Probabilistic assessment of doses to the public living in areas contaminated by the Fukushima Daiichi Nuclear Power Plant accident

福島第一原子力発電所事故によって汚染された地域に居住する住民の確率論的線量評価

高原 省五  ; 飯島 正史; 嶋田 和真 ; 木村 仁宣 ; 本間 俊充

Takahara, Shogo; Iijima, Masashi; Shimada, Kazumasa; Kimura, Masanori; Homma, Toshimitsu

本研究の目的は、福島第一原子力発電所事故時の避難において住民が受けた線量の範囲を科学的根拠に基づいて評価することである。この目的を達成するために、本研究では確率論的な線量評価を実施した。Csの地表面濃度の実測値及び生活行動時間の現地調査の結果を利用して評価した。避難区域から避難した住民の95%値はおおよそ1-10mSvの範囲となった。屋外での滞在が長い住民及び計画的避難区域から避難した一部の住民については、実効線量の95%値が10-50mSvの範囲となった。

The aim of this study is to provide the scientifically-based quantitative information about a range of received doses to the evacuees from the evacuation areas and the deliberate evacuation areas. To achieve the aim, we adopted a probabilistic approach. The dose assessments were performed based on the measurement data of the surface activity concentrations of Cs and the results of actual survey on behavioral patterns of the population groups living in Fukushima Prefecture. As the result of assessments, the 95th percentile of the annual effective doses received by the inhabitants evacuated from the evacuation areas were mainly in the 1-10 mSv dose band in the first year after the contamination. However, the 95th percentile of the doses received by some outdoor workers, inhabitants evacuated from the deliberate evacuation areas and highly contaminated areas were in the 10-50 mSv dose band.