New reference materials for analysis of uranium isotopes
The IRMM has released a new series of certified reference materials for the analysis of uranium isotope abundances. The new series consists of materials used earlier in a set of reference materials for mainly nuclear material accounting purposes (IRMM-183, -184, 185, -186 and -187) that have now been recertified. In addition, the concentrations of uranium in the new series has been reduced and are now more suitable for modern measurement techniques and for laboratories analysing environmental samples.
The new reference materials carry codes IRMM-3183, IRMM-3184, IRMM-3185, IRMM-3186 and IRMM-3187. The certified n(235U)/n(238U) are directly traceable to mixtures of highly enriched isotopes and the contents of minor isotopes of 234U and 236U have been certified using internal normalisation techniques. The 235U abundance varies from depleted to 4.5% enriched across the series making this set especially useful for measuring the isotopic abundances of uranium typically found in the nuclear fuel cycle and in the environment.