Towards a methodology for identifying non-nuclear sites with enhanced levels of radioactivity

On 12th December 1997, a new assignment was entrusted to ONDRAF/NIRAS via the publication of a framework act. Since then the agency has, among other things, been tasked with creating a repertory of the location and state of all nuclear installations and sites that contain radioactive substances. This repertory not only includes sites that have a nuclear licence, but also non-nuclear sites where increased levels of radioactivity can occur as a result of the presence of natural sources of radiation. The identification of the nuclear sites is based on an inventory of the nuclear licenses such as issued by the competent authorities in the course of the years. Non-nuclear sites do not actually have to hold such a license so that their identification required the development of a specific methodology. The development of such a methodology proved to be an extensive task that ONDRAF/NIRAS entrusted to a task group consisting of Controlatom, the SCK●CEN, the Dutch NRG and ONDRAF/NIRAS. This presentation describes the set-up and purpose of the methodology.