Advancements in NORM metrology – Results and impact of the European joint research project MetroNORM

The results of the three years European Metrology Research Programme's (EMRP) joint research project ‘Metrology for processing materials with high natural radioactivity’ (MetroNORM) are presented. In this project, metrologically sound novel instruments and procedures for laboratory and in-situ NORM activity measurements have been developed. Additionally, standard reference materials and sources for traceable calibration and improved decay data of natural radionuclides have been established. •Results of the three years European joint research project ‘MetroNORM’.•Development, design and test of novel NORM measurement instruments.•Production of traceable NORM reference materials and sources.•Revision of nuclear decay data of natural radionuclides.•Successful on-site tests of developed NORM instruments and materials.