Non-stoichiometry in U3Si2
File(s)
Accepted version
Author(s)
Middleburgh, SC
Grimes, RW
Lahoda, EJ
Stanek, CR
Andersson, DA
Type
Journal Article
Abstract
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. We also investigate the U5Si4 phase as a candidate for the equilibrium phase diagram.
Date Issued
2016-10-08
Date Acceptance
2016-10-06
Citation
Journal of Nuclear Materials, 2016, 482, pp.300-305
ISSN
0022-3115
Publisher
Elsevier
Start Page
300
End Page
305
Journal / Book Title
Journal of Nuclear Materials
Volume
482
Copyright Statement
© 2016 Elsevier Ltd. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/
Subjects
Science & Technology
Technology
Materials Science, Multidisciplinary
Nuclear Science & Technology
Materials Science
Accident tolerant fuel
Density functional theory
Stoichiometry
Silicide
STRUCTURAL STABILITY
MOLECULAR-DYNAMICS
URANIUM SILICIDES
FISSION-PRODUCTS
IRRADIATION
BEHAVIOR
PHASE
FABRICATION
CHEMISTRY
ELEMENTS
Publication Status
Published