Research on Preparation Technology of UO₂-Er₂O₃ Fuel Pellets

A preliminary study is conducted for the preparation technology of UO₂-Er₂O₃ burnable poisonous fuel pellets with Er₂O₃ mass fraction of 4.32%. We obtain the preparation technology by comparing the performance (integrity, density, and grain size) of the pellets under different conditions (mixing, pressing, and sintering). The experiments show that UO₂-Er₂O₃ fuel pellets with good integrity which theoretical density≥95% and grain size larger than 8 μm can be obtained by mixing the powders with planetary ball mill for 6 h and add 5‰ PVA, pressing under 300 ~350 MPa, sintering at 1700~1750℃ with hydrogen atmosphere for 2 ~3 h.