Abstract
Oxidation of uranium carbide (UC) small fragments from sintered pellets was experimentally tested to better understand UC safe-handling procedures given the renewed interest of non-oxide fuels for high temperature gas or liquid metal cooled reactors. Transformation from UC to U 3 O 8 via a selfignition reaction was observed at partial pressure of oxygen as low as 10 Pa. The heat output from UC self-ignition in fragments (not-free from UO 2 contamination) previously stored in either air atmosphere or inert-atmosphere during a three months period was monitored at 973 K and 1073 K in air atmosphere in a TGA/DTA and no difference could be observed. Residual carbon content, measured as amorphous carbon, carbide or CO/CO 2 , decreased with exposition temperature in U 3 O 8 resulting oxide, this is in contrast with zirconium carbide resulting oxide, ZrO 2. Cracking and stresses accumulated in the oxide were highest for UC to U 3 O 8 compared to UC to UO 2 reactions and ZrC to ZrO 2 reactions.