Deposition of radiocesium on the river flood plains around Fukushima.

The environment in the area around Fukushima Daiichi Nuclear Power Plant has been contaminated by widely deposited significant amount of radioactive materials, which were released to the atmosphere caused by the Fukushima Daiichi Nuclear Power Plant accident due to the Great East Japan Earthquake, which occurred on March 11, 2011. The radiocesium released in the accident mainly affects radiation dose in the environment. Decontamination work in the contaminated area except a mountain forests has been conducted to decrease the radiation dose. However, there are concerns that the redistribution of this radiation due to water discharge will occur due to the resulting transport of radiocesium. In particular, the deposition of soil particles containing radiocesium on the flood plains in the downstream areas of Fukushima's rivers can potentially increase the local radiation dose. Therefore, it is important to understand the influence of the deposition behavior of radiocesium on the radiation dose.