cavity. This ionizer cavity is a thin tube made of a refractory metal with a high work function allowing for collisions with the walls to liberate a single electron from a free atom (surface ionization effect). Once ionized, the radioactive species are accelerated by an electrostatic field and injected into an electromagnetic separator. As ions entering the separator are of approximately equal energy, those ions with a smaller mass will be deflected by the magnetic field by a greater amount than those with a heavier mass. This differing radius of curvature allows for isobaric purification to take place. Once purified isobarically, the ion beam is then sent to the individual experiments. In order to increase the purity of the isobaric beam, laser ionization can take place inside the ionizer cavity to selectively ionize a single element chain of interest. At CERN, this device is called the Resonance Ionization Laser Ion Source (RILIS). Currently over 60% of all experiments opt to use the RILIS to increase the purity of radioactive beams.

text: Radioactive beams of specific isotopes are widely used in the fields of experimental physics, biology and materials science. The production and formation of these radioactive atoms into an ionic beam for study is an entire field of research carried out at many laboratories throughout the world. The first isotope separator was developed at the Copenhagen Cyclotron by Bohr and co-workers using the principle of electromagnetic separation. Today, there are many laboratories around the world which supply beams of radioactive ions for use. Arguably the principal Isotope Separator On-Line (ISOL) is ISOLDE at CERN, which is a joint European facility spread across the Franco-Swiss border near the city of Geneva. This laboratory uses mainly proton spallation of uranium carbide targets to produce a wide range of radioactive fission fragments that are not found naturally on earth. During spallation (bombardment with high energy protons), a uranium carbide target is heated to several thousand degrees so that radioactive atoms produced in the nuclear reaction are released. Once out of the target, the vapour of radioactive atoms travels to an ionizer cavity. This ionizer cavity is a thin tube made of a refractory metal with a high

text: work function

text: allowing for collisions with the walls to liberate a single electron from a free atom (

text: surface ionization

text: effect). Once ionized, the radioactive species are accelerated by an electrostatic field and injected into an electromagnetic separator. As ions entering the separator are of approximately equal energy, those ions with a smaller mass will be deflected by the magnetic field by a greater amount than those with a heavier mass. This differing radius of curvature allows for isobaric purification to take place. Once purified isobarically, the ion beam is then sent to the individual experiments. In order to increase the purity of the isobaric beam, laser ionization can take place inside the ionizer cavity to selectively ionize a single element chain of interest. At CERN, this device is called the Resonance Ionization Laser Ion Source (RILIS). Currently over 60% of all experiments opt to use the RILIS to increase the purity of radioactive beams.

text: There are a total of thirty-three known radioisotopes in addition to Ba, but most of these are highly radioactive with half-lives in the several millisecond to several minute range. The only notable exceptions are Ba, which has a half-life of 10.51 years, Ba (11.5 days), and Ba (2.55 minutes), which is the decay product of Cs (30.17 years, and a common fission product).

text: There are a total of thirty-three known

text: radioisotope

text: s in addition to Ba, but most of these are highly

text: radioactive

text: with

text: half-lives

text: in the several millisecond to several minute range. The only notable exceptions are Ba, which has a half-life of 10.51 years, Ba (11.5 days), and Ba (2.55 minutes), which is the decay product of

text: Cs

text: (30.17 years, and a common

text: fission product

text: CME radiation is dangerous to astronauts on a space mission who are outside the shielding produced by the Earth's magnetic field. Future mission designs (e.g., for a Mars Mission) therefore incorporate a radiation-shielded "storm shelter" for astronauts to retreat to during such an event.

text: CME radiation is dangerous to

text: astronaut

text: s on a space mission who are outside the shielding produced by the

text: Earth's magnetic field

text: . Future mission designs (e.g., for a

text: Mars Mission

text: ) therefore incorporate a radiation-shielded "storm shelter" for astronauts to retreat to during such an event.

text: A criticality accident (also sometimes referred to as an "excursion" or "power excursion") occurs when a nuclear chain reaction is accidentally allowed to occur in fissile material, such as enriched uranium or plutonium. The Chernobyl accident is an example of a criticality accident. This accident destroyed a reactor at the plant and left a large geographic area uninhabitable.  In a smaller scale accident at Sarov a technician working with highly enriched uranium was irradiated while preparing an experiment involving a sphere of fissile material. The Sarov accident is interesting because the system remained critical for many days before it could be stopped, though safely located in a shielded experimental hall. This is an example of a limited scope accident where only a few people can be harmed, while no release of radioactivity into the environment occurred. A criticality accident with limited off site release of both radiation (gamma and neutron) and a very small release of radioactivity occurred at Tokaimura in 1999 during the production of enriched uranium fuel.  Two workers died, a third was permanently injured, and 350 citizens were exposed to radiation.

text: A

text: criticality accident

text: (also sometimes referred to as an "excursion" or "power excursion") occurs when a nuclear chain reaction is accidentally allowed to occur in

text: fissile material

text: , such as

text: enriched uranium

text: or

text: plutonium

text: . The

text: Chernobyl accident

text: is an example of a criticality accident. This accident destroyed a reactor at the plant and left a large geographic area uninhabitable.  In a smaller scale accident at

text: Sarov

text: a technician working with

text: highly enriched uranium

text: was irradiated while preparing an experiment involving a sphere of fissile material. The Sarov accident is interesting because the system remained critical for many days before it could be stopped, though safely located in a shielded experimental hall. This is an example of a limited scope accident where only a few people can be harmed, while no release of radioactivity into the environment occurred. A criticality accident with limited off site release of both radiation (

text: gamma

text: and

text: neutron

text: ) and a very small release of radioactivity occurred at

text: Tokaimura

text: in 1999 during the production of enriched uranium fuel.  Two workers died, a third was permanently injured, and 350 citizens were exposed to radiation.

text: Equipment assembled included remote-controlled bulldozers and robot-carts that could detect radioactivity and carry hot debris. Valery Legasov (first deputy director of the Kurchatov Institute of Atomic Energy in Moscow) said, in 1987: "But we learned that robots are not the great remedy for everything. Where there was very high radiation, the robot ceased to be a robot—the electronics quit working."

text: The survey meter could be compared to the speedometer, as it measures the speed, or rate, at which radiation is being picked up. When properly calibrated, used, and maintained, it allows the radiographer to see the current exposure to radiation at the meter. It can usually be set for different intensities, and is used to prevent the radiographer from being overexposed to the radioactive source, as well as for verifying the boundary that radiographers are required to maintain around the exposed source during radiographic operations.

text: The works gained notoriety because they were linked in the 1980s with a child cancer cluster in west Hull and surrounding villages; (Willerby and Kirk Ella) in 1988 the plant was part of a feature on radiation in Channel 4's Dispatches documentary "Radioactive Britain". A report from Professor M.S. Baxter of Glasgow University was commissioned by the East Yorkshire Health Authority; which found the previous statistical limits on radioactive exposure to be too high (by a factor of more than 100 times) and recommended revision of the Radioactive Substances Act 1960. A 1996 report recommended improvements in assessment, mitigation and monitoring of radioactive agents in the metallurgical refining industry be made. The Baxter report could not establish a link between the smelter and the cancer cases.

text: The works gained notoriety because they were linked in the 1980s with a child

text: cancer cluster

text: in west Hull and surrounding villages; (Willerby and Kirk Ella) in 1988 the plant was part of a feature on radiation in

text: Channel 4

text: 's

text: Dispatches

text: documentary "Radioactive Britain". A report from Professor M.S. Baxter of Glasgow University was commissioned by the

text: East Yorkshire Health Authority

text: ; which found the previous statistical limits on radioactive exposure to be too high (by a factor of more than 100 times) and recommended revision of the

text: Radioactive Substances Act 1960

text: . A 1996 report recommended improvements in assessment, mitigation and monitoring of radioactive agents in the metallurgical refining industry be made. The Baxter report could not establish a link between the smelter and the cancer cases.

text: Not all neutrons are emitted as a direct product of fission;  some are instead due to the radioactive decay of some of the fission fragments.  The neutrons that occur directly from fission are called "prompt neutrons," and the ones that are a result of radioactive decay of fission fragments are called "delayed neutrons." The fraction of neutrons that are delayed is called β, and this fraction is typically less than 1% of all the neutrons in the chain reaction.

text: Not all neutrons are emitted as a direct product of fission;  some are instead due to the

text: radioactive decay

text: of some of the fission fragments.  The neutrons that occur directly from fission are called "

text: prompt neutron

text: s," and the ones that are a result of radioactive decay of fission fragments are called "delayed neutrons." The fraction of neutrons that are delayed is called β, and this fraction is typically less than 1% of all the neutrons in the chain reaction.

text: Many airports now have radiation detectors to detect the smuggling of radioactive materials that may be used in nuclear weapons manufacture. Patients should be warned that if they travel by air, they may trigger radiation detectors at airports up to 95 days after their treatment with I.

text: When something is said to have radioactive contamination, it often means that there are beta particles being emitted from its surface, detectable with a Geiger counter or other radiation detector. When brought into proximity to the beta emitter, the detector will indicate a dramatic increase in radioactivity. When the detector probe is covered with a shield to block the beta rays, the indication will be reduced dramatically.

text: When something is said to have

text: radioactive contamination

text: , it often means that there are beta particles being emitted from its surface, detectable with a

text: Geiger counter

text: or other radiation detector. When brought into proximity to the beta emitter, the detector will indicate a dramatic increase in radioactivity. When the detector probe is covered with a shield to block the beta rays, the indication will be reduced dramatically.

text: Most fission products have too many neutrons to be stable so they are radioactive by beta decay, converting neutrons into protons by throwing off beta particles (electrons) and gamma rays. Their half lives range from milliseconds to about 200,000 years. Many decay into isotopes that are themselves radioactive, so from 1 to 6 (average 3) decays may be required to reach stability. In reactors, the radioactive products are the nuclear waste in spent fuel. In bombs, they become radioactive fallout, both local and global.

text: Most fission products have too many neutrons to be stable so they are radioactive by

text: beta decay

text: , converting neutrons into protons by throwing off beta particles (electrons) and gamma rays. Their half lives range from milliseconds to about 200,000 years. Many decay into isotopes that are themselves radioactive, so from 1 to 6 (average 3) decays may be required to reach stability. In reactors, the radioactive products are the nuclear waste in spent fuel. In bombs, they become radioactive fallout, both local and global.

text: Because the thyroid concentrates iodine, it also concentrates the various radioactive isotopes of iodine produced by nuclear fission. In the event of large accidental releases of such material into the environment, the uptake of radioactive iodine isotopes by the thyroid can, in theory, be blocked by saturating the uptake mechanism with a large surplus of non-radioactive iodine, taken in the form of potassium iodide tablets. One consequence of the Chernobyl disaster was an increase in thyroid cancers in children in the years following the accident.

text: Because the thyroid concentrates iodine, it also concentrates the various radioactive

text: isotope

text: s of iodine produced by

text: nuclear fission

text: . In the event of large accidental releases of such material into the environment, the uptake of radioactive iodine isotopes by the thyroid can, in theory, be blocked by saturating the uptake mechanism with a large surplus of

entity_section: Role of potassium iodide in radiological emergency preparedness

text: non-radioactive iodine

text: , taken in the form of potassium iodide tablets. One consequence of the

text: Chernobyl disaster

text: was an increase in

text: thyroid cancer

text: s in children in the years following the accident.

text: Due to the abundance of radioactive elements that can be incorporated into zircons, they are also susceptible to damage from radioactive decay through the process of metamictization. As radioactive elements within the crystal lattice decay, they bombard the interior of the crystal with radioactive particles. This weakens the crystal and leave it fractured or destroyed. This increases the chance of isotopes leaking out of the crystal and affecting titanium, or other elements, measurements.

text: Due to the abundance of radioactive elements that can be incorporated into zircons, they are also susceptible to damage from radioactive decay through the process of

text: metamictization

text: . As radioactive elements within the crystal lattice decay, they bombard the interior of the crystal with radioactive particles. This weakens the crystal and leave it fractured or destroyed. This increases the chance of isotopes leaking out of the crystal and affecting titanium, or other elements, measurements.

text: The information available on the effect of natural background radiation with respect anthropogenic pollution on wildlife is scarce and refers to very few species. It is very difficult to estimate from the available data the total doses that can accumulate during specific stages of the life cycle (embryonic development or reproductive age), in changes in behavior or depending on environmental factors such as seasonality. The phenomena of radioactive bioaccumulation, bioconcentration and biomagnification, however, are especially known to sea level. They are caused by the recruitment and retention of radioisotopes by bivalves, crustaceans, corals and phytoplankton, which then amounted to the rest of the food chain at low concentration factors.

text: The information available on the effect of natural background radiation with respect anthropogenic pollution on

text: wildlife

text: is scarce and refers to very few species. It is very difficult to estimate from the available data the total doses that can accumulate during specific stages of the

text: life cycle

text: embryonic development

text: or reproductive age), in changes in

text: behavior

text: or depending on

text: environmental factors

text: such as

text: seasonality

text: . The phenomena of radioactive

text: bioaccumulation

text: bioconcentration

text: and

text: biomagnification

text: , however, are especially known to sea level. They are caused by the recruitment and retention of radioisotopes by

text: bivalves

text: crustaceans

text: corals

text: and

text: phytoplankton

text: , which then amounted to the rest of the

text: food chain

text: at low concentration factors.

text: According to the World Health Organization, a radiation dose from it would be about 60% of that from purified natural uranium with the same mass; the radiological dangers are lower due to its longer half-life and the removal of the more radioactive isotopes.

text: According to the

text: World Health Organization

text: , a

text: radiation

text: dose

text: from it would be about 60% of that from purified natural uranium with the same mass; the

text: radiological

text: dangers are lower due to its longer half-life and the removal of the more radioactive isotopes.

text: In addition to commercial production, I (half-life 8 days) is one of the common radioactive fission-products of nuclear fission, and is thus produced inadvertently in very large amounts inside nuclear reactors. Due to its volatility, short half-life, and high abundance in fission products, I, (along with the short-lived iodine isotope I from the longer-lived Te with a half-life of 3 days) is responsible for the largest part of radioactive contamination during the first week after accidental environmental contamination from the radioactive waste from a nuclear power plant.

text: In addition to commercial production, I (half-life 8 days) is one of the common radioactive

text: fission-product

text: s of

text: nuclear fission

text: , and is thus produced inadvertently in very large amounts inside

text: nuclear reactor

text: s. Due to its volatility, short half-life, and high abundance in fission products, I, (along with the short-lived iodine isotope I from the longer-lived Te with a half-life of 3 days) is responsible for the largest part of radioactive contamination during the first week after accidental environmental contamination from the

text: radioactive waste

text: from a nuclear power plant.

text: Pierre and Marie further explored radioactivity by working to separate the substances in uranium ores and then using the electrometer to make radiation measurements to ‘trace’ the minute amount of unknown radioactive element among the fractions that resulted. Working with the mineral pitchblende, the pair discovered a new radioactive element in 1898. They named the element polonium, after Marie's native country of Poland. On December 21, 1898, the Curies detected the presence of another radioactive material in the pitchblende. They presented this finding to the French Academy of Sciences on December 26, proposing that the new element be called radium. The Curies then went to work isolating polonium and radium from naturally occurring compounds to prove that they were new elements. In 1902, the Curies announced that they had produced a decigram of pure radium, demonstrating its existence as a unique chemical element. While it took three years for them to isolate radium, they were never able to isolate polonium. Along with the discovery of two new elements and finding techniques for isolating radioactive isotopes, Curie oversaw the world's first studies into the treatment of neoplasms, using radioactive isotopes. With Henri Becquerel and her husband, Pierre Curie, she was awarded the 1903 Nobel Prize for Physics. She was the sole winner of the 1911 Nobel Prize for Chemistry. She was the first woman to win a Nobel Prize, and she is the only woman to win the award in two different fields.

text: Pierre and Marie further explored radioactivity by working to separate the substances in uranium ores and then using the

text: electrometer

text: to make radiation measurements to ‘trace’ the minute amount of unknown radioactive element among the fractions that resulted. Working with the mineral

text: pitchblende

text: , the pair discovered a new radioactive element in 1898. They named the element

text: polonium

text: , after Marie's native country of Poland. On December 21, 1898, the Curies detected the presence of another radioactive material in the pitchblende. They presented this finding to the

text: French Academy of Sciences

text: on December 26, proposing that the new element be called

text: radium

text: . The Curies then went to work isolating polonium and radium from naturally occurring compounds to prove that they were new elements. In 1902, the Curies announced that they had produced a decigram of pure radium, demonstrating its existence as a unique chemical element. While it took three years for them to isolate radium, they were never able to isolate polonium. Along with the discovery of two new elements and finding techniques for isolating radioactive isotopes, Curie oversaw the world's first studies into the treatment of

text: neoplasm

text: s, using radioactive isotopes. With Henri Becquerel and her husband, Pierre Curie, she was awarded the 1903

text: Nobel Prize for Physics

text: . She was the sole winner of the 1911

text: Nobel Prize for Chemistry

text: . She was the first woman to win a Nobel Prize, and she is the only woman to win the award in two different fields.

text: Gradually it was realized that the radiation produced by radioactive decay was ionizing radiation, and that even quantities too small to burn could pose a severe long-term hazard. Many of the scientists working on radioactivity died of cancer as a result of their exposure. Radioactive patent medicines mostly disappeared, but other applications of radioactive materials persisted, such as the use of radium salts to produce glowing dials on meters.

text: Gradually it was realized that the radiation produced by radioactive decay was

text: ionizing radiation

text: , and that even quantities too small to burn could pose a

text: severe long-term hazard

text: . Many of the scientists working on radioactivity died of

text: cancer

text: as a result of their exposure. Radioactive patent medicines mostly disappeared, but other applications of radioactive materials persisted, such as the use of radium salts to produce

text: glowing dials on meters

text: All of the elements have some isotopes that are radioactive (radioisotopes), although not all of these radioisotopes occur naturally. The radioisotopes typically decay into other elements upon radiating an alpha or beta particle. If an element has isotopes that are not radioactive, these are termed "stable" isotopes. All of the known stable isotopes occur naturally (see primordial isotope). The many radioisotopes that are not found in nature have been characterized after being artificially made. Certain elements have no stable isotopes and are composed only of radioactive isotopes: specifically the elements without any stable isotopes are technetium (atomic number 43), promethium (atomic number 61), and all observed elements with atomic numbers greater than 82.

text: All of the elements have some isotopes that are radioactive (

text: radioisotopes

text: ), although not all of these radioisotopes occur naturally. The radioisotopes typically decay into other elements upon radiating an

text: alpha

text: or

text: beta particle

text: . If an element has isotopes that are not radioactive, these are termed "stable" isotopes. All of the known stable isotopes occur naturally (see

text: primordial isotope

text: ). The many radioisotopes that are not found in nature have been characterized after being artificially made. Certain elements have no stable isotopes and are composed only of radioactive isotopes: specifically the elements without any stable isotopes are technetium (atomic number 43), promethium (atomic number 61), and all observed elements with atomic numbers greater than 82.

text: Most of the iodine not taken up by thyroid tissue is excreted through the kidneys into the urine. After radioiodine treatment the urine will be radioactive or 'hot', and the patients themselves will also emit gamma radiation. Depending on the amount of radioactivity administered, it can take days to weeks for the radioactivity to reduce to the point where the patient does not pose a radiation hazard to bystanders. There are strict radiation protection regulations governing the use of all radiopharmaceuticals.

text: Most of the iodine not taken up by thyroid tissue is

text: excreted

text: through the

text: kidney

text: s into the

text: urine

text: . After radioiodine treatment the urine will be radioactive or 'hot', and the patients themselves will also emit

text: gamma radiation

text: . Depending on the amount of radioactivity administered, it can take days to weeks for the radioactivity to reduce to the point where the patient does not pose a radiation hazard to bystanders. There are strict

text: radiation protection

text: regulations governing the use of all radiopharmaceuticals.

text: The releases of radioactivity from normal operations are the small planned releases from uranium ore processing, enrichment, power reactors, reprocessing plants and waste stores. These can be in a different chemical/physical form to the releases which could occur under accident conditions. In addition the isotope signature of a hypothetical accident may be very different from that of a planned normal operational discharge of radioactivity to the environment.

text: Instruments to detect this radiation commonly measure the Cherenkov radiation produced by secondary particles generated from an energetic photon entering the Earth's atmosphere. This method is called imaging atmospheric Cherenkov technique or IACT. A high-energy photon produces a cone of light confined to 1° of the original photon direction. About 10,000 m of the earth's surface is lit by each cone of light. A flux of 10 photons per square meter per second can be detected with current technology, provided the energy is above 0.1 TeV. Instruments include the planned Cherenkov Telescope Array, GT-48 in Crimea, MAGIC on La Palma, High Energy Stereoscopic System (HESS) in Namibia VERITAS and Chicago Air Shower Array which closed in 2001. Cosmic rays also produce similar flashes of light, but can be distinguished based on the shape of the light flash. Also having more than one telescope simultaneously observing the same spot can help exclude cosmic rays. Extensive air showers of particles can be detected for gamma rays above 100 TeV. Water scintillation detectors or dense arrays of particle detectors can be used to detect these particle showers.

text: Instruments to detect this radiation commonly measure the

text: Cherenkov radiation

text: produced by secondary particles generated from an energetic photon entering the Earth's atmosphere. This method is called imaging atmospheric Cherenkov technique or

text: IACT

text: . A high-energy photon produces a cone of light confined to 1° of the original photon direction. About 10,000 m of the earth's surface is lit by each cone of light. A flux of 10 photons per square meter per second can be detected with current technology, provided the energy is above 0.1 TeV. Instruments include the planned

text: Cherenkov Telescope Array

text: in Crimea,

text: MAGIC

text: on

text: La Palma

text: High Energy Stereoscopic System

text: (HESS) in Namibia

text: VERITAS

text: and

text: Chicago Air Shower Array

text: which closed in 2001. Cosmic rays also produce similar flashes of light, but can be distinguished based on the shape of the light flash. Also having more than one telescope simultaneously observing the same spot can help exclude cosmic rays.

text: Extensive air shower

text: s of particles can be detected for gamma rays above 100 TeV. Water scintillation detectors or dense arrays of particle detectors can be used to detect these particle showers.

text: Exposure to radon, a process known as radiation hormesis, has been suggested to mitigate auto-immune diseases such as arthritis. As a result, in the late 20th century and early 21st century, "health mines" established in Basin, Montana attracted people seeking relief from health problems such as arthritis through limited exposure to radioactive mine water and radon. The practice is discouraged because of the well-documented ill effects of high-doses of radiation on the body.

text: Exposure to radon, a process known as

text: radiation hormesis

text: , has been suggested to mitigate

text: auto-immune disease

text: s such as

text: arthritis

text: . As a result, in the late 20th century and early 21st century, "health mines" established in

text: Basin, Montana

text: attracted people seeking relief from health problems such as arthritis through limited exposure to radioactive mine water and radon. The practice is discouraged because of the well-documented ill effects of high-doses of radiation on the body.

text: The ionizing effect of radiation on a gas is extensively used for the detection of radiation such as alpha, beta, gamma and X-rays. The original ionization event in these instruments results in the formation of an "ion pair"; a positive ion and a free electron, by ion impact by the radiation on the gas molecules. The ionization chamber is the simplest of these detectors, and collects all the charges created by direct ionization within the gas through the application of an electric field.

text: The ionizing effect of radiation on a gas is extensively used for the detection of radiation such as

text: alpha

text: beta

text: gamma

text: and

text: X-rays

text: . The original ionization event in these instruments results in the formation of an "ion pair"; a positive ion and a free electron, by ion impact by the radiation on the gas molecules. The

text: ionization chamber

text: is the simplest of these detectors, and collects all the charges created by direct ionization within the gas through the application of an electric field.

text: The reliability of the first Soviet nuclear-powered submarines was relatively low because of the short service life of the steam generators in the main propulsion machinery, which caused an increase of the radioactivity level in the second loop of the reactor after several hundred hours of reactor operation. Machinery problems were the main reason why Project 627/627A submarines were not used during the Cuban Missile Crisis in autumn 1962. The reliability of the steam generators became better over the course of construction development, handling technical problems and training of crews, so Novembers began to frequently perform Arctic under-ice cruises and patrol missions to trace nuclear delivery vessels in Atlantic Ocean in the 1960s. Despite the common opinion about the dangers of radiation in the first Novembers, the background radiation levels in the compartments was usually normal because of relatively effective iron-water radiation protection of the reactor compartment and radiation monitoring.

text: The reliability of the first Soviet nuclear-powered submarines was relatively low because of the short service life of the steam generators in the main propulsion machinery, which caused an increase of the radioactivity level in the second loop of the reactor after several hundred hours of reactor operation. Machinery problems were the main reason why Project 627/627A submarines were not used during the

text: Cuban Missile Crisis

text: in autumn 1962. The reliability of the steam generators became better over the course of construction development, handling technical problems and training of crews, so Novembers began to frequently perform Arctic under-ice cruises and patrol missions to trace nuclear delivery vessels in Atlantic Ocean in the 1960s. Despite the common opinion about the dangers of radiation in the first Novembers, the background radiation levels in the compartments was usually normal because of relatively effective iron-water radiation protection of the reactor compartment and radiation monitoring.

text: A hot particle is a microscopic piece of radioactive material, which can become lodged in living tissue and deliver a concentrated dose of radiation to a small area. A controversial theory proposes that hot particles within the body are vastly more dangerous than external emitters delivering the same dose of radiation in a diffused manner. Other researchers claim that there is little or no difference in risk between internal and external emitters.

text: The second album continued in this vein, with Jeff Arwadi saying that the lyrics in Radioactive Zone 245 "are mostly about the destruction of Earth, both in smaller or larger scales; the process that mankind has made throughout history, and in the future we ourselves who will reap all that we sow. It’s very dark and seems like it may be too pessimistic, but the message is clearly positive. You cannot go away and forget what we’ve done to this Earth." According to Dark Thriller, the "245" in the title for the second album was based off the serial code X5-452 of the character Max Guevara in the TV series Dark Angel. "Radioactive Zone" was chosen because it was what came to mind when Dark Thriller heard the final mix.

text: The second album continued in this vein, with Jeff Arwadi saying that the lyrics in Radioactive Zone 245 "are mostly about the destruction of Earth, both in smaller or larger scales; the process that mankind has made throughout history, and in the future we ourselves who will reap all that we sow. It’s very dark and seems like it may be too pessimistic, but the message is clearly positive. You cannot go away and forget what we’ve done to this Earth." According to Dark Thriller, the "245" in the title for the second album was based off the serial code X5-452 of the character

text: Max Guevara

text: in the TV series

text: Dark Angel

text: . "Radioactive Zone" was chosen because it was what came to mind when Dark Thriller heard the final mix.

text: In 1913, Soddy also showed that an atom moves lower in atomic number by two places on alpha emission, higher by one place on beta emission. This was discovered at about the same time by Kazimierz Fajans, and is known as the radioactive displacement law of Fajans and Soddy, a fundamental step toward understanding the relationships among families of radioactive elements. Soddy published ''The Interpretation of Radium'' (1909) and Atomic Transmutation (1953).

text: In 1913, Soddy also showed that an atom moves lower in

text: atomic number

text: by two places on alpha emission, higher by one place on beta emission. This was discovered at about the same time by

text: Kazimierz Fajans

text: , and is known as the

text: , a fundamental step toward understanding the relationships among families of radioactive elements. Soddy published ''The Interpretation of Radium'' (1909) and Atomic Transmutation (1953).

text: The international radioactivity symbol (also known as trefoil) first appeared in 1946, at the University of California, Berkeley Radiation Laboratory. At the time, it was rendered as magenta, and was set on a blue background.

text: The international radioactivity symbol (also known as

text: trefoil

text: ) first appeared in 1946, at the

text: University of California, Berkeley

text: Radiation Laboratory. At the time, it was rendered as

text: magenta

text: , and was set on a blue background.

text: Much ionizing radiation originates from radioactive materials and space (cosmic rays), and as such is naturally present in the environment, since most rock and soil has small concentrations of radioactive materials. The radiation is invisible and not directly detectable by human senses; as a result, instruments such as Geiger counters are usually required to detect its presence. In some cases, it may lead to secondary emission of visible light upon its interaction with matter, as in the case of Cherenkov radiation and radio-luminescence.

text: Much ionizing radiation originates from radioactive materials and space (cosmic rays), and as such is naturally present in the environment, since most rock and soil has small concentrations of radioactive materials. The radiation is invisible and not directly detectable by human senses; as a result, instruments such as

text: Geiger counter

text: s are usually required to detect its presence. In some cases, it may lead to secondary emission of visible light upon its interaction with matter, as in the case of

text: Cherenkov radiation

text: and radio-luminescence.

text: Since its decommissioning, Caldas’ mine pit, which is approximately 180 meters (590 feet) deep and contains a diameter of about 1,200 meters (3,937 feet), has turned into a giant lake of acid water. Additionally, radioactive residues remain in the unit – approximately 11,000 tons of torta 2, a combination of uranium concentrate and thorium, and thousands of tons of mesothorium – making Caldas the country’s biggest radioactive waste deposit.

text: A synthetic radioisotope is a radionuclide that is not found in nature: no natural process or mechanism exists which produces it, or it is so unstable that it decays away in a very short period of time. Examples include technetium-95 and promethium-146. Many of these are found in, and harvested from, spent nuclear fuel assemblies. Some must be manufactured in particle accelerators.

text: A synthetic radioisotope is a

text: radionuclide

text: that is not found in nature: no natural process or mechanism exists which produces it, or it is so unstable that it decays away in a very short period of time. Examples include

text: technetium

text: -95 and

text: promethium

text: -146. Many of these are found in, and harvested from, spent nuclear fuel assemblies. Some must be manufactured in

text: particle accelerator

text: s.

text: See also Radioisotope thermoelectric generator

text: See also

text: Radioisotope thermoelectric generator

text: Fermium (Fm) is a synthetic element, and thus a standard atomic mass cannot be given. Like all artificial elements, it has no stable isotopes. The first isotope to be discovered (in fallout from nuclear testing) was Fm in 1952. Fm was independently synthesized shortly after the discovery of Fm. There are 20 known radioisotopes ranging in atomic mass from Fm to Fm (Fm is unconfirmed), and 2 nuclear isomers, Fm and Fm. The longest-lived isotope is Fm with a half-life of 100.5 days, and the longest-lived isomer is Fm with a half-life of 1.8 seconds.

text: Fermium

text: (Fm) is a

text: synthetic element

text: , and thus a standard

text: atomic mass

text: stable isotope

text: s. The first

text: isotope

text: to be discovered (in

text: fallout

text: from

text: nuclear testing

text: ) was Fm in 1952. Fm was independently synthesized shortly after the discovery of Fm. There are 20 known

text: radioisotope

text: s ranging in

text: atomic mass

text: from Fm to Fm (Fm is unconfirmed), and 2

text: nuclear isomer

text: s, Fm and Fm. The longest-lived isotope is Fm with a

text: half-life

text: of 100.5 days, and the longest-lived isomer is Fm with a half-life of 1.8 seconds.

text: Brachytherapy dates back to 1901 (shortly after the discovery of radioactivity by Henri Becquerel in 1896) when Pierre Curie suggested to Henri-Alexandre Danlos that a radioactive source could be inserted into a tumour.It was found that the radiation caused the tumour to shrink. Independently, Alexander Graham Bell also suggested the use of radiation in this way. In the early twentieth century, techniques for the application of brachytherapy were pioneered at the Curie institute in Paris by Danlos and at St Luke's and Memorial Hospital in New York by Robert Abbe.

text: Brachytherapy dates back to 1901 (shortly after the discovery of radioactivity by

text: Henri Becquerel

text: in 1896) when

text: Pierre Curie

text: suggested to

text: Henri-Alexandre Danlos

text: that a radioactive source could be inserted into a tumour.It was found that the radiation caused the tumour to shrink. Independently,

text: Alexander Graham Bell

text: also suggested the use of radiation in this way. In the early twentieth century, techniques for the application of brachytherapy were pioneered at the Curie institute in Paris by Danlos and at St Luke's and Memorial Hospital in New York by

text: Robert Abbe

text: The film follows the events that unfold at Tromaville High School in New Jersey, which is conveniently located next to a nuclear power plant. An accident at the nuclear plant is covered up by plant owner Mr Paley who doesn't want the facility shut down by the safety commission. The accident causes a radioactive water leak which ends up gruesomely killing a student at the school after the tainted water reaches the drinking fountain. The gang of the school, called "The Cretins", who were originally part of the honor society, torments the school, and its implied that they have been turned into violent psychopaths by the runoff from the plant. They pick leaves from a radioactive marijuana plant located in the yard of the nuclear plant and sell it to Eddie for $10. At his "indoor bikini beach party" that night, Eddie pressures his friend Warren and Warren's girlfriend Chrissy into smoking the radioactive joint, but it is accidentally ruined by the dancers before anyone else can try it. The mutated drug shows itself to have potent aphrodisiac effects, leading to Warren and Chrissy having sex in Eddie's loft. However, that same night, both of them have disturbing nightmares about hideously mutating, though these effects are seemingly gone by morning. Some time later, Chrissy discovers that she is pregnant, and spits a little monster into a nearby toilet. The creature travels through the water pipes and lands in a barrel filled with radioactive waste, and mutates into a bigger creature. Meanwhile, Warren, tired of the Cretins constant harassment, ends up going on a radiation-fueled rampage, killing two of them, with no memory of the event once he comes to his senses. The Cretins, expelled from the school and cut off from their customer base, assaults the principal and forces him to use the schools Radiation Alarm to cause an evacuation, letting the Cretins bar the building and occupy it. Capturing Chrissy as bait for Warren, the leader of the gang holds her hostage in the basement and plans to kill her in front of Warren, only to be interrupted by the now adult monster.

text: The film follows the events that unfold at Tromaville High School in

text: New Jersey

text: , which is conveniently located next to a

text: nuclear power plant

text: On 3 September 2011 radioactive caesium exceeding the government's safety limit had been detected in tea leaves in Chiba and Saitama prefectures, near Tokyo. This was the ministry's first discovery of radioactive substances beyond legal limits since the tests of food stuffs started in August. These tests were conducted in order to verify local government data using different numbers and kinds of food samples. Tea leaves of one type of tea from Chiba Prefecture contained 2,720 becquerels of radioactive caesium per kilogram, 5 times above the legal safety limit. A maximum of 1,530 becquerels per kilogram was detected in 3 kinds of tea leaves from Saitama Prefecture. Investigations were done to find out where the tea was grown, and to determine how much tea had already made its way to market. Tea producers were asked to recall their products, when necessary. As tea leaves are never directly consumed, tea produced from processed leaves are expected to contain no more than 1/35th the density of caesium (in the case of 2720bq/kg, the tea will show just 77bq/l, below the 200bq/l legal limit at the time)

text: Neutron radiation, alpha radiation, and extremely energetic gamma (> ~20 MeV) can cause nuclear transmutation and induced radioactivity. The relevant mechanisms are neutron activation, alpha absorption, and photodisintegration. A large enough number of transmutations can change macroscopic properties and cause targets to become radioactive themselves, even after the original source is removed.

text: Neutron radiation, alpha radiation, and extremely energetic gamma (> ~20 MeV) can cause

text: nuclear transmutation

text: and

text: induced radioactivity

text: . The relevant mechanisms are

text: neutron activation

text: alpha absorption

text: , and

text: photodisintegration

text: . A large enough number of transmutations can change macroscopic properties and cause targets to become radioactive themselves, even after the original source is removed.

text: The major natural source of radioactivity in plant tissue is potassium: 0.0117% of the naturally occurring potassium is the unstable isotope potassium-40 (K). This isotope decays with a half-life of about 1.25 billion years (4×10 seconds), and therefore the radioactivity of natural potassium is about 31 Bq/g – meaning that, in one gram of the element, about 31 atoms will decay every second. Plants naturally contain radioactive carbon-14 (C), but in a banana containing 15 grams of carbon this would give off only about 3 to 5 beta rays per second. Since a typical banana contains about half a gram of potassium, it will have an activity of roughly 15 Bq. Although the amount in a single banana is small in environmental and medical terms, the radioactivity from a truckload of bananas is capable of causing a false alarm when passed through a Radiation Portal Monitor used to detect possible smuggling of nuclear material at U.S. ports.

text: The major natural source of radioactivity in plant tissue is

text: potassium

text: : 0.0117% of the naturally occurring potassium is the unstable

text: isotope

text: (K). This isotope decays with a

text: half-life

text: of about 1.25 billion years (4×10 seconds), and therefore the

text: radioactivity

text: of natural potassium is about 31

text: Bq

text: g

text: – meaning that, in one gram of the element, about 31

text: atom

text: s will decay every

text: second

text: . Plants naturally contain radioactive

text: (C), but in a banana containing 15 grams of carbon this would give off only about 3 to 5 beta rays per second. Since a typical banana contains about half a gram of potassium, it will have an activity of roughly 15 Bq. Although the amount in a single banana is small in environmental and medical terms, the radioactivity from a truckload of bananas is capable of causing a

text: false alarm

text: when passed through a

text: Radiation Portal Monitor

text: used to detect possible

text: smuggling

text: of

text: nuclear material

text: at U.S. ports.

text: A SPECT measurement consists of 2-dimensional projections of the radioactive source distribution that are obtained with collimator(s) and gamma-detector(s). It is the goal of an image reconstruction algorithm to accurately reconstruct the unknown 3-dimensional distribution of the radioactivity.

text: Certain tests, such as the Schilling test and Urea breath test, use radioisotopes but are not used to produce a specific image.

text: Certain tests, such as the

text: Schilling test

text: and

text: Urea breath test

text: , use radioisotopes but are not used to produce a specific image.

text: ), is penetrating electromagnetic radiation of a kind arising from the radioactive decay of atomic nuclei. It consists of photons in the highest observed range of photon energy. Paul Villard, a French chemist and physicist, discovered gamma radiation in 1900 while studying radiation emitted by radium. In 1903, Ernest Rutherford named this radiation gamma rays. Rutherford had previously discovered two other types of radioactive decay, which he named alpha and beta rays.

text: ), is penetrating electromagnetic radiation of a kind arising from the radioactive decay of atomic nuclei. It consists of

text: photon

text: s in the highest observed range of

text: photon energy

text: Paul Villard

text: , a French chemist and physicist, discovered gamma radiation in 1900 while studying radiation emitted by

text: radium

text: . In 1903,

text: Ernest Rutherford

text: named this radiation gamma rays. Rutherford had previously discovered two other types of

text: radioactive decay

text: , which he named

text: alpha

text: and

text: beta

text: rays.

text: Once the blocks are used up they are removed. Their induced radioactivity qualifies them as low-level waste, and disposal is a tough job.Researchers at University of Bristol earlier showed that radioactive C-14 developed in waste blocks is mainly concentrated on the outer parts of the block. Due to this a lot it can be effectively removed from the blocks. This removal can be done by heating the blocks which will bring C-14 in gaseous form. After removal blocks will be less radioactive and easy to dispose.

text: Once the blocks are used up they are removed. Their

text: induced radioactivity

text: qualifies them as

text: low-level waste

text: , and disposal is a tough job.Researchers at University of Bristol earlier showed that radioactive C-14 developed in waste blocks is mainly concentrated on the outer parts of the block. Due to this a lot it can be effectively removed from the blocks. This removal can be done by heating the blocks which will bring C-14 in gaseous form. After removal blocks will be less radioactive and easy to dispose.

text: In December 2010 Wikileaks published cables that they alleged showed that US officials were ignoring reports of dangerously high levels of radiation  at Forrest's Luiswishi Mine, and implied that uranium was being separated from the ore which purportedly held only copper and cobalt.Groupe Forrest International refuted these rumors, saying that although uranium was present in the copper and cobalt ore from the mine, it was at far too low a grade to be exploited, and radioactivity in the Luiswishi mine was largely lower than the European standards.

text: In December 2010

text: Wikileaks

text: published cables that they alleged showed that US officials were ignoring reports of dangerously high levels of radiation  at Forrest's

text: Luiswishi Mine

text: , and implied that uranium was being separated from the ore which purportedly held only copper and cobalt.Groupe Forrest International refuted these rumors, saying that although uranium was present in the copper and cobalt ore from the mine, it was at far too low a grade to be exploited, and radioactivity in the Luiswishi mine was largely lower than the European standards.

text: The crystal scintillates in response to incident gamma radiation. When a gamma photon leaves the patient (who has been injected with a radioactive pharmaceutical), it knocks an electron loose from an iodine atom in the crystal, and a faint flash of light is produced when the dislocated electron again finds a minimal energy state. The initial phenomenon of the excited electron is similar to the photoelectric effect and (particularly with gamma rays) the Compton effect. After the flash of light is produced, it is detected. Photomultiplier tubes (PMTs) behind the crystal detect the fluorescent flashes (events) and a computer sums the counts. The computer reconstructs and displays a two dimensional image of the relative spatial count density on a monitor. This reconstructed image reflects the distribution and relative concentration of radioactive tracer elements present in the organs and tissues imaged.

text: The crystal

text: scintillate

text: s in response to incident gamma radiation. When a gamma photon leaves the patient (who has been injected with a

text: radioactive pharmaceutical

text: ), it knocks an electron loose from an iodine atom in the crystal, and a faint flash of light is produced when the dislocated electron again finds a minimal energy state. The initial phenomenon of the excited electron is similar to the

text: photoelectric effect

text: and (particularly with gamma rays) the

text: Compton effect

text: . After the flash of light is produced, it is detected.

text: Photomultiplier

text: tubes (PMTs) behind the crystal detect the fluorescent flashes (events) and a computer sums the counts. The computer reconstructs and displays a two dimensional image of the relative spatial count density on a monitor. This reconstructed image reflects the distribution and relative concentration of radioactive tracer elements present in the organs and tissues imaged.

text: His early research focused on an esoteric group of minerals, metamictization Nb-Ta-Ti oxides that are unusual because they have become amorphous due to radiation damage caused by the presence of radioactive decay elements. Over the past forty years, the early study of these unusual minerals has blossomed into a broadly based research program on radiation effects in complex ceramic materials.  This has led to the development of techniques to predict the long-term behavior of materials, such as those used in radioactive waste disposal.  He is the author or co-author of over 700 research publications and the editor or co-editor of 18 monographs, proceedings volumes or special issues of journals. He has published widely in mineralogy, geochemistry, materials science, nuclear materials, physics and chemistry in over 100 different ISI journals. He has been granted a patent for the development of a highly durable material for the immobilization of plutonium from dismantled nuclear weapons.  He is a Founding Editor of the magazine, Elements, which is now supported by 17 earth science societies. He is a Principal Editor for Nano LIFE, an interdisciplinary journal focused on collaboration between physical and medical scientists.  In 2014, he was appointed as one of the Founding Executive Editors of Geochemical Perspective Letters and to the Editorial Board of Applied Physics Reviews.

text: His early research focused on an esoteric group of minerals,

text: metamict

text: ization Nb-Ta-Ti oxides that are unusual because they have become amorphous due to

text: radiation damage

text: caused by the presence of

text: radioactive decay

text: elements. Over the past forty years, the early study of these unusual minerals has blossomed into a broadly based research program on radiation effects in complex ceramic materials.  This has led to the development of techniques to predict the long-term behavior of materials, such as those used in

text: radioactive waste

text: disposal.  He is the author or co-author of over 700 research publications and the editor or co-editor of 18 monographs, proceedings volumes or special issues of journals. He has published widely in mineralogy, geochemistry, materials science, nuclear materials, physics and chemistry in over 100 different ISI journals. He has been granted a patent for the development of a highly durable material for the immobilization of plutonium from dismantled nuclear weapons.  He is a Founding Editor of the magazine, Elements, which is now supported by 17 earth science societies. He is a Principal Editor for Nano LIFE, an interdisciplinary journal focused on collaboration between physical and medical scientists.  In 2014, he was appointed as one of the Founding Executive Editors of Geochemical Perspective Letters and to the Editorial Board of Applied Physics Reviews.

text: The principle behind the use of radioactive tracers is that an atom in a chemical compound is replaced by another atom, of the same chemical element. The substituting atom, however, is a radioactive isotope. This process is often called radioactive labeling. The power of the technique is due to the fact that radioactive decay is much more energetic than chemical reactions. Therefore, the radioactive isotope can be present in low concentration and its presence detected by sensitive radiation detectors such as Geiger counters and scintillation counters. George de Hevesy won the 1943 Nobel Prize for Chemistry "for his work on the use of isotopes as tracers in the study of chemical processes".

text: The principle behind the use of radioactive tracers is that an

text: atom

text: in a

text: chemical compound

text: is replaced by another atom, of the same chemical element. The substituting atom, however, is a radioactive isotope. This process is often called radioactive labeling. The power of the technique is due to the fact that radioactive decay is much more energetic than chemical reactions. Therefore, the radioactive isotope can be present in low concentration and its presence detected by sensitive

text: radiation detector

text: s such as

text: Geiger counter

text: s and

text: scintillation counter

text: s.

text: George de Hevesy

text: won the 1943

text: Nobel Prize for Chemistry

text: "for his work on the use of isotopes as tracers in the study of chemical processes".

text: Because of its wide availability as a drinking-water decontaminant, and high content of potassium iodide, emergency use of it was at first recommended to the Polish government in 1986, after the Chernobyl disaster to replace and block any intake of radioactive , even though it was known to be a non-optimal agent, due to its somewhat toxic free-iodine content. Other sources state that pure potassium iodide solution in water (SSKI) was eventually used for most of the thyroid protection after this accident.  There is "strong scientific evidence" for potassium iodide thyroid protection to help prevent thyroid cancer.  Potassium iodide does not provide immediate protection but can be a component of a general strategy in a radiation emergency.

text: Because of its wide availability as a drinking-water decontaminant, and high content of potassium iodide, emergency use of it was at first recommended to the Polish government in 1986, after the

text: Chernobyl disaster

text: to replace and block any intake of radioactive , even though it was known to be a non-optimal agent, due to its somewhat toxic free-iodine content. Other sources state that pure

text: potassium iodide

text: solution in water (

text: SSKI

text: ) was eventually used for most of the thyroid protection after this accident.  There is "strong scientific evidence" for potassium iodide thyroid protection to help prevent

text: thyroid cancer

text: .  Potassium iodide does not provide immediate protection but can be a component of a general strategy in a radiation emergency.

text: The height of the mast determines the radiation properties. For high power transmitters in the MW range, masts with heights around half of the radiated wavelength are preferred because they focus the radiated power better to the ground than structures with heights of quarter wavelengths, which are preferred for economical reasons for low power medium wave transmitters. A focus of radiated power towards the ground is much desired on frequencies below 3 megahertz, because groundwave propagation is very stable. Masts longer than five eighths of the wavelength are normally not used, because they show bad vertical radiation patterns, so masts for mediumwave transmitters do not normally exceed 300 metres.  For longwave transmitters, however, the construction of masts with heights of half-wave wavelength is generally not economically viable and in most cases impossible. The only longwave radio mast with a height of the half length of the radiated wavelength was the Warszawa Radio Mast at Konstantynów, Poland. At the time of its collapse in 1991 it was the tallest manmade structure in the world, at 646.38 metres (2,120.67 ft) tall, for a wavelength of 1292.76 metres (frequency 232 kHz).  For frequencies below longwave, masts are electrically enlarged by loading coils or capacity hats on the top, because masts of even quarter wavelength would be too high to be practical.

text: The height of the mast determines the radiation properties. For high power transmitters in the MW range, masts with heights around half of the radiated wavelength are preferred because they focus the radiated power better to the ground than structures with heights of quarter wavelengths, which are preferred for economical reasons for low power medium wave transmitters. A focus of radiated power towards the ground is much desired on frequencies below 3

text: megahertz

text: , because groundwave propagation is very stable. Masts longer than five eighths of the wavelength are normally not used, because they show bad vertical radiation patterns, so masts for mediumwave transmitters do not normally exceed 300 metres.  For

text: longwave

text: transmitters, however, the construction of masts with heights of half-wave wavelength is generally not economically viable and in most cases impossible. The only

text: longwave

text: radio mast with a height of the half length of the radiated wavelength was the

text: Warszawa Radio Mast

text: at

text: Konstantynów

text: Poland

text: . At the time of its collapse in 1991 it was the tallest manmade structure in the world, at 646.38 metres (2,120.67 ft) tall, for a wavelength of 1292.76 metres (frequency 232 kHz).  For frequencies below longwave, masts are electrically enlarged by

text: loading coil

text: s or capacity hats on the top, because masts of even quarter wavelength would be too high to be practical.

text: Background radiation is the ionizing radiation present in the environment. Background radiation originates from a variety of sources, both natural and artificial. Sources include cosmic radiation, naturally occurring radioactive materials such as radon, and fallout from nuclear weapons testing and nuclear accidents.

text: Background radiation is the ionizing radiation present in the environment. Background radiation originates from a variety of sources, both natural and artificial. Sources include

text: cosmic radiation

text: , naturally occurring radioactive materials such as

text: radon

text: , and

text: fallout

text: from

text: nuclear weapons testing

text: and

text: nuclear accident

text: s.

text: However, the biological effects of radiation due to radioactive substances were less easy to gauge. This gave the opportunity for many physicians and corporations to market radioactive substances as patent medicines. Examples were radium enema treatments, and radium-containing waters to be drunk as tonics. Marie Curie protested against this sort of treatment, warning that the effects of radiation on the human body were not well understood. Curie later died from aplastic anaemia, likely caused by exposure to ionizing radiation. By the 1930s, after a number of cases of bone necrosis and death of radium treatment enthusiasts, radium-containing medicinal products had been largely removed from the market (radioactive quackery).

text: However, the biological effects of radiation due to radioactive substances were less easy to gauge. This gave the opportunity for many physicians and corporations to market radioactive substances as

text: patent medicine

text: s. Examples were radium

text: enema

text: Marie Curie

text: protested against this sort of treatment, warning that the effects of radiation on the human body were not well understood. Curie later died from

text: aplastic anaemia

text: , likely caused by exposure to ionizing radiation. By the 1930s, after a number of cases of bone necrosis and death of radium treatment enthusiasts, radium-containing medicinal products had been largely removed from the market (

text: radioactive quackery

text: In the 19th century, experimenters began to detect unexpected forms of radiation: Wilhelm Röntgen caused a sensation with his discovery of X-rays in 1895; in 1896 Henri Becquerel discovered that certain kinds of matter emit radiation on their own accord. In 1897, J. J. Thomson discovered the electron, and new radioactive elements found by Marie and Pierre Curie raised questions about the supposedly indestructible atom and the nature of matter. Marie and Pierre coined the term "radioactivity" to describe this property of matter, and isolated the radioactive elements radium and polonium. Ernest Rutherford and Frederick Soddy identified two of Becquerel's forms of radiation with electrons and the element helium. Rutherford identified and named two types of radioactivity and in 1911 interpreted experimental evidence as showing that the atom consists of a dense, positively charged nucleus surrounded by negatively charged electrons. Classical theory, however, predicted that this structure should be unstable. Classical theory had also failed to explain successfully two other experimental results that appeared in the late 19th century. One of these was the demonstration by Albert A. Michelson and Edward W. Morley—known as the Michelson–Morley experiment—which showed there did not seem to be a preferred frame of reference, at rest with respect to the hypothetical luminiferous ether, for describing electromagnetic phenomena. Studies of radiation and radioactive decay continued to be a preeminent focus for physical and chemical research through the 1930s, when the discovery of nuclear fission opened the way to the practical exploitation of what came to be called "atomic" energy.

text: In the 19th century, experimenters began to detect unexpected forms of radiation:

text: Wilhelm Röntgen

text: caused a sensation with his discovery of

text: X-ray

text: s in 1895; in 1896

text: Henri Becquerel

text: discovered that certain kinds of matter emit radiation on their own accord. In 1897,

text: J. J. Thomson

text: discovered the

text: electron

text: , and new radioactive elements found by

text: Marie

text: and

text: Pierre Curie

text: raised questions about the supposedly indestructible atom and the nature of matter. Marie and Pierre coined the term "

text: radioactivity

text: " to describe this property of matter, and isolated the radioactive elements

text: radium

text: and

text: polonium

text: Ernest Rutherford

text: and

text: Frederick Soddy

text: identified two of Becquerel's forms of radiation with electrons and the element

text: helium

text: . Rutherford identified and named two types of radioactivity and in 1911 interpreted experimental evidence as showing that the atom consists of a dense, positively charged nucleus surrounded by negatively charged electrons. Classical theory, however, predicted that this structure should be unstable. Classical theory had also failed to explain successfully two other experimental results that appeared in the late 19th century. One of these was the demonstration by

text: Albert A. Michelson

text: and

text: Edward W. Morley

text: —known as the

text: Michelson–Morley experiment

text: —which showed there did not seem to be a preferred frame of reference, at rest with respect to the hypothetical

text: luminiferous ether

text: , for describing electromagnetic phenomena. Studies of radiation and radioactive decay continued to be a preeminent focus for physical and chemical research through the 1930s, when the discovery of

text: nuclear fission

text: opened the way to the practical exploitation of what came to be called

text: "atomic" energy

text: Most naturally occurring nuclides are stable (about 254; see list at the end of this article); and about 32 more (total of 286) are known radioactives with sufficiently long half-lives (also known) to occur primordially. If the half-life of a nuclide is comparable to, or greater than, the Earth's age (4.5 billion years), a significant amount will have survived since the formation of the Solar System, and then is said to be primordial. It will then contribute in that way to the natural isotopic composition of a chemical element. Primordially present radioisotopes are easily detected with half-lives as short as 700 million years (e.g., U). This is the present limit of detection, as shorter-lived nuclides have not yet been detected undisputedly in nature.

text: Most naturally occurring

text: nuclide

text: s are stable (about 254; see list at the end of this article); and about 32 more (total of 286) are known radioactives with sufficiently long half-lives (also known) to occur primordially. If the half-life of a

text: nuclide

text: is comparable to, or greater than, the Earth's age (4.5 billion years), a significant amount will have survived since the

entity_name: Formation and evolution of the Solar System

text: formation of the Solar System

text: , and then is said to be

text: primordial

text: . It will then contribute in that way to the natural isotopic composition of a chemical element. Primordially present radioisotopes are easily detected with half-lives as short as 700 million years (e.g.,

text: U

text: ). This is the present limit of detection, as shorter-lived nuclides have not yet been detected undisputedly in nature.

text: During 1903 and 1904, English scientists published research about radioactivity in the scientific journal Nature. In the first 1904 issue, R. J. Strutt identified that radium was detected in the gases of Bath springs. In the next issue, Baron Blythswood and H. S. Allen reported evidence of radioactive gases in Buxton mineral springs. Based on the findings, Sjögren recommended Sahlbom to analyze radioactivity in Swedish waters and referred her to Alexander Classen in Aachen. In 1904 Sahlbom was a pupil of Classen and reviewed radioactive techniques. In 1905 the initial iron springs she tested produced data that deviated, including among adjacent springs. In 1906, advocated by spas, she continued to analyze springs in central and southern Sweden. Her findings demonstrated a lack of correlation between the chemical composition of water resources and radioactivity as well as the depth of wells and radioactivity. A correlation between the geology of water resources and radioactivity was exhibited. Sandstone bedrock in Helsingborg and wells in granite displayed among the highest concentrations of radioactive gases. Sahlbom derived that water resources amassed radioactive gases from flowing through bedrock that contained radium. In 1907 Sahlbom and Sjögren published a paper on 59 springs and wells in Sweden. The paper supported evidence of radioactive emanation in mineral waters.

text: During 1903 and 1904, English scientists published research about

text: radioactivity

text: in the scientific journal

text: Nature

text: . In the first 1904 issue,

text: R. J. Strutt

text: identified that

text: radium

text: was detected in the gases of

text: Bath

text: springs. In the next issue,

text: Baron Blythswood

text: and H. S. Allen reported evidence of radioactive gases in

text: Buxton

text: mineral springs. Based on the findings, Sjögren recommended Sahlbom to analyze radioactivity in Swedish waters and referred her to

text: Alexander Classen

text: in

text: Aachen

text: . In 1904 Sahlbom was a pupil of Classen and reviewed radioactive techniques. In 1905 the initial iron springs she tested produced data that deviated, including among adjacent springs. In 1906, advocated by spas, she continued to analyze springs in central and southern Sweden. Her findings demonstrated a lack of correlation between the chemical composition of water resources and radioactivity as well as the depth of wells and radioactivity. A correlation between the geology of water resources and radioactivity was exhibited.

text: Sandstone

text: bedrock

text: in

text: Helsingborg

text: and wells in granite displayed among the highest concentrations of radioactive gases. Sahlbom derived that water resources amassed radioactive gases from flowing through bedrock that contained radium. In 1907 Sahlbom and Sjögren published a paper on 59 springs and wells in Sweden. The paper supported evidence of radioactive emanation in mineral waters.

text: The device consists of two constituent parts, a gamma radiation sensitive inner core which fits inside the spherical tungsten outer collimation sheath. The outside diameter of the device is 140 mm (approx 5 ½ inch) which allows deployment in to hard to reach areas whilst providing a 360 degree view of the area. The inner core is made up of material which changes colour when it is exposed to gamma radiation. Therefore, when the device is deployed inside a radioactive environment the collimation device preferentially allows gamma radiation to pass through the collimation holes which deposits tracks within the inner core. These tracks can then be analysed to provide a 3D visualisation of the radioactive environment predicting both source location and intensity.

text: The device consists of two constituent parts, a

text: gamma radiation

text: sensitive inner core which fits inside the spherical

text: tungsten

text: outer

text: collimation

text: sheath. The outside diameter of the device is 140 mm (approx 5 ½ inch) which allows deployment in to hard to reach areas whilst providing a 360 degree view of the area. The inner core is made up of material which changes colour when it is exposed to gamma radiation. Therefore, when the device is deployed inside a

text: radioactive

text: environment the collimation device preferentially allows gamma radiation to pass through the collimation holes which deposits tracks within the inner core. These tracks can then be analysed to provide a

text: 3D visualisation

text: of the radioactive environment predicting both source location and intensity.

text: In 2013 (two years after the incident), the World Health Organization indicated that the residents of the area who were evacuated were exposed to so little radiation that radiation induced health impacts are likely to be below detectable levels. The health risks in the WHO assessment attributable to the Fukushima radioactivity release were calculated by largely applying the conservative Linear no-threshold model of radiation exposure, a model that assumes even the smallest amount of radiation exposure will cause a negative health effect.

text: In 2013 (two years after the incident), the

text: World Health Organization

text: indicated that the residents of the area who were evacuated were exposed to so little radiation that radiation induced health impacts are likely to be below detectable levels. The health risks in the WHO assessment attributable to the Fukushima radioactivity release were calculated by largely applying the conservative

text: Linear no-threshold

text: model of radiation exposure, a model that assumes even the smallest amount of radiation exposure will cause a negative health effect.

text: The sievert is used for radiation dose quantities such as equivalent dose, effective dose, and committed dose. It is used to represent both the risk of the effect of external radiation from sources outside the body and the effect of internal irradiation due to inhaled or ingested radioactive substances. Conventionally, the sievert is not used for high dose rates of radiation that produce deterministic effects, which is the severity of acute tissue damage that is certain to happen. Such effects are compared to the physical quantity absorbed dose measured by the unit gray (Gy).

text: The sievert is used for radiation dose quantities such as

text: equivalent dose

text: effective dose

text: , and

text: committed dose

text: . It is used to represent both the risk of the effect of external radiation from sources outside the body and the effect of internal irradiation due to inhaled or ingested radioactive substances. Conventionally, the sievert is not used for high dose rates of radiation that produce deterministic effects, which is the severity of acute tissue damage that is certain to happen. Such effects are compared to the physical quantity

text: absorbed dose

text: measured by the unit

text: gray

text: (Gy).

text: Typical ionizing subatomic particles from radioactivity include alpha particles, beta particles and neutrons. Almost all products of radioactive decay are ionizing because the energy of radioactive decay is typically far higher than that required to ionize. Other subatomic ionizing particles which occur naturally are muons, mesons, positrons, neutrons and other particles that constitute the secondary cosmic rays that are produced after primary cosmic rays interact with Earth's atmosphere. Cosmic rays are generated by stars and certain celestial events such as supernova explosions. Cosmic rays may also produce radioisotopes on Earth (for example, carbon-14), which in turn decay and produce ionizing radiation. Cosmic rays and the decay of radioactive isotopes are the primary sources of natural ionizing radiation on Earth referred to as background radiation. Ionizing radiation can also be generated artificially using X-ray tubes, particle accelerators, and any of the various methods that produce radioisotopes artificially.

text: Typical ionizing subatomic particles from radioactivity include

text: alpha particle

text: s,

text: beta particle

text: s and

text: neutron

text: s. Almost all products of radioactive decay are ionizing because the energy of radioactive decay is typically far higher than that required to ionize. Other subatomic ionizing particles which occur naturally are

text: muon

text: s,

text: meson

text: s,

text: positron

text: s, neutrons and other particles that constitute the secondary

text: cosmic ray

text: s that are produced after primary

text: cosmic ray

text: s interact with Earth's atmosphere. Cosmic rays are generated by stars and certain celestial events such as

text: supernova

text: explosions. Cosmic rays may also produce radioisotopes on Earth (for example,

text: ), which in turn decay and produce ionizing radiation.

text: Cosmic ray

text: s and the decay of

text: radioactive

text: isotopes are the primary sources of natural ionizing radiation on Earth referred to as

text: background radiation

text: . Ionizing radiation can also be generated artificially using

text: X-ray tube

text: s,

text: particle accelerators

text: , and any of the various methods that produce

text: radioisotopes

text: artificially.

text: Frequent above-ground nuclear explosions between the 1940s and 1960s scattered a substantial amount of radioactive contamination. Some of this contamination is local, rendering the immediate surroundings highly radioactive, while some of it is carried longer distances as nuclear fallout; some of this material is dispersed worldwide. The increase in background radiation due to these tests peaked in 1963 at about 0.15 mSv per year worldwide, or about 7% of average background dose from all sources. The Limited Test Ban Treaty of 1963 prohibited above-ground tests, thus by the year 2000 the worldwide dose from these tests has decreased to only 0.005 mSv per year.

text: Frequent above-ground nuclear explosions between the 1940s and 1960s scattered a substantial amount of

text: radioactive contamination

text: . Some of this contamination is local, rendering the immediate surroundings highly radioactive, while some of it is carried longer distances as

text: nuclear fallout

text: ; some of this material is dispersed worldwide. The increase in background radiation due to these tests peaked in 1963 at about 0.15 mSv per year worldwide, or about 7% of average background dose from all sources. The

text: Limited Test Ban Treaty

text: of 1963 prohibited above-ground tests, thus by the year 2000 the worldwide dose from these tests has decreased to only 0.005 mSv per year.

text: In Rome Enrico Fermi bombarded heavier elements with neutrons and found the products to be radioactive.  By 1934 Fermi had used neutrons to induce radioactivity in 22 different elements, many of these elements of high atomic number.  Noticing that other experiments with neutrons at his laboratory seemed to work better on a wooden table than a marble table, Fermi suspected that the protons of the wood were slowing the neutrons and so increasing the chance for the neutron to interact with nuclei.  Fermi therefore passed neutrons through paraffin wax to slow them and found that the radioactivity of bombarded elements increased by a hundredfold.   The cross section for interaction with nuclei is much larger for slow neutrons than for fast neutrons.  In 1938 Fermi received the Nobel Prize in Physics "for his demonstrations of the existence of new radioactive elements produced by neutron irradiation, and for his related discovery of nuclear reactions brought about by slow neutrons".

text: In Rome Enrico Fermi bombarded heavier elements with neutrons and found the products to be radioactive.  By 1934 Fermi had used neutrons to induce radioactivity in 22 different elements, many of these elements of high atomic number.  Noticing that other experiments with neutrons at his laboratory seemed to work better on a wooden table than a marble table, Fermi suspected that the protons of the wood were slowing the neutrons and so increasing the chance for the neutron to interact with nuclei.  Fermi therefore passed neutrons through paraffin wax to slow them and found that the radioactivity of bombarded elements increased by a hundredfold.   The

text: cross section

text: for interaction with nuclei is much larger for slow neutrons than for fast neutrons.  In 1938 Fermi received the Nobel Prize in Physics "for his demonstrations of the existence of new radioactive elements produced by neutron irradiation, and for his related discovery of

text: nuclear reaction

text: s brought about by slow neutrons".

text: The Kangaroo's defeat threw him into a deep depression, resulting in Frank becoming a vagrant in New York City. While watching Spider-Man swing by, Frank reflected on his defeat and wished for a means to defeat Spider-Man. Shortly thereafter, Frank was approached by one Dr. Jonas Harrow, who wished to enhance the Kangaroo to a superhuman level. Frank agreed, and after a seven-hour procedure, found himself gifted with air jet-enhanced leaping and punching ability. Harrow wanted to use the Kangaroo as muscle, but the newly empowered Kangaroo resented being anyone's pawn. Smacking Dr. Harrow aside, the Kangaroo leapt away to pursue Spider-Man. Upon finding Spider-Man, the Kangaroo battled the web-slinger, who had underestimated his previously underpowered enemy. As the Kangaroo was gaining the upper-hand, however, Dr. Harrow activated an implant in Oliver's brain which caused him great pain. Forced by Dr. Harrow to obey him or suffer agony, the Kangaroo returned and was then ordered to retrieve a radioactive isotope. While breaking into the Hudson River lab which held the isotope, Frank once again encountered Spider-Man. As the two battled, Spider-Man found himself outmatched, and attempted to convince the Kangaroo of the dangers of the isotope's radiation. Refusing to listen to his enemy, the Kangaroo burst into the room which held the isotope and was reduced to a pile of ashes upon exposure to the radiation.

text: The Kangaroo's defeat threw him into a deep depression, resulting in Frank becoming a vagrant in New York City. While watching Spider-Man swing by, Frank reflected on his defeat and wished for a means to defeat Spider-Man. Shortly thereafter, Frank was approached by one Dr.

text: Jonas Harrow

text: , who wished to enhance the Kangaroo to a superhuman level. Frank agreed, and after a seven-hour procedure, found himself gifted with air jet-enhanced leaping and punching ability. Harrow wanted to use the Kangaroo as muscle, but the newly empowered Kangaroo resented being anyone's pawn. Smacking Dr. Harrow aside, the Kangaroo leapt away to pursue Spider-Man. Upon finding Spider-Man, the Kangaroo battled the web-slinger, who had underestimated his previously underpowered enemy. As the Kangaroo was gaining the upper-hand, however, Dr. Harrow activated an implant in Oliver's brain which caused him great pain. Forced by Dr. Harrow to obey him or suffer agony, the Kangaroo returned and was then ordered to retrieve a radioactive isotope. While breaking into the Hudson River lab which held the isotope, Frank once again encountered Spider-Man. As the two battled, Spider-Man found himself outmatched, and attempted to convince the Kangaroo of the dangers of the isotope's radiation. Refusing to listen to his enemy, the Kangaroo burst into the room which held the isotope and was reduced to a pile of ashes upon exposure to the radiation.

text: Dr. Belinsky was brought to the lab complex of Sergei Krylov, alias the "Presence", a scientific genius who had become one of the most influential men behind the scenes of the Soviet government.  Sergei mentally dominated Tania, and used a Chernobyl-like nuclear disaster to transform Tania into his super-powered thrall with nuclear powers. She battled the Defenders alongside the Presence, and then separated from him. She was later assigned to investigate the Presence's reappearance, and after battling a giant amoeba, she reunited with the Presence. Alongside the Presence, she encountered the Hulk, Darkstar, Crimson Dynamo, Vanguard, Ursa Major, and Professor Phobos. She and the Presence left Earth since their radiation levels were too dangerous for them to remain. Tania and Sergei were eventually revealed to be laboratory subjects on one of the Stranger's laboratory worlds. After regaining their freedom, Tania took the name Starlight, and returned to Earth with the Presence and Jack of Hearts. She battled Quasar and the Fantastic Four, and aided the Presence in his attempt to kill Eon, though she ultimately admitted only doing so because the Presence (the only person who could safely remain around her due to what he did to her, making her radioactive) threatened to abandon her if she did not serve as his henchwoman and lover. She was later seen battling Darkstar and the Black Widow.

text: Dr. Belinsky was brought to the lab complex of Sergei Krylov, alias the "

text: Presence

text: ", a scientific

text: genius

text: who had become one of the most influential men behind the scenes of the Soviet government.  Sergei mentally dominated Tania, and used a

text: Chernobyl

text: -like nuclear disaster to transform Tania into his super-powered thrall with nuclear powers. She battled the Defenders alongside the Presence, and then separated from him. She was later assigned to investigate the Presence's reappearance, and after battling a giant amoeba, she reunited with the Presence. Alongside the Presence, she encountered the Hulk,

text: Darkstar

text: Crimson Dynamo

text: Vanguard

text: Ursa Major

text: , and

text: Professor Phobos

text: . She and the Presence left Earth since their radiation levels were too dangerous for them to remain. Tania and Sergei were eventually revealed to be laboratory subjects on one of the

text: Stranger

text: 's laboratory worlds. After regaining their freedom, Tania took the name Starlight, and returned to Earth with the Presence and

text: Jack of Hearts

text: . She battled

text: Quasar

text: and the

text: Fantastic Four

text: , and aided the Presence in his attempt to kill

text: Eon

text: , though she ultimately admitted only doing so because the Presence (the only person who could safely remain around her due to what he did to her, making her radioactive) threatened to abandon her if she did not serve as his henchwoman and lover. She was later seen battling Darkstar and the

text: Black Widow

text: Film badges used to measure exposure to radioactivity indicated that no observers at N-10,000 had been exposed to more than 0.1 roentgens, but the shelter was evacuated before the radioactive cloud could reach it. The explosion was more efficient than expected and the thermal updraft drew most of the cloud high enough that little fallout fell on the test site. The crater was far more radioactive than expected due to the formation of trinitite, and the crews of the two lead-lined Sherman tanks were subjected to considerable exposure. Anderson's dosimeter and film badge recorded 7 to 10 roentgens, and one of the tank drivers, who made three trips, recorded 13 to 15 roentgens.

text: Film badges used to measure exposure to radioactivity indicated that no observers at N-10,000 had been exposed to more than 0.1

text: roentgens

text: , but the shelter was evacuated before the radioactive cloud could reach it. The explosion was more efficient than expected and the thermal updraft drew most of the cloud high enough that little fallout fell on the test site. The crater was far more radioactive than expected due to the formation of trinitite, and the crews of the two lead-lined Sherman tanks were subjected to considerable exposure. Anderson's dosimeter and film badge recorded 7 to 10 roentgens, and one of the tank drivers, who made three trips, recorded 13 to 15 roentgens.

text: The Department of Defense (DOD) sponsored a series of experiments for Koa: Projects 1.4, 1.7, 1.8, 1.9, 1.12, 2.9, 3.2, 3.6, 5.1, 5.3. 6.4, 6.5, 6.6, 6.9. and 6.11. Project 1.4, which sought to study land craters post detonation for several shots, took ground survey measurements from surface zero out to 2,500 feet (762 meters). Detailed measurements could not be made until four days after the blast due to radiation levels. Using a boat, the majority of the crater was mapped, though some measurements could not be made until 1959 due to radioactivity levels around the Koa blast site. In Project 1.9, the blast-induced pressure through the soil was measured by burying 43 drums at depths ranging from 0 to 20 feet and around 3,000 feet from the Koa blast site. The early radioactive cloud samples, normally collected post-shot as a part of Project 2.8 using a UCRL rocket sampler, were not collected after the Koa test due to technical difficulties. Fallout at high and low altitudes utilizing B-57D and WB-50 aircraft were measured with no technical problems. Project 3.6, which was conducted only on Koa, tested the effects of the blast on reinforced-concrete slabs buried close to surface zero. One station was located at 1,830 feet (558 meters) from the blast site, and the other was located 3,100 feet (945 meters) away. Project 5.2 was designed to measure the radiation levels using film badges on different areas of the aircraft and on the pilot directly. Koa had the lowest average radiation measurements of the eight shots on this project, with aircraft 827 ranging from 0.01-0.02R and aircraft 831 reporting levels between 0.03-0.19R. Unlike in the Cactus test, all nine film badges from both aircraft were successfully recovered and reported.

text: The

text: Department of Defense

text: Radon is a chemical element with symbol Rn and atomic number 86. It is a radioactive, colorless, odorless, tasteless noble gas, occurring naturally as a decay product of radium. Its most stable isotope, Rn, has a half-life of 3.8 days. Radon is one of the densest substances that remains a gas under normal conditions. It is also the only elemental gas under normal conditions that has no stable isotopes, and is considered a health hazard due to its radioactivity. Intense radioactivity has also hindered chemical studies of radon and only a few compounds are known.

text: Radon is a

text: chemical element

text: with symbol Rn and

text: atomic number

text: 86. It is a

text: radioactive

text: , colorless, odorless, tasteless

text: noble gas

text: , occurring naturally as a

text: decay product

text: of

text: radium

text: . Its most stable

text: isotope

text: Rn

text: , has a

text: half-life

text: of 3.8 days. Radon is one of the densest substances that remains a

text: gas

text: under normal conditions. It is also the only elemental gas under normal conditions that has no stable isotopes, and is considered a health hazard due to its radioactivity. Intense radioactivity has also hindered chemical studies of radon and only a few compounds are known.

text: For long duration space travel, radiation can pose an acute health hazard.Exposure to radiation sources such as high-energy, ionizing cosmic rays can result in fatigue, nausea, vomiting, as well as damage to the immune system and changes to the white blood cell count. Over longer durations, symptoms include an increased risk of cancer, plus damage to the eyes, nervous system, lungs and the gastrointestinal tract. On a round-trip Mars mission lasting three years, nearly the entire body would be traversed by high energy nuclei, each of which can cause ionization damage to cells. Fortunately, most such particles are significantly attenuated by the shielding provided by the aluminium walls of a spacecraft, and can be further diminished by water containers and other barriers. However, the impact of the cosmic rays upon the shielding produces additional radiation that can affect the crew. Further research will be needed to assess the radiation hazards and determine suitable countermeasures.

text: For long duration space travel, radiation can pose an

text: acute health hazard

text: .Exposure to radiation sources such as high-energy, ionizing

text: cosmic rays

text: can result in fatigue, nausea, vomiting, as well as damage to the immune system and changes to the

text: white blood cell

text: count. Over longer durations, symptoms include an increased risk of

text: cancer

text: , plus damage to the

text: eye

text: s,

text: nervous system

text: lung

text: s and the

text: gastrointestinal tract

text: . On a round-trip

text: Mars

text: mission lasting three years, nearly the entire body would be traversed by high energy nuclei, each of which can cause ionization damage to cells. Fortunately, most such particles are significantly attenuated by the shielding provided by the aluminium walls of a spacecraft, and can be further diminished by water containers and other barriers. However, the impact of the cosmic rays upon the shielding produces additional radiation that can affect the crew. Further research will be needed to assess the radiation hazards and determine suitable countermeasures.

text: UAEC is responsible for the regulation of the peaceful applications of ionising radiation, with the following specific objectives: (a) Protect the safety of individuals, society, and the environment from the dangers resulting from ionising radiation (b) Provide for the production and use of radiation sources and the management of radioactive waste (c) Provide for compliance with international safety requirements for the use of ionising radiation, radiation protection, and security of radioactive sources.

text: On 26 October 2011 the city of Yokosuka near Tokyo held its annual nuclear accident evacuation-drill. This drill was first held in 2008 when the nuclear-powered aircraft carrier USS George Washington was employed at the US naval base near this city. Some 70 people, residents and firefighters took part in this drill. Firefighters ordered the residents of the city to stay indoors, assuming abnormally high levels of radiation around the US base. Radioactive contamination was controlled in the emergency response center by city-officials. The US Navy refused to take part in all this, because the impossibility of radiation leaking outside the base. However, in December 2011 another drill was scheduled with Yokosuka and other cities to prepare for the possibility that people on board the ship might be exposed to radiation.

text: Researchers at nearby Dickinson Collegewhich had radiation monitoring equipment sensitive enough to detect Chinese atmospheric atomic weapons-testingcollected soil samples from the area for the ensuing two weeks and detected no elevated levels of radioactivity, except after rainfalls (likely due to natural radon plate-out, not the accident). Also, white-tailed deer tongues harvested over  from the reactor subsequent to the accident were found to have significantly higher levels of cesium-137 than in deer in the counties immediately surrounding the power plant. Even then, the elevated levels were still below those seen in deer in other parts of the country during the height of atmospheric weapons testing. Had there been elevated releases of radioactivity, increased levels of iodine-131 and cesium-137 would have been expected to be detected in cattle and goat's milk samples. Yet elevated levels were not found. A later scientific study noted that the official emission figures were consistent with available dosimeter data, though others have noted the incompleteness of this data, particularly for releases early on.

text: Researchers at nearby

text: Dickinson College

text: which had radiation monitoring equipment sensitive enough to detect Chinese atmospheric atomic weapons-testingcollected soil samples from the area for the ensuing two weeks and detected no elevated levels of radioactivity, except after rainfalls (likely due to natural

text: radon

text: plate-out, not the accident). Also, white-tailed deer tongues harvested over  from the reactor subsequent to the accident were found to have significantly higher levels of cesium-137 than in deer in the counties immediately surrounding the power plant. Even then, the elevated levels were still below those seen in deer in other parts of the country during the height of atmospheric weapons testing. Had there been elevated releases of radioactivity, increased levels of iodine-131 and cesium-137 would have been expected to be detected in cattle and goat's milk samples. Yet elevated levels were not found. A later scientific study noted that the official emission figures were consistent with available

text: dosimeter

text: data, though others have noted the incompleteness of this data, particularly for releases early on.

text: Iodine is the heaviest essential element utilized widely by life in biological functions (only tungsten, employed in enzymes by a few species of bacteria, is heavier). Iodine's rarity in many soils, due to initial low abundance as a crust-element, and also leaching of soluble iodide by rainwater, has led to many deficiency problems in land animals and inland human populations. Iodine deficiency affects about two billion people and is the leading preventable cause of intellectual disabilities.  Iodine is required by higher animals, which use it to synthesize thyroid hormones, which contain the element. Because of this function, radioisotopes of iodine are concentrated in the thyroid gland along with nonradioactive iodine. The radioisotope iodine-131, which has a high fission product yield, concentrates in the thyroid, and is one of the most carcinogenic of nuclear fission products.

text: Iodine is the heaviest

text: essential element

text: utilized widely by life in biological functions (only

text: tungsten

text: , employed in enzymes by a few species of bacteria, is heavier). Iodine's rarity in many soils, due to initial low abundance as a crust-element, and also leaching of soluble iodide by rainwater, has led to many deficiency problems in land animals and inland human populations.

text: Iodine deficiency

text: affects about two billion people and is the leading preventable cause of

text: intellectual disabilities

text: .  Iodine is required by higher animals, which use it to synthesize

text: thyroid hormones

text: , which contain the element. Because of this function,

text: radioisotopes

text: of iodine are concentrated in the

text: thyroid gland

text: along with nonradioactive iodine. The radioisotope

text: , which has a high

text: fission product yield

text: , concentrates in the thyroid, and is one of the most

text: carcinogenic

text: of

text: nuclear fission

text: products.

text: There is usually an option to produce audible clicks representing the number of ionization events detected. This is the distinctive sound normally associated with hand held or portable Geiger counters. The purpose of this is to allow the user to concentrate on manipulation of the instrument whilst retaining auditory feedback on the radiation rate.

text: There is usually an option to produce audible

text: clicks

text: representing the number of ionization events detected. This is the distinctive sound normally associated with hand held or portable Geiger counters. The purpose of this is to allow the user to concentrate on manipulation of the instrument whilst retaining auditory feedback on the radiation rate.

text: A sensitivie and simple procedure for the detection and quantitation of soluble complement (C)- fixing immune complexes in sera of patients with various disease states has been developed by utilizing C receptors on Raji cells. These cells lack membrane-bound immunoglobulin but have receptors for IgG Fc, C3b, C3d, and possibly with other C proteins. Uptake experiments showed that both aggregated human gamma globulin (AHG) and 7S IgG bound to receptors for IgG Fc; however, AHG reacted with C bound to cells only via receptors for C and this binding was much more efficient than via IgG Fc receptors. AHG was used as an in vitro model of human immune complexes and its uptake by Raji cells was quantitated by 125I-radiolabeled antihuman IgG. The limit of sensitivity of this test was 6 mug AHG/ml serum. The ability of Raji cells to detect AHG in serum depended on the amount of radioactive antibody used and the size of aggregates. The presence of an excess of C somewhat inhibited binding of AHG containing C to Raji cells. The efficient binding of AHG by receptors for C on Raji cells was used for the detection and quantitation of immune complexes in human sera. Raji cells were incubated with sera to be tested and then reacted with excess radiolabeled antihuman IgG; the amount of radioactivity bound to the washed cells was determined and referred to a standard curve of radioactive antibody uptake by cells previously incubated with increasing amounts of AHG in serum. Thereby immune complexes were detected and quantitated in serum hepatitis, systemic lupus erythematosus, vasculitis, subacute sclerosing panencephalitis, dengue hemorrhagic fever, and malignancies.

text: A sensitivie and simple procedure for the detection and quantitation of soluble complement (C)- fixing immune complexes in sera of patients with various disease states has been developed by utilizing C receptors on Raji cells. These cells lack membrane-bound immunoglobulin but have receptors for IgG Fc,

text: , and possibly with other C proteins. Uptake experiments showed that both aggregated human

text: gamma globulin

text: (AHG) and 7S IgG bound to receptors for IgG Fc; however, AHG reacted with C bound to cells only via receptors for C and this binding was much more efficient than via IgG Fc receptors. AHG was used as an in vitro model of human immune complexes and its uptake by Raji cells was quantitated by 125I-radiolabeled antihuman IgG. The limit of sensitivity of this test was 6 mug AHG/ml serum. The ability of Raji cells to detect AHG in serum depended on the amount of radioactive antibody used and the size of aggregates. The presence of an excess of C somewhat inhibited binding of AHG containing C to Raji cells. The efficient binding of AHG by receptors for C on Raji cells was used for the detection and quantitation of immune complexes in human sera. Raji cells were incubated with sera to be tested and then reacted with excess radiolabeled antihuman IgG; the amount of radioactivity bound to the washed cells was determined and referred to a standard curve of radioactive antibody uptake by cells previously incubated with increasing amounts of AHG in serum. Thereby immune complexes were detected and quantitated in

text: serum hepatitis

text: systemic lupus erythematosus

text: vasculitis

text: subacute sclerosing panencephalitis

text: dengue hemorrhagic fever

text: , and

text: malignancies

text: There is an increasing concern about radioactive contamination around the power plant. Several hotspots were discovered in the region, as the radiation monitoring effort was extended in recent years.

text: The energy and the type of the ionizing radiation emitted by a radioactive substance are also important factors in determining its threat to humans. The chemical properties of the radioactive element will determine how mobile the substance is and how likely it is to spread into the environment and contaminate humans. This is further complicated by the fact that many radioisotopes do not decay immediately to a stable state but rather to radioactive decay products within a decay chain before ultimately reaching a stable state.

text: The energy and the type of the

text: ionizing radiation

text: emitted by a radioactive substance are also important factors in determining its threat to humans. The chemical properties of the radioactive

text: element

text: will determine how mobile the substance is and how likely it is to spread into the environment and

text: contaminate

text: humans. This is further complicated by the fact that many radioisotopes do not decay immediately to a stable state but rather to radioactive

text: decay product

text: s within a

text: decay chain

text: before ultimately reaching a stable state.

text: Radioactive substances can harm human health via (i) local skin contamination, (ii) internal exposure due to ingestion of radioactive isotopes, and (iii) external overexposure by β-activity and γ-radiation. Together with radium and transuranium elements, actinium is one of the most dangerous radioactive poisons with high specific α-activity. The most important feature of actinium is its ability to accumulate and remain in the surface layer of skeletons. At the initial stage of poisoning, actinium accumulates in the liver. Another danger of actinium is that it undergoes radioactive decay faster than being excreted. Adsorption from the digestive tract is much smaller (~0.05%) for actinium than radium.

text: Radioactive substances can harm human health via (i) local skin contamination, (ii) internal exposure due to ingestion of radioactive isotopes, and (iii) external overexposure by

text: β-activity

text: and

text: γ-radiation

text: . Together with radium and transuranium elements, actinium is one of the most dangerous radioactive poisons with high specific

text: α-activity

text: . The most important feature of actinium is its ability to accumulate and remain in the surface layer of

text: skeleton

text: s. At the initial stage of poisoning, actinium accumulates in the

text: liver

text: . Another danger of actinium is that it undergoes radioactive decay faster than being excreted.

text: Adsorption

text: from the digestive tract is much smaller (~0.05%) for actinium than radium.

text: A radioisotope thermoelectric generator (RTG, RITEG) is an electrical generator that uses an array of thermocouples to convert the heat released by the decay of a suitable radioactive material into electricity by the Seebeck effect. This generator has no moving parts.

text: A radioisotope thermoelectric generator (RTG, RITEG) is an

text: electrical generator

text: that uses an array of

text: thermocouple

text: s to convert the

text: heat released by the decay

text: of a suitable

text: radioactive

text: material into

text: electricity

text: by the

text: Seebeck effect

text: . This generator has no moving parts.

text: There is no consensus for a definition distinguishing between X-rays and gamma rays. One common practice is to distinguish between the two types of radiation based on their source: X-rays are emitted by electrons, while gamma rays are emitted by the atomic nucleus. This definition has several problems: other processes also can generate these high-energy photons, or sometimes the method of generation is not known. One common alternative is to distinguish X- and gamma radiation on the basis of wavelength (or, equivalently, frequency or photon energy), with radiation shorter than some arbitrary wavelength, such as 10 m (0.1 Å), defined as gamma radiation.This criterion assigns a photon to an unambiguous category, but is only possible if wavelength is known. (Some measurement techniques do not distinguish between detected wavelengths.) However, these two definitions often coincide since the electromagnetic radiation emitted by X-ray tubes generally has a longer wavelength and lower photon energy than the radiation emitted by radioactive nuclei.Occasionally, one term or the other is used in specific contexts due to historical precedent, based on measurement (detection) technique, or based on their intended use rather than their wavelength or source.Thus, gamma-rays generated for medical and industrial uses, for example radiotherapy, in the ranges of 6–20 MeV, can in this context also be referred to as X-rays.

text: There is no consensus for a definition distinguishing between X-rays and gamma rays. One common practice is to distinguish between the two types of radiation based on their source: X-rays are emitted by

text: electron

text: s, while gamma rays are emitted by the

text: atomic nucleus

text: . This definition has several problems: other processes also can generate these high-energy photons, or sometimes the method of generation is not known. One common alternative is to distinguish X- and gamma radiation on the basis of wavelength (or, equivalently, frequency or photon energy), with radiation shorter than some arbitrary wavelength, such as 10 m (0.1

text: Å

text: ), defined as gamma radiation.This criterion assigns a photon to an unambiguous category, but is only possible if wavelength is known. (Some measurement techniques do not distinguish between detected wavelengths.) However, these two definitions often coincide since the electromagnetic radiation emitted by

text: X-ray tube

text: s generally has a longer wavelength and lower photon energy than the radiation emitted by

text: radioactive

text: nuclei

text: .Occasionally, one term or the other is used in specific contexts due to historical precedent, based on measurement (detection) technique, or based on their intended use rather than their wavelength or source.Thus, gamma-rays generated for medical and industrial uses, for example

text: radiotherapy

text: , in the ranges of 6–20

text: MeV

text: , can in this context also be referred to as X-rays.

text: Bomb development called for large detectors of ionising radiation, whose response is proportional to the energy released in the detector and follows rapid changes in radiation intensity.  From the earliest research on radioactivity, radiation had been measured in terms of Ionisation, but existing Ionisation chambers were slow to respond to changes.  To address this problem, Rossi and Staub carried out a careful analysis of the pulses that result when individual charged particles create ions within an ionisation chamber.  They realised that the high mobility of free electrons removed from ionised atoms means that the pulses produced by single particles can be very brief.  With James S. Allen, Rossi found gas mixtures of high electron mobility and low electron attachment.  On the basis of these investigations, Allen and Rossi invented the "fast ionisation chamber", which they patented after the war.  It was a crucial factor in the success of the Manhattan Project and became widely used in postwar research on particle physics.<ref name='MOMENTS pp. 76-78' />

text: Bomb development called for large detectors of ionising radiation, whose response is proportional to the energy released in the detector and follows rapid changes in radiation intensity.  From the

text: earliest research on radioactivity

text: , radiation had been measured in terms of

text: Ionisation

text: , but existing

text: Ionisation chamber

text: s were slow to respond to changes.  To address this problem, Rossi and Staub carried out a careful analysis of the pulses that result when individual charged particles create ions within an ionisation chamber.  They realised that the high

text: mobility

text: of free electrons removed from ionised atoms means that the pulses produced by single particles can be very brief.  With James S. Allen, Rossi found gas mixtures of high electron mobility and low

text: electron attachment

text: .  On the basis of these investigations, Allen and Rossi invented the "fast ionisation chamber", which they patented after the war.  It was a crucial factor in the success of the Manhattan Project and became widely used in postwar research on particle physics.<ref name='MOMENTS pp. 76-78' />

text: These temporary workers often have several motives for working under dangerous conditions, which may be high in radioactivity: most often cited are "high wages and a sense of duty", but they also do not comprehend the grave risks involved.  For example, one worker interviewed by The Guardian worked temporarily to assist his mother financially, which paid more than truck driving, but he did not realise until after the project completed that he'd been exposed to twice the radiation dose allowed by law.  Like all those who depend on casual work for survival, some workers may have alcohol abuse or have other personal issues that make them unsuitable for permanent work.  After a 1992 recession, some workers jumped for scarce work at the Fukushima nuclear power plant.  In 2011, they were paid the equivalent of $127 per day—much more than many other unskilled labor jobs, but a fraction of what the TEPCO staff earned.

text: These temporary workers often have several

text: motives

text: for working under dangerous conditions, which may be high in

text: radioactivity

text: : most often cited are "high wages and a sense of duty", but they also do not comprehend the grave risks involved.  For example, one worker interviewed by The Guardian worked temporarily to assist his mother financially, which paid more than

text: truck driving

text: , but he did not realise until after the project completed that he'd been exposed to twice the

text: radiation dose

text: allowed by law.  Like all those who depend on casual work for survival, some workers may have

text: alcohol abuse

text: or have other personal issues that make them unsuitable for permanent work.  After a 1992 recession, some workers jumped for scarce work at the

text: Fukushima nuclear power plant

text: .  In 2011, they were paid the equivalent of $127 per day—much more than many other

text: unskilled labor

text: jobs, but a fraction of what the TEPCO staff earned.

text: In 1896, Henri Becquerel was investigating phosphorescence in uranium salts when he discovered a new phenomenon which came to be called radioactivity. He, Pierre Curie and Marie Curie began investigating the phenomenon. In the process, they isolated the element radium, which is highly radioactive. They discovered that radioactive materials produce intense, penetrating rays of three distinct sorts, which they labeled alpha, beta, and gamma after the Greek letters. Some of these kinds of radiation could pass through ordinary matter, and all of them could be harmful in large amounts. All of the early researchers received various radiation burns, much like sunburn, and thought little of it.

text: In 1896,

text: Henri Becquerel

text: was investigating

text: phosphorescence

text: in

text: uranium

text: salts when he discovered a new phenomenon which came to be called

text: radioactivity

text: . He,

text: Pierre Curie

text: and

text: Marie Curie

text: began investigating the phenomenon. In the process, they isolated the element

text: radium

text: , which is highly radioactive. They discovered that radioactive materials produce intense, penetrating rays of three distinct sorts, which they labeled alpha, beta, and gamma after the

text: Greek letters

text: . Some of these kinds of radiation could pass through ordinary matter, and all of them could be harmful in large amounts. All of the early researchers received various

text: radiation burn

text: s, much like

text: sunburn

text: , and thought little of it.

text: On February 15, 2013, Governor Jay Inslee announced that a tank storing radioactive waste at the site had been leaking liquids on average of 150 to 300 gallons per year. He said that the leak posed no immediate health risk to the public, but said that should not be an excuse for not doing anything. On February 22, 2013, the Governor stated that "6 more tanks at Hanford site" were "leaking radioactive waste" , there are 177 tanks at Hanford, 149 of which have a single shell. Historically single shell tanks were used for storing radioactive liquid waste and designed to last 20 years. By 2005, some liquid waste was transferred from single shell tanks to (safer) double shell tanks. A substantial amount of residue remains in the older single shell tanks with one containing an estimated 447,000 gallons of radioactive sludge, for example. It is believed that up to six of these "empty" tanks are leaking. Two tanks are reportedly leaking at a rate of 300 gallons (1,136 liters) per year each, while the remaining four tanks are leaking at a rate of 15 gallons (57 liters) per year each.

text: On February 15, 2013, Governor

text: Jay Inslee

text: announced that a tank storing

text: radioactive waste

text: at the site had been leaking liquids on average of 150 to 300 gallons per year. He said that the leak posed no immediate health risk to the public, but said that should not be an excuse for not doing anything. On February 22, 2013, the Governor stated that "6 more tanks at Hanford site" were "leaking radioactive waste" , there are 177 tanks at Hanford, 149 of which have a single shell. Historically single shell tanks were used for storing radioactive liquid waste and designed to last 20 years. By 2005, some liquid waste was transferred from single shell tanks to (safer) double shell tanks. A substantial amount of residue remains in the older single shell tanks with one containing an estimated 447,000 gallons of radioactive sludge, for example. It is believed that up to six of these "empty" tanks are leaking. Two tanks are reportedly leaking at a rate of 300 gallons (1,136 liters) per year each, while the remaining four tanks are leaking at a rate of 15 gallons (57 liters) per year each.

text: The distinction between X-rays and gamma rays has changed in recent decades. Originally, the electromagnetic radiation emitted by X-ray tubes almost invariably had a longer wavelength than the radiation (gamma rays) emitted by radioactive nuclei. Older literature distinguished between X- and gamma radiation on the basis of wavelength, with radiation shorter than some arbitrary wavelength, such as 10 m, defined as gamma rays.However, with artificial sources now able to duplicate any electromagnetic radiation that originates in the nucleus, as well as far higher energies, the wavelengths characteristic of radioactive gamma ray sources vs. other types, now completely overlap. Thus, gamma rays are now usually distinguished by their origin: X-rays are emitted by definition by electrons outside the nucleus, while gamma rays are emitted by the nucleus. Exceptions to this convention occur in astronomy, where gamma decay is seen in the afterglow of certain supernovas, but radiation from high energy processes known to involve other radiation sources than radioactive decay is still classed as gamma radiation.

text: The distinction between

text: X-ray

text: s and gamma rays has changed in recent decades. Originally, the electromagnetic radiation emitted by

text: X-ray tube

text: s almost invariably had a longer

text: wavelength

text: than the radiation (gamma rays) emitted by

text: radioactive

text: nuclei

text: . Older literature distinguished between X- and gamma radiation on the basis of wavelength, with radiation shorter than some arbitrary wavelength, such as 10 m, defined as gamma rays.However, with artificial sources now able to duplicate any electromagnetic radiation that originates in the nucleus, as well as far higher energies, the wavelengths characteristic of radioactive gamma ray sources vs. other types, now completely overlap. Thus, gamma rays are now usually distinguished by their origin:

text: X-ray

text: s are emitted by definition by

text: electron

text: s outside the nucleus, while gamma rays are emitted by the

text: nucleus

text: . Exceptions to this convention occur in astronomy, where gamma decay is seen in the afterglow of certain supernovas, but radiation from high energy processes known to involve other radiation sources than radioactive decay is still classed as gamma radiation.

text: If these features are volcanic in origin, it is "'literally going to make geologists rewrite the textbooks about the moon'". According to the current scientific theories, the Moon's small size means that its mantle should have fully solidified by about 1 billion years ago, which is backed up by seismic data. This would prevent any further geological action by the Moon's interior. A recent (in geological terms) eruption would indicate that the Moon has cooled much more slowly than thought, possibly due to heat released from radioactive decay of radioisotopes in the Moon.

text: If these features are volcanic in origin, it is "'literally going to make geologists rewrite the textbooks about the moon'". According to the current scientific theories, the Moon's small size means that its

text: mantle

text: should have fully solidified by about 1 billion years ago, which is backed up by seismic data. This would prevent any further geological action by the Moon's interior. A recent (in geological terms) eruption would indicate that the Moon has cooled much more slowly than thought, possibly due to heat released from

text: radioactive decay

text: of radioisotopes in the Moon.

text: Carbonado exhibits strong luminescence (photoluminescence and cathodoluminescence) induced by nitrogen and by vacancies existing in the crystal lattice. Luminescence halos are present around radioactive inclusions, and it is suggested that the radiation damage occurred after formation of the carbonados, an observation perhaps pertinent to the radiation hypothesis listed below.

text: Carbonado exhibits strong luminescence (

text: photoluminescence

text: and

text: cathodoluminescence

text: ) induced by

text: nitrogen

text: and by

text: vacancies

text: existing in the crystal lattice. Luminescence halos are present around radioactive inclusions, and it is suggested that the radiation damage occurred after formation of the carbonados, an observation perhaps pertinent to the radiation hypothesis listed below.

text: It is now known by direct observation that much of the light curve (the graph of luminosity as a function of time) after the explosion of a Type II Supernova such as SN 1987A is provided its energy by those predicted radioactive decays. Although the luminous emission consists of optical photons, it is the radioactive power absorbed by the ejected gases that keeps the remnant hot enough to radiate light. The radioactive decay of Ni through its daughters Co to Fe produces gamma-ray photons , primarily of 847keV and 1238keV, that are absorbed and dominate the heating and thus the luminosity of the ejecta at intermediate times (several weeks) to late times (several months). Energy for the peak of the light curve of SN1987A was provided by the decay of Ni to Co (half life 6 days) while energy for the later light curve in particular fit very closely with the 77.3 day half-life of Co decaying to Fe. Later measurements by space gamma-ray telescopes of the small fraction of the Co  and Co gamma rays that escaped the SN 1987A remnant without absorption confirmed earlier predictions that those two radioactive nuclei were the power sources.

text: It is now known by direct observation that much of the

text: light curve

text: (the graph of luminosity as a function of time) after the explosion of a

text: Type II Supernova

text: such as SN 1987A is provided its energy by those predicted

text: radioactive decay

text: s. Although the luminous emission consists of optical photons, it is the radioactive power absorbed by the ejected gases that keeps the remnant hot enough to radiate light. The

text: radioactive decay

text: of

text: Ni

text: through its daughters

text: Co

text: to

text: Fe

text: produces gamma-ray

text: photon

text: s , primarily of 847keV and 1238keV, that are absorbed and dominate the heating and thus the luminosity of the ejecta at intermediate times (several weeks) to late times (several months). Energy for the peak of the light curve of SN1987A was provided by the decay of

text: Ni

text: to Co (half life 6 days) while energy for the later light curve in particular fit very closely with the 77.3 day half-life of

text: Co

text: decaying to Fe. Later measurements by space gamma-ray telescopes of the small fraction of the Co  and Co gamma rays that escaped the

text: SN 1987A

text: remnant without absorption confirmed earlier predictions that those two radioactive nuclei were the power sources.

text: Although it cannot be predicted whether any given atom of a radioactive substance will decay at any given time, the decay products of a radioactive substance are extremely predictable. Because of this, decay products are important to scientists in many fields who need to know the quantity or type of the parent product. Such studies are done to measure pollution levels (in and around nuclear facilities) and for other matters.

text: Radioisotope heater units (RHU) are small devices that provide heat through radioactive decay. They are similar to tiny radioisotope thermoelectric generators (RTG) and normally provide about one watt of heat each, derived from the decay of a few grams of plutonium-238—although other radioactive isotopes could be used. The heat produced by these RHUs is given off continuously for several decades and, theoretically, for up to a century or more.

text: Radioisotope heater units (RHU) are small devices that provide heat through

text: radioactive decay

text: . They are similar to tiny

text: radioisotope thermoelectric generator

text: s (RTG) and normally provide about one watt of heat each, derived from the decay of a few grams of

text: —although other

text: radioactive isotopes

text: could be used. The heat produced by these RHUs is given off continuously for several decades and, theoretically, for up to a century or more.

text: There are naturally occurring radioactive materials (NORM), for example radium, radon, uranium, and thorium, in shale deposits. Brine co-produced and brought to the surface along with the oil and gas sometimes contains naturally occurring radioactive materials; brine from many shale gas wells, contains these radioactive materials. When NORM is concentrated or exposed by human activities, such as hydraulic fracturing, EPA classifies it as TENORM (technologically enhanced naturally occurring radioactive material).

text: There are

text: s (NORM), for example

text: radium

text: radon

text: uranium

text: , and

text: thorium

text: , in shale deposits. Brine co-produced and brought to the surface along with the oil and gas sometimes contains naturally occurring radioactive materials; brine from many shale gas wells, contains these radioactive materials. When NORM is concentrated or exposed by human activities, such as hydraulic fracturing, EPA classifies it as TENORM (technologically enhanced naturally occurring radioactive material).

text: All other iodine radioisotopes have half-lives less than 60 days, and four of these are used as tracers and therapeutic agents in medicine. These are I, I, I, and I. All industrial production of radioactive iodine isotopes involves these four useful radionuclides.

text: The Piqua Nuclear Power Facility was a nuclear power plant which operated just outside the southern city limits of Piqua, Ohio in the United States.  The plant contained a 45.5-megawatt (thermal) organically cooled and moderated nuclear reactor (terphenyl, a biphenyl like oil) .  The Piqua facility was built and operated between 1963 and 1966 as a demonstration project by the Atomic Energy Commission.  The facility ceased operation in 1966.  It was dismantled between 1967 and 1969, and the radioactive coolant and most other radioactive materials were removed. The remaining radioactive structural components of the reactor were entombed in the reactor vessel under sand and concrete.

text: The Piqua Nuclear Power Facility was a

text: nuclear power plant

text: which operated just outside the southern city limits of

text: Piqua, Ohio

text: in the

text: United States

text: .  The plant contained a 45.5-

text: megawatt

text: (thermal) organically cooled and moderated nuclear reactor (

text: terphenyl

text: , a

text: biphenyl

text: like oil) .  The Piqua facility was built and operated between 1963 and 1966 as a demonstration project by the

text: Atomic Energy Commission

text: .  The facility ceased operation in 1966.  It was dismantled between 1967 and 1969, and the radioactive coolant and most other radioactive materials were removed. The remaining radioactive structural components of the reactor were entombed in the reactor vessel under sand and concrete.

text: Radiography started in 1895 with the discovery of X-rays (later also called Röntgen rays after the man who first described their properties in detail), a type of electromagnetic radiation. Soon after the discovery of X-rays, radioactivity was discovered. By using radioactive sources such as radium, far higher photon energies could be obtained than those from normal X-ray generators. Soon these found various applications, with one of the earliest users being Loughborough College. X-rays and gamma rays were put to use very early, before the dangers of ionizing radiation were discovered. After World War II new isotopes such as caesium-137, iridium-192 and cobalt-60 became available for industrial radiography, and the use of radium and radon decreased.

text: Radiography started in 1895 with the discovery of

text: X-ray

text: s (later also called

text: Röntgen

text: rays after the man who first described their properties in detail), a type of

text: electromagnetic radiation

text: . Soon after the discovery of X-rays,

text: radioactivity

text: was discovered. By using radioactive sources such as

text: radium

text: , far higher

text: photon

text: energies could be obtained than those from normal

text: X-ray generator

text: s. Soon these found various applications, with one of the earliest users being

text: Loughborough College

text: . X-rays and gamma rays were put to use very early, before the dangers of ionizing radiation were discovered. After

text: World War II

text: new isotopes such as

text: and

text: became available for industrial radiography, and the use of radium and radon decreased.

text: Other radioisotopes have an affinity for particular tissues, such as plutonium into bone, and may be retained there for years in spite of their foreign nature.In summary, not all radiation is harmful. The radiation can be absorbed through multiple pathways, varying due to the circumstances of the situation. If the radioactive material is necessary, it can be ingested orally via stable isotopes of specific elements. This is only suggested to those that have a lack of these elements however, because radioactive material can go from healthy to harmful with very small amounts. The most harmful way to absorb radiation is that of absorption because it is almost impossible to control how much will enter the body.

text: The pioneers of radioactivity were chemist Bertram B. Boltwood and the energetic Rutherford. Boltwood had conducted studies of radioactive materials as a consultant, and when Rutherford lectured at Yale in 1904, Boltwood was inspired to describe the relationships between elements in various decay series. Late in 1904, Rutherford took the first step toward radiometric dating by suggesting that the alpha particles released by radioactive decay could be trapped in a rocky material as helium atoms. At the time, Rutherford was only guessing at the relationship between alpha particles and helium atoms, but he would prove the connection four years later.

text: The pioneers of radioactivity were chemist

text: Bertram B. Boltwood

text: and the energetic Rutherford. Boltwood had conducted studies of radioactive materials as a consultant, and when Rutherford lectured at Yale in 1904, Boltwood was inspired to describe the relationships between elements in various decay series. Late in 1904, Rutherford took the first step toward radiometric dating by suggesting that the

text: alpha particle

text: s released by radioactive decay could be trapped in a rocky material as

text: helium

text: atoms. At the time, Rutherford was only guessing at the relationship between alpha particles and helium atoms, but he would prove the connection four years later.

text: A bone-seeking radioisotope is a radioactive substance that is given through a vein, and collects in bone cells and in tumor cells that have spread to the bone. It kills cancer cells by giving off low-level radiation.

text: A bone-seeking radioisotope is a

text: radioactive

text: substance that is given through a

text: vein

text: , and collects in

text: bone cells

text: and in

text: tumor cells

text: that have spread to the

text: bone

text: . It kills

text: cancer cells

text: by giving off

text: low-level

text: radiation

text: All radioactivity of F-FDG, both the 20% which is rapidly excreted in the first several hours of urine which is made after the exam, and the 80% which remains in the patient, decays with a half-life of 110 minutes (just under 2 hours). Thus, within 24 hours (13 half-lives after the injection), the radioactivity in the patient and in any initially voided urine which may have contaminated bedding or objects after the PET exam, will have decayed to 2 = 1/8192 of the initial radioactivity of the dose. In practice, patients who have been injected with F-FDG are told to avoid the close vicinity of especially radiation-sensitive persons such as infants, children and pregnant women, for at least 12 hours (7 half-lives, or decay to 1/128th the initial radioactive dose).

text: One point of concern has been the standard of radiation emission from 10,000 years to 1,000,000 years into the future. On August 9, 2005, the United States Environmental Protection Agency proposed a limit of 350 millirem per year for that period. In October 2007, the DOE issued a draft of the Supplemental Environmental Impact Statement in which it shows that for the first 10,000 years mean public dose would be 0.24 mrem/year and that thereafter to 1,000,000 years the median public dose would be 0.98 mrem/year, both of which are substantially below the proposed EPA limit. For comparison, a hip x-ray results in a dose around 83 mrem and a CT head or chest scan results in around 1,110 mrem. Annually, in the United States, an individual's doses from background radiation is about 350 mrem, although some places get more than twice that.

text: One point of concern has been the standard of radiation emission from 10,000 years to 1,000,000 years into the future. On August 9, 2005, the

text: proposed a limit of 350 millirem per year for that period. In October 2007, the DOE issued a draft of the Supplemental Environmental Impact Statement in which it shows that for the first 10,000 years mean public

text: dose

text: would be 0.24 mrem/year and that thereafter to 1,000,000 years the median public dose would be 0.98 mrem/year, both of which are substantially below the proposed EPA limit. For comparison, a hip x-ray results in a dose around 83 mrem and a CT head or chest scan results in around 1,110 mrem. Annually, in the United States, an individual's doses from background radiation is about 350 mrem, although some places get more than twice that.

text: Three Mile Island-2 was an accident of a completely different type from Chernobyl.  Chernobyl was a design flaw-caused power excursion causing a steam explosion resulting in a graphite fire, uncontained, which lofted radioactive smoke high into the atmosphere; TMI was a slow, undetected leak that lowered the water level around the nuclear fuel, resulting in over a third of it shattering when refilled rapidly with coolant.  Unlike Chernobyl, TMI-2's reactor vessel did not fail and contained almost all of the radioactive material.  Containment at TMI did not fail.  A small quantity of radioactive gases from the leak were vented into the atmosphere through specially designed filters under operator control.  A government report concluded that the accident caused no increase in cancer rates for local residents.

text: Three Mile Island-2 was an accident of a completely different type from Chernobyl.  Chernobyl was a design flaw-caused power excursion causing a steam explosion resulting in a graphite fire, uncontained, which lofted radioactive smoke high into the atmosphere; TMI was a slow, undetected leak that lowered the water level around the nuclear fuel, resulting in over a third of it shattering when refilled rapidly with coolant.  Unlike Chernobyl, TMI-2's reactor vessel did not fail and contained almost all of the radioactive material.

text: Containment

text: at TMI did not fail.  A small quantity of radioactive gases from the leak were vented into the atmosphere through specially designed filters under operator control.  A government report concluded that the accident caused no increase in cancer rates for local residents.

text: Probes for northern blotting are composed of nucleic acids with a complementary sequence to all or part of the RNA of interest, they can be DNA, RNA, or oligonucleotides with a minimum of 25 complementary bases to the target sequence.  RNA probes (riboprobes) that are transcribed in vitro are able to withstand more rigorous washing steps preventing some of the background noise.  Commonly cDNA is created with labelled primers for the RNA sequence of interest to act as the probe in the northern blot.  The probes must be labelled either with radioactive isotopes (P) or with chemiluminescence in which alkaline phosphatase or horseradish peroxidase (HRP) break down chemiluminescent substrates producing a detectable emission of light.  The chemiluminescent labelling can occur in two ways: either the probe is attached to the enzyme, or the probe is labelled with a ligand (e.g. biotin) for which the ligand (e.g., avidin or streptavidin) is attached to the enzyme (e.g. HRP).  X-ray film can detect both the radioactive and chemiluminescent signals and many researchers prefer the chemiluminescent signals because they are faster, more sensitive, and reduce the health hazards that go along with radioactive labels.  The same membrane can be probed up to five times without a significant loss of the target RNA.

text: Probes for northern blotting are composed of nucleic acids with a complementary sequence to all or part of the RNA of interest, they can be DNA, RNA, or oligonucleotides with a minimum of 25 complementary bases to the target sequence.  RNA probes (riboprobes) that are transcribed in vitro are able to withstand more rigorous washing steps preventing some of the background noise.  Commonly cDNA is created with labelled primers for the RNA sequence of interest to act as the probe in the northern blot.  The probes must be labelled either with radioactive isotopes (P) or with

text: chemiluminescence

text: in which

text: alkaline phosphatase

text: or

text: horseradish peroxidase

text: (HRP) break down chemiluminescent substrates producing a detectable emission of light.  The chemiluminescent labelling can occur in two ways: either the probe is attached to the enzyme, or the probe is labelled with a ligand (e.g.

text: biotin

text: ) for which the ligand (e.g.,

text: avidin

text: or

text: streptavidin

text: ) is attached to the enzyme (e.g. HRP).  X-ray film can detect both the radioactive and chemiluminescent signals and many researchers prefer the chemiluminescent signals because they are faster, more sensitive, and reduce the health hazards that go along with radioactive labels.  The same membrane can be probed up to five times without a significant loss of the target RNA.

text: Such contamination presents a hazard because of the radioactive decay of the contaminants, which emit harmful ionising radiation such as alpha particles or beta particles, gamma rays or neutrons. The degree of hazard is determined by the concentration of the contaminants, the energy of the radiation being emitted, the type of radiation, and the proximity of the contamination to organs of the body. It is important to be clear that the contamination gives rise to the radiation hazard, and the terms "radiation" and "contamination" are not interchangeable.

text: Such contamination presents a hazard because of the

text: radioactive decay

text: of the contaminants, which emit harmful

text: ionising radiation

text: such as

text: alpha particle

text: s or

text: beta particle

text: s,

text: gamma ray

text: s or

text: neutron

text: s. The degree of hazard is determined by the concentration of the contaminants, the energy of the radiation being emitted, the type of radiation, and the proximity of the contamination to organs of the body. It is important to be clear that the contamination gives rise to the radiation hazard, and the terms "radiation" and "contamination" are not interchangeable.

text: In the first six days after Baker, when radiation levels were highest, 4,900 men boarded target ships. Sailors tried to scrub off the radioactivity with brushes, water, soap, and lye. Nothing worked, short of sandblasting to bare metal.

text: In the first six days after Baker, when radiation levels were highest, 4,900 men boarded target ships. Sailors tried to scrub off the radioactivity with brushes, water, soap, and lye. Nothing worked, short of

text: sandblasting

text: to bare metal.

text: The theory of operation on which Hieronymus Machines are based is that all matter emits a kind of "radiation" that is not electromagnetic, but exhibits some of the characteristics of both light and electricity. The quality of this emanation is unique to every kind of matter, and therefore can be utilized for detection and analysis. Hieronymus coined the term "eloptic energy" to describe this radiation (from the words "electrical" and "optical".) All of his machines were designed to detect and manipulate this eloptic energy. Eloptic emanations have never been detected by instruments designed to measure electromagnetic energies, and no other evidence or mathematical proof for their existence have been produced, so the theory is considered pseudoscientific and is not accepted by mainstream science.

text: The theory of operation on which Hieronymus Machines are based is that all matter emits a kind of "radiation" that is not

text: electromagnetic

text: , but exhibits some of the characteristics of both light and electricity. The quality of this emanation is unique to every kind of matter, and therefore can be utilized for detection and analysis. Hieronymus coined the term "eloptic energy" to describe this radiation (from the words "electrical" and "optical".) All of his machines were designed to detect and manipulate this eloptic energy. Eloptic emanations have never been detected by instruments designed to measure electromagnetic energies, and no other evidence or mathematical proof for their existence have been produced, so the theory is considered pseudoscientific and is not accepted by mainstream science.

text: All sediments and soils contain trace amounts of radioactive isotopes of elements such as potassium, uranium, thorium, and rubidium. These slowly decay over time and the ionizing radiation they produce is absorbed by mineral grains in the sediments such as quartz and potassium feldspar. The radiation causes charge to remain within the grains in structurally unstable "electron traps". The trapped charge accumulates over time at a rate determined by the amount of background radiation at the location where the sample was buried. Stimulating these mineral grains using either light (blue or green for OSL; infrared for IRSL) or heat (for TL) causes a luminescence signal to be emitted as the stored unstable electron energy is released, the intensity of which varies depending on the amount of radiation absorbed during burial and specific properties of the mineral.

text: All

text: sediment

text: s and

text: soil

text: s contain trace amounts of

text: radioactive

text: isotope

text: s of elements such as

text: potassium

text: uranium

text: thorium

text: , and

text: rubidium

text: . These slowly

text: decay

text: over time and the

text: ionizing radiation

text: they produce is absorbed by mineral grains in the sediments such as

text: quartz

text: and

text: potassium feldspar

text: . The radiation causes charge to remain within the grains in structurally unstable "electron traps". The trapped charge accumulates over time at a rate determined by the amount of background radiation at the location where the sample was buried. Stimulating these mineral grains using either light (blue or green for OSL;

text: infrared

text: for IRSL) or heat (for TL) causes a luminescence signal to be emitted as the stored unstable electron energy is released, the intensity of which varies depending on the amount of radiation absorbed during burial and specific properties of the mineral.

text: Dr. John E. Rose would become Health Physics and radiological physics division director at Argonne. Rose was involved with radiation detection instrumentation, including hand and foot monitors and other detectors. Further note regarding Rose: it was in the Manhattan District of U.S. Army Corps of Engineers that the name "health physics" was born, and great advances were made in radiation safety. From the beginning, the leaders of the Manhattan District recognized that a new and intense source of radiation and radioactivity would be created, and thus, in the summer of 1942, asked Ernest O. Wollan, a cosmic ray physicist at the University of Chicago, to form a group to study and control radiation hazards. Thus, Wollan was the first to bear the title of health physicist. He was soon joined by Carl G. Gamertsfelder, recently graduated physics baccalaureate, and Herbert M. Parker, the noted British-American medical physicist. By mid 1943, six others had been added: Karl Z. Morgan, James C. Hart, Robert R. Coveyou, Ole G. Landsverk, Ph.D. of the Ryerson Physical Laboratory, University of Chicago, L.A. Pardue and Dr. John E. Rose.

text: Dr.

text: John E. Rose

text: would become

text: Health Physics

text: and radiological physics division director at Argonne. Rose was involved with radiation detection instrumentation, including hand and foot monitors and other detectors. Further note regarding Rose: it was in the

text: Manhattan District

text: of

text: U.S. Army Corps of Engineers

text: that the name "health physics" was born, and great advances were made in

text: radiation safety

text: . From the beginning, the leaders of the Manhattan District recognized that a new and intense source of

text: radiation

text: and

text: radioactivity

text: would be created, and thus, in the summer of 1942, asked

text: Ernest O. Wollan

text: , a cosmic ray

text: physicist

text: at the

text: University of Chicago

text: , to form a group to study and control radiation hazards. Thus, Wollan was the first to bear the title of

text: health physicist

text: . He was soon joined by

text: Carl G. Gamertsfelder

text: , recently graduated physics baccalaureate, and

text: Herbert M. Parker

text: , the noted British-American

text: medical physicist

text: . By mid 1943, six others had been added:

text: Karl Z. Morgan

text: James C. Hart

text: Robert R. Coveyou

text: , Ole G. Landsverk, Ph.D. of the Ryerson Physical Laboratory, University of Chicago,

text: L.A. Pardue

text: and Dr. John E. Rose.

text: The 1986 Chernobyl disaster triggered the release of substantial amounts of radioactivity into the atmosphere in the form of both particulate and gaseous radioisotopes. It is one of the most significant unintentional releases of radioactivity into the environment to present.

text: The 1986

text: Chernobyl disaster

text: triggered the release of substantial amounts of

text: radioactivity

text: into the atmosphere in the form of both particulate and gaseous

text: radioisotopes

text: . It is one of the most significant unintentional releases of

text: radioactivity

text: into the

text: environment

text: to present.

text: Twenty isotopes of sodium are known, but only Na is stable. Na is created in the carbon-burning process in stars by fusing two carbon atoms together; this requires temperatures above 600 megakelvins and a star of at least three solar masses. Two radioactive, cosmogenic isotopes are the byproduct of cosmic ray spallation: Na has a half-life of 2.6 years and Na, a half-life of 15 hours; all other isotopes have a half-life of less than one minute. Two nuclear isomers have been discovered, the longer-lived one being Na with a half-life of around 20.2 milliseconds. Acute neutron radiation, as from a nuclear criticality accident, converts some of the stable Na in human blood to Na; the neutron radiation dosage of a victim can be calculated by measuring the concentration of Na relative to Na.

text: Twenty isotopes of sodium are known, but only Na is stable. Na is created in the

text: carbon-burning process

text: in stars by fusing two

text: carbon

text: atoms together; this requires temperatures above 600 megakelvins and a star of at least three solar masses. Two

text: radioactive

text: cosmogenic

text: isotopes are the byproduct of

text: cosmic ray spallation

text: : Na has a

text: half-life

text: of 2.6 years and Na, a half-life of 15 hours; all other isotopes have a half-life of less than one minute. Two

text: nuclear isomer

text: s have been discovered, the longer-lived one being Na with a half-life of around 20.2 milliseconds. Acute neutron radiation, as from a nuclear

text: criticality accident

text: , converts some of the stable Na in human blood to Na; the neutron radiation dosage of a victim can be calculated by measuring the concentration of Na relative to Na.

text: Helmholz was born in Evanston, Illinois on May 24, 1915. He attended the Shattuck School military academy in Faribault, Minnesota, following which he went to Harvard University for his undergraduate education. In 1936, Helmholz won a fellowship to study at the Cambridge University for one year. On the advice of his family neighbour and future Nobel laureate Luis Alvarez, Helmolz moved to the University of California, Berkeley for his graduate education. At Berkeley, he worked with Ernest Lawrence and Edwin McMillan at the Berkeley Radiation Laboratory (which later became the Lawrence Berkeley National Laboratory) on radioactive materials. In 1942, Helmholz worked with the Manhattan Project for using cyclotron magnets to separate uranium which was later used in the development of the first atomic bomb.

text: Helmholz was born in

text: Evanston, Illinois

text: on May 24, 1915. He attended the

text: Shattuck School

text: military academy in

text: Faribault, Minnesota

text: , following which he went to

text: Harvard University

text: for his undergraduate education. In 1936, Helmholz won a fellowship to study at the

text: Cambridge University

text: for one year. On the advice of his family neighbour and future

text: Nobel laureate

text: Luis Alvarez

text: , Helmolz moved to the

text: University of California, Berkeley

text: for his graduate education. At Berkeley, he worked with

text: Ernest Lawrence

text: and

text: Edwin McMillan

text: at the

text: Berkeley Radiation Laboratory

text: (which later became the

text: Lawrence Berkeley National Laboratory

text: ) on radioactive materials. In 1942, Helmholz worked with the

text: Manhattan Project

text: for using

text: cyclotron

text: magnets to separate

text: uranium

text: which was later used in the development of the first

text: atomic bomb

text: C-14 has been chosen as the source of radioactivity mainly because it emits a short-range radiation which is easily absorbed by any solid.Such a radiation will be effectively absorbed by the diamond (one of the hardest solids on earth) which will not only increase the quantity of current generated but will also prevent dangerous radiation from leaking out of the battery.

text: C-14 has been chosen as the source of radioactivity mainly because it emits a short-range radiation which is easily absorbed by any solid.Such a radiation will be effectively absorbed by the

text: diamond

text: (one of the hardest solids on earth) which will not only increase the quantity of current generated but will also prevent dangerous radiation from leaking out of the battery.

text: The cockroach's ability to withstand radiation better than human beings can be explained through the cell cycle. Cells are most vulnerable to the effects of radiation when they are dividing. A cockroach's cells divide only once each time it molts, which is weekly at most in a juvenile roach. Since not all cockroaches would be molting at the same time, many would be unaffected by an acute burst of radiation, but lingering radioactive fallout would still be harmful.

text: Radiation therapy has been used both as a primary treatment and combined with surgery or drugs. It is usually reserved for patients who have tumor remaining after surgery. These patients often also receive medication to lower GH levels. Radiation therapy is given in divided doses over four to six weeks. This treatment lowers GH levels by about 50 percent over 2 to 5 years. Patients monitored for more than 5 years show significant further improvement. Radiation therapy causes a gradual loss of production of other pituitary hormones with time. Loss of vision and brain injury, which have been reported, are very rare complications of radiation treatments.

text: Working conditions at Mayak resulted in severe health hazards and many accidents. The most notable accident occurred on 29 September 1957, when the failure of the cooling system for a tank storing tens of thousands of tons of dissolved nuclear waste resulted in a chemical (non-nuclear) explosion having an energy estimated at about 75 tons of TNT (310 gigajoules).  This released 740 PBq (20 MCi) of fission products, of which 74 PBq (2 MCi) drifted off the site, creating a contaminated region of 15,000-20,000 km called the East Urals Radioactive trace. Subsequently, an estimated 49 to 55 people died of radiation-induced cancer, 66 were diagnosed with chronic radiation syndrome, 10,000 people were evacuated from their homes, and 470,000 people were exposed to radiation.

text: Working conditions at Mayak resulted in severe health hazards and many accidents. The most notable accident occurred on 29 September 1957, when the failure of the cooling system for a tank storing tens of thousands of tons of dissolved nuclear waste resulted in a chemical (non-nuclear) explosion having an energy estimated at about 75 tons of

text: TNT

text: gigajoules

text: ).  This released 740 PBq (20 MCi) of fission products, of which 74 PBq (2 MCi) drifted off the site, creating a contaminated region of 15,000-20,000 km called the East Urals Radioactive trace. Subsequently, an estimated 49 to 55 people died of

text: radiation-induced cancer

text: , 66 were diagnosed with

text: chronic radiation syndrome

text: , 10,000 people were evacuated from their homes, and 470,000 people were exposed to radiation.

text: There are two aspects to the harmful effects of plutonium: the radioactivity and the heavy metal poison effects. Isotopes and compounds of plutonium are radioactive and accumulate in bone marrow. Contamination by plutonium oxide has resulted from nuclear disasters and radioactive incidents, including military nuclear accidents where nuclear weapons have burned. Studies of the effects of these smaller releases, as well as of the widespread radiation poisoning sickness and death following the atomic bombings of Hiroshima and Nagasaki, have provided considerable information regarding the dangers, symptoms and prognosis of radiation poisoning, which in the case of the Japanese Hibakusha/survivors was largely unrelated to direct plutonium exposure.

text: There are two aspects to the harmful effects of plutonium: the radioactivity and the

text: heavy metal poison

text: effects. Isotopes and compounds of plutonium are radioactive and accumulate in

text: bone marrow

text: . Contamination by plutonium oxide has resulted from

entity_name: Lists of nuclear disasters and radioactive incidents

text: nuclear disasters and radioactive incidents

text: , including military nuclear accidents where nuclear weapons have burned. Studies of the effects of these smaller releases, as well as of the widespread radiation poisoning sickness and death following the

text: atomic bombings of Hiroshima and Nagasaki

text: , have provided considerable information regarding the dangers, symptoms and prognosis of

text: radiation poisoning

text: , which in the case of the Japanese

text: Hibakusha

text: /survivors was largely unrelated to direct plutonium exposure.

text: Calcium (Ca) has 24 isotopes, from Ca to Ca. There are five stable isotopes (Ca, Ca, Ca, Ca and Ca), plus one isotope (Ca) with such a long half-life that for all practical purposes it can be considered stable. The most abundant isotope, Ca, as well as the rare Ca, are theoretically unstable on energetic grounds, but their decay has not been observed. Calcium also has a cosmogenic isotope, radioactive Ca, which has a half-life of 102,000 years. Unlike cosmogenic isotopes that are produced in the atmosphere, Ca is produced by neutron activation of Ca. Most of its production is in the upper metre or so of the soil column, where the cosmogenic neutron flux is still sufficiently strong. Ca has received much attention in stellar studies because it decays to K, a critical indicator of solar-system anomalies. The most stable artificial radioisotope is Ca, with a half-life of 163 days.

text: Calcium

text: (Ca) has 24 isotopes, from Ca to Ca. There are five

text: stable isotope

text: s (Ca, Ca, Ca, Ca and Ca), plus one isotope (

text: Ca

text: ) with such a long

text: half-life

text: that for all practical purposes it can be considered stable. The most abundant isotope, Ca, as well as the rare Ca, are theoretically unstable on energetic grounds, but their decay has not been observed. Calcium also has a

text: cosmogenic isotope

text: radioactive

text: Ca, which has a

text: half-life

text: of 102,000 years. Unlike

text: cosmogenic isotope

text: s that are produced in the

text: atmosphere

text: , Ca is produced by

text: neutron activation

text: of Ca. Most of its production is in the upper metre or so of the soil column, where the cosmogenic neutron flux is still sufficiently strong. Ca has received much attention in stellar studies because it decays to K, a critical indicator of solar-system anomalies. The most stable artificial radioisotope is Ca, with a half-life of 163 days.

text: Gamma radiation as well as neutron radiation can cause RPMs to trigger an alarm procedure. Alarms caused by statistical fluctuations of detection rates are referred to as false alarms. Alarms caused by benign radioactive sources are referred to as nuisance alarms. Causes of nuisance alarms can be broken up into several large categories:

text: In neutron, X-ray, and gamma ray optics, a collimator is a device that filters a stream of rays so that only those traveling parallel to a specified direction are allowed through. Collimators are used in neutron, X-ray, and gamma-ray optics because it is not yet possible to focus radiation with such short wavelengths into an image through the use of lenses as is routine with electromagnetic radiation at optical or near-optical wavelengths. Collimators are also used with radiation detectors in nuclear power stations for monitoring sources of radioactivity.

text: In

text: neutron

text: X-ray

text: , and

text: gamma ray

text: optics, a collimator is a device that filters a stream of rays so that only those traveling parallel to a specified direction are allowed through. Collimators are used in neutron, X-ray, and gamma-ray optics because it is not yet possible to focus radiation with such short wavelengths into an image through the use of lenses as is routine with

text: electromagnetic radiation

text: at optical or near-optical wavelengths. Collimators are also used with radiation detectors in

text: nuclear power station

text: s for monitoring sources of

text: radioactivity

text: According to general relativity, gravitational radiation is generated in situations where the curvature of spacetime is oscillating, such as is the case with co-orbiting objects. The gravitational radiation emitted by the Solar System is far too small to measure. However, gravitational radiation has been indirectly observed as an energy loss over time in binary pulsar systems such as PSR B1913+16. It is believed that neutron star mergers and black hole formation may create detectable amounts of gravitational radiation. Gravitational radiation observatories such as the Laser Interferometer Gravitational Wave Observatory (LIGO) have been created to study the problem. In February 2016, the Advanced LIGO team announced that they had detected gravitational waves from a black hole collision. On September 14, 2015 LIGO registered gravitational waves for the first time, as a result of the collision of two black holes 1.3 billion light-years from Earth.<ref name='Clark 2016'></ref> This observation confirms the theoretical predictions of Einstein and others that such waves exist. The event confirms that binary black holes exist. It also opens the way for practical observation and understanding of the nature of gravity and events in the Universe including the Big Bang and what happened after it.

text: According to general relativity, gravitational radiation is generated in situations where the curvature of

text: spacetime

text: is oscillating, such as is the case with co-orbiting objects. The gravitational radiation emitted by the

text: Solar System

text: is far too small to measure. However, gravitational radiation has been indirectly observed as an energy loss over time in binary pulsar systems such as

text: PSR B1913+16

text: . It is believed that

text: neutron star

text: mergers and

text: black hole

text: formation may create detectable amounts of gravitational radiation. Gravitational radiation observatories such as the Laser Interferometer Gravitational Wave Observatory (

text: LIGO

text: ) have been created to study the problem. In February 2016, the Advanced LIGO team announced that they had detected gravitational waves from a black hole collision. On September 14, 2015 LIGO registered gravitational waves for the first time, as a result of the collision of two black holes 1.3 billion light-years from Earth.<ref name='Clark 2016'></ref> This observation confirms the theoretical predictions of Einstein and others that such waves exist. The event confirms that

text: binary black hole

text: s exist. It also opens the way for practical observation and understanding of the nature of gravity and events in the Universe including the Big Bang and what happened after it.

text: Carbon-11 is commonly used as a radioisotope for the radioactive labeling of molecules in positron emission tomography. Among the many molecules used in this context is the radioligand []DASB.

text: Carbon-11 is commonly used as a

text: radioisotope

text: for the radioactive labeling of molecules in

text: positron emission tomography

text: . Among the many molecules used in this context is the

text: radioligand

text: []DASB

text: They realized that atmospheric nuclear testing had provided them an opportunity to investigate this.  Such tests had dispersed radioactive contamination worldwide, and examination of human bodies could reveal how readily it was taken up and hence how much damage it caused.  Of particular interest was strontium-90 in the bones.  Infants were the primary focus, as they would have had a full opportunity to absorb the new contaminants.As a result of this conclusion, researchers began a program to collect human bodies and bones from all over the world, with a particular focus on infants.  The bones were cremated and the ashes analyzed for radioisotopes.  This project was kept secret primarily because it would be a public relations disaster; as a result parents and family were not told what was being done with the body parts of their relatives.

text: They realized that atmospheric

text: nuclear testing

text: had provided them an opportunity to investigate this.  Such tests had dispersed

text: radioactive contamination

text: worldwide, and examination of human bodies could reveal how readily it was taken up and hence how much damage it caused.  Of particular interest was

text: strontium

text: -90 in the bones.  Infants were the primary focus, as they would have had a full opportunity to absorb the new contaminants.As a result of this conclusion, researchers began a program to collect human bodies and bones from all over the world, with a particular focus on infants.  The bones were cremated and the ashes analyzed for radioisotopes.  This project was kept secret primarily because it would be a

text: public relations

text: disaster; as a result parents and family were not told what was being done with the body parts of their relatives.

text: A radioactive source or radiation source is a sample of a radionuclide, and emits ionizing radiation (one or more of gamma rays, alpha particles, beta particles, and neutron radiation). Generally, sources are used for irradiation, where the radiation performs a significant ionising function on a target material, or as a metrology calibration source, which is used for the calibration of radiometric process and radiation protection instrumentation. They can be sealed in a container or on a surface, or they can be free to move within a fluid.

text: A radioactive source or radiation source is a sample of a

text: radionuclide

text: , and emits

text: ionizing radiation

text: (one or more of

text: gamma ray

text: s,

text: alpha particle

text: s,

text: beta particle

text: s, and

text: neutron radiation

text: ). Generally, sources are used for irradiation, where the radiation performs a significant ionising function on a target material, or as a metrology calibration source, which is used for the calibration of radiometric process and

text: radiation protection

text: instrumentation. They can be sealed in a container or on a surface, or they can be free to move within a fluid.

text: U is also used as a radiation shield – its alpha radiation is easily stopped by the non-radioactive casing of the shielding and the uranium's high atomic weight and high number of electrons are highly effective in absorbing gamma rays and x-rays. It is not as effective as ordinary water for stopping fast neutrons. Both metallic depleted uranium and depleted uranium dioxide are used for radiation shielding. Uranium is about five times better as a gamma ray shield than lead, so a shield with the same effectiveness can be packed into a thinner layer.

text: U is also used as a

text: radiation shield

text: – its

text: alpha radiation

text: is easily stopped by the non-

text: radioactive

text: casing of the shielding and the uranium's high

text: atomic weight

text: and high number of

text: electron

text: s are highly effective in absorbing

text: gamma ray

text: s and

text: x-ray

text: s. It is not as effective as ordinary water for stopping

text: fast neutron

text: s. Both metallic depleted uranium and depleted

text: uranium dioxide

text: are used for radiation shielding. Uranium is about five times better as a gamma ray shield than

text: lead

text: , so a shield with the same effectiveness can be packed into a thinner layer.

text: The term is typically distinct from radioactive decay, in which an unstable atomic nucleus is transformed into a lighter nucleus accompanied by the emission of particles or radiation, although the two are conceptually similar and are often described using the same terminology.

text: The term is typically distinct from

text: radioactive decay

text: , in which an unstable

text: atomic nucleus

text: is transformed into a lighter nucleus accompanied by the emission of particles or radiation, although the two are conceptually similar and are often described using the same terminology.

text: The isotopes of neptunium range in atomic weight from 225.0339 u () to 244.068 u (). The primary decay mode before the most stable isotope, , is electron capture (with a good deal of alpha emission), and the primary mode after is beta emission. The primary decay products before  are isotopes of uranium and protactinium, and the primary products after are isotopes of plutonium. Uranium-237 and Neptunium-239 are regarded as the leading hazardous radioisotopes in the first hour-to-week period following nuclear fallout from a nuclear detonation, with Np-239 dominating "the spectrum for several days".

text: The isotopes of neptunium range in

text: atomic weight

text: from 225.0339

text: u

text: () to 244.068 u (). The primary

text: decay mode

text: before the most stable isotope, , is

text: electron capture

text: (with a good deal of

text: alpha emission

text: ), and the primary mode after is

text: beta emission

text: . The primary

text: decay product

text: s before  are

text: isotopes of uranium

text: and

text: protactinium

text: , and the primary products after are

text: isotopes of plutonium

text: and Neptunium-239 are regarded as the leading hazardous radioisotopes in the first hour-to-week period following

text: nuclear fallout

text: from a nuclear detonation, with Np-239 dominating "the spectrum for several days".

text: Radiation levels around the park vary; the liquidators washed radiation into the soil after the helicopters carrying radioactive materials used the grounds as a landing strip, so concreted areas are relatively safe. However, areas where moss has built up are dangerously high; some areas can emit 25 µSv/h, among the highest levels of radiation in the whole of Pripyat.

text: In October 2015 it was reported that Moldovan authorities working with the FBI have stopped four attempts from 2010 to 2015 by gangs with suspected connections to Russia's intelligence services that sought to sell radioactive material to ISIS and other Middle Eastern extremists. The last reported case came in February 2015-a smuggler with a large amount of radioactive caesium specifically sought a buyer from ISIS. The Criminal organizations are thriving on black market nuclear materials in Moldova, since relations between Russia and the West deteriorated, it is difficult to know whether smugglers are succeeding in selling radioactive material originating from Russia to Islamist terrorists and elsewhere.

text: In October 2015 it was reported that

text: Moldova

text: n authorities working with the FBI have stopped four attempts from 2010 to 2015 by gangs with suspected connections to Russia's intelligence services that sought to sell radioactive material to ISIS and other Middle Eastern extremists. The last reported case came in February 2015-a smuggler with a large amount of radioactive caesium specifically sought a buyer from ISIS. The Criminal organizations are thriving on black market nuclear materials in Moldova, since relations between Russia and the West deteriorated, it is difficult to know whether smugglers are succeeding in selling radioactive material originating from Russia to Islamist terrorists and elsewhere.

text: In 1935, while he was living at No 24, Schrödinger wrote his famous "Schrödinger's cat" paper, criticising the Copenhagen interpretation of quantum mechanics, which proposed that the exact state of a single atom was indeterminate until observed. Schrödinger's thought experiment imagined a cat in a steel box, together with a small sample of some radioactive material in which there was a 50% chance that, in any hour, one atom would decay and emit radioactivity. Any release of radioactivity, detected by a Geiger counter, would trigger a device that would cause a hammer to shatter a glass vial containing prussic acid, hence killing the cat. Schrödinger argued that, according to the Copenhagen Interpretation, the cat would be both alive and dead until someone opened the box after an hour to take a look.

text: In 1935, while he was living at No 24, Schrödinger wrote his famous "

text: Schrödinger's cat

text: " paper, criticising the

text: Copenhagen interpretation

text: of quantum mechanics, which proposed that the exact state of a single atom was indeterminate until observed. Schrödinger's

text: thought experiment

text: imagined a cat in a steel box, together with a small sample of some radioactive material in which there was a 50% chance that, in any hour, one atom would decay and emit radioactivity. Any release of radioactivity, detected by a Geiger counter, would trigger a device that would cause a hammer to shatter a glass vial containing prussic acid, hence killing the cat. Schrödinger argued that, according to the Copenhagen Interpretation, the cat would be both alive and dead until someone opened the box after an hour to take a look.

text: The 1903 Nobel Prize in Physics was awarded jointly to Becquerel for his discovery and to Pierre Curie and Marie Curie for their subsequent research into radioactivity. Rutherford was awarded the Nobel Prize in Chemistry in 1908 for his "investigations into the disintegration of the elements and the chemistry of radioactive substances".

text: The 1903

text: Nobel Prize

text: in Physics was awarded jointly to Becquerel for his discovery and to

text: Pierre Curie

text: and Marie Curie for their subsequent research into radioactivity. Rutherford was awarded the Nobel Prize in Chemistry in 1908 for his "investigations into the disintegration of the elements and the chemistry of radioactive substances".

text: As a result of large production of uranium and presence of other radioactive elements such thorium, radon or radioactive dust the radioactive background of the city is remarkable with the zones of radioactive anomaly which are spread around the city.

text: Twenty-nine radioisotopes have also been synthesized, ranging in atomic mass from 138 to 173. The most stable of these is Dy, with a half-life of approximately 3 years, followed by Dym with a half-life of 144.4 days. The least stable is Dy, with a half-life of 200 ms. As a general rule, isotopes that are lighter than the stable isotopes tend to decay primarily by β decay, while those that are heavier tend to decay by β decay. However, Dy decays primarily by alpha decay, and Dy and Dy decay primarily by electron capture. Dysprosium also has at least 11 metastable isomers, ranging in atomic mass from 140 to 165. The most stable of these is Dy, which has a half-life of 1.257 minutes. Dy has two metastable isomers, the second of which, Dy, has a half-life of 28 ns.

text: Twenty-nine

text: radioisotopes

text: have also been synthesized, ranging in atomic mass from 138 to 173. The most stable of these is Dy, with a

text: half-life

text: of approximately 3 years, followed by Dym with a half-life of 144.4 days. The least stable is Dy, with a half-life of 200 ms. As a general rule, isotopes that are lighter than the stable isotopes tend to decay primarily by

text: β decay

text: , while those that are heavier tend to decay by

text: β decay

text: . However, Dy decays primarily by alpha decay, and Dy and Dy decay primarily by

text: electron capture

text: . Dysprosium also has at least 11

text: metastable isomer

text: s, ranging in atomic mass from 140 to 165. The most stable of these is Dy, which has a half-life of 1.257 minutes. Dy has two metastable isomers, the second of which, Dy, has a half-life of 28 ns.

text: There have been some public concerns about use of radioactive sources in wells.  The difference between radiation dose and Radioactive contamination seems to be poorly understood. Well logs involving radioactive sources are a legal requirement.

text: There have been some public concerns about use of radioactive sources in wells.  The difference between

text: radiation dose

text: and

text: Radioactive contamination

text: seems to be poorly understood. Well logs involving radioactive sources are a legal requirement.

text: The Fission Product Pilot Plant, building 3515 at Oak Ridge National Laboratory, was built in 1948 to extract radioactive isotopes from liquid radioactive waste.  It was formerly known as the 'ruthenium-106 tank arrangement'. It is a relatively small facility; the task of extracting radioactive isotopes later took place at a number of specialised buildings nearby.

text: The Fission Product Pilot Plant, building 3515 at

text: Oak Ridge National Laboratory

text: , was built in 1948 to extract radioactive isotopes from liquid radioactive waste.  It was formerly known as the '

text: ruthenium

text: -106 tank arrangement'. It is a relatively small facility; the task of extracting radioactive isotopes later took place at a number of specialised buildings nearby.

text: Because Th is only mildly radioactive, but decays to more dangerous radionuclides such as radium and radon, emitting alpha and gamma radiation, a proper assessment of the radiological toxicity of Th must include the contribution of its daughters such as Ra, which are dangerous gamma emitters. There are concerns about the safety of thorium mantles, as the dangerous daughters of thorium have much lower melting points than thoria (except of course Th, which is chemically identical to its parent Th), and they would be volatilised every time the mantle is heated for use. For example, during burning, significant fractions of the thorium daughters Ra, Ra, Pb, and Bi are released in the first hour of use alone. Most of the radiation dose by a normal user arises from inhaling the radium, resulting in a radiation dose of up to 0.2 millisieverts per use, about a third of the dose sustained during a mammogram. If a mantle is ingested, 0.4% of the thorium and 90% of its dangerous daughters are leached into the body. Some nuclear safety agencies make recommendations about their use, and have raised some safety concerns regarding their manufacture and disposal, because while the radiation dose from one mantle is not a serious problem, that from many mantles gathered together in factories or landfills is.

text: Because Th is only mildly radioactive, but decays to more dangerous radionuclides such as radium and radon, emitting alpha and

text: gamma radiation

text: , a proper assessment of the radiological toxicity of Th must include the contribution of its daughters such as Ra, which are dangerous gamma emitters. There are concerns about the safety of thorium mantles, as the dangerous daughters of thorium have much lower melting points than thoria (except of course Th, which is chemically identical to its parent Th), and they would be volatilised every time the mantle is heated for use. For example, during burning, significant fractions of the thorium daughters Ra, Ra, Pb, and Bi are released in the first hour of use alone. Most of the radiation dose by a normal user arises from inhaling the radium, resulting in a radiation dose of up to 0.2

text: millisieverts

text: per use, about a third of the dose sustained during a

text: mammogram

text: . If a mantle is ingested, 0.4% of the thorium and 90% of its dangerous daughters are leached into the body. Some

text: nuclear safety

text: agencies make recommendations about their use, and have raised some safety concerns regarding their

text: manufacture

text: and disposal, because while the radiation dose from one mantle is not a serious problem, that from many mantles gathered together in factories or landfills is.

text: The Earth, and all living things on it, are constantly bombarded by radiation from outer space. This radiation primarily consists of positively charged ions from protons to iron and larger nuclei derived sources outside our solar system. This radiation interacts with atoms in the atmosphere to create an air shower of secondary radiation, including X-rays, muons, protons, alpha particles, pions, electrons, and neutrons. The immediate dose from cosmic radiation is largely from muons, neutrons, and electrons, and this dose varies in different parts of the world based largely on the geomagnetic field and altitude. This radiation is much more intense in the upper troposphere, around 10 km altitude, and is thus of particular concern for airline crews and frequent passengers, who spend many hours per year in this environment. During their flights airline crews typically get an extra dose on the order of 2.2 mSv (220 mrem) per year.

text: The Earth, and all living things on it, are constantly bombarded by radiation from outer space. This radiation primarily consists of positively charged ions from

text: proton

text: s to

text: iron

text: and larger

text: nuclei

text: derived sources outside our

text: solar system

text: air shower

text: of secondary radiation, including

text: X-ray

text: s,

text: muon

text: s,

text: proton

text: s,

text: alpha particle

text: s,

text: pion

text: s,

text: electron

text: s, and

text: neutron

text: geomagnetic field

text: and altitude. This radiation is much more intense in the upper

text: troposphere

text: airline

text: In 1934 Frédéric and Irène Joliot-Curie bombarded aluminium with alpha particles to effect the nuclear reaction  +  →  + , and observed that the product isotope  emits a positron identical to those found in cosmic rays by Carl David Anderson in 1932. This was the first example of  decay (positron emission). The Curies termed the phenomenon "artificial radioactivity," since  is a short-lived nuclide which does not exist in nature. The discovery of artificial radioactivity would be cited when the husband and wife team won the Nobel Prize.

text: In 1934

text: Frédéric

text: and

text: Irène Joliot-Curie

text: bombarded aluminium with alpha particles to effect the nuclear reaction  +  →  + , and observed that the product isotope  emits a positron identical to those found in cosmic rays by

text: Carl David Anderson

text: in 1932. This was the first example of  decay (positron emission). The Curies termed the phenomenon "artificial radioactivity," since  is a short-lived nuclide which does not exist in nature. The discovery of artificial radioactivity would be cited when the husband and wife team won the Nobel Prize.

text: Medicine has used radiation therapy as a treatment for cancer for more than 100 years, with its earliest roots traced from the discovery of x-rays in 1895 by Wilhelm Röntgen.  Emil Grubbe of Chicago was possibly the first American physician to use x-rays to treat cancer, beginning in 1896.

text: Medicine has used radiation therapy as a treatment for cancer for more than 100 years, with its earliest roots traced from the discovery of x-rays in 1895 by

text: Wilhelm Röntgen

text: Emil Grubbe

text: of Chicago was possibly the first American physician to use x-rays to treat cancer, beginning in 1896.

text: Detectable levels of radiation were found in an apartment building in Nihonmatsu, Fukushima, where the foundation was made using concrete containing crushed stone collected from a quarry near the troubled Fukushima Daiichi nuclear power plant, situated inside the evacuation-zone. Of the 12 households living there were 10 households relocated after the quake. After inspection at the quarry – situated inside the evacuation-zone around the nuclear plant—in the town of Namie, Fukushima between 11 and 40 microsieverts of radiation per hour were detected one meter above gravel held at eight storage sites in the open, while 16 to 21 microsieverts were detected in three locations covered by roofs. From this place about 5,200 metric tons of gravel was shipped from this place and used as building material. On 21 January 2012 the association of quarry agents in the prefecture Fukushima asked its members to voluntarily check their products for radioactivity to ease public concerns over radioactive contamination of building materials. The minister of Industry Yukio Edano did instruct TEPCO to pay compensation for the economical damages. Raised radiation levels were found on many buildings constructed after the quake. Schools, private houses, roads. Because of the public anger raised by these finds. the government of Nihonmatsu, Fukushima decided to examine all 224 city construction projects started after the quake. Some 200 construction companies received stone from the Namie-quarry, and the material was used in at least 1000 building-sites. The contaminated stone was found in some 49 houses and apartments. Radiation levels of 0.8 mSv per hour were found, almost as high as the radiation levels outside the homes. None of these represents a potential danger to human health.

text: Detectable levels of radiation were found in an apartment building in

text: Nihonmatsu, Fukushima

text: , where the foundation was made using concrete containing crushed stone collected from a quarry near the troubled Fukushima Daiichi nuclear power plant, situated inside the evacuation-zone. Of the 12 households living there were 10 households relocated after the quake. After inspection at the quarry – situated inside the evacuation-zone around the nuclear plant—in the town of

text: Namie, Fukushima

text: between 11 and 40 microsieverts of radiation per hour were detected one meter above gravel held at eight storage sites in the open, while 16 to 21 microsieverts were detected in three locations covered by roofs. From this place about 5,200 metric tons of gravel was shipped from this place and used as building material. On 21 January 2012 the association of quarry agents in the prefecture Fukushima asked its members to voluntarily check their products for radioactivity to ease public concerns over radioactive contamination of building materials. The minister of Industry Yukio Edano did instruct TEPCO to pay compensation for the economical damages. Raised radiation levels were found on many buildings constructed after the quake. Schools, private houses, roads. Because of the public anger raised by these finds. the government of

text: Nihonmatsu, Fukushima

text: decided to examine all 224 city construction projects started after the quake. Some 200 construction companies received stone from the Namie-quarry, and the material was used in at least 1000 building-sites. The contaminated stone was found in some 49 houses and apartments. Radiation levels of 0.8 mSv per hour were found, almost as high as the radiation levels outside the homes. None of these represents a potential danger to human health.

text: Two instruments known as the Submillimetre Common-User Bolometer Array, or SCUBA, have been used for detecting submillimetre radiation on the James Clerk Maxwell Telescope in Hawaii.

text: Two instruments known as the Submillimetre Common-User Bolometer Array, or SCUBA, have been used for detecting

text: submillimetre radiation

text: on the

text: James Clerk Maxwell Telescope

text: in

text: Hawaii

text: Some artificial radioisotopes such as iodine-131 are chemically identical to natural isotopes needed by the body, and may be more readily absorbed if the individual has a deficit of that element. For instance, Potassium iodide (KI), administered orally immediately after exposure, may be used to protect the thyroid from ingested radioactive iodine in the event of an accident or attack at a nuclear power plant, or the detonation of a nuclear explosive which would release radioactive iodine.

text: Some artificial radioisotopes such as

text: are chemically identical to natural isotopes needed by the body, and may be more readily absorbed if the individual has a deficit of that element. For instance,

text: Potassium iodide

text: (KI), administered orally immediately after exposure, may be used to protect the

text: thyroid

text: from ingested

text: radioactive iodine

text: in the event of an accident or attack at a nuclear power plant, or the detonation of a

text: nuclear explosive

text: which would release radioactive iodine.

text: Vehicles were subjected to rigorous checks to uncover escapees. Inspection pits and mirrors allowed the undersides of vehicles to be scrutinised. Probes were used to investigate the chassis and even the fuel tank, where an escapee might be concealed, and vehicles could be partially dismantled in on-site garages. At Marienborn there was even a mortuary garage where coffins could be checked to confirm that the occupants really were dead. From the late 1970s, the East Germans also installed concealed gamma-ray detectors ("gamma guns") at border crossings which used radioactive caesium-137 sources to detect people concealed inside vehicles. The discovery of this practice caused a health scare after reunification. A subsequent investigation by federal authorities found that these involuntary screenings did not result in "a harmful dose" despite violating basic radiation safety protocols.

text: Vehicles were subjected to rigorous checks to uncover escapees. Inspection pits and mirrors allowed the undersides of vehicles to be scrutinised. Probes were used to investigate the chassis and even the fuel tank, where an escapee might be concealed, and vehicles could be partially dismantled in on-site garages. At Marienborn there was even a mortuary garage where coffins could be checked to confirm that the occupants really were dead. From the late 1970s, the East Germans also installed concealed gamma-ray detectors ("gamma guns") at border crossings which used radioactive

text: sources to detect people concealed inside vehicles. The discovery of this practice caused a health scare after reunification. A subsequent investigation by federal authorities found that these involuntary screenings did not result in "a harmful dose" despite violating basic radiation safety protocols.

text: He sees a dentist for a troublesome tooth, deciding he will pursue her romantically. He gives Lisbetta, the dentist, a copy of his only book as a gift. She stands on the book to make it easier to care for her patients. He tells his colleague Unterholzer about this excellent new dentist. Unterholzer acts more quickly in courting Lisabeta, and the couple gets engaged to marry. Von Igelfeld endures the emotional challenge of attending their wedding. He then takes a vacation to Venice in September with the Prinzels, where he learns the Venetians are not fond of German tourists, as not enough of them have been visiting. Oddly, he chances upon a Geiger counter in their hotel. He finds no evidence of radiation on himself. When Florianus Prinzel tries the device, it reveals radioactivity on his shirt, where water splashed on him in a gondola ride with his wife. Von Igelfeld shares the remarks made to him about a problem with the water in Venice, leading to a decline of German tourists in the summer. The courses of their meal were measured, leading them to send the fish course back to the kitchen. The three decide to end their stay in Venice early, so Prinzel can seek medical advice in Germany. Then the boy Tadeusz, boy in a Polish family staying at the same hotel, walks past the measuring device, which reveals the highest level of radiation on the boy. Von Igelfeld approaches the mother, speaking in French, telling her that her son has an issue with radioactivity. She replies politely, thanking him for the information, and indicating she has a theory about children and radioactivity, saying no more. Von Igelfeld receives a telegram from Unterholzer about an award from the Portuguese government. He is happy because he thinks the curtly worded telegram meant it was for himself. As they drive through Austria back home, Prinzel points out that Unterholzer probably meant the award was given to him, not to von Igelfeld. After a moment of sadness, he realizes this is not the end, and the three head back to Germany, "where they belong."

text: He sees a dentist for a troublesome tooth, deciding he will pursue her romantically. He gives Lisbetta, the dentist, a copy of his only book as a gift. She stands on the book to make it easier to care for her patients. He tells his colleague Unterholzer about this excellent new dentist. Unterholzer acts more quickly in courting Lisabeta, and the couple gets engaged to marry. Von Igelfeld endures the emotional challenge of attending their wedding. He then takes a vacation to Venice in September with the Prinzels, where he learns the Venetians are not fond of German tourists, as not enough of them have been visiting. Oddly, he chances upon a

text: Geiger counter

text: in their hotel. He finds no evidence of radiation on himself. When Florianus Prinzel tries the device, it reveals

text: radioactivity

text: on his shirt, where water splashed on him in a gondola ride with his wife. Von Igelfeld shares the remarks made to him about a problem with the water in Venice, leading to a decline of German tourists in the summer. The courses of their meal were measured, leading them to send the fish course back to the kitchen. The three decide to end their stay in Venice early, so Prinzel can seek medical advice in Germany. Then the boy Tadeusz, boy in a Polish family staying at the same hotel, walks past the measuring device, which reveals the highest level of radiation on the boy. Von Igelfeld approaches the mother, speaking in French, telling her that her son has an issue with radioactivity. She replies politely, thanking him for the information, and indicating she has a theory about children and radioactivity, saying no more. Von Igelfeld receives a telegram from Unterholzer about an award from the Portuguese government. He is happy because he thinks the curtly worded telegram meant it was for himself. As they drive through Austria back home, Prinzel points out that Unterholzer probably meant the award was given to him, not to von Igelfeld. After a moment of sadness, he realizes this is not the end, and the three head back to Germany, "where they belong."

text: Researchers use radioactive atoms to determine the age of materials that were once part of a living organism. The age of such materials can be estimated by measuring the amount of radioactive carbon they contain in a process called radiocarbon dating. Similarly, using other radioactive elements, the age of rocks and other geological features (even some man-made objects) can be determined; this is called Radiometric dating. Environmental scientists use radioactive atoms, known as tracer atoms, to identify the pathways taken by pollutants through the environment.

text: Researchers use radioactive atoms to determine the age of materials that were once part of a living organism. The age of such materials can be estimated by measuring the amount of radioactive carbon they contain in a process called

text: radiocarbon dating

text: . Similarly, using other radioactive elements, the age of rocks and other geological features (even some man-made objects) can be determined; this is called

text: Radiometric dating

text: . Environmental scientists use radioactive atoms, known as

text: tracer atoms

text: , to identify the pathways taken by pollutants through the environment.

text: On 15 June 2012 TEPCO reported that a robot that was sent into the No. 2 reactor building on 13 June 2012 to take video images and radiation measurements, detected a reading of 880mSv (millisieverts) per hour of radiation on the fifth floor, which one floor (4.5 meters) directly above the reactor containment vessel.  TEPCO suspects that during initial accident in March 2011, that radioactive substances leaked from the No. 2 reactor moved through the building, but after analyzing the images taken by the robot it could not find the exact route the radioactive substances traveled, and images taken by the robot found no major damage on the fifth floor. During the March 2011 nuclear accident the No. 2 reactor is believed to have released the largest amount of radioactive substances. But the overall route the radioactive material traveled has yet to be determined. TEPCO needs to find and repair the damaged parts of the reactor to recover melted nuclear fuel before TEPCO can begin the process of decommissioning the reactor.  However high radiation often stops workers from entering the building. This scenario means it will take a long time to find the problems in the containment vessel.

text: The first PNE blast was Project Gnome, conducted on December 10, 1961 in a salt bed 24 mi (39 km) southeast of Carlsbad, New Mexico.  The explosion released 3.1 kilotons (13 TJ) of energy yield at a depth of 361 meters (1,184 ft) which resulted in the formation of a  diameter,  high cavity. The test had many objectives.  The most public of these involved the generation of steam which could then be used to generate electricity.  Another objective was the production of useful radioisotopes and their recovery.  Another experiment involved neutron time-of-flight physics.  A fourth experiment involved geophysical studies based upon the timed seismic source. Only the last objective was considered a complete success. The blast unintentionally vented radioactive steam while the press watched. The partly developed Project Coach detonation experiment that was to follow adjacent to the Gnome test was then canceled.

text: The first PNE blast was

text: Project Gnome

text: , conducted on December 10, 1961 in a salt bed 24 mi (39 km) southeast of

text: Carlsbad, New Mexico

text: .  The explosion released 3.1 kilotons (13 TJ) of energy yield at a depth of 361 meters (1,184 ft) which resulted in the formation of a  diameter,  high cavity. The test had many objectives.  The most public of these involved the generation of

text: steam

text: which could then be used to generate electricity.  Another objective was the production of useful

text: radioisotope

text: s and their recovery.  Another experiment involved

text: neutron

text: time-of-flight

text: physics

text: .  A fourth experiment involved geophysical studies based upon the timed seismic source. Only the last objective was considered a complete success. The blast unintentionally vented radioactive steam while the press watched. The partly developed

text: Project Coach

text: detonation experiment that was to follow adjacent to the

text: Gnome test

text: was then canceled.

text: The Anton type 213 Geiger-Müller tube performed as expected. The average rate was 0.6 counts per second. Increases in its counting rate were larger and more frequent than for the two larger tubes, since it was more sensitive to particles of lower energy. It detected 7 small solar bursts of radiation during September and October and 2 during November and December. The absence of a detectable magnetosphere was also confirmed by the tube; it detected no radiation belt at Venus similar to that of Earth. The count rate would have increased by 10, but no change was measured.

text: On 18 June 2012 it became known that from 17 to 19 March 2011 in the days directly after the explosions, American military aircraft gathered radiation data in an area with a radius of 45 kilometers around the plant for the U.S. Department of Energy. The maps revealed radiation levels of more than 125 microsieverts per hour at 25 kilometers northwest of the plant, which means that people in these areas were exposed to the annual permissible dose within eight hours. The maps were neither made public nor used for evacuation of residents.

text: In health physics neutron radiation is a type of radiation hazard. Another, sometimes more severe hazard of neutron radiation, is neutron activation, the ability of neutron radiation to induce radioactivity in most substances it encounters, including the body tissues. This occurs through the capture of neutrons by atomic nuclei, which are transformed to another nuclide, frequently a radionuclide. This process accounts for much of the radioactive material released by the detonation of a nuclear weapon. It is also a problem in nuclear fission and nuclear fusion installations as it gradually renders the equipment radioactive such that eventually it must be replaced and disposed of as low-level radioactive waste.

text: In

text: health physics

text: neutron radiation is a type of radiation hazard. Another, sometimes more severe hazard of neutron radiation, is

text: neutron activation

text: , the ability of neutron radiation to induce

text: radioactivity

text: in most substances it encounters, including the body tissues. This occurs through the capture of neutrons by atomic nuclei, which are transformed to another

text: nuclide

text: , frequently a

text: radionuclide

text: . This process accounts for much of the radioactive material released by the detonation of a

text: nuclear weapon

text: . It is also a problem in

text: nuclear fission

text: and

text: nuclear fusion

text: installations as it gradually renders the equipment radioactive such that eventually it must be replaced and disposed of as low-level

text: radioactive waste

text: The test succeeded in liberating large quantities of natural gas; however the resulting radioactivity left the gas contaminated and unsuitable for applications such as cooking and heating homes. Although projected public radiation exposures from commercial use of stimulated gas had been reduced to less than 1% of background, it became clear in the early 1970s that public acceptance within the U.S. of any product containing radioactivity, no matter how minimal, was difficult if not impossible. The Department of Energy began a cleanup of the site in the 1970s which was completed in 1998.  A buffer zone put in place by the state of Colorado still exists around the site.  A January 2005 report by the DOE stated that radioactivity levels were normal at the surface and in groundwater, though a later report due in 2007 was expected to more fully explore if there was subsurface contamination and whether or not radioactivity was still spreading outward from the blast site itself.

text: The test succeeded in liberating large quantities of natural gas; however the resulting radioactivity left the gas contaminated and unsuitable for applications such as cooking and heating homes. Although projected public radiation exposures from commercial use of stimulated gas had been reduced to less than 1% of background, it became clear in the early 1970s that public acceptance within the U.S. of any product containing radioactivity, no matter how minimal, was difficult if not impossible. The

text: Department of Energy

text: began a cleanup of the site in the 1970s which was completed in 1998.  A

text: buffer zone

text: put in place by the state of Colorado still exists around the site.  A January 2005 report by the DOE stated that radioactivity levels were normal at the surface and in

text: groundwater

text: , though a later report due in 2007 was expected to more fully explore if there was subsurface contamination and whether or not radioactivity was still spreading outward from the blast site itself.

text: The discovery of the X-ray in 1895 and radioactivity in 1896 caused a great public fascination with things that were previously invisible or unseen. In response, photographers began to explore how they could capture what could not been seen by normal human vision.

text: The discovery of the

text: X-ray

text: in 1895 and

text: radioactivity

text: in 1896 caused a great public fascination with things that were previously invisible or unseen. In response, photographers began to explore how they could capture what could not been seen by normal human vision.

text: Due to all these facts and the heavy industries along the shoreline, airborne and marine pollution are serious problems in the area. Environmental groups have raised concerns about the risks of oil spills and other types of pollution, particularly in the light of the bay's ecological importance. In May 1998, an accident at the Acerinox plant in Los Barrios, caused the release of a radioactive cloud. The radiation was not detected on site, but was eventually detected in France, Italy, Switzerland, Germany, and Austria. The radioactive levels measured were up to 142 times higher than normal. Due to the large number of ships that transit the strait, there is always a danger of accidents and in recent years there have been a small number of sinkings, groundings and collisions in both Gibraltar and Spain resulting in oil spills (New Flame, Spa Bunker IV, Samothraki, Sierra Nava, Tawe and Fedra).

text: Due to all these facts and the heavy industries along the shoreline, airborne and marine pollution are serious problems in the area. Environmental groups have raised concerns about the risks of oil spills and other types of pollution, particularly in the light of the bay's ecological importance. In May 1998, an

text: accident at the Acerinox plant

text: in

text: Los Barrios

text: , caused the release of a radioactive cloud. The radiation was not detected on site, but was eventually detected in

text: France

text: Italy

text: Switzerland

text: Germany

text: , and

text: Austria

text: . The radioactive levels measured were up to 142 times higher than normal. Due to the large number of ships that transit the strait, there is always a danger of accidents and in recent years there have been a small number of sinkings, groundings and collisions in both Gibraltar and Spain resulting in oil spills (

text: New Flame

text: , Spa Bunker IV, Samothraki, Sierra Nava, Tawe and

text: Fedra

text: In the United States, the person within an organization responsible for the safe use of radiation and radioactive materials as well as regulatory compliance. An organization licensed by the Nuclear Regulatory Commission to use radioactive materials must designate a Radiation Safety Officer in writing.

text: In the

text: United States

text: , the person within an organization responsible for the safe use of

text: radiation

text: and

text: radioactive

text: materials as well as regulatory compliance. An organization licensed by the

text: Nuclear Regulatory Commission

text: to use radioactive materials must designate a Radiation Safety Officer in writing.

text: On December 6, 2011, radioactive cesium was found in Meiji baby formula. The level of contamination was lower than the Japanese government's allowable limit of 200 becquerels per kilogram, which is 50 becquerels higher than the limit applied in the aftermath of the Chernobyl disaster. The company made the controversial claim that the infant milk was "within safety limits" and that it "didn't pose a health risk", despite a potentially large number of infants suffering internal radiation through ingesting the contaminated milk who were presumably already exposed to the external radiation originally unleashed in the March disaster. Meiji Dairies voluntarily recalled 400,000 cans of formula. The radioactive contamination was originally discovered by a citizen's group in Nihonmatsu City, Fukushima Prefecture as far back as November but the company found itself unable to act immediately upon the information.

text: On December 6, 2011, radioactive

text: cesium

text: was found in Meiji baby formula. The level of contamination was lower than the Japanese government's allowable limit of 200 becquerels per kilogram, which is 50 becquerels higher than the limit applied in the aftermath of the

text: Chernobyl disaster

text: . The company made the controversial claim that the infant milk was "within safety limits" and that it "didn't pose a health risk", despite a potentially large number of infants suffering internal radiation through ingesting the contaminated milk who were presumably already exposed to the external radiation originally unleashed in the March disaster. Meiji Dairies voluntarily recalled 400,000 cans of formula. The radioactive contamination was originally discovered by a citizen's group in Nihonmatsu City, Fukushima Prefecture as far back as November but the company found itself unable to act immediately upon the information.

text: Although betavoltaics use a radioactive material as a power source, the beta particles used are low energy and easily stopped by shielding, as compared to the gamma rays generated by more dangerous radioactive materials. With proper device construction (that is, proper containment), a betavoltaic device would not emit dangerous radiation. Leakage of the enclosed material would engender health risks, just as leakage of the materials in other types of batteries leads to significant health and environmental concerns.

text: Although betavoltaics use a radioactive material as a power source, the beta particles used are low energy and easily stopped by shielding, as compared to the

text: gamma rays

text: generated by more dangerous radioactive materials. With proper device construction (that is, proper containment), a betavoltaic device would not emit dangerous radiation. Leakage of the enclosed material would engender health risks, just as leakage of the materials in other types of batteries leads to significant health and environmental concerns.

text: Nineteen radioisotopes of americium have been characterized, with the most stable being Am with a half-life of 7,370 years, and Am with a half-life of 432.2 years. All of the remaining radioactive isotopes have half-lives that are less than 51 hours, and the majority of these have half-lives that are less than 100 minutes. This element also has 8 meta states, with the most stable being Am (t 141 years). The isotopes of americium range in atomic weight from 231.046 u (Am) to 249.078 u (Am).

text: Nineteen

text: radioisotope

text: s of americium have been characterized, with the most stable being Am with a

text: half-life

text: of 7,370 years, and Am with a half-life of 432.2 years. All of the remaining

text: radioactive

text: isotopes have half-lives that are less than 51 hours, and the majority of these have half-lives that are less than 100 minutes. This element also has 8

text: meta state

text: s, with the most stable being Am (t 141 years). The isotopes of americium range in

text: atomic weight

text: from 231.046

text: u

text: (Am) to 249.078 u (Am).

text: The I isotope is also used as a radioactive label for certain radiopharmaceuticals that can be used for therapy, e.g. I-metaiodobenzylguanidine (I-MIBG) for imaging and treating pheochromocytoma and neuroblastoma. In all of these therapeutic uses, I destroys tissue by short-range beta radiation. About 90% of its radiation damage to tissue is via beta radiation, and the rest occurs via its gamma radiation (at a longer distance from the radioisotope). It can be seen in diagnostic scans after its use as therapy, because I is also a gamma-emitter.

text: The I isotope is also used as a radioactive label for certain

text: radiopharmaceutical

text: s that can be used for therapy, e.g. I-

text: metaiodobenzylguanidine

text: (I-MIBG) for imaging and treating

text: pheochromocytoma

text: and

text: neuroblastoma

text: . In all of these therapeutic uses, I destroys tissue by short-range

text: beta radiation

text: . About 90% of its radiation damage to tissue is via beta radiation, and the rest occurs via its gamma radiation (at a longer distance from the radioisotope). It can be seen in diagnostic scans after its use as therapy, because I is also a gamma-emitter.

text: When conducting an OSI, a number of detection techniques can be used.  These techniques include position finding, visual observation, passive seismic measurements and radioactivity measurements including gamma radiation and radioactive noble gases such as Argon-37 and isotopes of Xenon for an initial period of up to 25 days. Further, for a continuation period of up to 60 days, more intrusive measurements can be used on-site including active and resonance seismic measurements as well as ground penetrating radar, gravity, and electric and magnetic field mappings. Argon-37 field measurement is a unique technology specially developed for the purpose of OSI. Drilling to obtain radioactive samples from a suspected underground explosion site is also allowed. Data collected from various methods have to be fused and interpreted for decision making purposes.  An important task of the CTBTO is to explore how recent scientific and technical advances in these technologies can be applied to an OSI.

text: When conducting an OSI, a number of detection techniques can be used.  These techniques include position finding, visual observation, passive seismic measurements and radioactivity measurements including gamma radiation and radioactive noble gases such as

text: and

text: isotopes of Xenon

text: for an initial period of up to 25 days. Further, for a continuation period of up to 60 days, more intrusive measurements can be used on-site including active and resonance seismic measurements as well as ground penetrating radar, gravity, and electric and magnetic field mappings. Argon-37 field measurement is a unique technology specially developed for the purpose of OSI. Drilling to obtain radioactive samples from a suspected underground explosion site is also allowed. Data collected from various methods have to be fused and interpreted for decision making purposes.  An important task of the CTBTO is to explore how recent scientific and technical advances in these technologies can be applied to an OSI.

text: Decay products are important in understanding radioactive decay and the management of radioactive waste.

text: Decay products are important in understanding radioactive decay and the management of

text: radioactive waste

text: In the measurement of gamma rays or other ionising radiation, a radiation monitor or dosimeter will commonly use a filter to attenuate those energy levels or wavelengths that cause the least damage to the human body but letting through those that do the most damage, so any source of radiation may be measured in terms of its true danger rather than just its strength. The resulting unit is the sievert or microsievert.

text: In the measurement of gamma rays or other ionising radiation, a radiation monitor or dosimeter will commonly use a filter to attenuate those energy levels or wavelengths that cause the least damage to the human body but letting through those that do the most damage, so any source of radiation may be measured in terms of its true danger rather than just its strength. The resulting unit is the

text: sievert

text: or microsievert.

text: The long half-life of technetium-99 and its ability to form an anionic species makes it (along with I) a major concern when considering long-term disposal of high-level radioactive waste. In addition, many of the processes designed to remove fission products from medium-active process streams in reprocessing plants are designed to remove cationic species like caesium (e.g., Cs, Cs) and strontium (e.g., Sr). Hence the pertechnetate is able to escape through these treatment processes. Current disposal options favor burial in geologically stable rock.  The primary danger with such a course is that the waste is likely to come into contact with water, which could leach radioactive contamination into the environment. The anionic pertechnetate and iodide are less able to adsorb onto the surfaces of minerals, so they are likely to be more mobile. By comparison plutonium, uranium, and caesium are much more able to bind to soil particles. For this reason, the environmental chemistry of technetium is an active area of research.In 2012 the crystalline compound Notre Dame Thorium Borate-1 (NDTB-1) was presented by researchers at the University of Notre Dame. It can be tailored to safely absorb radioactive ions from nuclear waste streams. Once captured, the radioactive ions can then be exchanged for higher-charged species of a similar size, recycling the material for re-use. Lab results using the NDTB-1 crystals removed approximately 96 percent of technetium-99.

text: The long half-life of technetium-99 and its ability to form an

text: anionic

text: species makes it (along with

text: I

text: ) a major concern when considering long-term disposal of high-level radioactive waste. In addition, many of the processes designed to remove fission products from medium-active process streams in reprocessing plants are designed to remove

text: cationic

text: species like

text: caesium

text: (e.g.,

text: Cs

text: Cs

text: ) and

text: strontium

text: (e.g.,

text: Sr

text: ). Hence the pertechnetate is able to escape through these treatment processes. Current disposal options favor burial in geologically stable rock.  The primary danger with such a course is that the waste is likely to come into contact with water, which could leach radioactive contamination into the environment. The anionic pertechnetate and

text: iodide

text: are less able to

text: adsorb

text: onto the surfaces of minerals, so they are likely to be more mobile. By comparison

text: plutonium

text: uranium

text: , and

text: caesium

text: are much more able to bind to soil particles. For this reason, the environmental chemistry of technetium is an active area of research.In 2012 the crystalline compound Notre Dame Thorium Borate-1 (NDTB-1) was presented by researchers at the University of Notre Dame. It can be tailored to safely absorb radioactive ions from nuclear waste streams. Once captured, the radioactive ions can then be exchanged for higher-charged species of a similar size, recycling the material for re-use. Lab results using the NDTB-1 crystals removed approximately 96 percent of technetium-99.

text: National production of tantalite was estimated to be 240,000 kilograms (kg) in 2006 compared with 281,212 kg in 2005. Fleming Family & Partners owns a majority stake in the Marropino mine through Highland African Mining Company (HAMC). The company was unable to produce at Marropino until the fourth quarter of 2006 because of financial and technical problems. It closed the mine in 2013, saying that the ore with the most tantalum had already been processed, and what remained was both more radioactive and deeper, making production more expensive. Also, no port in Mozambique is certified to handle the level of radioactivity it found, so the company was obliged to send its product by truck to Walvis Bay in Namibia. It had been losing $3 US for exery tonne processed.

text: National production of

text: tantalite

text: was estimated to be 240,000 kilograms (kg) in 2006 compared with 281,212 kg in 2005.

text: Fleming Family & Partners

text: owns a majority stake in the

text: Marropino mine

text: through Highland African Mining Company (HAMC). The company was unable to produce at Marropino until the fourth quarter of 2006 because of financial and technical problems. It closed the mine in 2013, saying that the ore with the most tantalum had already been processed, and what remained was both more radioactive and deeper, making production more expensive. Also, no port in Mozambique is certified to handle the level of radioactivity it found, so the company was obliged to send its product by truck to

text: Walvis Bay

text: in Namibia. It had been losing $3 US for exery tonne processed.

text: The intake of radioactive material can occur through four pathways:1.	inhalation of airborne contaminants such as radon 2.	ingestion of contaminated food or liquids3.	absorption of vapors such as tritium oxide through the skin4.	injection of medical radioisotopes such as technetium-99m Some artificial radioisotopes such as iodine-131 are chemically identical to natural isotopes needed by the body, and may be more readily absorbed if the individual has a deficit of that element. For instance, potassium iodide (KI), administered orally immediately after exposure, may be used to protect the thyroid from ingested radioactive iodine in the event of an accident or attack at a nuclear power plant, or the detonation of a nuclear explosive which would release radioactive iodine.Other radioisotopes have an affinity for particular tissues, such as plutonium into bone, and may be retained there for years in spite of their foreign nature.

text: From 1946 to 1953, at the Walter E. Fernald State School in Massachusetts, in an experiment sponsored by the U.S. Atomic Energy Commission and the Quaker Oats corporation, 73 mentally disabled children were fed oatmeal containing radioactive calcium and other radioisotopes, in order to track "how nutrients were digested". The children were not told that they were being fed radioactive chemicals; they were told by hospital staff and researchers that they were joining a "science club".

text: From 1946 to 1953, at the

text: Walter E. Fernald State School

text: in Massachusetts, in an experiment sponsored by the U.S. Atomic Energy Commission and the

text: Quaker Oats

text: corporation, 73 mentally disabled children were fed

text: oatmeal

text: containing radioactive

text: calcium

text: and other

text: radioisotope

text: s, in order to track "how nutrients were digested". The children were not told that they were being fed radioactive chemicals; they were told by hospital staff and researchers that they were joining a "science club".

text: Marie and Pierre Curie’s study of radioactivity is an important factor in science and medicine. After their research on Becquerel's rays led them to the discovery on both radium and polonium, they coined the term "radioactivity." Their research on the penetrating rays in uranium and discovery of radium launched an era of using radium for treatment of cancer. Their exploration of radium could be seen as the first peaceful use of nuclear energy and the start of modern nuclear medicine.

text: Marie

text: and

text: Pierre Curie

text: ’s study of radioactivity is an important factor in science and medicine. After their research on

text: Becquerel

text: 's rays led them to the discovery on both radium and polonium, they coined the term "radioactivity." Their research on the penetrating rays in uranium and discovery of

text: radium

text: launched an era of using radium for treatment of cancer. Their exploration of radium could be seen as the first peaceful use of nuclear energy and the start of modern nuclear medicine.

text: The U.S. EPA's proposed standard for greater than 10,000 years is 250 times more permissive than the European limit. The U.S. EPA proposed a legal limit of a maximum of 3.5 millisieverts (350 millirem) each annually to local individuals after 10,000 years, which would be up to several percent of the exposure currently received by some populations in the highest natural background regions on Earth, though the U.S. DOE predicted that received dose would be much below that limit. Over a timeframe of thousands of years, after the most active short half-life radioisotopes decayed, burying U.S. nuclear waste would increase the radioactivity in the top 2000 feet of rock and soil in the United States (10 million km) by ≈ 1 part in 10 million over the cumulative amount of natural radioisotopes in such a volume, but the vicinity of the site would have a far higher concentration of artificial radioisotopes underground than such an average.

text: The U.S. EPA's proposed standard for greater than 10,000 years is 250 times more permissive than the European limit. The U.S. EPA proposed a legal limit of a maximum of 3.5

text: millisievert

text: s (350

text: millirem

text: ) each annually to local individuals after 10,000 years, which would be up to several percent of the exposure currently received by some populations in the highest natural background regions on Earth, though the U.S.

text: DOE

text: predicted that

text: received dose would be much below that limit

text: . Over a timeframe of thousands of years, after the most active short half-life radioisotopes decayed, burying U.S. nuclear waste would increase the radioactivity in the top 2000 feet of rock and soil in the

text: United States

text: (10 million km) by

text: natural radioisotopes

text: in such a volume, but the vicinity of the site would have a far higher concentration of artificial radioisotopes underground than such an average.

text: Environmental Dosimetry is used where it is likely that the environment will generate a significant radiation dose. An example of this is radon monitoring. Radon is a radioactive gas generated by the decay of uranium, which is present in varying amounts in the earth's crust. Certain geographic areas, due to the underlying geology, continually generate radon which permeates its way to the earth's surface. In some cases the dose can be significant in buildings where the gas can accumulate. A number of specialised dosimetry techniques are used to evaluate the dose that a building's occupants may receive.

text: Environmental Dosimetry is used where it is likely that the environment will generate a significant radiation dose. An example of this is

text: radon

text: monitoring. Radon is a radioactive gas generated by the decay of uranium, which is present in varying amounts in the earth's crust. Certain geographic areas, due to the underlying geology, continually generate radon which permeates its way to the earth's surface. In some cases the dose can be significant in buildings where the gas can accumulate. A number of specialised dosimetry techniques are used to evaluate the dose that a building's occupants may receive.

text: A radioisotope of iridium, , is dangerous like other radioactive isotopes. The only reported injuries related to iridium concern accidental exposure to radiation from  used in brachytherapy. High-energy gamma radiation from  can increase the risk of cancer. External exposure can cause burns, radiation poisoning, and death. Ingestion of Ir can burn the linings of the stomach and the intestines. Ir, Ir, and Ir tend to deposit in the liver, and can pose health hazards from both gamma and beta radiation.

text: A radioisotope of iridium, , is dangerous like other radioactive isotopes. The only reported injuries related to iridium concern accidental exposure to radiation from  used in

text: brachytherapy

text: . High-energy gamma radiation from  can increase the risk of cancer. External exposure can cause burns,

text: radiation poisoning

text: , and death. Ingestion of Ir can burn the linings of the stomach and the intestines. Ir, Ir, and Ir tend to deposit in the

text: liver

text: , and can pose health hazards from both

text: gamma

text: and

text: beta

text: radiation.

text: Maintaining the satirical standards of the television show, these comics often parodied genre comic books, and the reader can follow the evolution of Radioactive Man from a 1950s irradiated hero through the politically reactionary or radical years of the 1960s and 1970s, and the dark, troubled years of the 1980s and 1990s comic book hero. Indeed, one comic displays a startling similarity to Alan Moore's Watchmen, with Radioactive Man taking the part of state-supported hero Doctor Manhattan. The comics are published as if they were the actual Simpsons universe's Radioactive Man comics; a "1970s"-published comic features a letter written by a ten-year-old Marge Bouvier, for instance. The comic also takes the idea that the title has been running since the 1950s and each issue of the real series is a random issue from that run. So one issue might be issue #357, the next #432 and the next #567 etc.

text: Maintaining the satirical standards of the television show, these comics often parodied genre comic books, and the reader can follow the evolution of Radioactive Man from a 1950s irradiated hero through the politically reactionary or radical years of the 1960s and 1970s, and the dark, troubled years of the 1980s and 1990s comic book hero. Indeed, one comic displays a startling similarity to Alan Moore's

text: Watchmen

text: , with Radioactive Man taking the part of state-supported hero Doctor Manhattan. The comics are published as if they were the actual Simpsons universe's Radioactive Man comics; a "1970s"-published comic features a letter written by a ten-year-old

text: Marge Bouvier

text: , for instance. The comic also takes the idea that the title has been running since the 1950s and each issue of the real series is a random issue from that run. So one issue might be issue #357, the next #432 and the next #567 etc.

text: One biological application is the study of DNA using radioactive phosphorus-32. In these experiments stable phosphorus is replaced by the chemical identical radioactive P-32, and the resulting radioactivity is used in analysis of the molecules and their behaviour.

text: One biological application is the study of

text: DNA

text: using radioactive

text: phosphorus

text: -32. In these experiments stable phosphorus is replaced by the chemical identical radioactive P-32, and the resulting radioactivity is used in analysis of the molecules and their behaviour.

text: In addition to the above light elements, tritium and isotopes of aluminium, carbon (carbon-14), chlorine, iodine and neon are formed within solar system materials through cosmic ray spallation, and are termed cosmogenic nuclides. Since they remain trapped in the atmosphere or rock in which they formed, some can be very useful in the dating of materials by cosmogenic radionuclide dating, particularly in the geological field. In formation of a cosmogenic nuclide, a cosmic ray interacts with the nucleus of an in situ solar system atom, causing cosmic ray spallation. These isotopes are produced within earth materials such as rocks or soil, in Earth's atmosphere, and in extraterrestrial items such as meteorites.  By measuring cosmogenic isotopes, scientists are able to gain insight into a range of geological and astronomical processes.  There are both radioactive and stable cosmogenic isotopes. Some of the well-known naturally-occurring radioisotopes are tritium, carbon-14 and phosphorus-32.

text: In addition to the above light elements,

text: tritium

text: and

text: isotopes

text: of

text: aluminium

text: carbon

text: chlorine

text: iodine

text: and

text: neon

text: are formed within solar system materials through cosmic ray spallation, and are termed

text: cosmogenic nuclide

text: s. Since they remain trapped in the atmosphere or rock in which they formed, some can be very useful in the dating of materials by

text: cosmogenic radionuclide dating

text: , particularly in the geological field. In formation of a cosmogenic nuclide, a

text: cosmic ray

text: interacts with the

text: nucleus

text: of an

text: in situ

text: solar system

text: atom

text: , causing cosmic ray spallation. These isotopes are produced within earth materials such as

text: rock

text: s or

text: soil

text: , in

text: Earth's

text: atmosphere

text: , and in extraterrestrial items such as

text: meteorite

text: s.  By measuring cosmogenic isotopes,

text: scientist

text: geological

text: and

text: astronomical

text: processes.  There are both

text: radioactive

text: and

text: stable

text: cosmogenic isotopes. Some of the well-known naturally-occurring radioisotopes are

text: tritium

text: , carbon-14 and

text: phosphorus

text: Radioactive waste is generated from the nuclear weapons program, commercial nuclear power, medical applications, and corporate and university-based research programs. Some of the materials LLW consists of are: "gloves and other protective clothing, glass and plastic laboratory supplies, machine parts and tools, and disposable medical items that have come in contact with radioactive materials". Waste is generally categorized as high level waste (HLW) and low-level waste (LLW). LLW contains materials such as irradiated tools, lab clothing, ion exchanger resins, animal carcasses, and trash from defense, commercial nuclear power, medical, and research activities. These materials usually have radioactivity that have short half lives—from ranges of multiple days to several hundred years. In 1990, 1.1 million cubic feet of LLW was produced. Currently, U.S. reactors generate about 40,000 cubic meters of low-level radioactive waste per year, including contaminated components and materials resulting from reactor decommissioning.

text: Radioactive waste

text: is generated from the

text: nuclear weapons

text: program, commercial

text: nuclear power

text: , medical applications, and corporate and university-based research programs. Some of the materials LLW consists of are: "gloves and other protective clothing, glass and plastic laboratory supplies, machine parts and tools, and disposable medical items that have come in contact with radioactive materials". Waste is generally categorized as

text: high level waste

text: (HLW) and

text: low-level waste

text: (LLW). LLW contains materials such as irradiated tools, lab clothing, ion exchanger resins, animal carcasses, and trash from defense, commercial nuclear power, medical, and research activities. These materials usually have

text: radioactivity

text: that have short

text: half lives

text: —from ranges of multiple days to several hundred years. In 1990, 1.1 million cubic feet of LLW was produced. Currently, U.S. reactors generate about 40,000 cubic meters of

text: low-level radioactive waste

text: per year, including contaminated components and materials resulting from reactor

text: decommissioning

text: There are two stable and naturally occurring isotopes of bromine, bromine-79 and bromine-81. A total of 32 isotopes of bromine have been discovered, with atomic masses ranging 67 to 98. There is one stable and naturally occurring isotope of iodine, iodine-127. However, there are trace amounts in nature of the radioactive isotope iodine-129, which occurs via spallation and from the radioactive decay of uranium in ores. Several other radioactive isotopes of iodine have also been created naturally via the decay of uranium. A total of 38 isotopes of iodine have been discovered, with atomic masses ranging from 108 to 145.

text: There are two stable and naturally occurring

text: isotopes of bromine

text: , bromine-79 and bromine-81. A total of 32 isotopes of bromine have been discovered, with atomic masses ranging 67 to 98. There is one stable and naturally occurring

text: isotope of iodine

text: . However, there are trace amounts in nature of the radioactive isotope

text: , which occurs via spallation and from the radioactive decay of uranium in ores. Several other radioactive isotopes of iodine have also been created naturally via the decay of uranium. A total of 38 isotopes of iodine have been discovered, with atomic masses ranging from 108 to 145.

text: Granite is a natural source of radiation, like most natural stones. However, some granites have been reported to have higher radioactivity, thereby raising some concerns about their safety.

text: Granite is a natural source of

text: radiation

text: , like most natural stones. However, some granites have been reported to have higher radioactivity, thereby raising some concerns about their safety.

text: Cobalt-60 (Co-60 or Co) is a radioactive metal that is used in radiotherapy. It produces two gamma rays with energies of 1.17 MeV and 1.33 MeV. The Co source is about 2 cm in diameter and as a result produces a geometric penumbra, making the edge of the radiation field fuzzy. The metal has the unfortunate habit of producing a fine dust, causing problems with radiation protection. The Co source is useful for about 5 years but even after this point is still very radioactive, and so cobalt machines have fallen from favor in the Western world where linacs are common.

text: Cobalt-60 (Co-60 or Co)

text: is a radioactive metal that is used in

text: radiotherapy

text: . It produces two

text: gamma ray

text: s with energies of 1.17

text: MeV

text: and 1.33 MeV. The Co source is about 2 cm in

text: diameter

text: and as a result produces a

text: geometric

text: penumbra

text: , making the edge of the

text: radiation

text: field fuzzy. The metal has the unfortunate habit of producing a fine dust, causing problems with radiation protection. The Co source is useful for about 5 years but even after this point is still very radioactive, and so cobalt machines have fallen from favor in the Western world where

text: linacs

text: are common.

text: The study of phosphorescent materials led to the discovery of radioactivity in 1896.

text: The study of phosphorescent materials led to the

text: discovery of radioactivity

text: in 1896.

text: The gamma ray log is a measurement of naturally occurring gamma radiation from the borehole walls.  Sandstones are usually nonradioactive quartz and limestones are nonradioactive calcite.  Shales however, are naturally radioactive due to potassium isotopes in clays, and adsorbed uranium and thorium.  Thus the presence or absence of gamma rays in a borehole is an indication of the amount of shale or clay in the surrounding formation.  The gamma ray log is useful in holes drilled with air or with oil based muds, as these wells have no SP voltage.  Even in water-based muds, the gamma ray and SP logs are often run together.  They comprise a check on each other and can indicate unusual shale sections which may either not be radioactive, or may have an abnormal ionic chemistry.  The gamma ray log is also useful to detect coal beds, which, depending on the local geology, can have either low radiation levels, or high radiation levels due to adsorption of uranium.  In addition, the gamma ray log will work inside a steel casing, making it essential when a cased well must be evaluated.

text: Radiation and radioactive substances are used for diagnosis, treatment, and research. X-rays, for example, pass through muscles and other soft tissue but are stopped by dense materials. This property of X-rays enables doctors to find broken bones and to locate cancers that might be growing in the body. Doctors also find certain diseases by injecting a radioactive substance and monitoring the radiation given off as the substance moves through the body. Radiation used for cancer treatment is called ionizing radiation because it forms ions in the cells of the tissues it passes through as it dislodges electrons from atoms. This can kill cells or change genes so the cells cannot grow. Other forms of radiation such as radio waves, microwaves, and light waves are called non-ionizing. They don't have as much energy and are not able to ionize cells.

text: Henri Becquerel discovered radioactivity in 1896 while working with phosphorescent materials. His work confirmed and explained earlier observations regarding uranium salts by Abel Niépce de Saint-Victor in 1857.

text: Henri Becquerel

text: discovered

text: radioactivity

text: in 1896 while working with

text: phosphorescent

text: materials. His work confirmed and explained earlier observations regarding

text: uranium

text: salts by

text: Abel Niépce de Saint-Victor

text: in 1857.

text: In experimental and applied particle physics, nuclear physics, and nuclear engineering, a particle detector, also known as a radiation detector, is a device used to detect, track, and/or identify ionising particles, such as those produced by nuclear decay, cosmic radiation, or reactions in a particle accelerator. Detectors can measure the particle energy and other attributes such as momentum, spin, charge, in addition to merely registering the presence of the particle.

text: In experimental and applied

text: particle physics

text: nuclear physics

text: , and

text: nuclear engineering

text: , a particle detector, also known as a radiation detector, is a device used to detect, track, and/or identify ionising

text: particle

text: s, such as those produced by

text: nuclear decay

text: cosmic radiation

text: , or reactions in a

text: particle accelerator

text: . Detectors can measure the particle energy and other attributes such as momentum, spin, charge, in addition to merely registering the presence of the particle.

text: The internal radiation dose due to ingested or inhaled radioactive substances is known as committed dose.

text: The internal radiation dose due to ingested or inhaled radioactive substances is known as

text: committed dose

text: In "What If the Radioactive Spider Had Bitten Someone Else?", Betty is one of three candidates - along with Flash Thompson and John Jameson - who is bitten by the radioactive spider which gave Spider-Man his powers. After confiding in Peter, and with his assistance, she begins to fight crime under the name "The Amazing Spider-Girl", with a mask similar to Spider-Man's but a very different costume. One time, she fails to stop a certain crook, who subsequently murders Peter's uncle Ben. The shock over the consequences of her failure makes Betty quit her Spider-Girl identity, although Peter takes up the identity of Spider-Man later on by synthetically recreating and ingesting the irradiated spider's venom. This incarnation also appears in the Spider-Verse.

text: In "

text: What If

text: the Radioactive Spider Had Bitten Someone Else?", Betty is one of three candidates - along with

text: Flash Thompson

text: and

text: John Jameson

text: - who is bitten by the radioactive spider which gave

text: Spider-Man

text: his powers. After confiding in Peter, and with his assistance, she begins to fight crime under the name "The Amazing Spider-Girl", with a mask similar to Spider-Man's but a very different costume. One time, she fails to stop a certain

text: crook

text: , who subsequently murders Peter's uncle

text: Ben

text: . The shock over the consequences of her failure makes Betty quit her Spider-Girl identity, although Peter takes up the identity of Spider-Man later on by synthetically recreating and ingesting the irradiated spider's venom. This incarnation also appears in the

text: Spider-Verse

text: Transmutation of transuranium elements (TRUs, i.e. actinides minus actinium to uranium) such as the isotopes of plutonium (about 1wt% in the Light Water Reactors' used nuclear fuel) or the minor actinides (MAs, i.e. neptunium, americium, and curium, about 0.1wt% each in LWRs' UNF) has the potential to help solve some problems posed by the management of radioactive waste by reducing the proportion of long-lived isotopes it contains. (This does not rule-out the need for a Deep Geological Repository (DGR) for High radioactive Level Waste (HLW).) When irradiated with fast neutrons in a nuclear reactor, these isotopes can  undergo nuclear fission, destroying the original actinide isotope and producing a spectrum of radioactive and nonradioactive fission products.

text: Transmutation of

text: transuranium element

text: s (TRUs, i.e.

text: actinides

text: minus

text: actinium

text: to

text: uranium

text: ) such as the

text: isotope

text: s of

text: plutonium

text: (about 1wt% in the

text: Light Water Reactor

text: s' used

text: nuclear fuel

text: ) or the minor actinides (MAs, i.e.

text: neptunium

text: americium

text: , and

text: curium

text: , about 0.1wt% each in LWRs' UNF) has the potential to help solve some problems posed by the management of

text: radioactive waste

text: by reducing the proportion of long-lived isotopes it contains. (This does not rule-out the need for a Deep Geological Repository (DGR) for High radioactive Level Waste (HLW).) When irradiated with

text: fast neutrons

text: in a

text: nuclear reactor

text: , these isotopes can  undergo

text: nuclear fission

text: , destroying the original

text: actinide

text: isotope and producing a spectrum of radioactive and nonradioactive

text: fission products

text: A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is an atom that has excess nuclear energy, making it unstable. This excess energy can be either emitted from the nucleus as gamma radiation, or create and emit from the nucleus a new particle (alpha particle or beta particle), or transfer this excess energy to one of its electrons, causing that electron to be ejected as a conversion electron. During those processes, the radionuclide is said to undergo radioactive decay. These emissions constitute ionizing radiation. The unstable nucleus is more stable following the emission, but will sometimes undergo further decay. Radioactive decay is a random process at the level of single atoms: it is impossible to predict when one particular atom will decay. However, for a collection of atoms of a single element the decay rate, and thus the half-life (t) for that collection can be calculated from their measured decay constants. The range of the half-lives of radioactive atoms have no known limits and span a time range of over 55 orders of magnitude.

text: A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is an

text: atom

text: that has excess nuclear energy, making it unstable. This excess energy can be either emitted from the nucleus as

text: gamma radiation

text: , or create and emit from the nucleus a new

text: particle

text: alpha particle

text: or

text: beta particle

text: ), or transfer this excess energy to one of its

text: electron

text: s, causing that electron to be ejected as a

text: conversion electron

text: . During those processes, the radionuclide is said to undergo

text: radioactive decay

text: . These emissions constitute

text: ionizing radiation

text: . The unstable nucleus is more stable following the emission, but will sometimes undergo further decay. Radioactive decay is a random process at the level of single atoms: it is impossible to predict when one particular atom will decay. However, for a collection of atoms of a single element the decay rate, and thus the

text: half-life

text: (t) for that collection can be calculated from their measured

text: decay constant

text: s. The range of the half-lives of radioactive atoms have no known limits and span a time range of over 55 orders of magnitude.

text: SN 1987A was a supernova in the outskirts of the Tarantula Nebula in the Large Magellanic Cloud (a nearby dwarf galaxy). It occurred approximately 51.4 kiloparsecs from Earth, approximately 168,000 light-years, close enough that it was visible to the naked eye. It could be seen from the Southern Hemisphere. It was the closest observed supernova since SN 1604, which occurred in the Milky Way itself. The light from the new supernova reached Earth on February 23, 1987. As it was the first supernova discovered in 1987, it was labeled “1987A”. Its brightness peaked in May with an apparent magnitude of about 3 and slowly declined in the following months. It was the first opportunity for modern astronomers to study the development of a supernova in detail, and observations have provided much insight into core-collapse supernovae. Of special importance, SN1987A provided the first chance to confirm by direct observation the radioactive source of the energy for visible light emissions by detection of predicted gamma-ray line radiation from two of its abundant radioactive nuclei, Co and Co. This proved the radioactive nature of the long-duration post-explosion glow of supernovae.

text: SN 1987A was a

text: supernova

text: in the outskirts of the

text: Tarantula Nebula

text: in the

text: Large Magellanic Cloud

text: (a nearby

text: dwarf galaxy

text: ). It occurred approximately 51.4

text: kiloparsecs

text: from

text: Earth

text: , approximately 168,000

text: light-year

text: s, close enough that it was visible to the

text: naked eye

text: . It could be seen from the Southern Hemisphere. It was the closest observed supernova since

text: SN 1604

text: , which occurred in the

text: Milky Way

text: itself. The light from the new supernova reached Earth on February 23, 1987. As it was the first supernova discovered in 1987, it was labeled “1987A”. Its brightness peaked in May with an

text: apparent magnitude

text: of about 3 and slowly declined in the following months. It was the first opportunity for modern

text: astronomers

text: to study the development of a supernova in detail, and observations have provided much insight into

text: core-collapse supernova

text: e. Of special importance, SN1987A provided the first chance to confirm by direct observation the radioactive source of the energy for visible light emissions by detection of predicted gamma-ray line radiation from two of its abundant radioactive nuclei,

text: Co

text: and

text: Co

text: . This proved the radioactive nature of the long-duration post-explosion glow of supernovae.

text: Radiochemistry also includes the study of the behaviour of radioisotopes in the environment; for instance, a forest or grass fire can make radioisotopes become mobile again. In these experiments, fires were started in the exclusion zone around Chernobyl and the radioactivity in the air downwind was measured.

text: Radiochemistry also includes the study of the behaviour of radioisotopes in the environment; for instance, a forest or grass fire can make radioisotopes become mobile again. In these experiments, fires were started in the exclusion zone around

text: Chernobyl

text: and the radioactivity in the air downwind was measured.

text: The heat index used by the U.S. National Weather Service and the humidex used by the Meteorological Service of Canada, along with the wind chill used in both countries, are also measures of perceived heat or cold, but they do not account for the effects of radiation. AccuWeather, a commercial weather forecasting company, offers a product known as the "RealFeel" temperature that purportedly takes radiation into account (presumably by approximation, since American weather observation systems do not measure solar radiation directly); the RealFeel formula is a proprietary trade secret.

text: The

text: heat index

text: used by the U.S.

text: National Weather Service

text: and the

text: humidex

text: used by the

text: Meteorological Service of Canada

text: , along with the

text: wind chill

text: used in both countries, are also measures of perceived heat or cold, but they do not account for the effects of radiation.

text: AccuWeather

text: , a commercial

text: weather forecast

text: ing company, offers a product known as the "RealFeel" temperature that purportedly takes radiation into account (presumably by

text: approximation

text: , since American

text: weather observation

text: systems do not measure solar radiation directly); the RealFeel formula is a proprietary

text: trade secret

text: Health physics and epidemiology continue to be major areas of activity for ORAU and ORISE. Activities include radiological surveys, dose reconstruction, and health screening for workers who may have been exposed to radioactive material, beryllium, or other toxins. The Radiation Emergency Assistance Center/Training Site (REAC/TS) continues to operate as a part of ORISE. A Cytogenetics Biodosimetry Laboratory has been established within ORISE to provide capabilities for measuring radiation dose and to conduct research to improve techniques for determining the doses received by victims of radiological accidents.

text: Health physics

text: and

text: epidemiology

text: continue to be major areas of activity for ORAU and ORISE. Activities include

text: radiological survey

text: s,

text: dose reconstruction

text: , and health screening for workers who may have been exposed to

text: radioactive material

text: beryllium

text: , or other

text: toxins

text: . The Radiation Emergency Assistance Center/Training Site (REAC/TS) continues to operate as a part of ORISE. A

text: Cytogenetics

text: Biodosimetry

text: Laboratory has been established within ORISE to provide capabilities for measuring

text: radiation dose

text: and to conduct research to improve techniques for determining the doses received by victims of radiological accidents.

text: The Farr assay is used to quantify the amount of anti-dsDNA antibodies in serum. Ammonium sulphate is used to precipitate antigen-antibody complexes that form if the sera contains antibodies to dsDNA. The quantity of these antibodies is determined by using radioactively labelled dsDNA. Although this test is very specific, it is of little use in routine diagnostic laboratories due to its laboriousness and use of radioactive materials. The Farr assay is one of the only tests available that detects high avidity antibodies (along with Crithidia luciliae) and also has the ability to detect antibodies of any isotype.

text: The Farr assay is used to quantify the amount of anti-dsDNA antibodies in

text: serum

text: Ammonium sulphate

text: is used to precipitate antigen-antibody complexes that form if the sera contains antibodies to dsDNA. The quantity of these antibodies is determined by using radioactively labelled dsDNA. Although this test is very specific, it is of little use in routine diagnostic laboratories due to its laboriousness and use of radioactive materials. The Farr assay is one of the only tests available that detects high avidity antibodies (along with Crithidia luciliae) and also has the ability to detect antibodies of any isotype.

text: She was towed to the Pacific via Philadelphia and the Panama Canal, departing on 3 March. The ship survived two atomic bomb blasts: Test Able, an air burst on 1 July 1946 and Test Baker, a submerged detonation on 25 July. Prinz Eugen was moored about  from the epicenter of both blasts and was only lightly damaged by them; the Able blast only bent her foremast and broke the top of her main mast. She suffered no significant structural damage from the explosions but was thoroughly contaminated with radioactive fallout. The irradiated ship was towed to the Kwajalein Atoll in the central Pacific, where a small leak went unrepaired due to the radiation danger. On 29 August 1946, the US Navy decommissioned Prinz Eugen.

text: She was towed to the Pacific via

text: Philadelphia

text: and the

text: Panama Canal

text: , departing on 3 March. The ship survived two atomic bomb blasts:

text: Test Able

text: , an air burst on 1 July 1946 and

text: Test Baker

text: , a submerged detonation on 25 July. Prinz Eugen was moored about  from the epicenter of both blasts and was only lightly damaged by them; the Able blast only bent her foremast and broke the top of her main mast. She suffered no significant structural damage from the explosions but was thoroughly contaminated with radioactive fallout. The irradiated ship was towed to the

text: Kwajalein Atoll

text: in the central Pacific, where a small leak went unrepaired due to the radiation danger. On 29 August 1946, the US Navy decommissioned Prinz Eugen.

text: The radiation exposure of these individuals is carefully monitored with the use of dosimeters and other radiological protection instruments which will measure radioactive particulate concentrations, area gamma dose readings and radioactive contamination. A legal record of dose is kept.

text: The radiation exposure of these individuals is carefully monitored with the use of

text: dosimeter

text: s and other radiological protection instruments which will measure radioactive particulate concentrations, area gamma dose readings and

text: radioactive contamination

text: . A legal record of dose is kept.

text: In 1903, the discoverer of the electron, J. J. Thomson, wrote a letter to the journal Nature in which he detailed his discovery of the presence of radioactivity in well water. Soon after, others found that the waters in many of the world's most famous health springs were also radioactive. This radioactivity is due to the presence of radium emanation produced by the radium that is present in the ground through which the waters flow. In 1904, Nature published a study on the natural radioactivity of different mineral waters.

text: In 1903, the discoverer of the electron,

text: J. J. Thomson

text: , wrote a letter to the journal Nature in which he detailed his discovery of the presence of radioactivity in well water. Soon after, others found that the waters in many of the world's most famous health springs were also radioactive. This radioactivity is due to the presence of radium emanation produced by the radium that is present in the ground through which the waters flow. In 1904, Nature published a study on the natural radioactivity of different mineral waters.

text: After an overhaul, Pioneer set out on 25 February 1962 to begin the 1962 field season, running a deep-sea sounding line to Hawaii. Departing Pearl Harbor on 16 March 1962, she resumed her survey of the North Pacific Ocean, running a sounding line to 35 degrees 30 minutes North latitude, and another sounding line to San Francisco, where she arrived on 25 March 1962. After 20 of her personnel attended Radiation and Decontamination School, she departed California on 20 April 1962 and conducted an investigation of Pacific waters which had seen recent underwater nuclear tests, including water temperature measurements, chemical analyses, measurements of radioactivity and of the different elements making up the radioactive water in the area of an underwater nuclear explosion, and study of the effects of radioactivity on plant and animal life in and near the test areas. She completed the project on 25 June 1962 and returned to California, arriving at Oakland. She had conducted gravimetric measurements continuously throughout the voyage.

text: After an overhaul, Pioneer set out on 25 February 1962 to begin the 1962 field season, running a deep-sea sounding line to Hawaii. Departing Pearl Harbor on 16 March 1962, she resumed her survey of the North Pacific Ocean, running a sounding line to

text: 35 degrees

text: 30 minutes North latitude, and another sounding line to San Francisco, where she arrived on 25 March 1962. After 20 of her personnel attended Radiation and Decontamination School, she departed California on 20 April 1962 and conducted an investigation of Pacific waters which had seen recent underwater nuclear tests, including water temperature measurements,

text: chemical analyses

text: , measurements of radioactivity and of the different elements making up the radioactive water in the area of an underwater nuclear explosion, and study of the effects of radioactivity on plant and animal life in and near the test areas. She completed the project on 25 June 1962 and returned to California, arriving at

text: Oakland

text: . She had conducted gravimetric measurements continuously throughout the voyage.

text: occurs in natural potassium (and thus in some commercial salt substitutes) in sufficient quantity that large bags of those substitutes can be used as a radioactive source for classroom demonstrations.  is the radioisotope with the largest abundance in the body. In healthy animals and people,  represents the largest source of radioactivity, greater even than . In a human body of 70 kg mass, about 4,400 nuclei of  decay per second. The activity of natural potassium is 31 Bq/g.

text: occurs in natural potassium (and thus in some commercial salt substitutes) in sufficient quantity that large bags of those substitutes can be used as a radioactive source for classroom demonstrations.  is the radioisotope with the largest abundance in the body. In healthy animals and people,  represents the largest source of radioactivity, greater even than . In a human body of 70 kg mass, about 4,400 nuclei of  decay per second. The activity of natural potassium is 31

text: Bq

text: /g.

text: In April 2011, the United States Department of Energy published projections of the radiation risks over the next year (that is, for the future) for people living in the neighborhood of the plant. Potential exposure could exceed 20 mSv/year (2 rems/year) in some areas up to 50 kilometers from the plant. That is the level at which relocation would be considered in the USA, and it is a level that could cause roughly one extra cancer case in 500 young adults. However, natural radiation levels are higher in some parts of the world than the projected level mentioned above, and about 4 people out of 10 can be expected to develop cancer without exposure to radiation. Further, the radiation exposure resulting from the incident for most people living in Fukushima is so small compared to background radiation that it may be impossible to find statistically significant evidence of increases in cancer.

text: During his investigations of radioactivity, Ernest Rutherford coined the terms alpha rays, beta rays and gamma rays for the three types of emissions that occur during radioactive decay.

text: During his investigations of radioactivity,

text: Ernest Rutherford

text: coined the terms

text: alpha rays

text: beta rays

text: and

text: gamma ray

text: s for the three types of emissions that occur during

text: radioactive decay

text: Radioactive decay (also known as nuclear decay or radioactivity) is the process by which the nucleus of an unstable atom loses energy by emitting radiation, including alpha particles, beta particles, gamma rays, and conversion electrons. A material that spontaneously emits such radiation is considered radioactive.

text: Radioactive decay (also known as nuclear decay or radioactivity) is the process by which the

text: nucleus

text: of an unstable

text: atom

text: loses energy by emitting radiation, including

text: alpha particle

text: s,

text: beta particle

text: s,

text: gamma ray

text: s, and

text: conversion electrons

text: . A material that spontaneously emits such radiation is considered radioactive.

text: All fission reactions necessarily generate fission products, the radioactive remains of the atomic nuclei split by the fission reactions. Many fission products are either highly radioactive (but short-lived) or moderately radioactive (but long-lived), and as such are a serious form of radioactive contamination if not fully contained. Fission products are the principal radioactive component of nuclear fallout.

text: All fission reactions necessarily generate

text: fission products

text: , the radioactive remains of the atomic nuclei split by the fission reactions. Many fission products are either highly radioactive (but short-lived) or moderately radioactive (but long-lived), and as such are a serious form of

text: radioactive contamination

text: if not fully contained. Fission products are the principal radioactive component of

text: nuclear fallout

text: The dangers of ionizing radiation due to radioactivity and X-rays were not immediately recognized.

text: The dangers of

text: ionizing radiation

text: due to radioactivity and X-rays were not immediately recognized.

text: Federal Communications Commission (FCC) investigators arrive in the San Fernando Valley after what appears to be a flying saucer crash, causing massive interference with tele-radio transmissions. During their investigation, they receive eyewitness reports of what appears to be a man dressed in a bizarre outfit, which appears to be radioactive and thus a public threat.

text: Federal Communications Commission

text: (FCC) investigators arrive in the

text: San Fernando Valley

text: after what appears to be a

text: flying saucer

text: crash, causing massive interference with tele-radio transmissions. During their investigation, they receive eyewitness reports of what appears to be a man dressed in a bizarre outfit, which appears to be radioactive and thus a public threat.

text: Clayton created new tools for calculating the interstellar abundances of radioactive nuclei in the Galaxy. In 1964 he discovered a new method for measuring the age of interstellar nuclei based on the larger than expected observed abundances of stable daughters of radioactive nuclei. The decays of rhenium-187 to osmium-187 and of uranium and thorium to three differing isotopes of lead (Pb) defined the cosmoradiogenic chronologies. Merging his method with an earlier method based only on the abundances of uranium and thorium themselves still did not yield a precise galactic age, however. Clayton wrote that the discord arose from inadequate treatments of both the history of star formation in the Galaxy and of the rate of infall of pristine metal-free gas onto the young Milky Way, compounded by a prevailing but erroneous technique for computation of the radioactive abundances within interstellar gas. Clayton reasoned that interstellar gas contains higher concentrations of shorter-lived radioactive nuclei than do the stars. With that insight he invented in 1985 new mathematical solutions for the simplified differential equation of galactic abundance evolution that for the first time rendered these relationships transparent, ending decades of confusion. Clayton calculated an age of 13-15 billion years for the oldest galactic nuclei, which would necessarily be approximately equal to the age of our galaxy. More recently radioactive  cosmochronology has diminished in importance because more accurate techniques for determining the age of the Milky Way have been discovered in the microwave background; but agreement confirmed correctness of his treatment of radioactivity in astronomy. His analytic mathematical models demonstrated that the concentration of short-lived radioactive nuclei in interstellar gas had routinely been underestimated by the factor 1/(k+1), where k is an integer near 2 or 3 that measures the steepness of the rate of decline of the infall of pristine gas onto our galaxy. In a parallel scientific development the identities and initial abundances of  shorter-lived radioactive nuclei that remained alive at variable levels within the interstellar gas cloud that formed the early solar system, but which are now extinct, has grown in importance with more experimental discoveries of such nuclei within the meteorites. These are called extinct radioactivities because none remain on earth today. Simultaneous solution for their abundances became the guiding principle for a new discipline of galactic abundance evolution that focuses on nucleosynthesis near the solar interstellar cloud during the billion years preceding solar birth. In 1983, at a time when astrophysicists were relying on only a uniform model of a well mixed interstellar gas,  Clayton introduced a new aspect of the ISM that has proven to be essential for understanding the abundances of the extinct radioactivities; namely the time required for isotopic mixing between freshly synthesized atoms ejected from supernovae with distinct physical phases of interstellar gas. He showed that owing to those time delays allowing more interstellar decay of radioactive nuclei, each phase of interstellar gas contains a distinctly different concentration of each of the extinct radioactive nuclides; but that the early solar system radioactivities measured specifically only abundances in the dense molecular-cloud phase in which the solar system had been born. In the 21st century many researchers have begun to present their own calculations of the effect of interstellar inter-phase mixing, often unaware of Clayton's (1983) paper owing to intervening decades. These aspects of interstellar phase mixing will remain important for decades to come while astronomers probe the circumstances of solar birth using accurate meteoritic data revealing the abundances of the extinct radioactive nuclei. Clayton gave emphasis to extinct radioactivity in the Glossary of his 2003 book on isotopes in the cosmos. Chapters 16 and 17 of "Catch a Falling Star".

text: Radiation burns may be caused by protracted exposure to ultraviolet light (such as from the sun, tanning booths or arc welding) or from ionizing radiation (such as from radiation therapy, X-rays or radioactive fallout). Sun exposure is the most common cause of radiation burns and the most common cause of superficial burns overall. There is significant variation in how easily people sunburn based on their skin type. Skin effects from ionizing radiation depend on the amount of exposure to the area, with hair loss seen after 3 Gy, redness seen after 10 Gy, wet skin peeling after 20 Gy, and necrosis after 30 Gy. Redness, if it occurs, may not appear until some time after exposure. Radiation burns are treated the same as other burns. Microwave burns occur via thermal heating caused by the microwaves. While exposures as short as two seconds may cause injury, overall this is an uncommon occurrence.

text: Radiation burn

text: s may be caused by protracted exposure to

text: ultraviolet light

text: (such as from the sun,

text: tanning booth

text: s or

text: arc welding

text: ) or from

text: ionizing radiation

text: (such as from

text: radiation therapy

text: X-rays

text: or

text: radioactive fallout

text: ). Sun exposure is the most common cause of radiation burns and the most common cause of superficial burns overall. There is significant variation in how easily people

text: sunburn

text: based on their

text: skin type

text: . Skin effects from ionizing radiation depend on the amount of exposure to the area, with hair loss seen after 3

text: Gy

text: , redness seen after 10 Gy, wet skin peeling after 20 Gy, and necrosis after 30 Gy. Redness, if it occurs, may not appear until some time after exposure. Radiation burns are treated the same as other burns.

text: Microwave burn

text: s occur via thermal heating caused by the

text: microwaves

text: . While exposures as short as two seconds may cause injury, overall this is an uncommon occurrence.

text: The largest natural contributor to public radiation dose is radon, a naturally occurring, radioactive gas found in soil and rock. If the gas is inhaled, some of the radon particles may attach to the inner lining of the lung. These particles continue to decay, emitting alpha particles, which can damage cells in the lung tissue. The death of Marie Curie at age 66 from aplastic anemia was probably caused by prolonged exposure to high doses of ionizing radiation, but it is not clear if this was due to alpha radiation or X-rays. Curie worked extensively with radium, which decays into radon, along with other radioactive materials that emit beta and gamma rays. However, Curie also worked with unshielded X-ray tubes during World War I, and analysis of her skeleton during a reburial showed a relatively low level of radioisotope burden.

text: The largest natural contributor to public radiation dose is

text: radon

text: , a naturally occurring, radioactive gas found in soil and rock. If the gas is inhaled, some of the radon particles may attach to the inner lining of the lung. These particles continue to decay, emitting alpha particles, which can damage cells in the lung tissue. The death of

text: Marie Curie

text: at age 66 from

text: aplastic anemia

text: was probably caused by prolonged exposure to high doses of ionizing radiation, but it is not clear if this was due to alpha radiation or X-rays. Curie worked extensively with radium, which decays into radon, along with other radioactive materials that emit

text: beta

text: and

text: gamma ray

text: s. However, Curie also worked with unshielded X-ray tubes during World War I, and analysis of her skeleton during a reburial showed a relatively low level of radioisotope burden.

text: In order for a terrorist organization to construct and detonate a dirty bomb, it must acquire radioactive material. Possible RDD material could come from the millions of radioactive sources used worldwide in the industry, for medical purposes and in academic applications mainly for research. Of these sources, only nine reactor produced isotopes stand out as being suitable for radiological terror: americium-241, californium-252, caesium-137, cobalt-60, iridium-192, plutonium-238, polonium-210, radium-226 and strontium-90, and even from these it is possible that radium-226 and polonium-210 do not pose a significant threat. Of these sources the U.S. Nuclear Regulatory Commission has estimated that within the U.S., approximately one source is lost, abandoned or stolen every day of the year. Within the European Union the annual estimate is 70. There exist thousands of such "orphan" sources scattered throughout the world, but of those reported lost, no more than an estimated 20 percent can be classified as a potential high security concern if used in a RDD. Especially Russia is believed to house thousands of orphan sources, which were lost following the collapse of the Soviet Union. A large but unknown number of these sources probably belong to the high security risk category. Noteworthy are the  beta emitting strontium-90 sources used as radioisotope thermoelectric generators for beacons in lighthouses in remote areas of Russia. In December 2001, three Georgian woodcutters stumbled over such a power generator and dragged it back to their camp site to use it as a heat source. Within hours they suffered from acute radiation sickness and sought hospital treatment. The International Atomic Energy Agency (IAEA) later stated that it contained approximately  of strontium, equivalent to the amount of radioactivity released immediately after the Chernobyl accident (though the total radioactivity release from Chernobyl was 2500 times greater at around ).

text: In order for a terrorist organization to construct and detonate a dirty bomb, it must acquire radioactive material. Possible RDD material could come from the millions of radioactive sources used worldwide in the industry, for medical purposes and in academic applications mainly for research. Of these sources, only nine reactor produced

text: isotope

text: s stand out as being suitable for radiological terror:

text: and

text: , and even from these it is possible that radium-226 and polonium-210 do not pose a significant threat. Of these sources the U.S.

text: Nuclear Regulatory Commission

text: has estimated that within the U.S., approximately one source is lost, abandoned or stolen every day of the year. Within the

text: European Union

text: the annual estimate is 70. There exist thousands of such "orphan" sources scattered throughout the world, but of those reported lost, no more than an estimated 20 percent can be classified as a potential high security concern if used in a RDD. Especially

text: Russia

text: is believed to house thousands of orphan sources, which were lost following the collapse of the

text: Soviet Union

text: . A large but unknown number of these sources probably belong to the high security risk category. Noteworthy are the  beta emitting strontium-90 sources used as

text: radioisotope thermoelectric generator

text: s for

text: beacon

text: s in lighthouses in remote areas of Russia. In December 2001, three

text: Georgian

text: woodcutters stumbled over such a power generator and dragged it back to their camp site to use it as a heat source. Within hours they suffered from acute radiation sickness and sought hospital treatment. The

text: International Atomic Energy Agency

text: (IAEA) later stated that it contained approximately  of strontium, equivalent to the amount of radioactivity released immediately after the

text: Chernobyl accident

text: (though the total radioactivity release from Chernobyl was 2500 times greater at around ).

text: Neutron activation analysis is a sensitive multi-element analytical technique used for both qualitative and quantitative analysis of major, minor, trace and rare elements. NAA was discovered in 1936 by Hevesy and Levi, who found that samples containing certain rare earth elements became highly radioactive after exposure to a source of neutrons. This observation led to the use of induced radioactivity for the identification of elements. NAA is significantly different from other spectroscopic analytical techniques in that it is based not on electronic transitions but on nuclear transitions. To carry out an NAA analysis, the specimen is placed into a suitable irradiation facility and bombarded with neutrons. This creates artificial radioisotopes of the elements present. Following irradiation, the artificial radioisotopes decay with emission of particles or, more importantly gamma rays, which are characteristic of the element from which they were emitted.

text: Neutron activation analysis is a sensitive multi-

text: element

text: analytical technique used for both

text: qualitative

text: and

text: quantitative

text: analysis of major, minor, trace and rare elements. NAA was discovered in 1936 by

text: Hevesy

text: and Levi, who found that samples containing certain

text: rare earth elements

text: became highly

text: radioactive

text: after exposure to a source of

text: neutrons

text: . This observation led to the use of induced radioactivity for the identification of elements. NAA is significantly different from other spectroscopic analytical techniques in that it is based not on electronic transitions but on nuclear transitions. To carry out an NAA analysis, the specimen is placed into a suitable irradiation facility and bombarded with neutrons. This creates artificial radioisotopes of the elements present. Following irradiation, the artificial

text: radioisotopes

text: decay with emission of particles or, more importantly

text: gamma ray

text: s, which are characteristic of the element from which they were emitted.

text: All of the alkali metals except lithium and caesium have at least one naturally occurring radioisotope: sodium-22 and sodium-24 are trace radioisotopes produced cosmogenically, potassium-40 and rubidium-87 have very long half-lives and thus occur naturally, and all isotopes of francium are radioactive. Caesium was also thought to be radioactive in the early 20th century, although it has no naturally occurring radioisotopes. (Francium had not been discovered yet at that time.) The natural long-lived radioisotope of potassium, potassium-40, makes up about 0.012% of natural potassium, and thus natural potassium is weakly radioactive. This natural radioactivity became a basis for a mistaken claim of the discovery for element 87 (the next alkali metal after caesium) in 1925. Natural rubidium is similarly slightly radioactive, with 27.83% being the long-lived radioisotope rubidium-87.

text: All of the alkali metals except lithium and caesium have at least one naturally occurring

text: radioisotope

text: and

text: are

text: trace radioisotope

text: s produced

text: cosmogenic

text: ally, potassium-40 and

text: have very long

text: half-lives

text: and thus occur naturally, and all

text: isotopes of francium

text: are

text: radioactive

text: . Caesium was also thought to be radioactive in the early 20th century, although it has no naturally occurring radioisotopes. (Francium had not been discovered yet at that time.) The natural long-lived radioisotope of potassium, potassium-40, makes up about 0.012% of natural potassium, and thus natural potassium is weakly radioactive. This natural radioactivity became a basis for a mistaken claim of the discovery for element 87 (the next alkali metal after caesium) in 1925. Natural rubidium is similarly slightly radioactive, with 27.83% being the long-lived radioisotope rubidium-87.

text: Roentgenium (Rg) is a synthetic element, and thus a standard atomic mass cannot be given. Like all synthetic elements, it has no stable isotopes. The first isotope to be synthesized was Rg in 1994, which is also the only directly synthesized isotope, all others are decay products of nihonium, moscovium, and tennessine. There are 7 known radioisotopes from Rg to Rg. The longest-lived isotope is Rg with a half-life of 2.1 minutes.

text: Roentgenium

text: (Rg) is a

text: synthetic element

text: , and thus a standard

text: atomic mass

text: cannot be given. Like all synthetic elements, it has no

text: stable isotope

text: s. The first

text: isotope

text: to be synthesized was Rg in 1994, which is also the only directly synthesized isotope, all others are

text: decay product

text: s of

text: nihonium

text: moscovium

text: , and

text: tennessine

text: . There are 7 known

text: radioisotope

text: s from Rg to Rg. The longest-lived isotope is Rg with a

text: half-life

text: of 2.1 minutes.

text: SPECT is similar to PET in its use of radioactive tracer material and detection of gamma rays. In contrast with PET, however, the tracers used in SPECT emit gamma radiation that is measured directly, whereas PET tracers emit positrons that annihilate with electrons up to a few millimeters away, causing two gamma photons to be emitted in opposite directions. A PET scanner detects these emissions "coincident" in time, which provides more radiation event localization information and, thus, higher spatial resolution images than SPECT (which has about 1 cm resolution). SPECT scans, however, are significantly less expensive than PET scans, in part because they are able to use longer-lived more easily obtained radioisotopes than PET.

text: Every element has one or more isotopes that have unstable nuclei that are subject to radioactive decay, causing the nucleus to emit particles or electromagnetic radiation. Radioactivity can occur when the radius of a nucleus is large compared with the radius of the strong force, which only acts over distances on the order of 1 fm.

text: The Bundesamt für Strahlenschutz (BfS) is the German Federal Office for Radiation Protection. The BfS was established in November 1989; the headquarters is located in Salzgitter, with branch offices in Berlin, Bonn, Freiburg, Gorleben, Oberschleißheim and Rendsburg. It has 708 employees (including 305 scientific) and an annual budget of around 305 million Euro (2009). Since 2009 the BfS is also responsible for the storage site of radioactive waste, Schacht Asse II.

text: The Bundesamt für Strahlenschutz (BfS) is the

text: German

text: Federal Office for Radiation Protection. The BfS was established in November 1989; the headquarters is located in

text: Salzgitter

text: , with branch offices in

text: Berlin

text: Bonn

text: Freiburg

text: Gorleben

text: Oberschleißheim

text: and

text: Rendsburg

text: . It has 708 employees (including 305 scientific) and an annual budget of around 305 million Euro (2009). Since 2009 the BfS is also responsible for the storage site of radioactive waste,

text: Schacht Asse II

text: In 1962, the US had resumed atmospheric tests of nuclear weapons at the Nevada test site in 1962. The State of Utah had set up its own network of monitoring facilities to test milk for radioiodine, since "data pertaining to the safety of the citizens of Utah was not forthcoming from the AEC", and the levels of radioactivity were found to be close to the limits prescribed by the Federal Radiation Council. The Commissioners of the AEC were "on the hot seat" and announced "a comprehensive, long-range program" to explore the effects of man-made radioactivity "upon plants, animals and human beings". At the request of the US Atomic Energy Commission and of LLNL's director John Foster, Gofman reluctantly accepted to establish the Biomedical Research Division for the LLNL in 1963. He served as the first director of the LLNL biomedical research division from 1963 to 1965 and as one of the nine associate directors of the entire lab until 1969.

text: In 1962, the US had resumed atmospheric tests of nuclear weapons at the Nevada test site in 1962. The State of Utah had set up its own network of monitoring facilities to test milk for radioiodine, since "data pertaining to the safety of the citizens of Utah was not forthcoming from the AEC", and the levels of radioactivity were found to be close to the limits prescribed by the Federal Radiation Council. The Commissioners of the AEC were "on the hot seat" and announced "a comprehensive, long-range program" to explore the effects of man-made radioactivity "upon plants, animals and human beings". At the request of the

text: US Atomic Energy Commission

text: and of LLNL's director

text: John Foster

text: , Gofman reluctantly accepted to establish the Biomedical Research Division for the LLNL in 1963. He served as the first director of the LLNL biomedical research division from 1963 to 1965 and as one of the nine associate directors of the entire lab until 1969.

text: Typically, when the food is being irradiated, pallets of food are exposed to a source of radiation for a specific time. Dosimeters are embedded in the pallet (at various locations) of food to determine what dose was achieved.Most irradiated food is processed by gamma irradiation., however the usage of electron beam and X-ray is becoming more popular as well . Special precautions are taken because gamma rays are continuously emitted by the radioactive material. In most designs, to nullify the effects of radiation, the radioisotope is lowered into a water-filled storage pool, which absorbs the radiation but does not become radioactive. This allows pallets of the products to be added and removed from the irradiation chamber and other maintenance to be done. Sometimes movable shields are used to reduce radiation levels in areas of the irradiation chamber instead of submerging the source. For x ray and electron irradiation these precautions are not necessary as the source of the radiation can be switched off.

text: Some studies have shown that thyroglobulin (Tg) testing combined with neck ultrasound is more productive in finding disease recurrence than full- or whole-body scans (WBS) using radioactive iodine. However, current protocol (in the USA) suggests a small number of clean annual WBS are required before relying on Tg testing plus neck ultrasound. When needed, whole body scans consist of withdrawal from thyroxine medication and/or injection of recombinant human Thyroid stimulating hormone (TSH). In both cases, a low iodine diet regimen must also be followed to optimize the takeup of the radioactive iodine dose. Low dose radioiodine of a few millicuries is administered. Full body nuclear medicine scan follows using a gamma camera. Scan doses of radioactive iodine may be I or I.

text: Some studies have shown that thyroglobulin (Tg) testing combined with neck

text: ultrasound

text: is more productive in finding disease recurrence than full- or

text: whole-body scans

text: (WBS) using radioactive iodine. However, current protocol (in the USA) suggests a small number of clean annual WBS are required before relying on Tg testing plus neck ultrasound. When needed, whole body scans consist of withdrawal from thyroxine medication and/or injection of recombinant human

text: Thyroid stimulating hormone

text: (TSH). In both cases, a low iodine diet regimen must also be followed to optimize the takeup of the radioactive iodine dose. Low dose radioiodine of a few millicuries is administered. Full body

text: nuclear medicine

text: scan follows using a

text: gamma camera

text: . Scan doses of radioactive iodine may be

text: I

text: or

text: I

text: Some induced radioactivity is produced by background radiation, which is mostly natural. However, since natural radiation is not very intense in most places on Earth, the amount of induced radioactivity in a single location is usually very small.

text: Some induced radioactivity is produced by

text: background radiation

text: , which is mostly natural. However, since natural radiation is not very intense in most places on

text: Earth

text: , the amount of induced radioactivity in a single location is usually very small.

text: Mathematical models are often used to describe sediment biogeochemistry. Commonly, these models take the form of ordinary differential equations or partial differential equations in which bioturbation appears as a diffusive term completed or not with advective terms. A diffusive description is often adopted to avoid quantifying the plethora of mixing modes resulting from faunal activities. The diffusion coefficient describing the intensity of bioturbation is usually determined by fitting mathematical models to vertical distributions of natural radioactive tracers, radioisotopes resulting from nuclear weapon testing, or introduced particles, such as glass beads tagged with radionuclides or inert fluorescent particles.

text: Mathematical model

text: s are often used to describe sediment

text: biogeochemistry

text: . Commonly, these

text: models

text: take the form of

text: ordinary differential equations

text: or

text: partial differential equations

text: in which bioturbation appears as a

text: diffusive

text: term completed or not with advective terms. A diffusive description is often adopted to avoid quantifying the plethora of mixing modes resulting from faunal activities. The diffusion coefficient describing the intensity of bioturbation is usually determined by fitting mathematical models to vertical distributions of natural

text: radioactive tracer

text: s,

text: radioisotopes

text: resulting from

text: nuclear weapon

text: testing, or introduced particles, such as

text: glass

text: bead

text: s tagged with

text: radionuclide

text: s or inert fluorescent particles.

text: Research on ionizing radiation included: plutonium exposure; internal dosimetry; radioactive discharges; nuclear accidents and wastes; radon hazards; medical x rays; epidemiology and molecular biology. Research on non-ionizing radiation included the physics and biology of exposure to ultraviolet sources, electricity supplies, and mobile phones.

text: Research on ionizing radiation included:

text: plutonium

text: exposure;

text: internal dosimetry

text: ; radioactive discharges;

text: nuclear accident

text: s and

text: wastes

text: radon

text: hazards; medical x rays;

text: epidemiology

text: and

text: molecular biology

text: . Research on non-ionizing radiation included the physics and biology of exposure to

text: ultraviolet sources

text: electricity

text: supplies, and

text: mobile phone

text: s.

text: In a nuclear power reactor, the main sources of radioactivity are fission products, actinides and activation products.  Fission products are the largest source of radioactivity for the first several hundred years, while actinides are dominant roughly 10 to 10 years after fuel use.

text: In a nuclear power reactor, the main sources of radioactivity are fission products,

text: actinide

text: s and

text: activation product

text: s.  Fission products are the largest source of radioactivity for the first several hundred years, while actinides are dominant roughly 10 to 10 years after fuel use.

text: In computer technology, dynamic random access memory (DRAM) "soft errors" were linked to alpha particles in 1978 in Intel's DRAM chips. The discovery led to strict control of radioactive elements in the packaging of semiconductor materials, and the problem is largely considered to be solved.

text: In computer technology,

text: dynamic random access memory

text: (DRAM) "

text: soft error

text: s" were linked to alpha particles in 1978 in

text: Intel

text: 's DRAM chips. The discovery led to strict control of radioactive elements in the packaging of semiconductor materials, and the problem is largely considered to be solved.

text: Although there are nine known isotopes of helium (He) (relative atomic mass: 4.002602(2)), only helium-3 () and helium-4 () are stable. All radioisotopes are short-lived, the longest-lived being  with a half-life of . The least stable is , with a half-life of , although it is possible that  has an even shorter half-life.

text: Although there are nine known

text: isotope

text: s of

text: helium

text: (He) (

text: relative atomic mass

text: : 4.002602(2)), only

text: () and

text: () are

text: stable

text: . All

text: radioisotope

text: s are short-lived, the longest-lived being  with a

text: half-life

text: of . The least stable is , with a

text: half-life

text: of , although it is possible that  has an even shorter half-life.

text: Cosmogenic isotopes (or cosmogenic nuclides) are rare isotopes created when a high-energy cosmic ray interacts with the nucleus of an in situ atom.  These isotopes are produced within earth materials such as rocks or soil, in Earth's atmosphere, and in extraterrestrial items such as meteorites.  By measuring cosmogenic isotopes, scientists are able to gain insight into a range of geological and astronomical processes.  There are both radioactive and stable cosmogenic isotopes.  Some of these radioisotopes are tritium, carbon-14 and phosphorus-32.

text: Cosmogenic isotopes (or

text: cosmogenic nuclide

text: s) are rare

text: isotope

text: s created when a high-energy

text: cosmic ray

text: interacts with the

text: nucleus

text: of an

text: in situ

text: atom

text: .  These isotopes are produced within earth materials such as

text: rock

text: s or

text: soil

text: , in

text: Earth's

text: atmosphere

text: , and in extraterrestrial items such as

text: meteorite

text: s.  By measuring cosmogenic isotopes,

text: scientist

text: geological

text: and

text: astronomical

text: processes.  There are both

text: radioactive

text: and

text: stable

text: tritium

text: carbon

text: -14 and

text: phosphorus

text: The law of radioactive displacements, also known as Fajans and Soddy law, in radiochemistry and nuclear physics, is a rule governing the transmutation of elements during radioactive decay. It is named after Frederick Soddy and Kazimierz Fajans, who independently arrived at it at about the same time in 1913.

text: The law of radioactive displacements, also known as Fajans and Soddy law, in

text: radiochemistry

text: and

text: nuclear physics

text: , is a rule governing the

text: transmutation of elements

text: during

text: radioactive decay

text: . It is named after

text: Frederick Soddy

text: and

text: Kazimierz Fajans

text: , who independently arrived at it at about the same time in 1913.

text: Bocking has one school called Bocking Church Street School. It used to have another school called Edith Borthwick School but they move to Springwood Drive in Braintree in September 2015 because their old school in Bocking is too small.

text: High radiation dose gives rise to deterministic effects which reliably occur above a threshold, and their severity increases with dose. Deterministic effects are not necessarily more or less serious than stochastic effects; either can ultimately lead to a temporary nuisance or a fatality. Examples are: radiation burns, and/or rapid fatality through acute radiation syndrome, chronic radiation syndrome, and radiation-induced thyroiditis.

text: High radiation dose gives rise to deterministic effects which reliably occur above a threshold, and their severity increases with dose. Deterministic effects are not necessarily more or less serious than stochastic effects; either can ultimately lead to a temporary nuisance or a fatality. Examples are:

text: radiation burns

text: , and/or rapid fatality through

text: acute radiation syndrome

text: chronic radiation syndrome

text: , and

text: radiation-induced thyroiditis

text: The altitude of the explosion was important because a ground or near ground burst would produce radioactive fallout, whereas an air burst would produce only short distance and short lived initial radiations (but no fallout). Once combined with the peak-overpressure readings from post Bomb Power Indicator readings the power of the burst in megatons could also be calculated by the Triangulation Team in the group control building, using a hand held plastic calculator device.

text: The altitude of the explosion was important because a ground or near ground burst would produce radioactive fallout, whereas an air burst would produce only short distance and short lived initial radiations (but no fallout). Once combined with the peak-overpressure readings from post

text: Bomb Power Indicator

text: readings the power of the burst in megatons could also be calculated by the Triangulation Team in the group control building, using a hand held plastic calculator device.

text: Governments around the world are considering a range of waste management and disposal options, usually involving deep-geologic placement, although there has been limited progress toward implementing long-term waste management solutions. This is partly because the timeframes in question when dealing with radioactive waste range from 10,000 to millions of years, according to studies based on the effect of estimated radiation doses.

text: The Granite Reef Diversion Dam, constructed near the confluence of the Salt and Verde rivers, does not actually hold back a reservoir but is used to divert water from those rivers into the system of canals feeding into the Phoenix area. It was actually the first of the dams constructed, finished in 1906 to replace the Arizona Dam, which had been washed away by floods the previous year.

text: The

text: Granite Reef Diversion Dam

text: , constructed near the confluence of the Salt and Verde rivers, does not actually hold back a reservoir but is used to divert water from those rivers into the system of canals feeding into the Phoenix area. It was actually the first of the dams constructed, finished in 1906 to replace the Arizona Dam, which had been washed away by floods the previous year.

text: Radiation monitors in general have a number of process-control applications in nuclear power plants; a major CPAM application in this area is the monitoring of the air intake for the plant control room. In the event of an accident, high levels of airborne radioactivity could be brought into the control room by its HVAC system; the CPAM monitors this air and is intended to detect high concentrations of radioactivity and shut down the HVAC flow when necessary.

text: After the discovery of X-rays by Wilhelm Röntgen, many scientists began to work on ionizing radiation. One of these was Henri Becquerel, who investigated the relationship between phosphorescence and the blackening of photographic plates. When Becquerel (working in France) discovered that, with no external source of energy, the uranium generated rays which could blacken (or fog) the photographic plate, radioactivity was discovered. Marie Curie (working in Paris) and her husband Pierre Curie isolated two new radioactive elements from uranium ore. They used radiometric methods to identify which stream the radioactivity was in after each chemical separation; they separated the uranium ore into each of the different chemical elements that were known at the time, and measured the radioactivity of each fraction. They then attempted to separate these radioactive fractions further, to isolate a smaller fraction with a higher specific activity (radioactivity divided by mass). In this way, they isolated polonium and radium. It was noticed in about 1901 that high doses of radiation could cause an injury in humans. Henri Becquerel had carried a sample of radium in his pocket and as a result he suffered a high localised dose which resulted in a radiation burn. This injury resulted in the biological properties of radiation being investigated, which in time resulted in the development of medical treatments.

text: After the discovery of

text: X-ray

text: s by

text: Wilhelm Röntgen

text: , many scientists began to work on ionizing radiation. One of these was

text: Henri Becquerel

text: , who investigated the relationship between

text: phosphorescence

text: and the blackening of

text: photographic plate

text: s. When Becquerel (working in France) discovered that, with no external source of energy, the uranium generated rays which could blacken (or fog) the photographic plate, radioactivity was discovered.

text: Marie Curie

text: (working in Paris) and her husband

text: Pierre Curie

text: isolated two new radioactive elements from uranium ore. They used

text: radiometric

text: methods to identify which stream the radioactivity was in after each chemical separation; they separated the uranium ore into each of the different chemical elements that were known at the time, and measured the radioactivity of each fraction. They then attempted to separate these radioactive fractions further, to isolate a smaller fraction with a higher specific activity (radioactivity divided by mass). In this way, they isolated

text: polonium

text: and

text: radium

text: . It was noticed in about 1901 that high doses of radiation could cause an injury in humans.

text: Henri Becquerel

text: had carried a sample of radium in his pocket and as a result he suffered a high localised dose which resulted in a

text: radiation burn

text: . This injury resulted in the biological properties of radiation being investigated, which in time resulted in the development of medical treatments.

text: Here is a list of radioisotopes formed by the action of cosmic rays on the atmosphere; the list also contains the production mode of the isotope. These data were obtained from the SCOPE50 report, see table 1.9 of chapter 1.

text: cosmic rays

text: on the atmosphere; the list also contains the production mode of the isotope. These data were obtained from the SCOPE50 report, see table 1.9 of chapter 1.

text: Tetravalent thorium compounds are usually colourless or yellow, like those of silver or lead, as the Th ion has no 5f or 6d electrons. Thorium and uranium are the most investigated of the radioactive elements because their radioactivity is slight enough to not pose major problems of handling and accessibility and they may be safely handled in a normal laboratory.

text: Tetravalent thorium compounds are usually colourless or yellow, like those of

text: silver

text: or lead, as the Th ion has no 5f or 6d electrons. Thorium and uranium are the most investigated of the radioactive elements because their radioactivity is slight enough to not pose major problems of handling and accessibility and they may be safely handled in a normal laboratory.

text: Into the mid 1970s, the United States Atomic Energy Commission and the Manhattan Project conducted other human radiation experiments. Radiation was known to be dangerous and the experiments were designed to ascertain the detailed effect of radiation on human health. In Nashville, pregnant women were given radioactive mixtures. In Cincinnati, some 200 patients were irradiated over a period of 15 years. In Chicago, 102 people received injections of strontium and cesium solutions. In Massachusetts, 74 schoolboys were fed oatmeal that contained radioactive substances.  In all these cases, the subjects did not know what was going on and did not give informed consent. The government covered up most of these radiation mishaps until 1993, when President Bill Clinton ordered a change of policy. The resulting investigation was undertaken by the  Advisory Committee on Human Radiation Experiments, and it uncovered much of the material included in The Plutonium Files.

text: Into the mid 1970s, the United States Atomic Energy Commission and the

text: Manhattan Project

text: conducted other

text: human radiation experiments

text: Radiation

text: was known to be dangerous and the experiments were designed to ascertain the detailed effect of radiation on human health. In Nashville, pregnant women were given radioactive mixtures. In Cincinnati, some 200 patients were irradiated over a period of 15 years. In Chicago, 102 people received injections of strontium and cesium solutions. In Massachusetts, 74 schoolboys were fed oatmeal that contained radioactive substances.  In all these cases, the subjects did not know what was going on and did not give informed consent. The government covered up most of these radiation mishaps until 1993, when President

text: Bill Clinton

text: ordered a change of policy. The resulting investigation was undertaken by the

text: , and it uncovered much of the material included in

text: The Plutonium Files

text: The basic approach is to label a candidate drug using the radioisotope carbon-14, and then administer the compound to human volunteers at levels typically about 100 times lower than the proposed therapeutic dosage (from around 1 to 100 micrograms but not above). How the body responds – for example, its conversion of the original drug into other molecules, and how long they stay in the body. The amount of radioactivity administered is typically around 200 nano Curies, which is low as to be considered 'non-radioactive' by authorities.

text: The basic approach is to

text: label

text: a candidate drug using the radio

text: isotope

text: , and then administer the compound to human volunteers at levels typically about 100 times lower than the proposed therapeutic dosage (from around 1 to 100

text: microgram

text: s but not above). How the body responds – for example, its conversion of the original drug into other molecules, and how long they stay in the body. The amount of radioactivity administered is typically around 200 nano

text: Curies

text: , which is low as to be considered 'non-radioactive' by authorities.

text: In Radiation Protection, an instrument which reads a rate of detected events is normally known as a ratemeter, which was first developed by R D Robley Evans in 1939. This provided a real-time dynamic indication of the radiation rate, and the principle has found widespread use in Health Physics and as radiation Survey meter.

text: The radioactivity of all radioactive waste diminishes with time. All radionuclides contained in the waste have a half-life—the time it takes for half of the atoms to decay into another nuclide—and eventually all radioactive waste decays into non-radioactive elements (i.e., stable nuclides). Certain radioactive elements (such as plutonium-239) will remain hazardous to humans and other creatures for hundreds or thousands of years. Other radionuclides remain radioactive for millions of years (though most of these products have so little activity as a result of their long half-lives that their radiation is lost in the background level). Thus, these wastes must be shielded for centuries and isolated from the living environment for millennia. Since radioactive decay follows the half-life rule, the rate of decay is inversely proportional to the duration of decay. In other words, the radiation from a long-lived isotope like iodine-129 will be much less intense than that of a short-lived isotope like iodine-131. The two tables show some of the major radioisotopes, their half-lives, and their radiation yield as a proportion of the yield of fission of uranium-235.

text: The radioactivity of all radioactive waste diminishes with time. All radionuclides contained in the waste have a

text: half-life

text: —the time it takes for half of the atoms to decay into another

text: nuclide

text: —and eventually all radioactive waste decays into non-radioactive elements (i.e.,

text: stable nuclide

text: s). Certain radioactive elements (such as

text: ) will remain hazardous to humans and other creatures for hundreds or thousands of years. Other radionuclides remain radioactive for millions of years (though most of these products have so little activity as a result of their long half-lives that their radiation is lost in the

text: background level

text: ). Thus, these wastes must be shielded for centuries and isolated from the living

text: environment

text: for millennia. Since radioactive decay follows the half-life rule, the rate of decay is inversely proportional to the duration of decay. In other words, the radiation from a long-lived isotope like

text: will be much less intense than that of a short-lived isotope like

text: . The two tables show some of the major radioisotopes, their half-lives, and their

text: radiation yield

text: as a proportion of the yield of fission of uranium-235.

text: SYERS previous version has also been used with the Lockheed U-2 reconnaissance aircraft.

text: SYERS previous version has also been used with the

text: Lockheed U-2

text: reconnaissance aircraft

text: The Radioactive Substances Act 1993 (RSA93) deals with the control of radioactive material and disposal of radioactive waste in the United Kingdom.

text: Harrison's observational research showed that the afterglows of gamma-ray bursts exhibit breaks in their decay rate due to collimation of the ejecta. Scientific highlights from the NuSTAR mission include mapping the radioactive debris in the Cassieopeia A supernova remnant to constrain the core collapse explosion mechanism, measurement of the spin of supermassive and stellar mass black holes, the discovery of a magnetar in the Galactic Center, and the discovery of an ultra luminous pulsar.

text: Harrison's observational research showed that the afterglows of gamma-ray bursts exhibit breaks in their decay rate due to collimation of the ejecta. Scientific highlights from the NuSTAR mission include mapping the radioactive debris in the

text: Cassieopeia A supernova remnant

text: to constrain the core collapse explosion mechanism, measurement of the spin of supermassive and stellar mass

text: black holes

text: , the discovery of a

text: magnetar

text: in the

text: Galactic Center

text: , and the discovery of an ultra luminous

text: pulsar

text: If the meter on any of the ion chamber devices are observed to respond at all to a radiation source, evacuation of the area should be considered. No legally exempt source of gamma radiation would be expected to cause any visible deflection of the meter on its most sensitive setting, so it might be assumed that such a radiation field could be dangerous. Such a meter would not be expected to detect the presence of radiation except the very high levels that might be found in the event of a nuclear weapon detonation or a major release of radioactive material as from a nuclear reactor meltdown. The CD V ion chamber units are now all approaching 50 years old at a minimum and that they contain parts that are sensitive to moisture, so relatively frequent calibration and inspection by an accredited and properly equipped facility is required to ensure reliable and accurate function.

text: If the meter on any of the ion chamber devices are observed to respond at all to a radiation source, evacuation of the area should be considered. No legally exempt source of gamma radiation would be expected to cause any visible deflection of the meter on its most sensitive setting, so it might be assumed that such a radiation field could be dangerous. Such a meter would not be expected to detect the presence of radiation except the very high levels that might be found in the event of a

text: nuclear weapon

text: detonation or a major release of radioactive material as from a

text: nuclear reactor meltdown

text: . The CD V ion chamber units are now all approaching 50 years old at a minimum and that they contain parts that are sensitive to moisture, so relatively frequent calibration and inspection by an accredited and properly equipped facility is required to ensure reliable and accurate function.