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斎藤 公明; 三上 智; 安藤 真樹; 松田 規宏; 木名瀬 栄; 津田 修一; 佐藤 哲朗*; 関 暁之; 眞田 幸尚; Wainwright-Murakami, Haruko*; et al.
Journal of Radiation Protection and Research, 44(4), p.128 - 148, 2019/12
Massive environmental monitoring has been conducted continuously after the Fukushima accident with different monitoring methods having different features together with migration studies of radiocesium in diverse environments. At three months after the accident, multiple radionuclides were detected at many places; while it was confirmed that radiocesium was most important from the viewpoint of long-term exposures. The air dose rates in environments related to human living have decreased faster than expected from radioactive decay by a factor of 2-3 on average. An empirical model for predicting air dose rate distribution was developed based on statistical analysis of massive car-borne survey data. Some trials were performed to integrate different types of contamination maps to obtain an integrated map of better quantity. Annual external exposure doses for residents who would return to their home were estimated to less than a few mSv as a whole. The environmental data and knowledge have been provided for diverse-spectrum of people in different ways.
飯島 敏哲
JAERI-M 7757, 97 Pages, 1978/07
国民線量評価には、原子力サイトを中心とする人口分布や食品生産分布とその消費過程に関する情報が必要である。一方我が国の人口や食品生産等については、国あるいは地方自治体が定期的に調査を行いそれぞれの統計結果を公表している。そこでこれらの既存統計資料の利用を考え、1976年に事例研究として東海サイトを中心とする人口分布、農畜産物生産量分布等に関する調査を実施し、既存統計資料の利用可能性も調べた。調査項目は(1)東海村を中心とする半径1000km以内の年令別、男女別人口分布および農畜産物の年間生産分布、(2)生産される農畜産物の消量割合、(3)農畜産物の生産から消費までの期間、(4)既存統計資料の利用上の問題点、(5)分布変化の予測方法である。本報告では、国民線量計算方法、調査内容、調査結果について記述し、さらに国民線量評価の観点から、得られた分布の特徴を考察する。
本間 俊充
no journal, ,
The accident at the Fukushima Daiichi NPP resulted in a substantial release of radioactive material to the atmosphere and marine environment and caused extensive contamination of the environment. This paper provides an overview of releases of radioactive material to the atmosphere and ocean, and the subsequent distributions of radioactive material in the environment, which are the basis of estimating radiological consequences to people and the environment. In addition, this paper will describe the protective actions that were implemented during the accident to protect people against radiation exposure. By providing an overview of the releases and distribution of radioactive material to the environment and the protective actions that were implemented in Japan, in combination with a comparison of the Chernobyl accident, this paper will contribute to an improved understanding of the radiological consequences from contamination of the environment due to the Fukushima Daiichi accident.
斎藤 公明
no journal, ,
Temporal change in radiological environments for five years after the Fukushima accident has been clarified on the basis of the large-scale environmental measurements repeatedly carried. Air dose rates in living environments have decreased much faster than the physical decay. A prediction model for air dose rate distribution has been developed according to statistical analyses of accumulated massive car-borne survey data. In June 2011 plural radionuclides were detected; while, radiocesium was found to be far more important than other radionuclides from a viewpoint of long-term exposure. The movement of radiocesium in horizontal directions in natural fields is generally slow, but radiocesium deposited on ground has gradually penetrated into deeper parts. The results obtained in the projects have been applied to different kinds of extensive analyses. Significant exposure doses to inhabitants have not been reported so far though further investigation is necessary.
