The thermal conductivity of mixed fuel UxPu1-xO2: molecular dynamics simulations
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Mixed oxides (MOX), in the context of nuclear fuels, are a mixture of the oxides of heavy actinide elements such as uranium, plutonium and thorium. The interest in the UO2-PuO2 system arises from the fact that these oxides are used both in fast breeder reactors (FBRs) as well as in pressurized water reactors (PWRs). The thermal conductivity of UO2 fuel is an important material property that affects fuel performance since it is the key parameter determining the temperature distribution in the fuel, thus governing, e.g., dimensional changes due to thermal expansion, fission gas release rates, etc. For this reason it is important to understand the thermal conductivity of MOX fuel and how it differs from UO2. Here, molecular dynamics (MD) simulations are carried out to determine quantitatively, the effect of mixing on the thermal conductivity of UxPu1-xO2, as a function of PuO2 concentrations, for a range of temperatures, 300 – 1500 K. The results will be used to develop enhanced continuum thermal conductivity models for MARMOT and BISON by INL. These models express the thermal conductivity as a function of microstructure state-variables, thus enabling thermal conductivity models with closer connection to the physical state of the fuel.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC52-06NA25396
- OSTI ID:
- 1223768
- Report Number(s):
- LA-UR-15-28079; TRN: US1500439
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
MIXED OXIDE FUELS
URANIUM DIOXIDE
PLUTONIUM OXIDES
THERMAL CONDUCTIVITY
PWR TYPE REACTORS
MOLECULAR DYNAMICS METHOD
FBR TYPE REACTORS
COMPUTERIZED SIMULATIONS
MIXTURES
TEMPERATURE DISTRIBUTION
MICROSTRUCTURE
PERFORMANCE
TEMPERATURE RANGE 0400-1000 K
TEMPERATURE RANGE 1000-4000 K