Application calculations
Thermodynamics applied to Severe Accidents in Nuclear Reactors

For the problem of corium containment inside the vessel, presented above, it is important to be able to predict the transfer to the liquid state of chemical species between a non-fully oxidized corium of composition UO ₂ -ZrO ₂ -Zr and steel, and this in order to determine the composition and proportion of the different phases (metallic liquid and oxide) present at thermodynamic equilibrium, which can be considered a reasonable assumption given the temperatures reached by the corium. Based on these compositions and proportions, it is then possible to estimate the respective thicknesses of the phases (in the event of corium stratification) and, consequently, the heat fluxes applied to the vessel, particularly at the level of the least dense metallic layer, which is likely to concentrate a significant...