News about certified nuclear isotope reference materials at Joint Research Centre – Unit G.2 - Geel

At the Joint Research Centre of the European Commission (EC-JRC), Directorate G (Nuclear Safety and Security), Unit G.2 (Standards for Nuclear Safety, Security and Safeguards, SN3S), in Geel (Belgium), formerly called IRMM (Institute for Reference Materials and Measurements), is engaged in the preparation and certification of nuclear isotopic reference materials. Within the several recent and the current year, the focus was on renewals of two Pu spike reference materials, namely IRMM-042a (244Pu spike) and IRMM-049e (242Pu spike), and in particular on the certification of the first Am spike isotope reference material, certified for the n(241Am)/n(243Am) isotope ratio using Thermal Ionisation Mass Spectrometry (TIMS) with total evaporation (TE) and the 241Am and 243Am amount concentrations. The certification of the 243Am amount concentration was performed by reverse IDMS due to the use of a highly enriched 241Pu material, which served to create a special in-house spike of 241Am grown in from the decay of the 241Pu. The new Am spike isotope reference material is applied for age dating in nuclear forensics using the n(241Pu)/n(241Am) clock.