Post irradiation examination for inventory estimation of Se and Cs in high-level radioactive wastes
高レベル放射性廃液中のSe及びCsのインベントリ評価を目的とした照射後試験
浅井 志保; 半澤 有希子 ; 奥村 啓介 ; 伊奈川 潤; 宝徳 忍 ; 篠原 伸夫 ; 鈴木 健介*; 金子 悟*
Asai, Shiho; Hanzawa, Yukiko; Okumura, Keisuke; Inagawa, Jun; Hotoku, Shinobu; Shinohara, Nobuo; Suzuki, Kensuke*; Kaneko, Satoru*
Se and Cs are long-lived radionuclides produced mainly by the fission of U and found in high-level radioactive wastes (HLW). Owing to their potential migration ability to the environment, the estimation of their inventories in HLW is essential for the safety assessment of a geological disposal of such nuclear wastes. However, their yields for U fission have not yet been sufficiently confirmed by post irradiation examination because of the difficulties in the measurements. In this study, the amounts of Se and Cs in the spent nuclear fuel were measured and compared with the calculated results with JENDL-3.3. About 5 g of irradiated fuel was sampled and dissolved in 4 M nitric acid. After Se and Cs were chemically separated, the mass spectrometric determinations of Se and Cs in the resultant solution were performed. The results obtained in this study showed a good agreement with those obtained by ORIGEN-2.