Mechanism for transient migration of xenon in UO{sub 2}
- Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
In this letter, we report recent work on atomistic modeling of diffusion migration events of the fission gas product xenon in UO{sub 2} nuclear fuel. Under nonequilibrium conditions, Xe atoms can occupy the octahedral interstitial site, in contrast to the thermodynamically most stable uranium substitutional site. A transient migration mechanism involving Xe and two oxygen atoms is identified using basin constrained molecular dynamics employing a Buckingham type interatomic potential. This mechanism is then validated using density functional theory calculations using the nudged elastic band method. An overall reduction in the migration barrier of 1.6-2.7 eV is obtained compared to vacancy-mediated diffusion on the uranium sublattice.
- OSTI ID:
- 21518384
- Journal Information:
- Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 15 Vol. 98; ISSN APPLAB; ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ACTINIDE COMPOUNDS
ACTINIDES
CALCULATION METHODS
CHALCOGENIDES
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
DENSITY FUNCTIONAL METHOD
DIFFUSION
ELEMENTS
ENERGY RANGE
ENERGY SOURCES
EV RANGE
EV RANGE 01-10
FISSION PRODUCTS
FLUIDS
FUELS
GASES
INTERSTITIALS
ISOTOPES
MATERIALS
METALS
MIGRATION
MOLECULAR DYNAMICS METHOD
NONMETALS
NUCLEAR FUELS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
POINT DEFECTS
RADIOACTIVE MATERIALS
RARE GASES
REACTOR MATERIALS
SIMULATION
STABILITY
THERMODYNAMIC PROPERTIES
TRANSIENTS
URANIUM
URANIUM COMPOUNDS
URANIUM DIOXIDE
URANIUM OXIDES
VACANCIES
VARIATIONAL METHODS
XENON