RECYCLE METHOD FOR PELLET SCRAP OF OXIDE NUCLEAR FUEL

摘要

PROBLEM TO BE SOLVED: To provide a method for recycling a large amount of pellet scrap without using a fluidized fed reaction furnace. SOLUTION: Pellet scrap containing exclusively UO2 or UO2 containing oxides of plutonium, gadolinium and erbium is oxidized under oxidizing gas atmosphere of 300 to 800 deg.C in a thermal processing furnace to produce regenerated particles of U3 O8 . Material powder containing regenerated particles U3 O8 to about 10 to 100 wt.% and the remainder consisting exclusively of UO2 or UO2 powder containing oxides of plutonium, gadolinium and erbium is constituted. After adding a sintering assistant, oxide or compound of niobium(Nb), titanium(Ti), lithium(Li), vanadium(V), tin(Sn), aluminum(Al), magnesium(Mg) and silicon(Si) to the stuff powder by 0.02 to 2 wt.% of the element weight, mixing and molding, the material is sintered for 1 to 20 hours under reducing atmosphere of 1500 to 1800 deg.C to produce new nuclear fuel pellets.