The Dynamics in the Development of the Corium-Melt Pool at the Cooled Bottom of a VVER Vessel and Its Influence on the Temperature State of the Vessel

A computational analysis of the influence of the development of the corium-melt pool at the bottom of the vessel of a VVER reactor on the temperature state of the vessel during a severe accident with melting of the core was conducted. It was shown that the specifics of the design of the VVER-640 reactor make the liquid steel surface layer quite deep. As a result, the heat flowrate to the vessel wall does not exceed allowable limits.