Recovery of minor actinides from spent fuel using TPEN-immobilized gels

固定TPENゲルを用いた照射済燃料中のMA回収

小山 真一  ; 須藤 光雄; 大林 弘 ; 緒明 博*; 竹下 健二*

Koyama, Shinichi; Suto, Mitsuo; Obayashi, Hiroshi; Oaki, Hiroshi*; Takeshita, Kenji*

照射済燃料からMAの回収を実証するため、TPEN(分離錯体)誘導体を化学的に高分子ゲルに固定したゲルで作成したカラム(TPPENゲル)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。Amの吸着係数向上と、溶離液の温度効果を確認するため、10モル%のTPPENゲルを用い、温度をスイングさせた試験を実施した。その結果、5Cの0.01M NaNOH(pH3.5)溶液により90%のEuが溶離した。その後、溶離液温度を32Cに変化させたところ、Amが溶離された。さらに溶離液のpHを2.0に変え、ゲルに残った全てのAmを回収することができた。

A series of separation experiments was performed in order to study the recovery process for minor actinides (MAs) from the actual spent fuel by using an extraction chromatographic technique. The 10 mol% TPPEN-gel was used to improve adsorption coefficient of Am and a condition of eluent temperature was changed in order to confirm the temperature swing effect on TPEN-gel for MA. More than 90% Eu was detected in the eluent after washing with 0.01M NaNO (pH 3.5) at 5C. Americium was backwardly detected and eluted continuously during in the same condition. After removal of Eu, the eluent temperature was changed to 32C, then Am was detected (pH 3.0). Finally remained Am could be stripped from TPPEN-gel by changing the pH of the eluent to 2.0.