Details

Autor(en) / Beteiligte

• Wilkerson, Marianne P.
• Hernandez, Sarah C.
• Mullen, W. Tyler
• Nelson, Andrew T.
• Pugmire, Alison L.
• Scott, Brian L.
• Sooby, Elizabeth S.
• Tamasi, Alison L.
• Wagner, Gregory L.
• Walensky, Justin R.

Titel

Hydration of α-UO 3 following storage under controlled conditions of temperature and relative humidity

Ist Teil von

• Dalton transactions : an international journal of inorganic chemistry, 2020-08, Vol.49 (30), p.10452-10462

Ort / Verlag

United Kingdom: Royal Society of Chemistry (RSC)

Erscheinungsjahr

2020

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Changes in chemical speciation of uranium oxides following storage under varied conditions of temperature and relative humidity are valuable for characterizing material provenance. In this study, subsamples of high purity α-UO 3 were stored under four sets of controlled conditions of temperature and relative humidity over several years, and then measured periodically for chemical speciation. Powder X-ray diffraction (XRD) analysis and extended X-ray absorption fine structure spectroscopy confirm hydration of α-UO 3 to a schoepite-like end product following storage under each of the varied storage conditions, but the species formed during exposure to the lower relative humidity and lower temperature condition follows different trends from those formed under the other three storage conditions (high relative humidity with high or low temperatures, and low relative humidity with a high temperature). Thermogravimetry coupled with XRD analysis was carried out to distinguish desorption pathways of water from the hydrated end products. Density functional theory calculations discern changes in the structure of α-UO 3 following incorporation of 1, 2 or 3 H 2 O molecules or 1, 2 or 3 OH groups into the orthorhombic lattice, revealing differences in lattice constants, U–O bond lengths, and U–U distances. The collective results from this analysis are in contrast to analogous studies that report that U 3 O 8 is oxidized and hydrated in air during storage under high relative humidity conditions.