Thermal Conductivities of Granular UO Compacts with/without Uranium Particles

None

石井 徹哉; 油田 良一*; 平井 睦*; 坪井 靖*; 鵜飼 重治  

Ishii, Tetsuya; Yuda, Ryoichi*; Hirai, Mutsumi*; Tsuboi, Yasushi*; Ukai, Shigeharu

振動充填燃料の熱特性評価のため、不定形状のUO粒子充填体と10wt.%の金属ウラン顆粒を混合した不定形状のUO粒子充填体の熱伝導度を測定した。その結果から、金属ウラン顆粒を添加することで、充填体の熱伝導度が改善されることを明らかにし、その効果を定量的に評価するモデルを構築した。

The thermal conductivities of granular UO compacts with and without uranium particles were measured to evaluate the thermal performance of vibro-packed granular MOX fuels containing metallic fine particle oxygen getters. The thermal conductivity of the compact with 10wt.% of the uranium particles was higher than without uranium particles and after heating beyond 1408K, the melting point of the uranium particle, the thermal conductivity further increased..The evaluation model for analyzing such phenomena were developed and it was revealed that once the UO compact with the uranium particles was exposed to the temperature beyond 1408K, the uranium particle should melt and provide interconnect area between the UO granules and uranium particles, and between the uranium particles with each other. The resulting increase of the thermal conductivity was reasonably expressed by the effect of necks in the compact on the heat conduction.