再処理施設における放射性物質の移行挙動に関する研究,6; コールド基礎試験(その3)FP濃度の影響

Study on release and transport of aerial radioactive materials in reprocessing plant, 6; Cold test (Part 3) Effect of FP concentration in mocked HLLW to ARF

田代 信介 ; 松本 哲也; 片岡 修; 天野 祐希 ; 阿部 仁 ; 山根 祐一  ; 吉田 一雄 ; 石川 淳 ; 内山 軍蔵 ; 上田 吉徳*; 藤根 幸雄*; 野島 康夫*; 小玉 貴司*; 中野 正直*; 松岡 伸吾*

Tashiro, Shinsuke; Matsumoto, Tetsuya; Kataoka, Osamu; Amano, Yuki; Abe, Hitoshi; Yamane, Yuichi; Yoshida, Kazuo; Ishikawa, Jun; Uchiyama, Gunzo; Ueda, Yoshinori*; Fujine, Sachio*; Nojima, Yasuo*; Kodama, Takashi*; Nakano, Masanao*; Matsuoka, Shingo*

高レベル濃縮廃液が沸騰して乾固状態に至る事故時における放射性物質の放出挙動にかかわる研究を行っている。非放射性の模擬FP元素(27元素)を硝酸溶液に溶解させて作製した模擬高レベル濃縮廃液(模擬廃液)を用いた実験室規模コールド実験を行い、模擬廃液が沸騰して乾固状態(300C)に至る過程における模擬FP元素の気相への移行割合を初期FP元素濃度をパラメーターとして取得した。模擬FP元素の分析にはICP-MSを用いた。実験の結果、Ruの積算移行割合は初期Ru濃度が増加すると減少するが、CsやNdの積算移行割合は初期FP濃度にほとんど依存しないことがわかった。

The release behavior of radioactive materials from high-level radioactive liquid wastes (HLW) from reprocessing plants under an accidents of boiling to dryness of HLW condition has been studied. The influences of FP concentration in the simulated HLW on the release ratio of FP from the waste were measured in the laboratory-scaled experiments using non-radioactive simulated HLW which was prepared by dissolving 27 FP elements into nitric acid and adjusted to 2 M acidity. The simulated HLW was heated up to 300C under the constant air ventilation condition. The accumulated release ratios of FP elements from samples were determined using ICP-MS analysis. It was found that the accumulated release ratio of Ru was decreased with the increase of the initial Ru concentration in the simulated HLW. However, those of Cs and Nd were not influenced by the initial concentrations of them.