Reprocessing method, nuclear fuel

Wymer, R.G. 1999. Reprocessing of nuclear fuel. In Chemical Separation Technologies and Related Methods ofNuclearWaste Management Application, Problems and Research Needs. Choppin, G.R., Khankhasayev, M.Kh. Eds. Kluwer Academic, Netherlands, pp. 29-52. 

Actinide separation techniques and methods play a very important role in analysis and production of nuclear materials, reprocessing of nuclear fuels, nuclear waste management, and other aspects of the nuclear fuel cycle. Professionals from several disciplines—analytical chemists, chemical engineers, process chemists, etc.—make much use of this technology. 

Knighton, J. B. Johnson, I. Steunenberg, R. K., "Uranium and Plutonium Purification hy the Salt Transport Method," in "Symposium on Reprocessing of Nuclear Fuels, The Metallurgical Society of AIME, Ames, IA, August 1979," Nucl. Metallurgy,... 

Research should continue on traditional separation methods. For example, there is a continuing need for more selective extraction agents for liquid-liquid and ion-exchange extractions. High-temperature processes that use liquid metals or molten salts as extraction agents should have potential in nuclear fuel reprocessing and... 

The two principal methods by which actinides may enter the body are inhalation and penetration through wounds. These two routes of entry are of obvious concern to those individuals working in nuclear fuel reprocessing plants. The principal route of entry by which most of the general public is likely to be exposed to the actinides could be expected to be via the food chain. However, Bennett (176) has indicated that inhalation of 239>(i) 240Pii is more important by a factor of 1000 compared to the uptake by ingestion in contributing to the body burden. 

The tests on the detoxification and reclamation method have demonstrated the following advantages in reprocessing metal-bearing spent acids from nuclear fuel fabrication ... 

It is apparent from the foregoing discussion that both ILs and supercritical carbon dioxide do indeed offer promise as alternative solvents in the reprocessing of spent nuclear fuel and the treatment of nuclear wastes. It is equally apparent, however, that considerable additional work lies ahead before this promise can be fully realized. Of particular importance in this context is the need for an improved understanding of the fundamental aspects of metal ion transfer into ILs, for a thorough evaluation of the desirability of extractant functionalization of ILs, and for the development of new methods for both the recovery of extracted ions (e.g., uranium) and the recycling of extractants in supercritical C02-based systems. Only after such issues have been addressed might these unique solvents reasonably be expected to provide the basis of improved approaches to An or FP separations. 

An alternative to permanent isolation of the spent nuclear fuel is monitored, retrievable storage. This method has an advantage since, if reprocessing to remove potentially useful materials such as plutonium becomes feasible, the wastes are still accessible. The argument for this plan is that the technologies and alternatives available to society a few hundred years... 

A full account of the problems considered in collecting, storing, and processing marine samples for transuranic analysis is given in the above-mentioned review (4). The specific methods discussed here were foimd effective at least for the transuranic analyses of seawater and sediments contaminated by global fallout, nuclear fuel reprocessing wastes, or nuclear power plant operation waste. In these cases, a preliminary acid treatment of the sample in the presence of suitable yield monitors seems to solubilize the transuranic elements and achieves isotopic equilibration between the yield monitor and sample. The yield monitors used were either Pu or sep qj. 238,239,240,24ip whereas Am was used for Am, 2 Cm, and by inference, Cf. In addition, it was convenient to use 50 mg of a lanthanide (neodymium) as a carrier for americium to purify the separated americium fraction. 

Aqueous reprocessing methods have been developed to effect an efficient and thorough separation of fissile elements from the contaminating fission products in spent fuel( l). While these processes may be altered to yield a proliferations-resistant product by coprocessing or by the addition of radioactive material that will contaminate the clean fissile material, it still is necessary to safeguard some of the process steps to ensure that material useful in nuclear weapons will not be diverted (3). The safeguard requirements and the ease of subversion of such provisions make many versions of the conventional processes subject to unacceptable proliferation risks. 

The pyrochemical coprocessing of spent nuclear fuel by the Salt Transport Process appears to be a potentially viable reprocessing method, not only as an "exportable proliferation resistant technology," but as a domestic reprocessing operation. All operations are nonaqueous and waste generation is in solid form, thus requiring no conversion from aqueous solutions to solids. 

B. Amecke, Contributions to the Reprocessing of Thorium-Uranium Nuclear Fuels with the Salt-Transport Method, Dissertation Technical University of Carolo-Wilhelmina at Braunschweig, ANL-TRANS-1141 (1978). 

Brambilla, G. Caporali, G. Zambianchi, M. "Reprocessing Method of Ceramic Nuclear Fuels in Low-Melting Nitrate Molten Salts", U.S. Patent 3 981 960, 1976. 

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