某些场所氡及其子体平衡因子的测量

环境氡子体所致剂量大多采用环境氡暴露量和推荐的氡及氡子体平衡因子来近似估算。但不同场所的环境条件差异很大,氡及氡子体的平衡因子也相差较大,从而导致此种估算方法存在较大的误差。为了提高基于氡暴露量估算氡子体所致剂量的质量,典型场所氡及其子体平衡因子的测量是必要的。采用南华大学研制的NRL-Ⅱ氡连续测量仪和NR-200A氡子体连续监测仪,在秦山核电基地、湖南省湘雅附一医院、湖南省肿瘤医院、锦原铀业等几个特殊工作场所进行空气中氡及其子体的平衡因子测量。测量结果表明,在沿海地区室内及放疗场所的平衡因子都比推荐值要小约40%;有些通风好且采取空气净化措施的区域平衡因子更小;内陆大部分室内的平衡因子与推荐值相近。

Measurements of equilibrium factor of radon and its progenies in some fields

Dose caused by environmental radon progeny is approximately estimated mainly by using the environmental radon exposure and the recommended equilibrium factor of radon and radon progeny. However, environmental conditions vary greatly in different places, and therefore the equilibrium factor of radon and radon progeny also vary greatly, and the estimation method results in a big estimation error. To improve the quality of the dose caused by radon progeny estimated based on radon exposure, it is necessary to measure the equilibrium of radon and radon progeny in typical places. By adopting the NRL-Ⅱcontinuous radon monitor and NR-200A continuous radon daughters monitor developed by the University of South China, the equilibrium factors of radon and its daughters in the air are measured in fields including Qinshan Nuclear Power Base, Hunan Xiangya Hospital, Hunan Provincial Tumor Hospital and Jinyuan Uranium Industry Company. The results show that the equilibrium factors of Radon and its Progenies in coastal areas and Radiation Therapy Center was 40% less than the recommended value. The regional equilibrium factors of Radon and its Progenies in some fields with good ventilation and air purification measures are even smaller, and the equilibrium factors of radon and its Progenies in the indoor environment of inland provinces are similar with the recommended value.