摘要 |
Fluorine or a fluorine compound is subjected to a reaction with a spent oxide fuel to produce fluorides of uranium and plutonium, and recovering the fluorides using a difference in volatility behavior. The method includes steps of: subjecting a mixture of UO<SUB>2 </SUB>and PuO<SUB>2 </SUB>with hydrogen fluoride mixed with hydrogen to HF-fluorinate uranium and plutonium into UF<SUB>4 </SUB>and PuF<SUB>3</SUB>; subjecting UF<SUB>4 </SUB>and PuF<SUB>3 </SUB>with a fluorine gas to F<SUB>2</SUB>-fluorinate uranium and plutonium into UF<SUB>6 </SUB>and PuF<SUB>6</SUB>; and fractionating UF<SUB>6 </SUB>and PuF<SUB>6 </SUB>using a difference in phase change of obtained UF<SUB>6</SUB>and PuF<SUB>6</SUB>, removing a part of UF<SUB>6</SUB>, and volatilizing the remaining UF<SUB>6 </SUB>and PuF<SUB>6 </SUB>at the same time. By such a reprocessing method, PuF<SUB>4 </SUB>hard to undergo a reaction is prevented from being formed as an intermediate fluoride, the material of a reactor is hard to be corroded, and a consumption of expensive fluorine gas is reduced.
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