IAEA-447: A new certified reference material for environmental radioactivity measurements

The environment program of the International Atomic Energy Agency (IAEA) includes activities to produce and certify reference materials for environmental radioactivity measurements. This paper describes methodologies applied in preparation and certification of the new IAEA-447 moss-soil certified reference material. In this work, the massic activities and associated standard uncertainties of 40K, 90Sr, 137Cs, 208Tl, 210Pb, 210Po, 212Pb, 214Pb, 214Bi, 226Ra, 228Ac, 234Th, 234U, 238U, 238Pu, 239+240Pu, 241Pu and 241Am were established. Details of the analytical methods including radiochemical procedures were reported. Analytical challenges and lessons learned from the reported results in the worldwide IAEA proficiency test using this material was summarized and best analytical practices to improve the performance for environmental radioactivity determinations were recommended. IAEA-447 is an important reference material for quality control and method validation of gamma-ray spectrometry and radiochemical analytical procedures.