Development of dose evaluation method for confirmation of completion of decommissioning, 3; Development of dose estimation method considering changes in surface soil contamination distribution

Miwa, Kazuji ; Namekawa, Masakazu*; Shimada, Taro ; Takeda, Seiji 

The distribution of surface soil contamination on the site of nuclear facilities after confirmation of the decommissioning may be changed by rainfall. In this study, the radionuclides migration model is developed to evaluate the radiation dose to the public including radionuclides distribution change. The result of radionuclides migration estimation on virtual site condition suggests that radionuclides which is migrated by surface water and soil migration gather in depression area. It is also shown that radionuclides migration on surface is more significant path to the ocean than radionuclides migration in groundwater. Based on these findings, it is suggested that the radiation dose considering change of radionuclides distribution may be larger than that from initial radionuclides distribution.