Caesium-137 (), cesium-137 (US), or radiocaesium, is a
radioactive
Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is consi ...
isotope of caesium that is formed as one of the more common
fission products by the
nuclear fission of
uranium-235
Uranium-235 (235U or U-235) is an isotope of uranium making up about 0.72% of natural uranium. Unlike the predominant isotope uranium-238, it is fissile, i.e., it can sustain a nuclear chain reaction. It is the only fissile isotope that exi ...
and other
fissionable
In nuclear engineering, fissile material is material capable of sustaining a nuclear fission chain reaction. By definition, fissile material can sustain a chain reaction with neutrons of thermal energy. The predominant neutron energy may be typi ...
isotope
Isotopes are two or more types of atoms that have the same atomic number (number of protons in their nuclei) and position in the periodic table (and hence belong to the same chemical element), and that differ in nucleon numbers (mass numbers) ...
s in
nuclear reactor
A nuclear reactor is a device used to initiate and control a fission nuclear chain reaction or nuclear fusion reactions. Nuclear reactors are used at nuclear power plants for electricity generation and in nuclear marine propulsion. Heat fr ...
s and
nuclear weapon
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission bomb) or a combination of fission and fusion reactions ( thermonuclear bomb), producing a nuclear explosion. Both bom ...
s. Trace quantities also originate from
spontaneous fission of
uranium-238
Uranium-238 (238U or U-238) is the most common isotope of uranium found in nature, with a relative abundance of 99%. Unlike uranium-235, it is non-fissile, which means it cannot sustain a chain reaction in a thermal-neutron reactor. However, it ...
. It is among the most problematic of the short-to-medium-lifetime fission products. Caesium-137 has a relatively low
boiling point of and is volatilized easily when released suddenly at high temperature, as in the case of the
Chernobyl nuclear accident
The Chernobyl disaster was a nuclear accident that occurred on 26 April 1986 at the No. 4 nuclear reactor, reactor in the Chernobyl Nuclear Power Plant, near the city of Pripyat in the north of the Ukrainian Soviet Socialist Republic, Ukrainia ...
and with
atomic explosions, and can travel very long distances in the air. After being deposited onto the soil as
radioactive fallout
Nuclear fallout is the residual radioactive material propelled into the upper atmosphere following a nuclear blast, so called because it "falls out" of the sky after the explosion and the shock wave has passed. It commonly refers to the radioac ...
, it moves and spreads easily in the environment because of the high water solubility of
caesium's most common
chemical compound
A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...
s, which are
salts
In chemistry, a salt is a chemical compound consisting of an ionic assembly of positively charged cations and negatively charged anions, which results in a compound with no net electric charge. A common example is table salt, with positively c ...
. Caesium-137 was discovered by
Glenn T. Seaborg
Glenn Theodore Seaborg (; April 19, 1912February 25, 1999) was an American chemist whose involvement in the synthesis, discovery and investigation of ten transuranium elements earned him a share of the 1951 Nobel Prize in Chemistry. His work i ...
and
Margaret Melhase
Margaret Melhase Fuchs (August 13, 1919August 8, 2006) was an American chemist and a co-discoverer, with Glenn T. Seaborg, of the isotope caesium-137.
Education and research career
In 1940, Melhase was an undergraduate in the college of chemis ...
.
Decay
Caesium-137 has a
half-life
Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable at ...
of about 30.05 years.
[Bé, M. M., Chisté, V., Dulieu, C., Browne, E., Baglin, C., Chechev, V., ... & Lee, K. B. (2006)]
Table of Radionuclides (vol. 3–A= 3 to 244)
''Monographie BIPM'', ''5''.
About 94.6%
decay
Decay may refer to:
Science and technology
* Bit decay, in computing
* Software decay, in computing
* Distance decay, in geography
* Decay time (fall time), in electronics
Biology
* Decomposition of organic matter
* Tooth decay (dental caries ...
s by
beta emission
In nuclear physics, beta decay (β-decay) is a type of radioactive decay in which a beta particle (fast energetic electron or positron) is emitted from an atomic nucleus, transforming the original nuclide to an isobar of that nuclide. For exam ...
to a
metastable
In chemistry and physics, metastability denotes an intermediate Energy level, energetic state within a dynamical system other than the system's ground state, state of least energy.
A ball resting in a hollow on a slope is a simple example of me ...
nuclear isomer
A nuclear isomer is a metastable state of an atomic nucleus, in which one or more nucleons (protons or neutrons) occupy excited state, higher energy levels than in the ground state of the same nucleus. "Metastable" describes nuclei whose excited ...
of barium:
barium-137m (
137mBa, Ba-137m). The remainder directly populates the ground state of
137Ba, which is stable. Metastable Ba has a half-life of about 153 seconds, and is responsible for all of the
gamma ray
A gamma ray, also known as gamma radiation (symbol γ or \gamma), is a penetrating form of electromagnetic radiation arising from the radioactive decay of atomic nuclei. It consists of the shortest wavelength electromagnetic waves, typically ...
emissions in samples of
137Cs. Barium-137m decays to the ground state by emission of
photon
A photon () is an elementary particle that is a quantum of the electromagnetic field, including electromagnetic radiation such as light and radio waves, and the force carrier for the electromagnetic force. Photons are massless, so they a ...
s having energy 0.6617 MeV. A total of 85.1% of
137Cs decay generates gamma ray emission in this manner. One gram of
137Cs has an
activity of 3.215 tera
becquerel
The becquerel (; symbol: Bq) is the unit of radioactivity in the International System of Units (SI). One becquerel is defined as the activity of a quantity of radioactive material in which one nucleus decays per second. For applications relatin ...
(TBq).
Uses
Caesium-137 has a number of practical uses. In small amounts, it is used to calibrate radiation-detection equipment.
In medicine, it is used in
radiation therapy
Radiation therapy or radiotherapy, often abbreviated RT, RTx, or XRT, is a therapy using ionizing radiation, generally provided as part of cancer treatment to control or kill malignant cells and normally delivered by a linear accelerator. Radi ...
.
In industry, it is used in
flow meter
Flow measurement is the quantification of bulk fluid movement. Flow can be measured in a variety of ways. The common types of flowmeters with industrial applications are listed below:
* a) Obstruction type (differential pressure or variable area) ...
s, thickness gauges,
moisture-density gauges (for density readings, with
americium-241
Americium-241 (, Am-241) is an isotope of americium. Like all isotopes of americium, it is radioactive, with a half-life of . is the most common isotope of americium as well as the most prevalent isotope of americium in nuclear waste. It is com ...
/beryllium providing the moisture reading),
and in
gamma ray well logging devices.
Caesium-137 is not widely used for
industrial radiography
Industrial radiography is a modality of non-destructive testing that uses ionizing radiation to inspect materials and components with the objective of locating and quantifying defects and degradation in material properties that would lead to the ...
because it is hard to obtain a very high specific activity material with a well defined (and small) shape as caesium from used nuclear fuel contains stable caesium-133 and also long-lived
caesium-135
Caesium (55Cs) has 40 known isotopes, making it, along with barium and mercury, one of the elements with the most isotopes. The atomic masses of these isotopes range from 112 to 151. Only one isotope, 133Cs, is stable. The longest-lived radioisot ...
.
Isotope separation
Isotope separation is the process of concentrating specific isotopes of a chemical element by removing other isotopes. The use of the nuclides produced is varied. The largest variety is used in research (e.g. in chemistry where atoms of "marker" n ...
is too costly compared to cheaper alternatives. Also the higher specific activity caesium sources tend to be made from very soluble
caesium chloride
Caesium chloride or cesium chloride is the inorganic compound with the formula Cs Cl. This colorless salt is an important source of caesium ions in a variety of niche applications. Its crystal structure forms a major structural type where each ...
(CsCl), as a result if a radiography source was damaged it would increase the spread of the contamination. It is possible to make water insoluble caesium sources (with various
ferrocyanide
Ferrocyanide is the name of the anion CN)6">cyanide.html" ;"title="e(cyanide">CN)6sup>4−. Salts of this coordination complex give yellow solutions. It is usually available as the salt potassium ferrocyanide, which has the formula K4Fe(CN)6. e ...
compounds such as , and ammonium ferric hexacyano ferrate (AFCF), Giese salt, ferric ammonium ferrocyanide) but their specific activity will be much lower. Other chemically inert Caesium compounds include Caesium-
Aluminosilicate
Aluminosilicate minerals ( IMA symbol: Als) are minerals composed of aluminium, silicon, and oxygen, plus countercations. They are a major component of kaolin and other clay minerals.
Andalusite, kyanite, and sillimanite are naturall ...
-glasses akin to the natural mineral
pollucite
Pollucite is a zeolite mineral with the formula with iron, calcium, rubidium and potassium as common substituting elements. It is important as a significant ore of caesium and sometimes rubidium. It forms a solid solution series with analcime. ...
. The latter has been used in demonstration of chemically stable water-insoluble forms of nuclear waste for disposal in
deep geological repositories. A large emitting volume will harm the image quality in radiography. and , are preferred for radiography, since these are chemically non-reactive metals and can be obtained with much higher specific activities by the activation of stable cobalt or iridium in high flux reactors. However, while is a waste product produced in great quantities in nuclear fission reactors, and are specifically produced in commercial and
research reactor
Research reactors are nuclear fission-based nuclear reactors that serve primarily as a neutron source. They are also called non-power reactors, in contrast to power reactors that are used for electricity production, heat generation, or marit ...
s and their life cycle entails the destruction of the involved high-value elements. Cobalt-60 decays to stable
nickel
Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow ...
, whereas iridium-192 can decay to either stable osmium or platinum. Due to the residual radioactivity and legal hurdles, the resulting material is not commonly recovered even from "spent" radioactive sources, meaning in essence that the entire mass is "lost" for non-radioactive uses.
As an almost purely human-made isotope, caesium-137 has been used to date wine and detect counterfeits and as a relative-dating material for assessing the age of sedimentation occurring after 1945.
Caesium-137 is also used as a radioactive tracer in geologic research to measure soil erosion and deposition.
Health risk of radioactive caesium
Caesium-137 reacts with water, producing a water-soluble compound (
caesium hydroxide
Caesium hydroxide is a strong base (pKa= 15.76) containing the highly reactive alkali metal caesium, much like the other alkali metal hydroxides such as sodium hydroxide and potassium hydroxide. Caesium hydroxide is corrosive enough to quickly ...
). The biological behaviour of caesium is similar to that of
potassium
Potassium is the chemical element with the symbol K (from Neo-Latin ''kalium'') and atomic number19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmosphe ...
and
rubidium. After entering the body, caesium gets more or less uniformly distributed throughout the body, with the highest concentrations in
soft tissue
Soft tissue is all the tissue in the body that is not hardened by the processes of ossification or calcification such as bones and teeth. Soft tissue connects, surrounds or supports internal organs and bones, and includes muscle, tendons, ...
.
However, unlike
group 2 The term Group 2 may refer to:
* Alkaline earth metal, a chemical element classification
* Astronaut Group 2, also known as The New Nine, the second group of astronauts selected by NASA in 1962
* Group 2 (racing), an FIA classification for cars in ...
radionuclides like
radium
Radium is a chemical element with the symbol Ra and atomic number 88. It is the sixth element in group 2 of the periodic table, also known as the alkaline earth metals. Pure radium is silvery-white, but it readily reacts with nitrogen (rathe ...
and
strontium-90
Strontium-90 () is a radioactive isotope of strontium produced by nuclear fission, with a half-life of 28.8 years. It undergoes β− decay into yttrium-90, with a decay energy of 0.546 MeV. Strontium-90 has applications in medicine and ...
, caesium does not
bioaccumulate
Bioaccumulation is the gradual accumulation of substances, such as pesticides or other chemicals, in an organism. Bioaccumulation occurs when an organism absorbs a substance at a rate faster than that at which the substance is lost or eliminated ...
and is excreted relatively quickly. The
biological half-life
Biological half-life (also known as elimination half-life, pharmacologic half-life) is the time taken for concentration of a biological substance (such as a medication) to decrease from its maximum concentration ( Cmax) to half of Cmax in the bl ...
of caesium is about 70 days.
A 1961 experiment showed that mice dosed with 21.5
μCi/g had a 50% fatality within 30 days (implying an
LD50 of 245 μg/kg). A similar experiment in 1972 showed that when dogs are subjected to a
whole body burden of 3800
μCi/kg (140 MBq/kg, or approximately 44 μg/kg) of caesium-137 (and 950 to 1400
rads), they die within 33 days, while animals with half of that burden all survived for a year. Important researches have shown a remarkable concentration of
137Cs in the exocrine cells of the pancreas, which are those most affected by cancer. In 2003, in autopsies performed on 6 children dead in the polluted area near Chernobyl where they also reported a higher incidence of pancreatic tumors, Bandazhevsky found a concentration of
137Cs 40-45 times higher than in their liver, thus demonstrating that pancreatic tissue is a strong accumulator and secretor in the intestine of radioactive cesium.
Accidental ingestion of caesium-137 can be treated with
Prussian blue
Prussian blue (also known as Berlin blue, Brandenburg blue or, in painting, Parisian or Paris blue) is a dark blue pigment produced by oxidation of ferrous ferrocyanide salts. It has the chemical formula Fe CN)">Cyanide.html" ;"title="e(Cyani ...
(Fe
CN).html" ;"title="Cyanide.html" ;"title="e(Cyanide">CN)">Cyanide.html" ;"title="e(Cyanide">CN), which binds to it chemically and reduces the biological half-life to 30 days.
Radioactive caesium in the environment
![Cs-137 from nuclear tests vector](https://upload.wikimedia.org/wikipedia/commons/3/3c/Cs-137_from_nuclear_tests_vector.svg)
Caesium-137, along with other radioactive isotopes caesium-134, iodine-131, xenon-133, and
strontium-90
Strontium-90 () is a radioactive isotope of strontium produced by nuclear fission, with a half-life of 28.8 years. It undergoes β− decay into yttrium-90, with a decay energy of 0.546 MeV. Strontium-90 has applications in medicine and ...
, were released into the environment during nearly all
nuclear weapon test
Nuclear weapons tests are experiments carried out to determine nuclear weapons' effectiveness, yield, and explosive capability. Testing nuclear weapons offers practical information about how the weapons function, how detonations are affected by ...
s and some
nuclear accident
A nuclear and radiation accident is defined by the International Atomic Energy Agency (IAEA) as "an event that has led to significant consequences to people, the environment or the facility. Examples include lethal effects to individuals, lar ...
s, most notably the
Chernobyl disaster
The Chernobyl disaster was a nuclear accident that occurred on 26 April 1986 at the No. 4 reactor in the Chernobyl Nuclear Power Plant, near the city of Pripyat in the north of the Ukrainian SSR in the Soviet Union. It is one of only two nuc ...
and the
Fukushima Daiichi disaster
The was a nuclear accident in 2011 at the Fukushima Daiichi Nuclear Power Plant in Ōkuma, Fukushima, Japan. The proximate cause of the disaster was the 2011 Tōhoku earthquake and tsunami, which occurred on the afternoon of 11 March 2011 a ...
.
Caesium-137 in the environment is substantially
anthropogenic (human-made). Caesium-137 is produced from the nuclear fission of
plutonium
Plutonium is a radioactive chemical element with the symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, and forms a dull coating when oxidized. The element normally exhibi ...
and
uranium
Uranium is a chemical element with the symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium is weak ...
, and decays into
barium-137
Naturally occurring barium (56Ba) is a mix of six stable isotopes and one very long-lived radioactive primordial isotope, barium-130, identified as being unstable by geochemical means (from analysis of the presence of its daughter xenon-130 in roc ...
. Before the construction of the first artificial
nuclear reactor
A nuclear reactor is a device used to initiate and control a fission nuclear chain reaction or nuclear fusion reactions. Nuclear reactors are used at nuclear power plants for electricity generation and in nuclear marine propulsion. Heat fr ...
in late 1942 (the
Chicago Pile-1), caesium-137 had not occurred on Earth in significant amounts for about
1.7 billion years. By observing the characteristic gamma rays emitted by this isotope, one can determine whether the contents of a given sealed container were made before or after the first
atomic bomb explosion (
Trinity test
Trinity was the code name of the first detonation of a nuclear weapon. It was conducted by the United States Army at 5:29 a.m. on July 16, 1945, as part of the Manhattan Project. The test was conducted in the Jornada del Muerto desert abo ...
, 16 July 1945), which spread some of it into the atmosphere, quickly distributing trace amounts of it around the globe. This procedure has been used by researchers to check the authenticity of certain rare wines, most notably the purported "
Jefferson bottles". Surface soils and sediments are also dated by measuring the activity of
137Cs.
Chernobyl disaster
As of today and for the next few hundred years or so, caesium-137 and
strontium-90
Strontium-90 () is a radioactive isotope of strontium produced by nuclear fission, with a half-life of 28.8 years. It undergoes β− decay into yttrium-90, with a decay energy of 0.546 MeV. Strontium-90 has applications in medicine and ...
continue to be the principal source of radiation in the
zone of alienation
The Chernobyl Nuclear Power Plant Zone of Alienation, Belarusian: Хона адчужэння Чарнобыльскай АЭС, ''Zona adčužennia Čarnobyĺskaj AES'', russian: Зона отчуждения Чернобыльской АЭС ...
around the
Chernobyl nuclear power plant
The Chernobyl Nuclear Power Plant (ChNPP; ; ), is a nuclear power plant undergoing decommissioning. ChNPP is located near the abandoned city of Pripyat in northern Ukraine northwest of the city of Chernobyl, from the Belarus–Ukraine borde ...
, and pose the greatest risk to health, owing to their approximately 30 year half-life and biological uptake. The mean contamination of caesium-137 in Germany following the Chernobyl disaster was 2000 to 4000 Bq/m
2. This corresponds to a contamination of 1 mg/km
2 of caesium-137, totaling about 500 grams deposited over all of Germany. In Scandinavia, some reindeer and sheep exceeded the Norwegian legal limit (3000 Bq/kg) 26 years after Chernobyl. As of 2016, the Chernobyl caesium-137 has decayed by half, but could have been locally concentrated by much larger factors.
Fukushima Daiichi disaster
![Fukushima- Panache-25-mars](https://upload.wikimedia.org/wikipedia/commons/3/32/Fukushima-_Panache-25-mars.svg)
In April 2011, elevated levels of caesium-137 were also being found in the environment after the
Fukushima Daiichi nuclear disasters in Japan. In July 2011, meat from 11 cows shipped to Tokyo from
Fukushima Prefecture was found to have 1,530 to 3,200
becquerel
The becquerel (; symbol: Bq) is the unit of radioactivity in the International System of Units (SI). One becquerel is defined as the activity of a quantity of radioactive material in which one nucleus decays per second. For applications relatin ...
s per kilogram of
137Cs, considerably exceeding the Japanese legal limit of 500 becquerels per kilogram at that time. In March 2013, a fish caught near the plant had a record 740,000 becquerels per kilogram of radioactive caesium, above the 100 becquerels per kilogram government limit. A 2013 paper in ''
Scientific Reports'' found that for a forest site 50 km from the stricken plant,
137Cs concentrations were high in leaf litter, fungi and
detritivores, but low in herbivores.
By the end of 2014, "Fukushima-derived radiocaesium had spread into the whole western North Pacific Ocean", transported by the
North Pacific current
The North Pacific Current (sometimes referred to as the North Pacific Drift) is a slow warm water current that flows west-to-east between 30 and 50 degrees north in the Pacific Ocean. The current forms the southern part of the North Pacific Su ...
from Japan to the
Gulf of Alaska
The Gulf of Alaska (Tlingit: ''Yéil T'ooch’'') is an arm of the Pacific Ocean defined by the curve of the southern coast of Alaska, stretching from the Alaska Peninsula and Kodiak Island in the west to the Alexander Archipelago in the east ...
. It has been measured in the surface layer down to 200 meters and south of the current area down to 400 meters.
Caesium-137 is reported to be the major health concern in Fukushima. A number of techniques are being considered that will be able to strip out 80% to 95% of the caesium from contaminated soil and other materials efficiently and without destroying the organic material in the soil. These include hydrothermal blasting. The caesium precipitated with ferric
ferrocyanide
Ferrocyanide is the name of the anion CN)6">cyanide.html" ;"title="e(cyanide">CN)6sup>4−. Salts of this coordination complex give yellow solutions. It is usually available as the salt potassium ferrocyanide, which has the formula K4Fe(CN)6. e ...
(
Prussian blue
Prussian blue (also known as Berlin blue, Brandenburg blue or, in painting, Parisian or Paris blue) is a dark blue pigment produced by oxidation of ferrous ferrocyanide salts. It has the chemical formula Fe CN)">Cyanide.html" ;"title="e(Cyani ...
) would be the only waste requiring special burial sites. The aim is to get annual exposure from the contaminated environment down to 1
mSv
mSv or MSV may refer to:
* Maize streak virus, a plant disease
* Medium-speed vehicle, US category
* Medium Systems Vehicle, a class of fictional artificially intelligent starship in The Culture universe of late Scottish author Iain Banks
* Mill ...
above background. The most contaminated area where radiation doses are greater than 50 mSv/year must remain off limits, but some areas that are currently less than 5 mSv/year may be decontaminated, allowing 22,000 residents to return.
Incidents and accidents
Caesium-137 gamma sources have been involved in several radiological accidents and incidents.
1987 Goiânia, Goiás, Brazil
In the
Goiânia accident
The Goiânia accident was a radioactive contamination accident that occurred on September 13, 1987, in Goiânia, Goiás, Brazil, after a forgotten radiotherapy source was stolen from an abandoned hospital site in the city. It was subsequent ...
of 1987, an improperly disposed of radiation therapy system from an abandoned clinic in
Goiânia
Goiânia (; ) is the capital and largest city of the Brazilian state of Goiás. With a population of 1,536,097, it is the second-largest city in the Central-West Region and the 10th-largest in the country. Its metropolitan area has a population ...
, Brazil, was removed then cracked to be sold in junkyards, and the glowing
caesium salt sold to curious, unadvised buyers. This led to four confirmed deaths and several serious injuries from radiation contamination.
Caesium gamma-ray sources that have been encased in metallic housings can be mixed in with scrap metal on its way to smelters, resulting in production of steel contaminated with radioactivity.
1989 Kramatorsk, Donetsk, Ukraine
The
Kramatorsk radiological accident
The Kramatorsk radiological accident was a radiation accident that happened in Kramatorsk, in the Ukrainian SSR from 1980 to 1989. A small capsule containing highly radioactive caesium-137 was found inside the concrete wall of an apartment build ...
happened in 1989 when a small capsule containing highly radioactive caesium-137 was found inside the concrete wall of an apartment building in
Kramatorsk
Kramatorsk ( uk, Краматорськ, translit=Kramatorsk ) is a city and the administrative centre of Kramatorsk Raion in the northern portion of Donetsk Oblast, in eastern Ukraine. Prior to 2020, Kramatorsk was a City of regional significa ...
,
Ukrainian SSR
The Ukrainian Soviet Socialist Republic ( uk, Украї́нська Радя́нська Соціалісти́чна Респу́бліка, ; russian: Украи́нская Сове́тская Социалисти́ческая Респ ...
. It is believed that the capsule, originally a part of a measurement device, was lost in the late 1970s and ended up mixed with gravel used to construct the building in 1980. Over 9 years, two families had lived in the apartment. By the time the capsule was discovered, 6 residents of the building had died from
leukemia
Leukemia ( also spelled leukaemia and pronounced ) is a group of blood cancers that usually begin in the bone marrow and result in high numbers of abnormal blood cells. These blood cells are not fully developed and are called ''blasts'' or ' ...
and 17 more had received varying doses of radiation.
1997, Georgia
In 1997, several
Georgian
Georgian may refer to:
Common meanings
* Anything related to, or originating from Georgia (country)
** Georgians, an indigenous Caucasian ethnic group
** Georgian language, a Kartvelian language spoken by Georgians
**Georgian scripts, three scrip ...
soldiers suffered radiation poisoning and burns. They were eventually traced back to training sources abandoned, forgotten, and unlabeled after the
dissolution of the Soviet Union
The dissolution of the Soviet Union, also negatively connoted as rus, Разва́л Сове́тского Сою́за, r=Razvál Sovétskogo Soyúza, ''Ruining of the Soviet Union''. was the process of internal disintegration within the Sov ...
. One was a caesium-137 pellet in a pocket of a shared jacket that put out about 130,000 times the level of background radiation at 1 meter distance.
1998, Los Barrios, Cádiz, Spain
In the
Acerinox accident
The Acerinox accident was a radioactive contamination accident in the province of Cádiz. In May 1998, a caesium-137 source managed to pass through the monitoring equipment in an Acerinox scrap metal reprocessing plant in Los Barrios, Spain. When ...
of 1998, the Spanish recycling company
Acerinox accidentally melted down a mass of radioactive caesium-137 that came from a
gamma-ray generator.
2009 Tongchuan, Shaanxi, China
In 2009, a Chinese cement company (in
Tongchuan
Tongchuan () is a prefecture-level city located in central Shaanxi province, People's Republic of China on the southern fringe of the Loess Plateau that defines the northern half of the province (Shanbei) and the northern reaches of the Guanzho ...
,
Shaanxi Province
Shaanxi (alternatively Shensi, see § Name) is a landlocked province of China. Officially part of Northwest China, it borders the province-level divisions of Shanxi (NE, E), Henan (E), Hubei (SE), Chongqing (S), Sichuan (SW), Gansu (W), Ni ...
) was demolishing an old, unused
cement plant
A cement is a binder, a chemical substance used for construction that sets, hardens, and adheres to other materials to bind them together. Cement is seldom used on its own, but rather to bind sand and gravel ( aggregate) together. Cement mi ...
and did not follow standards for handling radioactive materials. This caused some caesium-137 from a measuring instrument to be included with eight truckloads of
scrap metal
Scrap consists of recyclable materials, usually metals, left over from product manufacturing and consumption, such as parts of vehicles, building supplies, and surplus materials. Unlike waste, scrap has monetary value, especially recovered me ...
on its way to a
steel mill
A steel mill or steelworks is an industrial plant for the manufacture of steel. It may be an integrated steel works carrying out all steps of steelmaking from smelting iron ore to rolled product, but may also be a plant where steel semi-finish ...
, where the radioactive caesium was melted down into the steel.
March 2015, University of Tromsø, Norway
In March 2015, the Norwegian
University of Tromsø
The University of Tromsø – The Arctic University of Norway (Norwegian: ''Universitetet i Tromsø – Norges arktiske universitet''; Northern Sami: ''Romssa universitehta – Norgga árktalaš universitehta'') is a state university in Norway an ...
lost 8 radioactive samples including samples of caesium-137,
americium-241
Americium-241 (, Am-241) is an isotope of americium. Like all isotopes of americium, it is radioactive, with a half-life of . is the most common isotope of americium as well as the most prevalent isotope of americium in nuclear waste. It is com ...
, and
strontium-90
Strontium-90 () is a radioactive isotope of strontium produced by nuclear fission, with a half-life of 28.8 years. It undergoes β− decay into yttrium-90, with a decay energy of 0.546 MeV. Strontium-90 has applications in medicine and ...
. The samples were moved out of a secure location to be used for education. When the samples were supposed to be returned the university was unable to find them. the samples are still missing.
March 2016 Helsinki, Uusimaa, Finland
On 3 and 4 March 2016, unusually high levels of caesium-137 were detected in the air in
Helsinki
Helsinki ( or ; ; sv, Helsingfors, ) is the Capital city, capital, primate city, primate, and List of cities and towns in Finland, most populous city of Finland. Located on the shore of the Gulf of Finland, it is the seat of the region of U ...
, Finland. According to
STUK, the country's nuclear regulator, measurements showed 4,000 μBq/m
3 – about 1,000 times the usual level. An investigation by the agency traced the source to a building from which STUK and a radioactive waste treatment company operate.
May 2019 Seattle, Washington, United States of America
Thirteen people were exposed to caesium-137 in May 2019 at the Research and Training building in the
Harborview Medical Center
Harborview Medical Center is a public hospital located in the First Hill neighborhood of Seattle, Washington, United States. It is managed by UW Medicine.
Overview
Harborview Medical Center is the designated Disaster Control Hospital for Seat ...
complex. A contract crew was transferring the caesium from the lab to a truck when the powder was spilled. Five people were decontaminated and released, but 8 who were more directly exposed were taken to the hospital while the research building was evacuated.
See also
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Commonly used gamma-emitting isotopes
Radionuclides which emit gamma radiation are valuable in a range of different industrial, scientific and medical technologies. This article lists some common gamma-emitting radionuclides of technological importance, and their properties.
Fissio ...
References
Bibliography
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External links
NLM Hazardous Substances Databank – Cesium, RadioactiveCesium-137 dirty bombs by Theodore Liolios
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Isotopes of caesium
Fission products
Radioisotope fuels
Radioactive contamination