Iodine-129 , nuclear fuel reprocessing

If the spent fuel is processed in a nuclear fuel reprocessing plant, the radioactive iodine species (elemental iodine and methyl iodide) trapped in the spent fuel elements ate ultimately released into dissolver off gases. The radioactive iodine may then be captured by chemisorption on molecular sieve 2eohtes containing silver (89). 

D. W. HoWid.2cy, A Eiterature Survey Methodsfor the Removal of Iodine Spedafrom Off-Gas andEiquid Waste Streams of Nuclear Power and Nuclear Fuel Reprocessing Plants, with Emphasis on Solid Sorbents, ORNL/TM-6350, Oak Ridge National Laboratory, Oak Ridge, Term., 1979. 

Robens, E. Aumann, D.C. (1988) Iodine-129 in the environment of a nuclear fuel reprocessing plant 1.129I and1271 contents of soils, food crops and animal products. Journal of Environmental Radioactivity, 7,159-75. 

CnH2314CH2125I has been prepared429 from the 14C-labelled 1-dodecanol and labelled phosphorus iodide (equation 203). Double-labelling has been chosen to optimize the radioiodine decontamination of the organic phase of the nuclear fuel reprocessing cycle and to study the exchange kinetics of iodine between the elemental and the bound forms430. 

A notable exception to the above is the airborne effluent from spent nuclear fuel reprocessing and from tritium production. In this case, iodine-131 volatilizes from fuel reprocessing and must be removed by passing the... 

The coexistence of various inorganic and organic iodine species, in different proportions, has been reported in various environments (Liss et al., 1973 Couture and Seitz, 1983 Yuita, 1992, 1994 Yamada et al., 1999 Muramatsu and Ohmono, 1988 Baker et al., 2001). Organically bound iodine can be a significant fraction of total iodine in aqueous systems and in the atmosphere. For example, methyl iodide is an important gaseous form of iodine in the marine atmosphere and in releases from nuclear fuel reprocessing facilities, while dissolved organo-I compounds comprise up to 50% of total iodine in aqueous samples from estuaries, rivers, and rain (Santschi and Schwehr, 2004). 

Anywhere spent nuclear liiel is handled, there is a chance that iodine-129 and iodine-131 will escape into the environment. Nuclear fuel reprocessing plants dissolve the spent fuel rods in strong acids to recover plutonium and other valuable materials. In the process, they also release iodine-129 and -131 into the airborne, liquid, and solid waste processing systems. In the U.S., spent nuclear fuel is no longer reprocessed, becau.se of concerns about nuclear weapons proliferation. 

Holladay, D.W. 1979. A literature survey Methods for the removal of iodine species from off-gases and liquid waste streams of nuclear power and nuclear fuel reprocessing plants, with emphasis on solid sorbents. ORNL/TM-6350. Oak Ridge, TN Oak Ridge National Laboratory. 

Daly, J.C., Goodyear, S., Paperiello, C.J. and Matuszek, J.M. (1974). Iodine-129 levels in milk and water near a nuclear fuel reprocessing plant, Health Phys. 26, 33. 

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). 

Magno, P.G., Reavey, T.C. and Apidianakis, J.C. (1972). Iodine-129 in the Environment Around a Nuclear Fuel Reprocessing Plant (Office of Radiation Programs, U.S. Environmental Protection Agency, Washington). 

The Japan Nuclear Fuel Service Company reprocesses LWR fuel in faciUties which take advantage of French shear and dissolver designs, German iodine removal technology, and British reduced-pressure evaporation. 

Figure XIX-5 presents the specific long-lived radiotoxicity of spent nuclear fuel within the nuclear fuel cycle as a function of energy produced by the SVBR-75/100 reactors. These calculations show that specific radiotoxicity of the technetium-99, iodine-129 and caesium-135 before the final disposal is 0.014 km /GW(e)/year, without taking into account the losses in reprocessing. It is nearly equal to the specific radiotoxicity of natural uranium extracted from Earth and added to the fuel cycle each year.

Iodine-129 produced in nuclear power reactors and released during fuel reprocessing represents an essentially permanent contaminant of the biosphere where it will appear as a fraction of the total environmental iodine. 

The following equations represent reactions that involve only halogen atoms. Iodine pentafluoride, IF5, is used to add fluorine atoms to other compounds, bromine pentafluoride, BrF5, is an oxidizing agent in liquid rocket propellants, and chlorine trifluoride, CIF3, is used to reprocess nuclear reactor fuels. 

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