Remobilization mechanism of radiocesium from bottom sediments in reservoir

Funaki, Hironori ; Nakanishi, Takahiro   ; Yoshimura, Kazuya  ; Sakuma, Kazuyuki   ; Tsuji, Hideki*; Hayashi, Seiji*

Reservoir sediments generally act as a sink for radionuclides derived from nuclear accidents, but under anaerobic conditions, several radionuclides remobilize in bioavailable form from sediments to water columns, which may contribute to the long-term contamination of aquatic products. This study systematically investigated the Cs activities of sediment and pore water, providing a direct evidence of the remobilization of bioavailable Cs from sediments in a highly contaminated reservoir (Ogaki Dam Reservoir) affected by the Fukushima Dai-ichi Nuclear Power Station accident.