Patent ID: 6156183
Filing Date: 2000-12-05
Classification: C25C,G21C,Y02E,Y02W

Abstract:
A method of processing a spent reactor fuel for recovering at least any one of metallic nuclear fuel materials of uranium, plutonium and transuranium element from the spent reactor fuel, in which the reactor fuel as a processing target is composed by covering the metallic nuclear fuel material with a cladding tube made of magnesium alloy and having a melting point lower than that of the metallic nuclear fuel material and end plugs made of alloy are mounted to both ends thereof, in a case of processing the spent reactor fuel as it is or processing the spent reactor fuel in a state of cutting and removing both the end plugs in a preprocess, or in a case of processing the end plugs after the cutting thereof to which a fuel component adheres, said processing method comprising:a cladding tube smelting separation process of heating the processing target at a temperature more than a melting point of the magnesium alloy cladding tube and less than a melting point of the metallic nuclear fuel material so as to smelt and separate the magnesium alloy cladding tube or the end plugs from the metallic nuclear fuel material;a molten salt electrorefining process of immersing the metallic nuclear fuel material, in which the magnesium alloy cladding tube or end plug is removed in the smelting separation process, in a salt consisting of a molten alkaline metal chloride or alkaline earth metal chloride or a mixture thereof to be used as an anode while a solid electrode or a molten metal electrode being used as a cathode, and dissolving the metallic nuclear fuel material in the salt by applying a current between the anode and cathode while depositing uranium, uranium and plutonium or uranium, plutonium and transuranium elements to the cathode; anda salt evaporation separation process of taking out the processing target from the salt and heating chloride or alkaline earth metal adhering to the deposited element which is deposited and adheres to the cathode in a normal pressure state or in a pressure reducing state so that the chloride or alkaline earth metal is evaporated and separated and recovering metallic uranium, uranium and plutonium, or uranium, plutonium and transuranium elements.