Method For Fabricating Porous UO2 Sintered Pellet For Electrolytic Reduction Process For Recovering Metallic Nuclear Fuel Using Continuous Process Of Atmospheric Sintering And Reduction, And Porous UO2 Sintered Pellet Fabricated By The Same

摘要

A method for fabricating porous UO₂ sintered pellets to be fed into an electrolytic reduction process for the purpose of metallic nuclear fuel recovery is provided, which includes forming a powder containing U₃O₈ by oxidizing a spent nuclear fuel containing uranium dioxide (UO₂) (step 1), fabricating U₃O₈ green pellets by compacting the powder formed in step 1 (step 2), and fabricating UO₂ sintered pellets by sintering the U₃O₈ green pellets fabricated in step 2 at 1000 to 1600° C., in an atmospheric gas, and cooling the same for reduction, by changing the atmosphere to a reducing atmospheric gas (step 3). The porous UO₂ sintered pellets can be fabricated, which do not have any defects. The volatile fission products are sufficiently removed from the fabricated porous UO₂ sintered pellet, the O/U ratio is 2.00, the permeation of the electrolyte during reduction is facilitated, and the electrolytic reduction velocity increases.