Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

Melting behaviour of americium-doped uranium dioxide

Prieur, D., Lebreton, F., Caisso, M., Martin, P. M., Scheinost, A. C., Delahaye, T., Manara, D.
J. Chem. Thermodyn. 2016, 97, 244-252
ABSTRACT
(Uranium + americium) mixed oxides are considered as potential targets for americium transmutation in fast neutron reactors. Their thermophysical properties and notably their melting behaviour have not been assessed properly although required in order to evaluate the safety of these compounds under irradiation. In this study, we measured via laser heating, the melting points under inert atmosphere (Ar) of U1 xAmxO2+-d samples with x = 0.10, 0.15, 0.20. The obtained melting/solidification temperatures, measured here, indicate that under the current experimental conditions in the investigated AmO2 content range, the solidus line of the (UO2 + AmO2) system follows with very good agreement the ideal solution behaviour. Accordingly, the observed liquidus formation temperature decreases from (3130 +- 20) K for pure UO2 to (3051 +- 28) K for U0.8Am0.2O2+-d. The melted and quenched materials have been characterised by combining X-ray diffraction and X-ray absorption spectroscopy.
Compounds
# Formula Name
1 O2U uranium dioxide
2 AmO2 americium-241 dioxide
Datasets
The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type Compound-# Property Variable Constraint Phase Method #Points
  • POMD
  • 1
  • 2
  • Solid-liquid equilibrium temperature, K ; Crystal
  • Mole fraction - 2; Crystal
  • Pressure, kPa; Crystal
  • Crystal
  • Liquid
  • laser heating and fast multi-channel pyrometry
  • 2
  • POMD
  • 1
  • 2
  • Solid-liquid equilibrium temperature, K ; Crystal
  • Mole fraction - 2; Crystal
  • Pressure, kPa; Crystal
  • Crystal
  • Liquid
  • laser heating and fast multi-channel pyrometry
  • 1