MOXの自己照射による熱伝導率の低下と熱回復挙動

Recovery behaviors of thermal conductivities in self-irradiated MOX fuel

森本 恭一 ; 加藤 正人   ; 小笠原 誠洋*

Morimoto, Kyoichi; Kato, Masato; Ogasawara, Masahiro*

長期保管に伴って、MOX燃料中では自己照射効果により格子欠陥が蓄積し、欠陥の増加によってMOX燃料の熱伝導率は低下する。また、これらの欠陥は熱処理によって減少し、熱伝導率は回復する。本研究において長期保管されたMOX燃料の熱伝導率の熱回復挙動に関する試験を実施し、温度や時間と関係づけて評価した。

In MOX fuel stored for long term, the defects induced by self-irradiation (alpha decay) increase with an increase of storage time, and consequently its thermal conductivities decrease by an accumulation of these defects. Some investigators showed that these defects were decreased or annihilated by heat treatment, and then the lattice parameter, thermal conductivity, etc of fuel were recovered. In this study, we prepared the specimens divided from MOX fuels stored for about fifteen years. We investigated a recovery behavior of the thermal conductivities of this specimen and evaluated this behavior as functions of heating temperature and heating time.