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Title: Lattice expansion by intrinsic defects in uranium by molecular dynamics simulation

Authors:
; ; ; ;
Publication Date:
Research Org.:
Energy Frontier Research Centers (EFRC) (United States). Center for Materials Science of Nuclear Fuel (CMSNF)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1369982
DOE Contract Number:
AC07-05ID14517
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Nuclear Materials; Journal Volume: 475; Related Information: CMSNF partners with Idaho National Laboratory (lead); Colorado School of Mines; University of Florida; Oak Ridge National Laboratory; Purdue University; University of Wisconsin at Madison
Country of Publication:
United States
Language:
English

Citation Formats

Li, Yangzhong, Chernatynskiy, Aleksandr, Kennedy, J. Rory, Sinnott, Susan B., and Phillpot, Simon R. Lattice expansion by intrinsic defects in uranium by molecular dynamics simulation. United States: N. p., 2016. Web. doi:10.1016/j.jnucmat.2016.03.018.
Li, Yangzhong, Chernatynskiy, Aleksandr, Kennedy, J. Rory, Sinnott, Susan B., & Phillpot, Simon R. Lattice expansion by intrinsic defects in uranium by molecular dynamics simulation. United States. doi:10.1016/j.jnucmat.2016.03.018.
Li, Yangzhong, Chernatynskiy, Aleksandr, Kennedy, J. Rory, Sinnott, Susan B., and Phillpot, Simon R. 2016. "Lattice expansion by intrinsic defects in uranium by molecular dynamics simulation". United States. doi:10.1016/j.jnucmat.2016.03.018.
@article{osti_1369982,
title = {Lattice expansion by intrinsic defects in uranium by molecular dynamics simulation},
author = {Li, Yangzhong and Chernatynskiy, Aleksandr and Kennedy, J. Rory and Sinnott, Susan B. and Phillpot, Simon R.},
abstractNote = {},
doi = {10.1016/j.jnucmat.2016.03.018},
journal = {Journal of Nuclear Materials},
number = ,
volume = 475,
place = {United States},
year = 2016,
month = 7
}
  • Uranium dioxide (UO 2) is the most commonly used fuel in light-water nuclear reactors and thermal conductivity controls the removal of heat produced by fission, thereby governing fuel temperature during normal and accident conditions. The use of fuel performance codes by the industry to predict operational behavior is widespread. A primary source of uncertainty in these codes is thermal conductivity, and optimized fuel utilization may be possible if existing empirical models are replaced with models that incorporate explicit thermal-conductivity-degradation mechanisms during fuel burn up. This approach is able to represent the degradation of thermal conductivity due to each individual defectmore » type, rather than the overall burn-up measure typically used, which is not an accurate representation of the chemical or microstructure state of the fuel that actually governs thermal conductivity and other properties. To generate a mechanistic thermal conductivity model, molecular dynamics (MD) simulations of UO 2 thermal conductivity including representative uranium and oxygen defects and fission products are carried out. These calculations employ a standard Buckingham-type interatomic potential and a potential that combines the many-body embedded-atom-method potential with Morse-Buckingham pair potentials. Potential parameters for UO 2+x and ZrO 2 are developed for the latter potential. Physical insights from the resonant phonon-spin-scattering mechanism due to spins on the magnetic uranium ions are introduced into the treatment of the MD results, with the corresponding relaxation time derived from existing experimental data. High defect scattering is predicted for Xe atoms compared to that of La and Zr ions. Uranium defects reduce the thermal conductivity more than oxygen defects. For each defect and fission product, scattering parameters are derived for application in both a Callaway model and the corresponding high-temperature model typically used in fuel-performance codes. The model is validated by comparison to low-temperature experimental measurements on single-crystal hyperstoichiometric UO 2+x samples and high-temperature literature data. Furthermore, this work will enable more accurate fuel-performance simulations and will extend to new fuel types and operating conditions, all of which improve the fuel economics of nuclear energy and maintain high fuel reliability and safety.« less
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