EXPERIMENTAL EVALUATION OF OXYGEN SOLUBILITY IN UN, PUN AND (U, PU)N

Oxygen solubility in UN and PuN has been determined experimentally by lattice parameter measurements. Samples of U(N, C, O), Pu(N, C, O) and (U, Pu)(N, C, O) solid solutions of different C/N mole ratio and oxyg en content have been prepared by carbothermic synthesis of tabletted m ixtures of oxide and graphite at 1823 K in flowing N2 followed by N2 H-2, gas mixture. The results indicate that if UN dissolves any oxyge n, it is not more than 3 mol% of (UO) while PuN dissolves 13 +/- 3 mol % of (PuO).