METHOD AND DEVICE FOR PELLETIZING NUCLEAR FUEL FROM URANIUM OXIDE WASTES Russian patent published in 2000 - IPC

FIELD: production of reconditioned nuclear fuel from rejected pellets and nuclear fuel wastes. SUBSTANCE: nuclear fuel wastes, ground powder, scrape oxides, and ash are subjected to thermal oxidation in the open prior to aqueous cleaning to obtain U₃O₈oxide; pellets rejected in the process and oxides of nuclear fuel wastes are weighed out, total content of uranium and mass proportion of U₂₃₅ in mixture of uranium isotopes are determined, calculations are made of amount of U₃O₈ with high proportion of U₂₃₅ in uranium isotope mixture to be added to U₃O₈ oxide so as to produce mixture with rated mass proportion of U₂₃₅ in uranium isotope mixture using formula for two contents of mass proportions of U₂₃₅, Device implementing this method is provided with two units for thermal oxidizing in the open to obtain U₃O₈ oxide of nuclear fuel wastes, two weighing units with U₃O₈ oxide batcher of which one has high mass proportion of U₂₃₅ in uranium isotope mixture and other one, low mass proportion of U₂₃₅ in uranium isotope mixture, unit for dry mixing of U₃O₈ oxides having high and low mass proportions of U₂₃₅ in uranium isotope mixture, wet correction unit with batchers of uranyl nitrate having high and low mass proportions of U₂₃₅ in uranium isotope mixture; all units are arranged in tandem and provided with facilities for conveying wastes being recovered and their half-finished products from one unit to other. EFFECT: improved yield of recovered products. 7 cl, 1 dwg