Oxygen potential measurement of (Pu 0.928Am0.072)O 2-x at high temperatures

Abstract

The oxygen potentials of (Pu0.928Am0.072)O2-x were measured as a function of oxygen to metal ratio (O/M) in the temperature range from 1473 to 1873 K by the gas equilibrium method using thermogravimetry. The measured data were about 200 kJ/mol higher in the O/M ratio range from 2.00 to 1.96 and about 50 kJ/mol higher in the reducing region (below O/M ratio = 1.94) compared with those of PuO2-x. The measured oxygen potentials were analyzed by the point defect chemistry method. From this analysis, the oxygen potential of (Pu0.928Am0.072)O2-x was represented as a function of O/M ratio and temperature and calculated results were consistent with the measured data.