Gamma heating rate evaluation for material irradiation test in the Joyo experimental fast reactor

高速実験炉「常陽」における材料照射試験のための発熱評価

前田 茂貴   ; 内藤 裕之; 曽我 知則 ; 青山 卓史 

Maeda, Shigetaka; Naito, Hiroyuki; Soga, Tomonori; Aoyama, Takafumi

高速炉での発熱の空間分布の評価では、すべての線放出成分を考慮する必要がある。しかし、アクチニド核種の遅発線の生成収率等のデータはJENDLやENDFのような汎用核データライブラリには格納されていない。すべての線生成を考慮するため、JENDL-3.2及びJENDL-4.0に遅発線データを追加した。この修正版のJENDL3.2及びJENDL4.0を用いて、MATXSLIB形式の多群ライブラリを作成した。高速実験炉「常陽」を対象に、固定線源の輸送問題において本ライブラリを適用したところ、線束が遅発線を考慮しない場合に比べて40%増加することが確認できた。また、この計算値の検証として、計測線付実験装置により得られた測定値と比較したところ、3-12%でよい一致を示した。

The evaluation of the spatial distribution of heating in fast reactors requires consideration of all the intensity components. However, the delayed ray yield data of all actinides are not prepared in evaluated nuclear data files such as ENDF or JEDNL. In this study, new neutron/ cross section constants based on JENDL-3.2 and -4 were developed. The delayed yields were added to JENDL-3.2 and JENDL-4. Based on these modified JENDL-3.2 and -4, MATXSLIB-type library for conventional discrete ordinate multi-group transport code were generated. Neutron and ray coupling calculations for the experimental fast reactor Joyo core, based on transport theory as a fixed source problem, revealed that the flux increased by approximately 40% when the delayed intensity in both JENDL-3.2 and -4 were considered. The calculated heat rates were verified by comparison with the measured data obtained by on-line irradiation rigs. It was confirmed that the calculated heat rates agreed with the measurements within 3-12%.