Thermodynamics of fission products in dispersion fuel designs - first principles modeling of defect behavior in bulk and at interfaces

Conference · Thu Jan 01 04:00:00 EST 2009

DOI:https://doi.org/10.1016/j.nimb.2010.05.030· OSTI ID:992210

Liu, Xiang-yand ^[1]; Uberuaga, Blas P ^[1]; Nerikar, Pankaj ^[1]; Sickafus, Kurt E ^[1]; Stanek, Chris R ^[1]

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1. Los Alamos National Laboratory

Density functional theory (DFT) calculations of fission product (Xe, Sr, and Cs) incorporation and segregation in alkaline earth metal oxides, HfO{sub 2} and UO{sub 2} oxides, and the MgO/(U, Hf, Ce)O{sub 2} interfaces have been carried out. In the case of UO{sub 2}, the calculations were performed using spin polarization and with a Hubbard U term characterizing the on-sit Coulomb repulsion between the localized 5f electrons. The fission product solution energies in bulk UO{sub 2{+-}x} have been calculated as a function of non-stoichiometry x, and were compared to that in MgO. These calculations demonstrate that the fission product incorporation energies in MgO are higher than in HfO{sub 2}. However, this trend is reversed or reduced for alkaline earth oxides with larger cation sizes. The solution energies of fission products in MgO are substantially higher than in UO{sub 2{+-}x}, except for the case of Sr in the hypostoichiometric case. Due to size effects, the thermodynamic driving force of segregation for Xe and Cs from bulk MgO to the MgO/fluorite interface is strong. However, this driving force is relatively weak for Sr.

• Research Organization: Los Alamos National Laboratory (LANL)
• Sponsoring Organization: DOE
• DOE Contract Number: AC52-06NA25396
• OSTI ID: 992210
• Report Number(s): LA-UR-09-05335; LA-UR-09-5335
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALKALINE EARTH METALS
CATIONS
COULOMB FIELD
DEFECTS
ELECTRONS
FISSION PRODUCTS
FUNCTIONALS
OXIDES
POLARIZATION
RADIATION EFFECTS
SEGREGATION
SIMULATION
SPIN
THERMODYNAMICS