ONORM S 5200: radioactivity in building materials ( a standard in Austria to limit natural radioactivity in building materials)

The Austrian Standard ONORM S 5200 provides criteria to assess the radiation dose from building materials. It takes the gamma radiation of the radionuclides 40K, 226Ra and Th into account, as well as the dose due to the noble gas radon, which is released from building materials after the decay of radium. A building material is considered acceptable if its dose rate in a room does not exceed 2 mSv.y-1. Provisions are made to minimise the required experimental effort to prove compliance with the Standard. A limit of 1 μSv.h-1 for external beta radiation due to surface radiation, e.g. uranium-glazed tiles is also given. A few results of an intercomparison run for gamma spectrometers in Austria due to natural radioactivity are presented. (author)