四川省广元市环境天然贯穿辐射水平调查

Investigation and Study on Natural Penetration Radiation Level in Guangyuan City,Sichuan Province

作为1987年四川省环境天然放射性水平调查的一部分,对广元市环境天然贯穿辐射剂量水平进行了调查。此次调查中,共布设测量点61个,其中,25 km×25 km网格点26个,在市区、各县城区、某核设施厂区周围布设加密点35个。调查结果表明:(1)广元市原野、道路、建筑物室内γ辐射剂量率,按测点平均分别为72.9、64.3、103.9nGy/h;(2)宇宙射线电离成分(不包括中子)所致空气吸收剂量率,室内、室外均值分别为28.53、3.4 nGy/h;(3)天然贯穿辐射剂量率,室内、室外均值分别为132.31、06.4 nGy/h;(4)宇宙射线、天然陆地γ辐射、天然贯穿辐射所致人均年有效剂量当量分别为0.26、0.590、.85 mSv。

Based on the investigation of the environmental natural background radioactivity level in 1987 in Sichuan Province, the paper analyses the environmental natural penetration radiation dose level in Guangyuan City. 26 grid points were distributed in terms of 25 km×25 km with 35 densed points around the urban area, counties and a nuclear facility. The results indicate that： （1） the average values of γ radiation dose rate for fields, roads and buildings indoors are 72.9, 64.3 and 103.9 nGy/h,respectively; （2） that of air absorbed dose rate from cosmic rays （excluding neutron） indoors and outdoors are 28.5 and 33.4 nGy/h; （3） that of natural penetration radiation dose rate indoors and outdoors are 132.3 and 106.4 nGy/h, respectively; （4） that of annual effective doses from cosmic rays, natural γ radiation and natural penetration radiation are 0.26, 0.59 and 0.85 mSv. The γ radiation dose level in Guangyuan is high.