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Title: A combined experimental and computational thermodynamic investigation of the U-Th-O system

Here, the thermodynamics of the U–Th–O system have been assessed using the Calphad method. The compound energy formalism (CEF) and a partially ionic two-sublattice liquid model (TSLM) were used for the fluorite U 1–yTh yO 2±x, γ-(U,Th) 4O 9, and the U–Th–O melt. The O 2 activity of fluorite U 1–yTh yO 2±x with temperature and composition was determined by thermogravimetric analysis. Thermodynamic studies for the Th–O binary and U–Th–O ternary available in the open literature were critically reviewed. A self-consistent data set was selected and compiled with the equilibrium oxygen pressures determined by thermogravimetry in order to optimize the adjustable parameters of models selected to represent the phases in the Th–O and U–Th–O systems.
 [1] ;  [2] ;  [3]
  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  3. Univ. of South Carolina, Columbia, SC (United States)
Publication Date:
OSTI Identifier:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Journal of the American Ceramic Society
Additional Journal Information:
Journal Volume: 99; Journal Issue: 6; Journal ID: ISSN 0002-7820
American Ceramic Society
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). High Temperature Materials Lab. (HTML)
Sponsoring Org:
USDOE Office of Nuclear Energy (NE)
Country of Publication:
United States