Preparing the Building Industry for the New Euratom BSS

In the proposed new Euratom Basic Safety Standards (EU-BSS), a reference level of 1 mSv/a is set for indoor external exposure to gamma rays emitted by building materials. An activity concentration index (ACI) is proposed as a conservative screening parameter for identifying building materials that may cause the reference level to be exceeded. An alternative in situ ACI determination method was developed and the validation of this method is discussed. This screening method was used to analyse numerous building materials available on the Belgian market. An attempt was made to identify building materials containing residues from naturally occurring radioactive material processing industries that pass through Belgium, by analysing results from a large scale radiological study of the container traffic in the port of Antwerp. In addition to the regulation provided on the gamma exposure from building materials, specific parts of the proposed new EU-BSS are dealing with radon issues separately. A reference level of 300 Bq/m³ for indoor radon concentration is proposed for the EU-BSS. Relationships between radon exposure and type of building material used, the airtightness of the building and the stage of construction work were determined. (author)