Decontamination and solidification treatment on spent liquid scintillation cocktail

Watanabe, So  ; Takahatake, Yoko  ; Ogi, Hiromichi*; Osugi, Takeshi  ; Taniguchi, Takumi ; Sato, Junya ; Arai, Tsuyoshi*; Kajinami, Akihiko*

Treatment of spent scintillation cocktail generated by analysis of radioactivity is one of important tasks for management of nuclear laboratories. This study proposed a procedure consists of adsorption of radioactivity and solidification of residual liquid wastes, and fundamental performance of each step was experimentally tested. Batch-wise adsorption showed excellent adsorption performance of Ni onto silica-based adsorbent, and chelate reaction was suggested as the adsorption mechanism by EXAFS analysis. Alkaline activate material successfully solidified the liquid waste, and TG/DTA and XRD analyses revealed that the organic compounds exist inside the matrix. Only 1% of the loaded organic compounds were leaked from the matrix by a leaching test, and most of the organic compounds should be stably kept inside the matrix.