Oxygen self-diffusion in near stoichiometric (U,Pu)O at high temperatures of 1673-1873 K

1673-1873Kにおける定比組成近傍の(U,Pu)O中の酸素自己拡散

渡部 雅  ; 加藤 正人   ; 砂押 剛雄*

Watanabe, Masashi; Kato, Masato; Sunaoshi, Takeo*

高温における定比組成近傍の(U,Pu)Oの酸素自己拡散係数を熱重量法と酸素同位体交換法を組み合わせた手法によって測定することに成功した。(U,Pu)Oの定比組成における酸素拡散の活性化エネルギーを実験データから評価し、その値を248kJ/molと決定した。また、(U,Pu)Oの欠陥移動エネルギーを導出し、これらを用いて酸素自己拡散係数を評価した。その結果、実験データと評価結果は良く一致した。

The oxygen self-diffusion coefficients in near stoichiometric (U,Pu)O at high temperatures were successfully measured by thermogravimetry combined with the oxygen isotope exchange method. The activation energy for oxygen diffusion in the stoichiometric composition of (U,Pu)O was evaluated from experimental data, and the value was determined to be 248 kJ/mol. In addition, the defect migration energies of (U,Pu)O were derived, and the oxygen self-diffusion coefficients were evaluated using these. As a result, good agreement was found between the experimental data and the oxygen self-diffusion coefficients calculated using the defect migration energies.