Characterisation of the IAEA-152 Milk Powder Reference Material for Radioactivity with Assigned Values Traceable to the SI Units

Abstract

The Institute for Reference Materials and Measurements (IRMM) participated at an International Atomic Energy Agency (AAEA) organised research project (CRP) entitled "Upgrading of Analytical Quality Control Services (AQCS) intercomparison materials to reference materials (RM) with assigned property values traceable to the International System of Units". The aim of the work described in this article was to establish full traceability to the International System of Units (SI) of the activity concentrations of the radionuclides 134Cs, 137Cs, 40K, and 90Sr in the IAEA-152 milk powder RM. The choice of the particular reference material was based on the particular concern about radioactivity levels in foodstuff. The sample preparation and the assaying of the activity concentrations in the milk powder, the methods used to achieve instrument calibrations and measurements traceable to the SI units, the data reduction and analysis and, finally, the results obtained are presented.