南宁市地铁1号线各站段氡浓度水平以及地表γ剂量率水平研究

Study on the radon concentration and the surface level of γ radiation dose rate in the stations of Nanning metro line

目的掌握南宁市地铁1号线车站内氡浓度水平以及γ射线辐射水平,评价其对地铁工作人员造成的辐射剂量。方法采用闪烁瓶法和瞬时监测相结合的方法,对南宁市地铁1号线氡浓度水平和γ射线瞬时剂量率进行监测,并对数据进行分析和比较,根据联合国原子辐射效应科学委员会推荐的评价方法估算地铁工作人员受到氡及其衰变子体以及γ辐射水平造成的人均年有效照射剂量,评价其卫生学效应。结果南宁市地铁1号线全线氡浓度水平均值为18.5 Bq/m^3,地铁氡及其子体给工作人员造成的人均年有效剂量为0.133 mSv/a,地铁站地表γ射线辐射水平均值为0.097μSv/h,所造成的地铁工作人员年有效剂量0.194 mSv/a,二者造成的总剂量为0.327 mSv/a。结论南宁市地铁1号线氡浓度水平和γ射线瞬时剂量率不会对地铁工作人员和乘客造成额外明显的受照负担。

Objective To understand the levels of radon concentration andγradiation in the stations of Nanning Metro Line 1,and evaluate the radiation dose exposed to the subway staff.Methods With scintillation flask and instantaneous monitoring instument,the radon concentrations and the gamma instantaneous dose rates of Nanning Metro Line 1 were determined,and the data were analyzed and compared.According to the evaluation method recommended by United Nations Scientific Committee on the effects of atomic radiation,the annual effective radiation dose caused by radon and its progeny andγradiation,and its health effects on subway workers were estimated.Results the average radon concentration in Nanning Metro Line 1 was 18.5 Bq/m^3;the average annual effective dose of radon and its decay products was 0.133 mSv/a;the average gamma radiation level was 0.097 u Sv/h;the annual effective dose exposed to subway workers was 0.194 mSv/a,and the combined dose was 0.327 mSv/a.Conclusion Radon concentration level andγinstantaneous dose rate of Nanning Metro Line 1 will not cause an additional health deterioration on the subway staff and passengers.