CsSr吸着剤の耐放射線性試験

Study on stability of CsSr solvent impregnated resin against irradiation

星 陽崇; 菊池 孝浩; 森田 泰治  ; 木村 貴海 

Hoshi, Harutaka; Kikuchi, Takahiro; Morita, Yasuji; Kimura, Takaumi

新規に調製したCsSr吸着剤の線に対する耐久性を評価した。濃度の異なるの硝酸溶液にCs吸着剤及びSr吸着剤を浸積させた状態でCo線源により線を照射し、線照射時の硝酸濃度の影響を調べた。照射後の吸着剤をろ過後、乾燥させ、Cs又はSrの飽和吸着容量をバッチ法により測定した。Cs吸着剤,Sr吸着剤ともに高濃度の硝酸中では硝酸濃度の増加に伴い、飽和吸着容量が低下する傾向が現れた。CsSr吸着剤の飽和吸着容量は線照射後に低下したが、含浸させた抽出剤が液相に溶出することが原因であり、線照射による劣化の寄与はわずかであることがわかった。線を照射した吸着剤を用いて模擬高レベル廃液からのCs及びSrのカラム分離試験を行い、それぞれ照射後もCs又はSrに対する高い選択性を維持していることが明らかになった。

Novel solvent impregnated resins (SIR), which have significant selectivity for Cs or Sr, were examined their stability against irradiation. SIR was soaked in nitric acid solution and was irradiated by Co source. After the irradiation, resin was filtrated and air-dried. The capacity of Cs or Sr was examined by batch method. The capacity reduced with nitric acid concentration, however, it was mainly caused by elution of impregnated extractant into aqueous phase. Thus, these resins indicated rather stability against irradiation. Selectivity was also examined through a column packed with irradiated resin. Cs or Sr was effectively separated from other typical fission products by using simulated high level liquid waste.