Development of dose evaluation method for confirmation of completion of decommissioning, 1; Development of estimation method of contamination distribution for dose evaluation

Shimada, Taro ; Nabekura, Nobuhide*; Miwa, Kazuji ; Takeda, Seiji 

It is required to confirm that dose of public using the land after site release for is less than the criteria by dose evaluation based on the contamination distribution obtained by site survey before the completion of the decommissioning of nuclear facilities. Therefore JAEA is developing the methodology to evaluate public dose. We studied estimating methods for contamination distribution based on the data from the scoping survey and the final sampling measurement with errors using external drift kriging. As a result, it is indicated that estimated distribution by external drift kriging using scoping survey results with measurement errors is the same as that without measurement error. Estimation variance was increased with measurement errors. Therefore the evaluation method will be applied to determine the radioactivity distribution with uncertainty.