土壤氡析出率活性炭累积吸附法

为解决大面积多点快速土壤氡析出率测量问题, 设计开发并进行了土壤氡析出率活性炭累积吸附法的方法技术研究.在参考氡析出率装置和野外实验数据的基础上, 进行了测量装置及材料的选择、装置刻度、野外累积暴露时间、活性炭盒吸附氡有效衰变常数等研究.通过2002-2003年22次重复观测, 北京西北郊区粘土类土壤氡析出率平均值为20.15mBq.m-2.s-1, 最大值和最小值分别为26.75和13.49mBq.m-2.s-1, 标准偏差为3.55mBq.m-2.s-1.与仪器静电收集法比对结果表明, 两种方法的相对误差小于±10%.实验结果表明: 活性炭方法测量结果稳定可靠, 简便易行, 适用于全国大面积土壤氡析出率调查. 

Activated Charcoal Cumulated Adsorption Method for Measuring Radon Exhalation Rate from Soil

We designed and developed an activated charcoal cumulated adsorption method for measuring radon exhalation rate from soil to perform rapid observation at many sites in a large area. Based on the data of measurements on the radon exhalation facility and real-time soil radon exhalation rate in the field, we studied the types of the activated charcoal and sampling device, accumulated exposure time and radon effective decay constant. We investigated the soil radon exhalation in a university yard (sandy loam) from 2002-2003. The average of radon exhalation rate is 20.15 mBq·m-2·s-1; the standard deviation is 3.55 mBq·m-2·s-1, and the variety ranges from 13.49 to 26.75 mBq·m-2·s-1. By comparison, the results of activated charcoal absorption and an equipment of electrostatic collection are coincident with each other. The results revealed that the method of activated charcoal absorption is practical, feasible and rapid for measuring the 222Rn exhalation rate from soil in the field.