Method for reprocessing spent nuclear fuel and method for reprocessing spent nuclear fuel

摘要

PROBLEM TO BE SOLVED: To improve the decontamination factor of products and the recovery factor of Pu by fluorinating a spent nuclear fuel with a fluorinating agent and separating and recovering uranium (U), a mixture of U and plutonium (Pu) and nuclear fission products respectively on the basis of the difference in the volatility of them. SOLUTION: Spent nuclear fuel rods are loaded into a fluorinating device 3, a fluorinating agent 1 selecting fluorides that fluorinate only uranium (U) is supplied, and high-purity uranium is obtained by converting U into an uranium hexafluoride (UF6) and volatilizing it. At the time, the amount of the uranium that must be mixed with plutonium (Pu) is preserved in the fluorinating device 3 and the volatilized UF6 is stored in a cylinder after the purification of it. Then, a fluorinating agent 2 to which a reagent that is strong enough to volatilize all the amount of Pu is applied is supplied to a fluorinating device 3, and all the amount of Pu and the rest of U are fluorinated and volatilized. A recovered mixture of U and Pu is converted into an oxide and is recycled as a mixed oxide (MOX) fuel. Ultimately, non-volatile nuclear fission products that is preserved as high-level wastes in the fluorinating device 3 can stably be stored and disposed of by compressing, fabricating and vitrifying them.