山岭隧道施工人员辐射剂量评估方法及应用

Evaluation Method for Radiation Dose of Workers during Mountain-crossing Tunnel Construction and Its Application

为合理评估山岭隧道施工阶段的辐射对施工人员的影响,通过测试隧道内环境的γ辐射剂量率、空气氡浓度、粉尘质量浓度、围岩放射性核素比活度等环境参数,以工人年均个人剂量为主要评估指标,推荐了一套基于新奥法施工的山岭隧道施工阶段辐射对施工人员影响的评估方法。运用该方法对摩岗岭隧道不同施工工序下的各项辐射指标进行测试和评估,研究得出:摩岗岭隧道施工人员各工序年均个人剂量为0.203~1.13 m Sv,隧道内部辐射环境对施工人员的影响处于较低范围。该评估方法不仅考虑了隧道不同工序施工人员接受辐射时间、辐射来源等问题,而且辐射指标的选取符合山岭隧道施工的实际情况,对隧道穿越辐射异常区的施工安全和辐射防治具有指导作用。

In order to evaluate the radiation and its impacts on workers during mountain-crossing tunnel construction,a suit of evaluation methods applicable to the tunnel construction with New Austrian Tunneling Method（ NATM） is recommended. The average individual radiation dose of tunnel workers per year is chosen as evaluating indicator,and the environmental factors including air radon concentration,environmental gamma radiation dose rate,dust concentration and radionuclides specific activity are tested. The above-mentioned assessment method is applied to the radiation environment of Mogangling Tunnel under different working processes. The assessment results show that the average individual radiation dose of workers in Mogangling Tunnel construction per year ranges from 0. 203 to 1. 13 m Sv;therefore,the impact of radiation environment on workers is relatively low. The assessment method in this study considers different irradiation time of tunnel workers in different processes as well as multifarious radiation sources,and the selection of radiation indicators meets the actual situation at the same time. The study results can provide guidance for construction safety and radiation control in tunnel construction at abnormal radiation area.