Nuclear fuel, long-lived radionuclides

Different applications of mass spectrometry in the trace and ultratrace determination of long lived radionuclides in nuclear fuel, solid radioactive waste samples, radioactive solutions and... 

The reasons why solvent extraction has become the reference technique for the reprocessing of spent nuclear fuels at industrial scale (and will probably also be chosen in the future for the recovery of long-lived radionuclides) are the following (32, 33) ... 

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. 

At any stage of nuclear material management (closure of plutonium facilities, vitrification processes, fabrication of MOX fuel, metallic plutonium conversion into oxide, etc.), the long-lived radionuclides appearing in case of any deviation from the standard process can be reliably isolated from the environment only by their final disposal in geologic formations. 

Spent nuclear fuel can either be reprocessed (see O Sect. 52.3.4) or put directly into a deep underground repository like in, e.g., Sweden or Finland. In both cases, the material stored in the repository contains long-lived radionuclides like Np and Am as well as varying amounts of plutonium. Therefore, the storage facility has to fulfill strict safety requirements for a very long time, typically several hundred thousand years for unreprocessed fuel. 

Rosenberg RJ (1992) Non-conventional measurement techniques for the determination of some long-lived radionuclides produced in nuclear fuel, VTT-TIED-1357... 

Kantelo, M.V., Tiffany, B., and Anderson, T.J. (1982). Iodine-129 distribution in the terrestrial environment surrounding a nuclear fuel reprocessing plant after 25 years of operation, page 495 in Environmental Migration of Long-Lived Radionuclides, IAEA Publication No. STI/PUB/ 597 (International Atomic Energy Agency, Vienna). 

Liquid wastes. Historically, the most important radioactive wastes have been liquid wastes that arise from chemical reprocessing of spent nuclear fuel for defense production purposes, i.e., for the purpose of extracting plutonium for use in nuclear weapons. These wastes contain varying concentrations of many radionuclides, primarily fission products and long-lived, alpha-emitting transuranium isotopes. 

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