Strontium radioactive hazard

Operational experience gained on LMFRs, such as BN-350, Phenix, PFR, BN-600 etc. has proved, that sodium is practically non-corrosive to stainless steel, and content of impurities, mainly oxygen and carbon, are maintained at acceptably low level by the cold traps installed in the bypass of the main coolant circuit. Radioactive hazardous isotopes (caesium, tritium, strontium and iodine) are retained by sodium. 

The radiation hazard associated with fallout from nuclear weapons testing arises from radioactive isotopes such as these. One of the most dangerous is strontium-90. In the form of strontium carbonate, SrC03, it is incorporated into the bones of animals and human beings, where it remains far a lifetime. 

Spent fuel from a reactor contains unused uranium as well as plutonium-239 which has been created by bombardment of neutrons during the fission process. Mixed with these useful materials are other highly radioactive and hazardous fission products, such as cesium-137 and strontium-90. Since reprocessed fuels contain plutonium, well suited for making nuclear weapons, concern has been expressed over the possible capture of some of this material by agents or terrorists operating on behalf of unfriendly governments that do not have a nuclear weapons capability. 

The anthropogenic radionuclides of most concern are those produced as fission products from nuclear weapons and nuclear reactors. The most devastating release from the latter source to date resulted from the April 26, 1986, explosion, partial meltdown of the reactor core, and breach of confinement structures by a power reactor at Chernobyl in the Ukraine. This disaster released 5 x 107 Ci of radionuclides from the site, which contaminated large areas of Soviet Ukraine and Byelorussia, as well as areas of Scandinavia, Italy, France, Poland, Turkey, and Greece. Radioactive fission products that are the same or similar to elements involved in life processes can be particularly hazardous. One of these is radioactive iodine, which tends to accumulate in the thyroid gland, which may develop cancer or otherwise be damaged as a result. Radioactive cesium exists as the Cs+ ion and is similar to sodium and potassium in its physiological behavior. Radioactive strontium forms the Sr2+ ion and substitutes for Ca2+, especially in bone. 

Strontium is a naturally occurring element found in rocks, soil, dust, coal, and oil. Naturally occurring strontium is not radioactive and is referred to as stable strontium. Stable strontium in the environment exists in four stable isotopes, " Sr (read as strontium 84), Sr, Sr, and Sr. Twelve other unstable isotopes are known to exist. Its radioactive isotopes are Sr and °Sr. Strontium is chemically similar to calcium. It was discovered in 1790. The isotope Sr is a highly radioactive poison, and was present in fallout from atmospheric nuclear explosions and is created in nuclear reactors. Atmospheric tests of nuclear weapons in the 1950s resulted in deposits and contaminations. °Sr has a half-life of 28 years and is a high-energy beta emitter. Its common cationic salts are water soluble it forms chelates with compounds such as ethylenediaminetetraacetic acid strontium coordination compounds are not common. Powdered metallic strontium may constitute an explosion hazard when exposed to flame. 

Strontium is a less well-known element of Group 2, but it s important, nevertheless. Because of its chemical similarity to calcium, strontium can replace calcium in the hydroxyapatite of bones and form Sr5(P04)30H. This could be a problem only if the strontium atoms are the radioactive isotope strontium-90, which is hazardous if it is incorporated into a person s bones. 

It is possible that higher-than-normal levels of stable strontium may occur naturally in soil in some places or that higher levels of radioactive strontium may be found in soil near hazardous waste sites. Some children eat a lot of dirt. You should prevent your children from eating dirt. Make sure they wash their hands frequently, and before eating. If you live near a hazardous waste site, discourage your children from putting their hands in their mouths or from engaging in other hand-to-mouth activities. 

C. Food harvested from an area that is contaminated by radiation may present a hazard. Meats and milk are the most vulnerable products because of the possibility for concentrations of radioactive isotopes (strontium, cesium, and iodine). All unpackaged and uncovered food, such as vegetables, fruits, and carcass meats, should be considered contaminated if obtained from a known area of contamination. If food supplies are critically low, the contaminated supplies may have to be consumed. In this event, it may be advisable to dilute the contaminated food by mixing with uncontaminated food. For more information, see page 1-34 of Effects of Nuclear Weapons and Directed Energy on Military Operations published by the AMEDD Center and School. 

One of the most hazardous fission products is Sr, because of its long half-life (28 years) and because strontium is concentrated in bone. For the determination of total radioactive strontium and Sr in water, the following procedme is used. 

Nuclear weapons present hazards in virtually all areas of their life cycle. Production and testing have their own impacts. The U.S. National Cancer Institute estimated that the release of iodine-131 in fallout from U.S. nuclear test explosions was by itself responsible for 49,000 excess cases of thyroid cancer among the U.S. popnlation [8]. A 1991 pubhcation by the hitemational Physicians for the Prevention of Nnclear War estimated that the strontium-90, cesium-137, carbon-14, and poloninm-239 released worldwide in all nuclear test explosions would be responsible for 430,000 cancer deaths by 2000 [9]. Additional widespread health and enviromnental effects of nuclear-weapons prodnction include massive contamination of land by radioactive materials and toxic chemicals. 

Radioactive isotopes of strontium were produced by the explosion of nuclear weapons. They were considered serious health hazards because they were incorporated into the bones of animals that ingested them. Explain why strontium would be likely to be deposited in bones. 

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