METHOD FOR REMELTING STRUCTURAL MATERIALS OF SHELLS OF SPENT FUEL RODS AND STRUCTURAL MATERIALS OF SPENT FUEL ASSEMBLIES Russian patent published in 2023 - IPC G21F9/28 

FIELD: metallurgy.

SUBSTANCE: invention relates to the field of metallurgy, namely, to pyrometallurgical processing of metal radioactive waste represented by shells of spent fuel rods. Method includes the stage of pre-mixing fragments of structural materials (SM) of spent shells of fuel rods made of zirconium alloys with SMs of spent fuel assemblies (SFA) made of stainless steels, followed by remelting under a layer of pre-fused three-component flux containing magnesium, calcium, and aluminium oxides. The process is implemented in a chamber with an inert atmosphere using a water-cooled melter equipped with an induction, electric arc, plasma, or combined heating source. The resulting metal ingot does not have surface contamination, is resistant to external effects, therefore being suitable for safe long-term storage. The slag can be reused, whereafter said slag must be immobilised into stable matrices or recycled in order to extract and return fissile materials to the nuclear fuel cycle.

EFFECT: possibility of extracting up to 19% and 70% of the uranium and plutonium contained in the shells, respectively, therefrom.

6 cl, 1 dwg