Thermodynamic assessment of the Pu-U, Pu-Zr, and Pu-U-Zr systems

Based on thermodynamic and phase diagram data, the Gibbs energies of mixing of the solution phases in the Pu-U and Pu-Zr systems were calculated using an optimization procedure. The use of thermodynamic data in the optimization made it possible to accurately calculate thermodynamic properties as well as the phase diagrams, which were in good agreement with the respective experimental values. The Pu-U-Zr ternary isotherms were calculated by using the optimized parameters of the three binary subsystems. The results agreed reasonably well with the experimental ones.