Reprocessing method by fluoride volatility process using solid-gas separation

A reprocessing method by a fluoride volatility process using solid-gas separation in which fluorine or a fluorine compound is subjected to a reaction with a spent oxide fuel to produce fluorides of uranium and plutonium, and recover uranium and plutonium as the fluorides using a difference in volatility behavior, the reprocessing method comprising the steps of:

• HF fluorination of the spent oxide fuel in the reaction thereof with a hydrogen fluoride gas using a fluidized bed furnace operated in a temperature range of 350 to 430° C., thereby converting uranium and plutonium compounds and most impurities in the spent oxide fuel into nonvolatile solid fluorides or oxides having low valences to inhibit volatilization thereof;
• and
• F2 fluorination of the HF fluorination product in the reaction thereof with a fluorine gas which reaction is controlled in two stages:
• the first stage at a lower temperature using a fluidized bed furnace operated in a temperature range of 350 to 430° C. and the second stage at a higher temperature using a fluidized bed furnace operated in a temperature range of 730 to 800° C., thereby separating an arbitrary amount of gaseous uranium hexafluoride and volatile impurities with plutonium kept in a solid form in the first stage, and fluorinating the mixed fluorides of the remaining uranium and plutonium into hexafluorides at the same time in the second stage.