Nuclear plants radioactive source, activity

Cesium 137 is an artificial radionuclide used in clinical, industrial, and research applications and one of the main radioactive products of fission reactions taking place in nuclear reactors. The possibility that the anomalous radioactivity derived from active nuclear plants can be rule out as the i Cs was not accompanied by the other radionuclides produced during fission. Towards the end of April 1998, an incident occurred at the Algeciras steel works in southern Spain with emissions of Cs coming from a radioactive source no longer in use. This source ended up in the foundry. The fact that the presence of Cs was interrupted for a week and then resumed is not unusual as the transport and soil deposition of air-dispersed pollutants is strictly linked to wind and precipitation. The levels of radioactivity were negligible and many times below every alarm threshold, but the bee matrix promptly revealed the presence, albeit minimal, of Cs... 

The other types of radioactive materials cited in this section (medical industry and food industry sources) produce significantly lower activity levels than fuel from a nuclear power plant. However, these sources of radioactive materials may be appealing to terrorists because they are far more accessible. Thousands of hospitals, medical treatment facilities, and food industry plants scattered across the U.S. are protected by relatively low levels of security. 

The third principal component of environmental radioactivity is that due to the activities of humans, the anthropogenic radionuclides. This group of nuclides includes the previously discussed cases of 3H and 14C along with the fission products and the transuranium elements. The primary sources of these nuclides are nuclear weapons tests and nuclear power plant accidents. These events and the gross nuclide releases associated with them are shown in Table 3.1. Except for 14C and... 

Table 19.5 shows the physical effects of short-term exposure to various doses of radiation, and Table 19.6 gives the sources and amounts of the radiation to which a typical person in the United States is exposed each year. Note that natural sources contribute about twice as much as human activities do to the total exposure. However, although the nuclear industry contributes only a small percentage of the total exposure, controversy surrounds nuclear power plants because of their potential for creating radiation hazards. These hazards arise mainly from two sources accidents allowing the release of radioactive materials, and improper disposal of the radioactive products in spent fuel elements. 

The anthropogenic sources of radioactivity in the environment include the testing of nuclear weapons and radioactive material handling, especially in nuclear power plants. In the explosion of atomic bombs or in nuclear reactors, a complex mixture of different radionucHdes is produced, namely uranium plutonium Pu, caesium Cs (half-Hfe of 30 years), strontium Sr (half-life of 28 years), cobalt Co (half-Hfe of 5.3 years), caesium Cs (half-Hfe of 2 years), ruthenium Ru (half-Hfe of 1 year) and iodine 1 (half-Hfe of 8 days). A number of other radionucHdes result from an atomic explosion by coUision of neutrons with the atoms of elements that are contained in the casing of the non-explosive parts of the atomic bomb. For example, these activation products include zinc Zn (half-Hfe of 245 days). 

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