Radionuclides from nuclear weapons testing

Tihe atmosphere contains many radionuclides which result from nuclear weapons testing and from natural processes. The nuclear weapons-produced radionuclides include both fission products and activation products from the construction materials of the device. The natural radionuclides include the decay products of radon and thoron, the natural radionuclides in the airborne dust, and the cosmic-ray-produced radionuclides which result from spallation reactions in the atmosphere. Through the determination of the absolute and relative concentrations of this wide spectrum of radionuclides, it should be possible to define the rates of both the long term stratospheric processes and the shorter term tropospheric processes. At the beginning of 1962 a ground-level... 

Radioactive substances The principal sources of radionuclides released into the environment include nuclear weapon testing fallout from accidents such as the Chernobyl accident in 1986 or from foundering of nuclear submarines from the dumping of nuclear waste into the deep ocean and from discharges from nuclear power plants and nuclear reprocessing plants. 

Among common radionuclide sources are the natural environment, fallout from nuclear weapon tests, effluents from nuclear research laboratories, the nuclear power fuel cycle, radiopharmaceutical development, manufacturing, and various application, teaching and research uses. Decontamination and decommissioning activities at former nuclear facilities and the potential of terrorist radionuclide uses are current topics of interest for radioanalytical chemistry laboratories. Simplified information on the numerous radionuclides is conveniently found in Charts of the Nuclides such as Nuclides and Isotopes (revised by J. R. Parrington, H. D. Knox, S. L. Breneman, E. M. Baum, and F. Feiner, 15th Edition, 1996, distributed by GE Nuclear Energy). 

T1 adiochemical methods have proved effective for studying fractiona-tion of radionuclides resulting from atmospheric nuclear weapon tests and the deposition of these radionuclides by meteorological processes. 

Besides the analysis of nuclear fuel and of radioactive waste materials, the determination of contamination and enrichment of selected radioactive nuclides, e.g., which is one of the most important environmental indicators of nuclear accidents, Se, Tc, Np, Pu, °Pu and "Am at ultratrace concentration levels, is useful for environmental monitoring of fallout from nuclear weapons testing, nuclear power plants or nuclear accidents. ". Selected application fields for the determination of natural and artificial long-lived radionuclides (LLR) and radionuclides investigated by mass spectrometric techniques are summarized in Tables 9.36 and 9.37, respectively. 

In addition to these ordinary constituents, infiltrating meteoric waters may contain more exotic solutes that are particularly useful for tracing of water flow paths and residence times. Prominent among these are radionuclides produced by the action of cosmic rays on the atmosphere. The most commonly employed are H, and C1, but many others are described in this chapter. Another category of useful tracers is that produced by human activity, whose atmospheric concentration histories are generally known. Those frequently employed for subsurface tracing include H, C, and C1 produced by atmospheric nuclear-weapons testing, Kr and released from nuclear... 

Six long-lived radionuclides beyond uranium exist which have half-lives greater than 100 ka ( Np, Np, Pu, Pu and Cm). The first two are natural by-products of the nuclear industry. Nuclear-weapons tests will generate the plutonium and curium isotopes although attempts have been made to detect pre-solar system Pu in ores (Hoffman et al., 1971) or Pu from more recent supernova debris. The detection of these isotopes is still in the development stage. Unlike the natural elements, isobaric... 

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