Discovery of radiocesium-bearing microparticles in river water and their influence on the solid-water distribution coefficient () of radiocesium in the Kuchibuto River in Fukushima

Miura, Hikaru*; Kurihara, Yuichi*  ; Sakaguchi, Aya*; Tanaka, Kazuya  ; Yamaguchi, Noriko*; Higaki, Shogo*; Takahashi, Yoshio*

Solid-water distribution coefficient () of radiocesium in rivers is apparently increased due to the possible presence of highly radioactive radiocesium-bearing microparticles (CsMPs) in the solid phase. In this study, we evaluated the contribution of CsMPs to apparent Kd values. The ratio of the radioactivity of the separated CsMPs to the total radiocesium on fluvial suspended particles ranged from 0 to 46%. This means that the existence of CsMPs in fluvial suspended partcles did not change apparent Kd values in order magnitude.