Non-stoichiometry in U3Si2
- Westinghouse Electric Sweden AB, Vasteras (Sweden); Imperial College London, London (United Kingdom)
- Imperial College London, London (United Kingdom)
- Westinghouse Electric Co. LLC, Cranberry Woods, PA (United States)
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Uranium silicides, in particular U3Si2, are being explored as an advanced nuclear fuel with increased accident tolerance as well as competitive economics compared to the baseline UO2 fuel. Here we use density functional theory calculations and thermochemical analysis to assess the stability of U3Si2 with respect to non-stoichiometry reactions in both the hypo- and hyper-stoichiometric regimes. We find that the degree of non-stoichiometry in U3Si2 is much smaller than in UO2 and at most reaches a few percent at high temperature. Non-stoichiometry impacts fuel performance by determining whether the loss of uranium due to fission leads to a non-stoichiometric U3Si2±x phase or precipitation of a second U-Si phase. Lastly, we also investigate the U5Si4 phase as a candidate for the equilibrium phase diagram.
- Research Organization:
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE Office of Nuclear Energy (NE)
- Grant/Contract Number:
- AC52-06NA25396
- OSTI ID:
- 1343721
- Alternate ID(s):
- OSTI ID: 1396826
- Report Number(s):
- LA-UR-17-20854; TRN: US1701554
- Journal Information:
- Journal of Nuclear Materials, Vol. 482, Issue C; ISSN 0022-3115
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Uranium nitride-silicide advanced nuclear fuel: higher efficiency and greater safety
|
journal | October 2018 |
A first-principles study on the influences of metal species Al, Zr, Mo and Tc on the mechanical properties of U 3 Si 2
|
journal | January 2020 |
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