Enthalpy and heat capacity of the actinide oxides

Journal Article · Fri Jan 01 00:00:00 EST 1982 · Int. J. Thermophys.; (United States)

DOI:https://doi.org/10.1007/BF00503638· OSTI ID:5754835

Fink, J K

The available enthalpy data on UO/sub 2/, ThO/sub 2/, PuO/sub 2/, (Th, U)O/sub 2/, and (Pu, U)O/sub 2/ have been analyzed and equations have been derived to fit the data. Phase transitions were found in UO/sub 2/, ThO/sub 2/ (Th, U)O/sub 2/, and (Pu, U)O/sub 2/. The high temperature PuO/sub 2/ data were too scattered to determine whether a phase transition exists. Above the phase transition temperature, the enthalpy data were fit with a linear equation. Enthalpy data for PuO/sub 2/ and ThO/sub 2/ below the phase transition temperature were fit with two-term equations whose contributions are due to phonons and thermal expansion. For UO/sub 2/ below its phase transition, a term for an electronic contribution was added to this basic equation. Below the phase transitions for (Th, U)O/sub 2/, enthalpy data were fit by a mole average of the equations used to fit the ThO/sub 2/ and UO/sub 2/ data below their phase transitions; however, the mole average equation was not valid for 90 and 92% ThO/sub 2/ in the mixed oxide. Since it was found that mole averages of the PuO/sub 2/ and UO/sub 2/ data do not fit the (Pu, U)O/sub 2/ data, these data were fit with an equation of the same form as that used for UO/sub 2/. 51 references, 14 figures, 7 tables.

• Research Organization: Argonne National Lab., IL
• OSTI ID: 5754835
• Journal Information: Int. J. Thermophys.; (United States), Vol. 3:2
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
PLUTONIUM DIOXIDE
ENTHALPY
SPECIFIC HEAT
THORIUM OXIDES
URANIUM DIOXIDE
EXPERIMENTAL DATA
PHASE STUDIES
ACTINIDE COMPOUNDS
CHALCOGENIDES
DATA
INFORMATION
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
PLUTONIUM COMPOUNDS
PLUTONIUM OXIDES
THERMODYNAMIC PROPERTIES
THORIUM COMPOUNDS
TRANSURANIUM COMPOUNDS
URANIUM COMPOUNDS
URANIUM OXIDES
400702* - Radiochemistry & Nuclear Chemistry- Properties of Radioactive Materials
050700 - Nuclear Fuels- Fuels Production & Properties