[2B05-09] Environmental Radiation in Fukushima River

[2B06] Estimations of dissolved radiocesium concentration based on the solid-liquid partition coefficient in rivers in the Hamadori area, Fukushima prefecture

*Yukio Takeuchi¹, Koki Nasu¹, Ayumi Irisawa¹, Shaoyan Fan¹, Keisuke Taniguchi², Yuichi Onda³ (1. Fukushima Prefectural Centre for Environmental Creation, 2. National Institute of Technology, Tsuyama College, 3. Univ. of Tsukuba, Center for Research in Isotopes and Environmental Dynamics)

Keywords:river, radiocesium, dissolved radiocesium, riverbed sediment

Since the TEPCO’s FDNPS accident, the radiocesium concentrations in river in Fukushima Prefecture has been decreased. In particular, the dissolved Cs-137 concentration is extremely low. Therefore, it is essential to further increase the amount of water sampled and the filtration time for its determination. In contrary, the Cs-137 concentrations in sediment are being quantified in many cases. Thus, we have been trying to clarify whether the dissolved Cs-137 concentrations can be estimated by Cs-137 concentrations in sediments and the apparent distribution coefficient (Kd value) between those. The river waters and sediments were collected in the Hamadori area. We calculated the Kd values and evaluate the applicability of this estimation and discuss the possible factors affecting the precision.