Recovery of minor actinides from spent fuel via an extraction chromatographic technique using TPPEN-immobilized gels

固定TPENゲルを用いた抽出クロマト技術による照射済燃料からのMAの回収

小山 真一  ; 須藤 光雄; 大林 弘 ; 竹下 健二*; 尾形 剛志*; 緒明 博*; 稲葉 優介*

Koyama, Shinichi; Suto, Mitsuo; Obayashi, Hiroshi; Takeshita, Kenji*; Ogata, Takeshi*; Oaki, Hiroshi*; Inaba, Yusuke*

照射済燃料からMAの回収を実証するため、東京工業大学がTPEN(分離錯体)を化学的に高分子ゲルに固定することに成功した。このTPENゲルで作成したカラムにより照射済燃料を用いた抽出クロマト分離試験を行った結果、0.01M NaNOH(pH4)溶液によりMAをカラムに吸着させた状態で希土類を溶離し、溶離液を0.01M NaNOH(pH2)に変えることでMAを回収できる可能性があることを明らかにした。

A series of separation experiments was performed to study the recovery process for minor actinides (MAs) from the actual spent fuel by using an extraction chromatographic technique. TPPEN gel was used as a new extraction chromatographic agent. Mixed oxide fuel was used as a reference spent fuel to demonstrate the recovery of the MAs. The MOX fuel, including 29.9 wt% plutonium (Pu), was irradiated up to 119 GWd/MTM, and the fuel was then prepared for the extraction experiment. A Mixed solution of MAs and lanthanides (Lns) was prepared. The TPPEN gel was immersed in a 0.01 M NaNO solution, and the pH was adjusted to 4.0. Next, an extraction column was prepared using the TPPEN gel, and the mixed solution of MAs and Lns was passed through the column. The Lns were detected in the eluent after washing with 0.01 M NaNO (pH 4.0). For detecting the MAs, the pH of the eluent was changed to 2.0.