The existence of an immiscibility region in the $\mathrm{U}$–$\mathrm{Zr}$-$\mathrm{O}$ system

This paper is devoted to the study into the structure of core melts of reactors such as water-moderated water-cooled power reactors. The quenching method is used to experimentally investigate the structure of $\mathrm{U}$–$\mathrm{Zr}$-$\mathrm{O}$ melts with an atomic ratio of $\mathrm{U}/\mathrm{Zr}=1.2-1.6$ at a temperature of $2773$ K. It is found that, for the most probable compositions of $\mathrm{U}$–$\mathrm{Zr}$-$\mathrm{O}$ melts under conditions of heavy accident with the $\mathrm{Zr}$ oxidation level above $30\%$, no separation of the corium melt into immiscible liquids is observed.