Production and characterization of a traceable NORM material and its use in proficiency testing of gamma-ray spectrometry laboratories

This paper outlines the process of characterizing a new NORM material for proficiency testing made of quartz sand with significantly elevated levels of 226Ra obtained from the backflush of a drinking water treatment facility. Samples of the fully characterized NORM material were sent to European laboratories concerned with radioactivity measurements and environmental monitoring by gamma-ray spectrometry for proficiency testing. The paper discusses the results, specific requirements, problems and solutions that were found during the characterization process and the proficiency test. •A traceably characterized NORM material was produced and studied.•The NORM material is made of quartz sand from a drinking water production site.•A proficiency test with the new material was conducted.•The samples were measured using high-resolution gamma-ray spectrometry.•The paper outlines common problems with regard to proficiency tests of NORM.