Preparation and characterisation of a ²²⁶Ra spiked slag as reference material for radioactive control of steelworks

One of the issues of the European Research Project MetroMetal is to develop reference materials in order to provide SI-traceable radioactivity monitoring in foundries. For this purpose, a protocol for preparing a set of identical standard slag samples, containing known activity concentrations of ²²⁶Ra, has been developed. This paper describes the preparation of the raw material, the characterisation in terms of its mineralogical, chemical and radiological features, the spiking procedure and the homogeneity testing of the spiked samples. - Highlights: • Slags from an electric arc furnace have been studied and characterised. • Physical, chemical and mineralogical characteristics have been determined. • After preparation, material was spiked with Ra-226 to produce reference sources. • Homogeneity tests were successful. • The sources can be used to test the radioactive contamination in Steelworks