The thermodynamics of $\mathrm{U}$–$\mathrm{Zr}$–$\mathrm{Fe}$–$\mathrm{O}$ melts

The scope and reliability of experimental data on the thermodynamic properties of $\mathrm{U}$–$\mathrm{O}$, $\mathrm{Zr}$–$\mathrm{O}$, and $\mathrm{U}$–$\mathrm{Zr}$–$\mathrm{O}$ systems, as well as on the solubility of oxygen in molten uranium and zirconium, are not sufficient for constructing a thermodynamic model of interaction of molten corium with $\text{Fe}$-based alloys. It is suggested to treat an atomic substitutional solution exhibiting the properties of regular solution as a model of melt of multi-component corium consisting of metals and metalloids. The requisite parameters of interaction between metal atoms and oxygen are determined from analysis of equilibrium between oxide and metal melts in experiments of the STFM-$\text{Fe}$ series. The model formulated as a result enables one to make prediction estimates of the interaction between $\mathrm{U}$–$\mathrm{Zr}$–$\mathrm{O}$ corium melt and iron.