[1D01-04] Environmental Radioacitivty and Remediation

[1D04] Radiocaesium dynamics in a river affected by the decontamination work in the watershed

*Keisuke Taniguchi¹, Yukio Takeuchi¹, Kazuki Fujita¹, Hirotsugu Arai¹, Hirofumi Yoshita¹, Takayuki Kuramoto², Yuichi Onda³ (1. FPCEC, 2. Tokai University, 3. University of Tsukuba)

Keywords:Radiocaesium, River, TEPCO’s Fukushima Daiichi Nuclear Power Plant accident, Decontamination work

After the TEPCO’s Fukushima Daiichi Nuclear Power Plant accident, decontamination works were conducted in the eastern part of Japan. Although the air dose rate in the target area had decreased, the impact on the downstream area of the watershed caused by the decontamination in the upstream area has not been sufficiently evaluated.
The Kuchibuto River had the special decontamination area (SDA) in the upper reach of the watershed. In the SDA, the decontamination works had been conducted by Ministry of the Environment between March 2013 and December 2015. We will report the change of the concentration and flux of radiocaesium in the river water before and after the decontamination works based on the long-term monitoring results.