Thermodynamic modeling of the C–Pu system

The thermodynamic modelling of the binary C–Pu system was performed in the framework of the development of a thermodynamic database for nuclear materials, for increasing the knowledge of the physico-chemical behaviour of the fuel and surrounding materials implicated in GFR (gas cooled fast reactor) systems. The critical assessment was carried out using the CALPHAD approach, based on available experimental data on phase diagram and thermodynamic properties of the solid phases. The models for the different phases are chosen to be compatible with the systems previously included in the nuclear database, particularly that of plutonium mono-carbide. A set of self-consistent thermodynamic parameters was produced. A satisfactory agreement was obtained between the experimental data and the calculated results.