TY - JOUR
T1 - Solubility and clustering of ruthenium fission products in uranium dioxide as determined by density functional theory
AU - Hong, Minki
AU - Phillpot, Simon R.
AU - Lee, Chan Woo
AU - Nerikar, Pankaj
AU - Uberuaga, Blas P.
AU - Stanek, Christopher R.
AU - Sinnott, Susan B.
PY - 2012/4/16
Y1 - 2012/4/16
N2 - One of the consequences of the fission process in uranium dioxide (UO 2) fuels in nuclear reactors is the eventual formation of metallic fission product inclusions and precipitates. Here, the stability and clustering behavior of one particular metallic fission product-ruthenium (Ru)-is investigated using density functional theory in combination with classical thermodynamics. In particular, the solution energies of individual Ru atoms, dimers, and trimers at interstitial, uranium and oxygen vacancy, divacancy, and Schottky defect sites are calculated. Ru is predicted to be insoluble in most cases, but is soluble in uranium vacancy sites under hyperstoichiometric conditions (UO 2+x). Density of states analysis reveals the metallic nature of even the smallest Ru aggregates. Finally, by analyzing the binding characteristics of Ru in UO 2, metallic dimers in Schottky defects are identified as the probable nucleus of metallic precipitates in UO 2.
AB - One of the consequences of the fission process in uranium dioxide (UO 2) fuels in nuclear reactors is the eventual formation of metallic fission product inclusions and precipitates. Here, the stability and clustering behavior of one particular metallic fission product-ruthenium (Ru)-is investigated using density functional theory in combination with classical thermodynamics. In particular, the solution energies of individual Ru atoms, dimers, and trimers at interstitial, uranium and oxygen vacancy, divacancy, and Schottky defect sites are calculated. Ru is predicted to be insoluble in most cases, but is soluble in uranium vacancy sites under hyperstoichiometric conditions (UO 2+x). Density of states analysis reveals the metallic nature of even the smallest Ru aggregates. Finally, by analyzing the binding characteristics of Ru in UO 2, metallic dimers in Schottky defects are identified as the probable nucleus of metallic precipitates in UO 2.
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U2 - 10.1103/PhysRevB.85.144110
DO - 10.1103/PhysRevB.85.144110
M3 - Article
AN - SCOPUS:84860303985
SN - 1098-0121
VL - 85
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 14
M1 - 144110
ER -