| 摘要 |
<P>PROBLEM TO BE SOLVED: To more efficiently precipitate and collect uranium in an oxalic acid precipitation step in a used fuel reprocessing method. <P>SOLUTION: A used fuel reprocessing method 1 includes a dissolution step 2 of dissolving a used oxide fuel to a nitric acid solution, electrolytic reduction valence adjustment step 4 for uranium extraction of reducing plutonium to be trivalent, a centrifugal extraction step 5 of collecting hexavalent uranium, an electrolytic reduction valence adjustment step 6 for oxalic acid precipitation of adjusting valence of uranium residual in the nitric acid solution from hexavalent to quadrivalent, an oxalic acid precipitation step 7 of precipitating valence adjusted uranium, minor actinide and fission product as oxalic acid precipitate, an oxide transformation step 8 of transforming the oxalic acid precipitate to a precipitate oxide, and an electrolytic reduction step 9 of immersing the precipitate oxide in mixed fused salt, bringing the precipitate oxide in contact with a cathode and collecting uranium, plutonium and minor actinide in the precipitate oxide. <P>COPYRIGHT: (C)2013,JPO&INPIT |
