Formation of ammonium uranate on uranium dioxide during aging under controlled storage conditions
Source abstract
Abstract
Abstract The analysis and characterization of uranium dioxide (UO2) under controlled storage conditions can provide insight into potential alteration products and overall stability, which has relevance for nuclear fuel cycle processes, environmental management, and the stability of used nuclear fuel in a repository. In this work, UO2 was monitored as a function of time (6–24 months) and temperature at constant relative humidity (81% RH) in the presence of ammonium sulfate. The morphology of the aged material was described using scanning electron microscopy and a previously published lexicon, while phase changes were confirmed using X-ray diffraction. Additional characterization was carried out using energy dispersive X-ray spectroscopy, transmission electron microscopy, Raman spectroscopy, and Fourier transform infrared spectroscopy to further identify aging effects. Over time, UO2 transitioned to a mixed phase assemblage. Among the alteration was ammonium uranate, a common fuel cycle compound, which was identified from its morphological and spectral characteristics. This work highlights the affinity and persistence of ammonium uranate compounds and emphasizes the need to continue investigating these alteration systems.
Source: openaire · Quality: candidate unverified · Source record ↗
Research context
OpenAlex topics: Radioactive element chemistry and processing · Nuclear Materials and Properties · Nuclear reactor physics and engineering
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (31)
Show source-provided references
1. Fuel fabrication
2. Particle properties and sintering behaviour of uranium dioxide10.1016/0022-3115(67)90002-5 ↗
3. A study of the factors influencing the sinterability of uranium dioxide10.1080/0371750X.1966.10855552 ↗
4. Study of calcinations of ammonium diuranate at different temperatures10.1016/j.jnucmat.2012.03.035 ↗
5. Study of crystallization and morphology of ammonium diuranate and uranium oxide10.1016/j.jnucmat.2012.02.012 ↗
6. Comparison of morphologies of a uranyl peroxide precursor and calcination products10.1007/s10967-016-4692-x ↗
7. Quantifying morphological features of α-U3O8 with image analysis for nuclear forensics10.1021/acs.analchem.6b05020 ↗
8. Uranium oxide synthetic pathway discernment through thermal decomposition and morphological analysis10.1515/ract-2018-3033 ↗
9. The conversion of UO2 via ammonium uranyl carbonate: study of precipitation, chemical variation and powder properties10.1016/0022-3115(81)90182-3 ↗
10. Some results uranium dioxide powder structure investigation10.3103/S1067821209030183 ↗
11. Ten-year results from unsaturated drip tests with UO2 at 90 C: implications for the corrosion of spent nuclear fuel10.1016/S0022-3115(96)00383-2 ↗
12. Morphology of U3O8 materials following storage under controlled conditions of temperature and relative humidity10.1007/s10967-016-4923-1 ↗
13. Oxidation and hydration of U3O8 materials following controlled exposure to temperature and humidity10.1021/ac504105t ↗
14. Microscopy and spectroscopy of plutonium dioxide aging under ambient and near-ambient conditions10.1016/j.jallcom.2020.156277 ↗
15. ASTM E104-02 (2012). Standard Practice for Maintaining Constant Relative Humidity By Means of Aqueous Solutions. ASTM International: West Conshohocken, PA, 2012.
16. On the uranates of ammonium–I: the ternary system NH3•UO3•H2O10.1016/0022-1902(62)80184-5 ↗
17. SingleCrystal. In. (2020). (Version 4.0.2) CrystalMaker Software Ltd.
18. Applicability of Raman spectroscopy as a tool in nuclear forensics for analysis of uranium ore concentrates10.1524/ract.2013.2110 ↗
19. On art and science in curve-fitting vibrational spectra10.1016/j.vibspec.2005.03.003 ↗
20. Characterization and classification of uranium ore concentrates (yellow cakes) using infrared spectrometry10.1524/ract.2011.1886 ↗
21. A lexicon for consistent description of material images for nuclear forensics10.1007/s10967-015-4455-0 ↗
22. Significance of physical state of starting precipitate in growth of uranium dioxide particles10.1016/0022-3115(64)90124-2 ↗
23. In situ studies of the decomposition of ammonium uranyl carbonate in an electron microscope10.1016/0022-3115(84)90087-4 ↗
24. Raman spectroscopic studies of defect structures and phase transition in hyper-stoichiometric UO2+x10.1039/b925495a ↗
25. A detailed Raman and X-ray study of UO2+x oxides and related structure transitions10.1039/C6CP03800J ↗
26. Assessing UO2 sample quality with μ-Raman spectroscopy10.1016/j.jnucmat.2018.11.009 ↗
27. Raman spectrum of U4O9: a new interpretation of damage lines in UO210.1002/jrs.3054 ↗
28. Characterization of uranium oxides using in situ micro-Raman spectroscopy10.1366/0003702001951057 ↗
29. Formation of uranium trioxide hydrates on UO2 fuel in air-steam mixtures near 200 °C10.1016/0022-3115(89)90566-7 ↗
30. The vapour pressures of saturated aqueous solutions of potassium bromide, ammonium sulfate, copper (II) sulfate, iron (II) sulfate, and manganese (II) dichloride, at temperatures from 283K to 308K10.1006/jcht.1993.1151 ↗
31. Vapor pressure of ammonium sulfates10.1016/0004-6981(79)90174-4 ↗