METHOD FOR SEPARATING ACTINIDE ELEMENT GROUP AND RARE EARTH ELEMENT GROUP CONTAINED IN HIGH-LEVEL RADIOACTIVE MOLTEN SALT GENERATED IN PYRO-PROCESSING USING LIQUID METAL OF BISMUTH OR BISMUTH-LEAD ALLOY, AND SEPARATION APPARATUS USING SAME

摘要

The present invention relates to a method and an apparatus for purifying all high-level wastes to mid-level wastes or low-level wastes by lowering the radioactive level and thermal density of the final wastes generated during a dry separation process by separating the actinide element group and the rare earth element group contained in a molten salt generated during pyrolysis processing of spent fuel by using a liquid metal of bismuth or a bismuth-lead alloy at a high temperature, wherein the actinide group and the rare earth element group contained in the molten salt are reduced and dissolved into the liquid metal of the bismuth or bismuth-lead alloy from electrolytic smelting to form heterometallic compounds in liquid or solid state within the liquid metal of the bismuth or bismuth-lead alloy while the equilibrium potential between elements in the same element group becomes close to each other, thereby making it difficult to separate elements by element, wherein the density of the heterometallic compounds is larger or smaller than the density of the liquid metal of the bismuth or bismuth-lead alloy, such that the heterometallic compounds of the two element groups are separated using a difference in density, and to this end, an apparatus comprising a filter, a stirrer, a centrifuge, a magnetic field generator, piping, and valves can be configured, and the remaining liquid metal of the bismuth or bismuth-lead alloy after collecting the heterometallic compounds can be self-purified after separation, and can be reused in electrolytic electrodeposition.