A new Austrian recommendation guide for radon prevention in the design and construction of new buildings in areas with highly elevated radon levels

摘要

The identification and localisation of extremely high indoor air radon levels (maximum 274 kBq m~(-3)) in the village of Umhausen (Tyrol, Austria) in 1992 led to the urgent need for adequate radon prevention guidelines for the architects of new buildings taking into account the very high radon potential in this specific area (maximum soil-gas radon concentration about 600 kBq m~(-3)). Therefore a team of architects, scientists and engineers created a manual with detailed descriptions and recommendations of adequate radon prevention measures for the design and construction of new buildings in this area on behalf of and financially supported by the Government of Tyrol. The scientific background, the technical methods, and the practical implementation of the recommended prevention measures are shown. The radon prevention concept of the guide is based on three main principles: (1) Air-tight sealing of soil-contact building parts (e.g. basement) and installation penetrations with barriers against radon diffusion and convection. (2) Reduction of vertical convective connections inside the building to limit the vertical temperature and meteorological-driven pressure gradient and decreasing the inflow of soil-gas radon into the building. (3) Installation of a gravel layer under the basement for the possibility of the later installation of a sub-floor depressurisation facility in the case of a decreasing radon barrier effect of the sealing materials. The first experiences with the practical implementation of the new guide, the financial implications for the builder, and the most important aspects of the general application of the proposed radon prevention principles are discussed.