Thermal conductivity of (U,Pu,Np)O solid solutions

(U,Pu,Np)O固溶体の熱伝導率

森本 恭一 ; 加藤 正人   ; 小笠原 誠洋*; 鹿志村 元明

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

MAを含有したMOX燃料は高い核拡散抵抗性や環境負荷低減の観点からFBR燃料として注目されている。MOX燃料へのMAの含有はその熱伝導率へ影響する。熱伝導率は燃料設計や照射挙動評価を行ううえで重要な熱物性値のひとつである。本試験ではMOX燃料に6及び12%のNpOを含有させた試料を準備し、これらの試料の熱伝導率をレーザーフラッシュ法によって9001770Kの温度範囲で測定した。また、これらの結果は先に報告されたAmを含有するMOXの熱伝導率と比較され、さらにNpOを50%含むUOのデータや純粋なNpOのデータを比較された。これらの比較より熱伝導率に対するNp含有の影響が議論された。

Recently, the MOX fuel containing MA has attracted attention as a fuel of FBR which has profit in the high proliferation resistance and low environmental impact. The addition of MA into MOX fuel has an effect on the thermal conductivity of MOX fuel. In the development of MOX fuel containing MA like americium and neptunium, thermal conductivity is one of the important properties for fuel design and performance analyses. In this study, two MOX fuels containing 6 and 12% NpO were prepared, and their thermal conductivities were measured in the temperature range from 900 to 1770 K by the laser flash method. The results obtained in this method were compared with the data on the MOX fuel containing AmO obtained in the previous our study. In addition, our results were compared with the data of UO containing 50% NpO by Schmidt et al. and those of pure NpO by Nishi et al.. From these comparisons, the effect of Np addition into MOX fuel was discussed.