Effect of oxygen potential on the sintering behavior of MgO-based heterogeneous fuels containing (Pu, Am)O sub(2-x)

The effect of oxygen potential on the sintering behavior of MgO-based heterogeneous fuels containing (Pu, Am)O sub(2-x) was experimentally investigated. Sintering tests in various atmospheres, i.e. air, moisturized 4%H sub(2)-Ar, and 4%H sub(2)-Ar atmosphere, were carried out. The sintering behavior was found to be significantly affected by the oxygen potential in the sintering atmosphere. The sintered density decreased with decreasing oxygen potential. The (Pu, Am)O sub(2-x) phase sintered in a reductive atmosphere had hypostoichiometry. The aggregates of the (Pu, Am)O sub(2-x) phase sintered in the reductive atmosphere grew, in comparison with those in the oxidizing one. The sintering mechanism was discussed in terms of the difference in sintering behavior of (Pu, Am)O sub(2-x) and MgO.