Development of the ORIGEN2 library for light water reactors based on JENDL-4.0

JENDL-4.0に基づく軽水炉用ORIGEN2ライブラリの開発

奥村 啓介 ; 小嶋 健介; 岡本 力

Okumura, Keisuke; Kojima, Kensuke; Okamoto, Tsutomu

JENDL-4.0に基づく軽水炉用のORIGEN2ライブラリ(ORLIBJ40)を開発した。使用済み燃料の照射後試験解析によりライブラリ検証を行った結果、従来のライブラリ(オリジナル版及びORLIBJ33)に比べて、特にマイナーアクチノイド(Np, Am, Cm同位体)や断面積に大きな感度がある核分裂生成物(EuやSm同位体)に対して、顕著な改善効果が見られた。また、ガラス固化体廃棄物の地層処分の長期安全性評価において重要とされるSeやCsといった長寿命核分裂生成物の放射能量が半減期データの改訂により大きく改善された。

New ORIGEN2 libraries (ORLIBJ40) for light water reactors were developed based on JENDL-4.0. It was validated by post irradiation examination analyses of nuclear spent fuels. As a result, it was found that drastic improvements were achieved especially for the inventory estimations of minor actinides (Np, Am and Cm isotopes) and fission products sensitive to cross sections (Eu and Sm isotopes) compared with old ORIGEN2 libraries. Furthermore, radioactivity of long-lived fission products, such as Se and Cs were also improved because of implementations of new half-life data. These nuclides are very important for long-term safety assessment of a geological disposal of the vitrified wastes.