Novel Approaches to Modeling Heat Transfer in a Late Stage of a Severe Core-Meltdown Accident at a Water-Moderated Water-Cooled Power Reactor

The authors have described the key features of approaches to numerical modeling of the interaction of the core melt of a water-moderated water-cooled power reactor with the NPP structures, that are aimed at accelerating the cal- culation to preserve the approximation by using 0D + 2D finite-element schemes with an adaptive 2D grid for the wall and a 0D grid for the melt. The composition of the melt of interacting components and their properties, and also the properties of the heating material of the wall are determined in the process of calculation. The given examples of calculations of the thermal erosion of the wall by the melt with in-vessel retention of the melt and melt–concrete interaction illustrate the computational efficiency of the proposed approaches.