Evaluation of remaining spent extraction solvent in vermiculite by PIXE analysis

PIXE分析によるバーミキュライトに残留する使用済抽出溶媒の評価

荒井 陽一  ; 渡部 創  ; 長谷川 健太; 岡村 信生 ; 渡部 雅之; 武田 啓佑*; 福元 博基*; 吾郷 友宏*; 羽倉 尚人*; 塚原 剛彦*

Arai, Yoichi; Watanabe, So; Hasegawa, Kenta; Okamura, Nobuo; Watanabe, Masayuki; Takeda, Keisuke*; Fukumoto, Hiroki*; Ago, Tomohiro*; Hagura, Naoto*; Tsukahara, Takehiko*

The spent extraction solvent, which mainly consists of tributyl phosphate (TBP) and normal dodecane, is generated by solvent extraction of Plutonium and Uranium in the reprocessing. The spent solvent should be appropriately treated for disposal or storage. One of the treatment options for storage of the spent solvent is adsorption of the liquid into vermiculite. Our previous experiments on the adsorption of spent solvent into the vermiculite have shown that some parts of loaded solvent gradually leaked out from the vermiculite. In order to investigate the adsorption mechanism and capacity more precisely, elution behavior of loaded solvent into hexane or acetone was evaluated. In this study, the adsorption capacity of the vermiculite was evaluated through amount of remaining solvent after washing with diluents. The amount of the remaining solvent was analyzed by Particle Induced X-ray Emission (PIXE) on P contained in TBP. Peak intensity of P-K line depended on the washing condition, and the behavior qualitatively agreed with the results of the leaching test.