Certification of the First Uranium Oxide micro-particle reference materials for Nuclear Safety and Security, IRMM-2329P and IRMM-2331P

Production of mixed element actinide reference particulates to support nuclear safeguards using THESEUS, an aerosol-based particulate synthetic methodology

“…However, robust quantitative analysis is not possible with current SEM/EDS instrumentation due to the limited sample volume of individual particles. However, the approximate mass per 1μm particle is likely in the range of 1–5 pg, based on U 3 O 8 particles produced using a similar approach, see Richter et al 11…”

“…Engineering developmental efforts for uranium-bearing QC reference particulates continue and include: (1) scaling up the manufacturing processes, (2) developing a pedigree of commercially available particulate laden substrates, and (3) shelf-life characterization studies. 3,11–13…”

“…The technologies pursued thus far can be divided into two categories: hydrothermal chemical synthesis [7][8][9][10] and aerosol-based spray drying. 4,11,12 Both methodologies have demonstrated viability for the manufacture of uranium oxide, fit-for-purpose QC materials, with varying and targeted 235 U/ 238 U isotopic compositions. The desired specifications of the engineered particulate materials have focused on various analytical use aspects, including particle size (i.e., mean value) and population distribution targets, specifically particulates 1 µm in diameter and monodisperse populations.…”

Hydrothermal synthesis of homogenous and size-controlled uranium-thorium oxide micro-particles for nuclear safeguards

“…Hence, a few laboratories involved in particle analysis have attempted to develop analytical procedures to carry out agedetermination at the particle scale by means of SIMS [10,11]. However, these analyses suffer from the lack of reference materials for validating the methods and evaluating their performance, although uranium oxide micro-particles were recently certified in this aim [12]. Another key-point is the determination of the U-Th fractionation factor, which may be time and matrix-dependent.…”

Synthesis and Morphological Control of UO2F2Particulates

“…Therefore, routine environmental monitoring provides an avenue to explore isotopic, chemical, and morphological fingerprint signatures of declared or undeclared facilities. In most cases, particulate samples are collected and sent to the IAEA’S Network Analytical Laboratories for analyses. − However, to ensure data validity, these instruments required certified reference materials for calibration, with particular concern for particle size, composition, phases, and isotopic properties. Currently, no reliable UO 2 F 2 particulate reference materials are available to the nuclear forensic community for analyses and method developments.…”