First-principles study of fission product (Xe, Cs, Sr) incorporation and segregation in alkaline earth metal oxides, HfO2, and MgO-HfO2 interface

Journal Article · Tue Jan 01 04:00:00 EST 2008 · Journal of Physics. Condensed Matter

DOI:https://doi.org/10.1088/0953-8984/21/4/045403· OSTI ID:960734

Liu, Xiang-yang ^[1]; Uberuaga, Blas P ^[1]; Sickafus, Kurt E ^[1]

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1. Los Alamos National Laboratory

In order to close the nuclear fuel cycle, advanced concepts for separating out fission products are necessary. One approach is to use a dispersion fuel form in which a fissile core is surrounded by an inert matrix that captures and immobilizes the fission products from the core. If this inert matrix can be easily separated from the fuel, via e.g. solution chemistry, the fission products can be separated from the fissile material. We examine a surrogate dispersion fuel composition, in which hafnia (HfO{sub 2}) is a surrogate for the fissile core and alkaline earth metal oxides are used as the inert matrix. The questions of fission product incorporation in these oxides and possible segregation behavior at interfaces are considered. Density functional theory based calculations for fission product elements (Xe, Sr, and Cs) in these oxides are carried out. We find smaller incorporation energy in hafnia than in MgO for Cs and Sr, and Xe if variation of charge state is allowed. We also find that this trend is reversed or reduced for alkaline earth metal oxides with large cation sizes. Model interfacial calculations show a strong tendency of segregation from bulk MgO to MgO-HfO{sub 2} interfaces.

• Research Organization: Los Alamos National Laboratory (LANL)
• Sponsoring Organization: DOE
• DOE Contract Number: AC52-06NA25396
• OSTI ID: 960734
• Report Number(s): LA-UR-08-06281; LA-UR-08-6281
• Journal Information: Journal of Physics. Condensed Matter, Journal Name: Journal of Physics. Condensed Matter Journal Issue: 4 Vol. 21; ISSN 0953-8984
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALKALINE EARTH METALS
BEHAVIOR
CATIONS
CHARGE STATES
CHEMISTRY
DENSITY
DENSITY FUNCTIONAL METHOD
DISPERSIONS
ELEMENTS
ENERGY
FISSILE MATERIALS
FISSION PRODUCTS
FUEL CYCLE
INTERFACES
NUCLEAR FUELS
OXIDES
SEGREGATION
SOLUTIONS
USES
VARIATIONS