Calculations of Heat Flowrates to the VVER-440 Reactor Vessel during Interaction of Corium Melt with the Reactor Vessel

摘要

Quasi-steady-state thermal conditions of the corium bath found on a reactor vessel bottom is considered. Using approximate heat transfer models proposed earlier, a conjugate problem is solved with taking into account radiation heat transfer in the space above the bath surface. The results of calculations of heat flow-rates from the corium bath to the VVER-440 reactor vessel are presented. It is shown that water delivery to the bath surface leads to an essential decrease in the heat flowrate towards the wall in the most dangerous area, where a layer of melted steel contacts the reactor vessel, and retains a possibility of keeping the melt inside the reactor vessel under external cooling.