Computational model for oxidation of the core melt with surface oxidic crust
In case of a severe accident with core melt at PWR NPPs the retention of corium in a cooled reactor vessel is the most effective method of core melt confinement. The retention possibility depends on the corium-to-vessel heat flow which increases during core melt oxidation by steam due to exothermic reaction heat. The most realistic core melt pool is a metal-oxide pool with the surface oxidic crust and the top position of a metal core melt. On the basis of experimental data the paper presents and verifies the model of oxidizer mass transfer through the crust to calculate the oxidation rate of core melt under specified conditions.