Reprocessing method by fluoride volatility process using fractional distillation

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 UO₂ and PuO₂ with hydrogen fluoride mixed with hydrogen to HF-fluorinate uranium and plutonium into UF₄ and PuF₃; subjecting UF₄ and PuF₃ with a fluorine gas to F₂-fluorinate uranium and plutonium into UF₆ and PuF₆; and fractionating UF₆ and PuF₆ using a difference in phase change of obtained UF₆and PuF₆, removing a part of UF₆, and volatilizing the remaining UF₆ and PuF₆ at the same time. By such a reprocessing method, PuF₄ 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.