METHOD FOR MANUFACTURING MIXED-OXIDE NUCLEAR FUEL PELLETS FROM STAGNANT URANIUM OXIDE POWDER

摘要

FIELD: nuclear power engineering; fuel pellets manufacture. SUBSTANCE: method for producing mixed oxide (U,Pu)O₂ from stagnant UO₂ powders includes dosing and initial mixing (1) of PuO₂ and UO₂ powders and/or rejected products of fuel manufacture, microprocessing (2) and second forced sieving (3) of this first mixture, new dosing and second mixing (4) of first UO₂ powder mixture processed in this way and, if necessary, rejected products of fuel manufacture, introduction of additives (5), pelletization (6) of second mixture, and sintering (7) of pellets formed in this way. In addition stagnant UO₂ is selected for part of UO₂ powders and subjected to mechanical treatment (29) by granulation to make it runny prior to introducing UO₂ granulated in this way into second mixture. EFFECT: enhanced mechanical strength and, hence, enlarged range of these uranium dioxide powders for producing mixed-oxide fuel. 11 cl, 3 dwg