The Dutch norm for the determination of natural radioactivity levels in construction materials applied to concrete samples

In the near future, Dutch legislation will set an upper limit for the natur al radiation exposure of inhabitants in newly built houses. Therefore, it i s necessary to have standardized procedures available for the determination of the radon exhalation rate of and the activity levels in construction ma terials. In this paper we describe a method for determination of activity l evels in construction materials. This method comprises radionuclide-specifi c calibration of Marinelli-beaker geometries with a range of material densi ties. This standard method was validated in a round-robin involving 6 labor atories, organized by two of the authors (M.B. and H.J.G.) of this paper. I n this paper, results obtained according to the norm are compared with resu lts obtained at IRI with a more elegant but possibly less robust method.