Wrocław University of Science and Technology, Faculty of Civil Engineering, Wybrzeże S. Wyspiańskiego 27, 27-50-370, Wrocław, Poland.
Wrocław University of Science and Technology, Faculty of Geoengineering, Mining and Geology, Laboratory of Geology and Planetary Sciences, Wybrzeże S. Wyspiańskiego 27, 50-370, Wrocław, Poland.
J Environ Radioact. 2023 Sep;265:107225. doi: 10.1016/j.jenvrad.2023.107225. Epub 2023 Jun 22.
The authors characterize the use of Rn as an effective tracer of natural ventilation of an underground site where air circulates within a whole system of workings and ventilation intensity (the number of air exchanges in the space) is determined by atmospheric factors. A radon-related database containing results of measurements conducted at various intervals and at different stages of site accessibility was compiled. During 8 months of the calendar year Rn activity concentration exceeds the mean annual reference value established by Polish law (300 Bq/m). These months correspond to periods with low intensity of natural ventilation of the workings and reduced efficiency of air exchange between the site and the atmosphere. They occur in autumn - in the second half of September, in October and November, and in May in spring, and persist for 7 to even 14 days. During these periods, the time spent inside the facility which is considered safe in terms of radiation protection is limited to an average of 6-8 h a day, i.e. from 6 a.m. to 6 p.m. in October, from 11 a.m. to 6 p.m. in November and from 11 a.m. to 5 p.m. in May. The length of a safe stay in the facility is determined by atmospheric factors, mainly the air and ground temperature. The concentrations of other gases in the atmosphere inside the facility comply with Polish mining regulations.
作者描述了使用 Rn 作为一种有效的示踪剂来监测地下场所的自然通风的方法，在这种地下场所中，空气在整个工作系统内循环，通风强度（空间内的空气交换次数）由大气因素决定。编译了一个包含在不同时间间隔和场地可达性不同阶段进行的测量结果的氡相关数据库。在日历年的 8 个月中，Rn 活动浓度超过了波兰法律规定的平均年参考值（300 Bq/m）。这些月份对应于工作场所自然通风强度低和场地与大气之间空气交换效率降低的时期。它们发生在秋季 - 9 月下旬、10 月和 11 月，以及春季 5 月，持续 7 天甚至 14 天。在此期间，考虑到辐射防护方面的安全，在设施内的停留时间被限制在平均每天 6-8 小时，即在 10 月，从上午 6 点到下午 6 点，在 11 月从上午 11 点到下午 6 点，在 5 月从上午 11 点到下午 5 点。在设施内安全停留的时间长短取决于大气因素，主要是空气和地面温度。设施内大气中其他气体的浓度符合波兰采矿法规。
