The oxidation rate of (U_(0.7)PU_(0.3)O_(2-X) with two fcc phases

摘要

The kinetics of the oxidation in hypo-stoichiometric MOX with 30 percent Pu content was investigated using thermal gravity and differential thermal analysis to evaluate the variation of oxygen-to-metal ratio (O/M) in the fuel fabrication process. In the isothermal oxidation examination, the O/M ratio of the MOX gradually approached 2.00 at temperatures below 200 deg C. Therefore it was considered that the oxidation reaction below 200 deg C proceeded by increasing the amount of fcc phase with O/M = 2.00. Finally, the oxidation rate of hypo-stoichiometric MOX was evaluated, and the effective oxygen chemical diffusion coefficient was estimated.