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

MgOを母材とした(Pu,Am)O含有非均質燃料の焼結に及ぼす酸素ポテンシャルの影響

三輪 周平  ; 石 洋平*; 逢坂 正彦  

Miwa, Shuhei; Ishi, Yohei*; Osaka, Masahiko

MgOを母材とした(Pu,Am)O含有非均質型燃料の焼結に及ぼす酸素ポテンシャルの影響を評価するために、空気,加湿4%H-Ar,4%H-Arの各雰囲気での焼結試験を実施した。(Pu,Am)O含有非均質型燃料の焼結挙動は焼結雰囲気中の酸素ポテンシャルに大きく依存し、酸素ポテンシャルが低いほど焼結密度は低くなった。低酸素ポテンシャルで焼結した非均質型燃料の(Pu,Am)O相は亜定比組成を示し、顆粒は高酸素ポテンシャルで焼結したものに比べ大きくなっていた。これらの挙動を踏まえ、(Pu,Am)OとMgOの焼結挙動の違いの観点から、焼結のメカニズムについて考察を行った。

The effect of oxygen potential on the sintering behavior of MgO based heterogeneous fuels containing (Pu,Am)O was experimentally investigated. Sintering tests in various atmospheres, i.e. air, moisturized 4%H-Ar, and 4%H-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 phase sintered in a reductive atmosphere had hypostoichiometry. The aggregates of the (Pu,Am)O 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 and MgO.