Results from the international evaluation exercise for uranium enrichment measurements

An international evaluation exercise for uranium enrichment measurement was organized by the ESARDA (European Safeguards Research and Development Asso ciation) Working Group on Techniques and Standards for Non-Destructive Anal ysis. The aim of this exercise was to test the different methods and more p articularly X- and gamma-ray spectrometry methods used in the determination of uranium enrichment. Sets of samples of different uranium enrichments pr epared by IRMM (Institute for Reference Materials and Measurements) and BNF L (British Nuclear Fuels) were measured by 15 participants in the IRMM labo ratories, A description of this exercise is given here and the final result s with their uncertainties are compared to the reference values obtained fr om mass spectrometry measurements. The main conclusions from this exercise are proposed; in particular, it appears necessary to improve the nuclear da ta used in the spectral modeling of the XKalpha region. (C) 2000 Elsevier S cience Ltd. All rights reserved.