Actinide elements separation from used nuclear fuels

The first attention given to actinide photochemistry was for the purpose of identifying any photochemical activity which might alter the efficiency of the extraction or exchange processes. Subsequently, the identification of photochemically active species of uranium and plutonium gave some indication that the photoreactions could be turned to a useful end and, perhaps, offer a cleaner way to separate actinides from each other and from the other elements accompanying them in nuclear fuel elements. 

Pyrochemical reprocessing using molten salts has the potential to recover actinides from spent nuclear fuels [1,2], Since some fission products of rare earth elements have large neutron capture cross-sections, separating them from actinides is desirable. In order to control the separation performance, monitoring the concentration of each element is important. Absorption spectrophotometric analysis is superior to determine the solute concentration and hence its application is examined. 

Separation of Actinides from the Samples of Irradiated Nuclear Fuels. For the purpose of chemical measurements of burnup and other parameters such as accumulation of transuranium nuclides in irradiated nuclear fuels, an ion-exchange method has been developed to separate systematically the transuranium elements and some fission products selected for burnup monitors (16) Anion exchange was used in hydrochloric acid media to separate the groups of uranium, of neptunium and plutonium, and of the transplutonium elements. Then, cation and anion exchange are combined and applied to each of those groups for further separation and purification. Uranium, neptunium, plutonium, americium and curium can be separated quantitatively and systematically from a spent fuel specimen, as well as cesium and neodymium fission products. 

The mutual separation of actinide elements and the selective isolation of useful actinides from fission products are indispensable for the nuclear fuel cycle and have become important subjects of investigation for the development of advanced nuclear fuel reprocessing and TRU (TRans Uranium elements) waste management [1], A variety of research concerning the separation chemistry of actinides has so far been accumulated [2]. There are, however, only a few theoretical studies on actinides in solution[3-5]. Schreckenbach et a), discussed the stability of uranyl (VI) tetrahydroxide [UO,(OH) ] [3] and Spencer and co-workers calculated the optimized structures of some uranyl and plutonyl hydrates [AcO, nH,0 (Ac = U, Pu and n = 4,5,6)] [4],... 

---