Improvement of the sinterability of thermally-treated UO2 powder by horizontal rotary ball milling

Horizontal rotary ball milling has been demonstrated to be a useful method for reducing the particle size of ceramic powder in remote operation in shielded hot cells. Techniques, equipment and operating parameters, such as milling media, media wear and rotor speed were investigated with Al2O3 powder to evaluate its performance prior to contamination with nuclear fuel material. The established operating parameters were then verified with UO2 powder, which had been produced by a thermal process to make fuel pellets. The sintering of the milled UO2 powder showed the higher sintered densities obtainable by the milling, and the milling process seemed to be an important factor in improving the powder characteristics.