The delineation of radon prone areas is one of the central requirements of the European Council Directive 2013/59/EURATOM. It is quite a complex task which usually requires the collection of radon data through an appropriate survey as a first step. This paper presents the design and methodology of the recent Austrian radon survey (ÖNRAP 2, 2013–2019) and its implementation. It details the results of the nationwide survey as well as correlations and dependencies with geology and building characteristics. The paper also discusses the representativeness of the survey as well as advantages and disadvantages of the selected approach.

For the purpose of establishing a new delineation of radon prone areas in Austria we distributed approximately 75,000 passive long-term radon detectors. They were offered to selected members of the voluntary fire brigades and this resulted in about 50,000 radon measurements. Thus, a return rate of about 67% was achieved. The distribution of the radon results closely follows a log-normal distribution with a median of 99 Bq/m³, a geometric mean of 109 Bq/m³, and a geometric standard deviation factor of 2.29. 11% of the households show a mean radon concentration above the national reference level of 300 Bq/m³.

Important data on building characteristics and the location of the measured rooms were collected by means of a specific questionnaire and a measurement protocol that were handed out together with the radon detectors. We were able to identify significant correlations between the indoor radon concentration and geology, the year of construction, and the coupling of the room to the ground (basement yes/no, floor level).

Being a geographically-based and not a population-weighted survey, the comparison of building characteristics with the Austrian census data confirms that rural areas are over-represented in this survey.

As a summary, the selected approach of conducting passive long-term radon measurements in selected dwellings of members of the voluntary fire brigades proved to be an efficient method to collect reliable data as a basis for the delineation of radon prone areas. The next step was to eliminate factors that influence the measured radon concentration through appropriate modelling. Based on the results predicted by the model radon areas are then be classified. This will be presented in a subsequent publication.

划定容易ne气的区域是欧洲理事会指令2013/59 / EURATOM的主要要求之一。这是一项非常复杂的任务，通常首先需要通过适当的调查收集of数据。本文介绍了最近的奥地利ra气调查（ÖNRAP2，2013–2019）的设计和方法及其实施。它详细介绍了全国范围的调查结果以及与地质和建筑特征的相关性和依赖性。本文还讨论了调查的代表性以及所选方法的优缺点。

为了在奥地利建立新的ra易发地区，我们分发了大约75,000个无源长期ra探测器。它们被提供给自愿消防队的选定成员，这导致了约50,000次ra的测量。因此，获得了约67％的回报率。don气的分布非常接近对数正态分布，中位数为99 Bq /m³，几何平均值为109 Bq /m³，几何标准偏差系数为2.29。11％的家庭的平均ra气浓度高于国家参考水平300 Bq /m³。

关于建筑物特征和被测量房间位置的重要数据是通过与questionnaire探测器一起分发的特定调查表和测量规程收集的。我们能够确定室内ra浓度与地质，建造年份以及房间与地面的耦合程度（地下室是/否，楼层）之间的显着相关性。

作为基于地理的调查，而不是人口加权的调查，建筑特征与奥地利人口普查数据的比较证实，农村地区在本次调查中所占比例过高。

综上所述，在自愿消防队成员的选定住宅中进行被动长期ra测量的所选方法被证明是收集可靠数据的有效方法，可作为划定易发生areas区域的基础。下一步是通过适当的建模消除影响测得ra浓度的因素。然后根据模型预测的结果对ra区域进行分类。这将在以后的出版物中介绍。