@book{JRC41172, editor = {}, address = {Luxembourg (Luxemborg)}, year = {2007}, author = {Pereira De Oliveira Junior O and De Bolle W and Alonso Munoz A and Kuhn H and Richter S and Wellum R}, isbn = {}, abstract = {Uranium isotope reference materials are essential tools to provide accurate and therefore reliable measurement results of nuclear materials. In order to improve the trust in the nuclear materials safeguards system in South America, ten materials in the form of uranium hexafluoride with isotopes amount ratios ranging from 0.5 to 20.0 % of 235U in mass were recently prepared. They were enriched, purified and characterized in the Brazilian laboratories but the isotopic measurements were performed in the Institute of Reference Materials and Measurements. Modern concepts of metrology in chemical measurement were employed throughout to provide reference materials with certified values traceable to the SI and having the lowest achievable uncertainties. }, title = {A New Set of Uranium Isotope Reference Materials for the Improvement of Nuclear Safeguards in South America}, url = {}, volume = {}, number = {}, journal = {}, pages = {1-13}, issn = {}, publisher = {Office for Official Publications of the European Communities (OPOCE)}, doi = {} }