Results of a simple intercomparison of natural radioactivity measurements using a "blue concrete" sample

A simple intercomparison of natural radioactivity and radon emanation factor measurementscoordinated by the Medical Physics Department of the University of Cantabria UC, Spain, has beencarried out during 1998 in the framework of the EU Concerted Action ERRICCA (European Researchinto Radon in Construction Concerted Actio). All the measurements have been made on a "blueconcrete" sample friendly delivered by Dr. G. Akerblom from Swedish Radiation Protection Institute.In addition to UC, two other participant laboratories, STUK from Finland and ZVD from Republic ofSlovenia, have contributed to the development of the intercomparison exercise. Considering theuncertainties of the measurements, a good agreement between the results obtained by the threeparticipating laboratories has been ascertained. On the other hand, in accordance with experimentalresults obtained by other authors, data reported by UC show a significant decrease of the radonemanation factor as moisture content of the sample decreases below 5 % (per weight).