検索対象:     
報告書番号:
※ 半角英数字
 年 ~ 
 年

PHITSによる家屋内線量率への周辺斜面の影響の解析

Analysis of influence of slopes nearby buildings on indoor radiation dose rates using PHITS

古田 琢哉   ; 高橋 史明  

Furuta, Takuya; Takahashi, Fumiaki

福島第一原子力発電所事故後の放射線防護対策では、住民生活を反映して、屋外の放射線モニタリング結果に基づく線量評価を行う場合、滞在時間の長い建物内の線量低減を加味した線量評価が重要となる。我々はひらけた水平面の土地に立つ建物内の線量低減効果の解析を進めてきたが、福島県等では斜面近傍に家屋が立つ状況が多く見受けられる。そこで、福島県内の住宅で占有率の高い木造家屋が斜面近くに立つ環境を設定し、放射線輸送計算コードPHITSで家屋内の線量率を解析した。ここでは、斜面を含む地表面に一様な放射性セシウムの汚染が存在する状況で家屋内の線量率を計算し、水平面に立つ家屋内の線量率と比較した。その結果、斜面の有無による家屋内の線量率の差は大きくないことを確認し、斜面近くの家屋内で高い線量率が実測された場合、例えば、斜面の植栽等に沈着した放射性セシウム等の地形以外の原因が多く影響していると推測される。

After the accident at the Fukushima Daiichi Nuclear Power Station, it became important to assess radiation doses accounting dose reduction by buildings in order to take measures for radiation protection reflecting life-styles of residents according to data of the radiation monitoring in open air. We have been analyzed the radiation dose reduction in buildings standing on a flat ground. However, slopes nearby buildings can be found in many situations of houses in Fukushima area. We performed simulation using PHITS and analyzed radiation dose rates in a wooden house, which is the most popular residential house in Fukushima area, standing nearby a slope. Here, radiation dose rates in the house were computed in a situation where radioactive cesium was distributed homogenously over the ground including the slope and compared with those in the house standing on a flat ground. We found that the variation of the dose rates in the house was not significant with and without the slope. Accordingly, high dose rates possibly found in a house nearby slopes are more likely, for instance, because of contaminated plants at the slopes than due to the geometrical effect of the slopes.

Access

:

- Accesses

InCites™

:

Altmetrics

:

[CLARIVATE ANALYTICS], [WEB OF SCIENCE], [HIGHLY CITED PAPER & CUP LOGO] and [HOT PAPER & FIRE LOGO] are trademarks of Clarivate Analytics, and/or its affiliated company or companies, and used herein by permission and/or license.