Abstract An increase in ambient dose equivalent rate during precipitation events is a well known phenomenon that is easily identified by dose rate monitoring networks. Despite the invaluable information these monitors usually provide, they cannot identify the radioisotopes involved in these radiological alterations nor quantify their activity concentrations. Commercial systems based on passive gamma spectrometry using scintillation detectors allow to identify the radionuclides that increase during rainfall events but they cannot infer if they are deposited on ground or linked to the airborne particles. In 2016 an air monitoring station based on sample retention and scintillator gamma spectrometer was custom-designed and integrated into the automatic and quasi-real-time Radiological Alert Network of Extremadura (RARE) in south western Spain. In this work, it is presented how the capabilities of our system take advantage of the distinction between the radionuclides that are deposited and the radionuclides that are presented in airborne during rainy events. However, during the operation of RARE's homemade monitoring station based on sample retention and gamma-spectrometry, some shortcomings to meet the requirements appertained to real-time radiological networks, such as efficiency, were identified. Concretely, the station was targeted at monitoring the activity of gamma-emitting radioisotopes in airborne, but the relatively poor energy resolution of the gamma scintillation detectors employed meant that exceptionally high concentrations of radon decay products (such as 214Pb) in the area made it very difficult to identify and quantify the activity levels of some anthropogenic radioisotopes such as 131I, with there being a significant number of false positives and substantial increase in those isotopes' minimum detectable activities. This paper describes the simple approach that has been implemented in order to overcome the aforementioned analytical difficulty in situations where the activity concentration of radioiodine in air could be of the order of natural radon concentration, for example, when effluent releases from nuclear facilities permitted under authorities’ regulations.

中文翻译：

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基于样本保留的自动空气监测伽马光谱站对降雨引起的剂量学变化和具有广泛氡水平的环境的响应

摘要 降水事件期间环境剂量当量率的增加是众所周知的现象，剂量率监测网络很容易识别。尽管这些监测器通常会提供宝贵的信息，但它们无法识别参与这些放射性改变的放射性同位素，也无法量化其活动浓度。基于使用闪烁探测器的被动伽马能谱测定法的商业系统可以识别在降雨事件期间增加的放射性核素，但它们无法推断它们是否沉积在地面上或与空气中的颗粒有关。2016 年，一个基于样品保留和闪烁体伽马光谱仪的空气监测站被定制设计并集成到西班牙西南部埃斯特雷马杜拉的自动和准实时放射警报网络 (RARE) 中。在这项工作中，介绍了我们系统的功能如何利用沉积的放射性核素与雨天期间空气中存在的放射性核素之间的区别。然而，在 RARE 基于样本保留和伽马光谱测定的自制监测站的运行过程中，发现了一些满足实时放射网络要求的不足，例如效率。具体而言，该站的目标是监测空气中发射 γ 放射性同位素的活动，但是所采用的伽马闪烁探测器的能量分辨率相对较差，这意味着该地区异常高浓度的氡衰变产物（例如 214Pb）使得识别和量化某些人为放射性同位素（例如 131I）的活动水平变得非常困难，其中大量的假阳性和这些同位素的最小可检测活性的显着增加。本文描述了在空气中放射性碘的活度浓度可能接近天然氡浓度的情况下为克服上述分析困难而实施的简单方法，例如，当当局允许从核设施中排放废水时'规定。这些同位素的最低可检测活性存在大量假阳性和大幅增加。本文描述了在空气中放射性碘的活度浓度可能接近天然氡浓度的情况下为克服上述分析困难而实施的简单方法，例如，当当局允许从核设施中排放废水时'规定。这些同位素的最低可检测活性存在大量假阳性和大幅增加。本文描述了在空气中放射性碘的活度浓度可能接近天然氡浓度的情况下为克服上述分析困难而实施的简单方法，例如，当当局允许从核设施中排放废水时'规定。