External dose assessments of the population living in Fukushima Prefecture, 2; Deterministic and probabilistic assessment of external doses to the population

Takahara, Shogo  ; Shimada, Kazumasa 

Doses from external exposures to the population are one of the important factors to optimize protective strategies in the contaminated areas resulting from Fukushima Dai-ichi Nuclear Power Station accident. Doses to the public, however, cannot be measured directly without considerable difficulty. Therefore it is necessary to assess individual doses based on area monitoring data and habit data using deterministic or probabilistic approach. To implement the assessment using deterministic and probabilistic methodologies, we have measured ambient dose equivalents and surveyed spending time at outdoors in Fukushima prefecture. In addition, to verify the results of these assessments, individual doses due to external exposures were measured using personal dosimeters. As a result, it was found that assessments using deterministic and probabilistic methodology are useful tools to determine the dose that is representative of the more highly exposed individuals in the population group.