Influence of the oxygen potential on the sintering of UO2-45% PuO2

Pu distribution within U0.55Pu0.45O2±x ceramics obtained from powders mixing sintered at 1700 °C under an oxygen potential of around −425 kJ mol−1 was studied as a function of dwell time by means of XRD, EPMA and XAS analyses. The optimal homogeneity of the Pu distribution was achieved after 24 h sintering. XANES results confirmed the sample oxidation and could demonstrate the only presence of tetravalent Pu whereas Am is partially reduced.