Strontium-90
Encyclopedia
Strontium-90 is a radioactive isotope
of strontium
, with a half-life
of 28.8 years.
with decay energy
of 0.546 MeV
distributed to an electron
, an anti-neutrino, and the yttrium
isotope 90Y, which in turn undergoes β− decay
with half-life
of 64 hours and decay energy 2.28 MeV distributed to an electron, an anti-neutrino, and 90Zr
(zirconium), which is stable. Note that 90Sr/Y is almost a perfectly pure beta
source; the gamma photon emission from the decay of 90Y is so weak that it can normally be ignored.
can be used in treatment of bone cancer. As the radioactive decay of strontium-90 generates significant amount of heat, and is cheaper than the alternative 238Pu
, it is used as a heat source in many Russian/Soviet radioisotope thermoelectric generator
s, usually in the form of strontium fluoride
. It is also used as a radioactive tracer
in medicine and agriculture.
A study of hundreds of thousands of deciduous teeth
, collected by Dr. Louise Reiss
and her colleagues as part of the Baby Tooth Survey
, found a large increase in 90Sr levels through the 1950s and early 1960s. The study's final results showed that children born in 1963 had levels of 90Sr in their deciduous teeth that was 50 times higher than that found in children born in 1950, before the advent of large-scale atomic testing. An article with the study's initial findings was circulated to U.S. President John F. Kennedy
in 1961, and helped convince him to sign the Partial Nuclear Test Ban Treaty with the United Kingdom
and Soviet Union
, ending the above-ground nuclear weapons testing that placed the greatest amounts of nuclear fallout
into the atmosphere.
. It is present in significant amount in spent nuclear fuel
and in radioactive waste
from nuclear reactor
s and in nuclear fallout
from nuclear tests.
For thermal neutron fission as in today's nuclear power plants, the fission product yield
from U-235
is 5.8%, from U-233
6.8%, but from Pu-239 only 2.1%.
, 137Cs
, and iodine isotope 131I
it was among the most important isotopes regarding health impacts after the Chernobyl disaster
.
Strontium-90 is a "bone seeker
" that exhibits biochemical behavior similar to calcium
, the next lighter Group 2 element. After entering the organism, most often by ingestion with contaminated food or water, about 70–80% of the dose gets excreted. Virtually all remaining strontium-90 is deposited in bone
s and bone marrow
, with the remaining 1% remaining in blood and soft tissues. Its presence in bones can cause bone cancer, cancer of nearby tissues, and leukemia
. Exposure to 90Sr can be tested by a bioassay
, most commonly by urinalysis
.
(bass, vocals), Sting (bass, vocals), Stewart Copeland
(drums), and Andy Summers
(guitar). The band is most notable for introducing Summers to Sting and Copeland, as this trio would go on to massive success as The Police
.
Also, in the 2008 GOTY Fallout 3
, a consumable drink called "Nuka-Cola Quantum" is said to use this isotope of strontium
to give it its signature blue glow.
Isotope
Isotopes are variants of atoms of a particular chemical element, which have differing numbers of neutrons. Atoms of a particular element by definition must contain the same number of protons but may have a distinct number of neutrons which differs from atom to atom, without changing the designation...
of strontium
Strontium
Strontium is a chemical element with the symbol Sr and the atomic number 38. An alkaline earth metal, strontium is a soft silver-white or yellowish metallic element that is highly reactive chemically. The metal turns yellow when exposed to air. It occurs naturally in the minerals celestine and...
, with a half-life
Half-life
Half-life, abbreviated t½, is the period of time it takes for the amount of a substance undergoing decay to decrease by half. The name was originally used to describe a characteristic of unstable atoms , but it may apply to any quantity which follows a set-rate decay.The original term, dating to...
of 28.8 years.
Radioactivity
Natural strontium is nonradioactive and nontoxic, but 90Sr is a radioactivity hazard. 90Sr undergoes β− decayBeta decay
In nuclear physics, beta decay is a type of radioactive decay in which a beta particle is emitted from an atom. There are two types of beta decay: beta minus and beta plus. In the case of beta decay that produces an electron emission, it is referred to as beta minus , while in the case of a...
with decay energy
Decay energy
The decay energy is the energy released by a radioactive decay. Radioactive decay is the process in which an unstable atomic nucleus loses energy by emitting ionizing particles and radiation...
of 0.546 MeV
Electronvolt
In physics, the electron volt is a unit of energy equal to approximately joule . By definition, it is equal to the amount of kinetic energy gained by a single unbound electron when it accelerates through an electric potential difference of one volt...
distributed to an electron
Electron
The electron is a subatomic particle with a negative elementary electric charge. It has no known components or substructure; in other words, it is generally thought to be an elementary particle. An electron has a mass that is approximately 1/1836 that of the proton...
, an anti-neutrino, and the yttrium
Yttrium
Yttrium is a chemical element with symbol Y and atomic number 39. It is a silvery-metallic transition metal chemically similar to the lanthanides and it has often been classified as a "rare earth element". Yttrium is almost always found combined with the lanthanides in rare earth minerals and is...
isotope 90Y, which in turn undergoes β− decay
Beta decay
In nuclear physics, beta decay is a type of radioactive decay in which a beta particle is emitted from an atom. There are two types of beta decay: beta minus and beta plus. In the case of beta decay that produces an electron emission, it is referred to as beta minus , while in the case of a...
with half-life
Half-life
Half-life, abbreviated t½, is the period of time it takes for the amount of a substance undergoing decay to decrease by half. The name was originally used to describe a characteristic of unstable atoms , but it may apply to any quantity which follows a set-rate decay.The original term, dating to...
of 64 hours and decay energy 2.28 MeV distributed to an electron, an anti-neutrino, and 90Zr
Zirconium
Zirconium is a chemical element with the symbol Zr and atomic number 40. The name of zirconium is taken from the mineral zircon. Its atomic mass is 91.224. It is a lustrous, grey-white, strong transition metal that resembles titanium...
(zirconium), which is stable. Note that 90Sr/Y is almost a perfectly pure beta
Beta particle
Beta particles are high-energy, high-speed electrons or positrons emitted by certain types of radioactive nuclei such as potassium-40. The beta particles emitted are a form of ionizing radiation also known as beta rays. The production of beta particles is termed beta decay...
source; the gamma photon emission from the decay of 90Y is so weak that it can normally be ignored.
Applications
90Sr finds extensive use in medicine and industry, as a radioactive source for thickness gauges and for superficial radiotherapy of some cancers. Controlled amounts of 90Sr and 89SrStrontium-89
Strontium-89 is an isotope of strontium.It is treated by the body in a similar manner to calcium, and is preferentially deposited metabolically active regions of the bone.It is an artificial radioisotope which is used in treatment of bone cancer...
can be used in treatment of bone cancer. As the radioactive decay of strontium-90 generates significant amount of heat, and is cheaper than the alternative 238Pu
Plutonium-238
-External links:**...
, it is used as a heat source in many Russian/Soviet radioisotope thermoelectric generator
Radioisotope thermoelectric generator
A radioisotope thermoelectric generator is an electrical generator that obtains its power from radioactive decay. In such a device, the heat released by the decay of a suitable radioactive material is converted into electricity by the Seebeck effect using an array of thermocouples.RTGs can be...
s, usually in the form of strontium fluoride
Strontium fluoride
Strontium fluoride, SrF2, also called strontium difluoride and strontium fluoride, is a fluoride of strontium. It is a stable brittle white crystalline solid with melting point of 1477°C and boiling point 2460°C.-Preparation:...
. It is also used as a radioactive tracer
Radioactive tracer
A radioactive tracer, also called a radioactive label, is a substance containing a radioisotope that is used to measure the speed of chemical processes and to track the movement of a substance through a natural system such as a cell or tissue...
in medicine and agriculture.
A study of hundreds of thousands of deciduous teeth
Deciduous teeth
Deciduous teeth, otherwise known as reborner teeth, baby teeth, temporary teeth and primary teeth, are the first set of teeth in the growth development of humans and many other mammals. In some Asian countries they are referred to as fall teeth as they will eventually fall out, while in almost all...
, collected by Dr. Louise Reiss
Louise Reiss
Louise Marie Zibold Reiss was an American physician who coordinated what became known as the Baby Tooth Survey, in which deciduous teeth from children living in the St. Louis, Missouri area who were born in the 1950s and 1960s were collected and analyzed over a period of 12 years...
and her colleagues as part of the Baby Tooth Survey
Baby Tooth Survey
The Baby Tooth Survey was initiated by the Greater St. Louis Citizens' Committee for Nuclear Information in conjunction with Saint Louis University and the Washington University School of Dental Medicine as a means of determining the effects of nuclear fallout in the human anatomy by examining the...
, found a large increase in 90Sr levels through the 1950s and early 1960s. The study's final results showed that children born in 1963 had levels of 90Sr in their deciduous teeth that was 50 times higher than that found in children born in 1950, before the advent of large-scale atomic testing. An article with the study's initial findings was circulated to U.S. President John F. Kennedy
John F. Kennedy
John Fitzgerald "Jack" Kennedy , often referred to by his initials JFK, was the 35th President of the United States, serving from 1961 until his assassination in 1963....
in 1961, and helped convince him to sign the Partial Nuclear Test Ban Treaty with the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
and Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
, ending the above-ground nuclear weapons testing that placed the greatest amounts of nuclear fallout
Nuclear fallout
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 shock wave have passed. It commonly refers to the radioactive dust and ash created when a nuclear weapon explodes...
into the atmosphere.
Fission product
90Sr is a product of nuclear fissionNuclear fission
In nuclear physics and nuclear chemistry, nuclear fission is a nuclear reaction in which the nucleus of an atom splits into smaller parts , often producing free neutrons and photons , and releasing a tremendous amount of energy...
. It is present in significant amount in spent nuclear fuel
Spent nuclear fuel
Spent nuclear fuel, occasionally called used nuclear fuel, is nuclear fuel that has been irradiated in a nuclear reactor...
and in radioactive waste
Radioactive waste
Radioactive wastes are wastes that contain radioactive material. Radioactive wastes are usually by-products of nuclear power generation and other applications of nuclear fission or nuclear technology, such as research and medicine...
from nuclear reactor
Nuclear reactor
A nuclear reactor is a device to initiate and control a sustained nuclear chain reaction. Most commonly they are used for generating electricity and for the propulsion of ships. Usually heat from nuclear fission is passed to a working fluid , which runs through turbines that power either ship's...
s and in nuclear fallout
Nuclear fallout
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 shock wave have passed. It commonly refers to the radioactive dust and ash created when a nuclear weapon explodes...
from nuclear tests.
For thermal neutron fission as in today's nuclear power plants, the fission product yield
Fission product yield
Nuclear fission splits a heavy nucleus such as uranium or plutonium into two lighter nuclei, which are called fission products. Yield refers to the fraction of a fission product produced per fission.Yield can be broken down by:#Individual isotope...
from U-235
Uranium-235
- References :* .* DOE Fundamentals handbook: Nuclear Physics and Reactor theory , .* A piece of U-235 the size of a grain of rice can produce energy equal to that contained in three tons of coal or fourteen barrels of oil. -External links:* * * one of the earliest articles on U-235 for the...
is 5.8%, from U-233
Uranium-233
Uranium-233 is a fissile isotope of uranium, bred from Thorium as part of the thorium fuel cycle. It has been used in a few nuclear reactors and has been proposed for much wider use as a nuclear fuel. It has a half-life of 160,000 years....
6.8%, but from Pu-239 only 2.1%.
Biochemistry
Together with caesium isotopes 134CsCaesium
Caesium or cesium is the chemical element with the symbol Cs and atomic number 55. It is a soft, silvery-gold alkali metal with a melting point of 28 °C , which makes it one of only five elemental metals that are liquid at room temperature...
, 137Cs
Caesium-137
Caesium-137 is a radioactive isotope of caesium which is formed as a fission product by nuclear fission.It has a half-life of about 30.17 years, and decays by beta emission to a metastable nuclear isomer of barium-137: barium-137m . Caesium-137 is a radioactive isotope of caesium which is formed...
, and iodine isotope 131I
Iodine-131
Iodine-131 , also called radioiodine , is an important radioisotope of iodine. It has a radioactive decay half-life of about eight days. Its uses are mostly medical and pharmaceutical...
it was among the most important isotopes regarding health impacts after the Chernobyl disaster
Chernobyl disaster
The Chernobyl disaster was a nuclear accident that occurred on 26 April 1986 at the Chernobyl Nuclear Power Plant in Ukraine , which was under the direct jurisdiction of the central authorities in Moscow...
.
Strontium-90 is a "bone seeker
Bone seeker
Bone seeker describes an element, often a radioisotope, that tends to accumulate in the bones of humans and animals when it is introduced into the body. An example is 90Sr, which behaves chemically like calcium and can replace the calcium in bones....
" that exhibits biochemical behavior similar to calcium
Calcium
Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...
, the next lighter Group 2 element. After entering the organism, most often by ingestion with contaminated food or water, about 70–80% of the dose gets excreted. Virtually all remaining strontium-90 is deposited in bone
Bone
Bones are rigid organs that constitute part of the endoskeleton of vertebrates. They support, and protect the various organs of the body, produce red and white blood cells and store minerals. Bone tissue is a type of dense connective tissue...
s and bone marrow
Bone marrow
Bone marrow is the flexible tissue found in the interior of bones. In humans, bone marrow in large bones produces new blood cells. On average, bone marrow constitutes 4% of the total body mass of humans; in adults weighing 65 kg , bone marrow accounts for approximately 2.6 kg...
, with the remaining 1% remaining in blood and soft tissues. Its presence in bones can cause bone cancer, cancer of nearby tissues, and leukemia
Leukemia
Leukemia or leukaemia is a type of cancer of the blood or bone marrow characterized by an abnormal increase of immature white blood cells called "blasts". Leukemia is a broad term covering a spectrum of diseases...
. Exposure to 90Sr can be tested by a bioassay
Bioassay
Bioassay , or biological standardization is a type of scientific experiment. Bioassays are typically conducted to measure the effects of a substance on a living organism and are essential in the development of new drugs and in monitoring environmental pollutants...
, most commonly by urinalysis
Urinalysis
A urinalysis , also known as Routine and Microscopy , is an array of tests performed on urine, and one of the most common methods of medical diagnosis...
.
Dispersal hazards
Accidental mixing of radioactive sources containing strontium with metal scrap can result in production of radioactive steel. Discarded radioisotope thermoelectric generators are a major source of 90Sr contamination in the area of the former Soviet Union.In popular culture
Strontium 90 was the name of a short-lived 1977 British band with members Mike HowlettMike Howlett
Mike Howlett is a Fijian-born musician, Grammy Award winning producer and teacher based in the United Kingdom and Australia....
(bass, vocals), Sting (bass, vocals), Stewart Copeland
Stewart Copeland
Stewart Armstrong Copeland is an American musician, best known as the drummer for the band The Police. During the group's extended hiatus from the mid-1980s to 2007, he played in other bands and composed soundtracks...
(drums), and Andy Summers
Andy Summers
Andy Summers is an English guitarist born in Poulton-le-Fylde, Lancashire, England. Best known as the guitarist for rock band The Police, he has also recorded twelve solo albums, collaborated with many other artists, toured extensively under his own name, published several books, and composed...
(guitar). The band is most notable for introducing Summers to Sting and Copeland, as this trio would go on to massive success as The Police
The Police
The Police were an English rock band formed in London in 1977. For the vast majority of their history, the band consisted of Sting , Andy Summers and Stewart Copeland...
.
Also, in the 2008 GOTY Fallout 3
Fallout 3
Fallout 3 is an action role-playing game released by Bethesda Game Studios, and the third major installment in the Fallout series. The game was released in North America, Europe and Australia in October 2008, and in Japan in December 2008 for Microsoft Windows, PlayStation 3 and Xbox 360...
, a consumable drink called "Nuka-Cola Quantum" is said to use this isotope of strontium
Strontium
Strontium is a chemical element with the symbol Sr and the atomic number 38. An alkaline earth metal, strontium is a soft silver-white or yellowish metallic element that is highly reactive chemically. The metal turns yellow when exposed to air. It occurs naturally in the minerals celestine and...
to give it its signature blue glow.