一种地下工程防氡效果评价方法

Evaluation method of radon preventing effect in underground construction

针对地下工程中高湿度条件下测量仪器的工作时间短、防氡效果评价难的问题,提出了一种快速评价方法。在密闭的地下工程试验房中,氡的实测浓度由即时本底理论衰变浓度和未屏蔽部分组成,结合初浓度便可计算出屏蔽率。实验表明,得到的地下工程屏蔽率随时间变化而保持一定的稳定,实测的相对标准偏差为3.95%,可以通过短时间内测得的屏蔽率作为最终屏蔽率,从而实现地下工程特殊条件下的氡防护效果快速测定和评价。在地面实验室采用局部静态法进行了对比实验,得到的氡屏蔽率基本相符。

Background： It＇s difficult to evaluate the radon prevention effect because of the short operating time of measuring instrument under the circumstances of high humidity in underground construction. Purpose： A new rapid method to evaluate the radon prevention efficiency of underground construction was introduced. Methods： The radon concentrations before and after shielding operation were determined, and according to the regularity of radon decay, the shielding rate can be calculated. Results： The results showed that radon shielding rate in underground construction remains generally stable with variation of time, and the actual relatively standard deviation was 3.95%. So the rapid determination and evaluation of radon preventing effect under special conditions in underground construction can be realized by taking shielding rate in a short time for the final shielding rate. Compared with those by the local static method in ground lab, the results were similar. Conclusion： This paper provided a prompt, accurate and practicable way for the evaluation of radon prevention in underground construction, having a certain reference value.