The hydrolysis and morphological effect of amorphous (A)-UO3 following aging under varying temperature and relative humidity has been studied. This work provides insight to U-oxide speciation following storage, the U-oxide quantitative morphology database, and the overall characterization of nuclear material provenance. A-UO3 was synthesized by the washed uranyl peroxide synthetic route and aged by a 3-factor circumscribed central composite design of experiment. Target aging times include 2.569, 7, 14, 21, and 25.431 days, temperatures of 5.505, 15, 30, 45, and 54.495°C, and relative humidities of 14.175, 30, 55, 80, and 95.825% were investigated. Following storage, crystallographic changes were quantified via powder X-ray diffraction (p-XRD) and an internal standard Rietveld refinement method. Particle morphology from scanning electron microscopy (SEM) images was quantified via Morphological Analysis of MAtierals (MAMA) software. Largely hydrated samples were found to have a much larger, plate-like morphology compared to the unaged control samples. Predictive modeling via response surface model determined that, while aging time, temperature, and relative humidity all have a quantifiable effect on A-UO3 crystallography and morphology, relative humidity is the greatest driving factor.

Impact of controlled storage conditions on the hydrolysis and surface morphology of amorphous-UO3

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.