长沙市地铁一号线车站内氡活度浓度的调查与评价

为了调查长沙市地铁一号线车站内氡活度浓度水平,采样典型抽样法,随机抽取5个车站对其中的氡活度浓度进行测量及评价。借助于径迹蚀刻片,用累积法对车站内的车控室、站台、客服中心的氡活度浓度进行调查。结果表明,长沙市地铁1号线车站内氡活度浓度的范围为22.5~53.0 Bq/m 3,均值为35.3 Bq/m 3,与长沙市室内氡活度浓度平均值(37.4 Bq/m 3)的偏差仅为5.6%,远低于国家现行标准《公共地下建筑及地热水应用中氡的放射防护要求》(WS/T 668—2019)的限制要求;车站内氡活度浓度所致工作人员及公众的年均有效剂量分别为0.28 mSv和0.08 mSv,地铁内的氡气所致工作人员及公众年均有效剂量处在本底水平范围内,满足《电离辐射防护与辐射源安全基本标准》(GB 18871—2002)的限制要求。

Investigation and evaluation of radon activity concentration in thestations of Changsha Metro Line 1

Abstract:In order to investigate the activity concentration level of radon in the stations of Changsha Metro Line 1, we have used typical sampling method and randomly selected 5 stations to measure and evaluated the radon activity concentration. With the aid of the track etched sheet, we have used accumulation method to investigate the radon activity concentration of the vehicle control room, platform and customer service center in the stations. The results showed that the activity concentration of radon in the stations of Changsha Metro Line 1 was in the range of 22.5-53.0 Bq/m³, with a mean value of 35.3 Bq/m³, which is only 5.6% deviation from the average radon activity concentration (37.4 Bq/m³) in Changsha city. The radon activity concentration was far below the restriction of Standard for controlling radon and its progenies in underground space, GBZ 116—2002 (Equilibrium Equivalent Radon Concentration 400 Bq/m³); The average dose of the staff and public caused by radon activity concentration in stations was 0.28 mSv and 0.08 mSv respectively. The average dose of the staff and public caused by radon concentration was at the background level, and meeting the requirements of the Basic Standards for Protection against Ionizing Radiation and for the safety of radiation sources, GB 18871—2002.