Nuclear isotopic reference materials from EU/JRC in Geel/Belgium

Abstract:

This poster describes nuclear isotope reference materials recently produced and currently being certified at the European Commission's Joint Research Centre (JRC) in Geel/Belgium. These materials are needed for instrument calibration, quality control and method development. The new IRMM-3000 series is a set of five highly enriched uranium nitrate solutions with 235U enrichments (235U/U ratios) of 20%, 35%, 50%, 75% and 90%. The 235U/238U isotope ratios are being certified with a relative expended uncertainty (coverage factor k=2) of 0.02%. This is an improvement of a factor five compared to other highly enriched reference materials with uncertainties at the level of 0.1%. This series is ideal to investigate and/or verify the linearity of mass spectrometer systems like TIMS and MC-ICPMS. Furthermore, the IRMM-2019-2029 series of low enriched uranium nitrate solutions with 235U enrichments of up to 5% is being extended by the new reference material IRMM-2030 with 6% 235U. In addition to the new reference materials, the IRMM-3636a double spike (233U/236U=1), the IRMM-074 and IRMM-075 series are reviewed.