Fig. 1. Structure diagram of VVER core catcher

Fig. 2. Schematic of axisymmetric computational domain model for heat exchanger of VVER core catcher

Fig. 3. Temperature distribution on the axis of calculation domain under different mesh number and tolerance factor

Fig. 4. Distribution of velocity field in corium pool (a) 24 h, (b) 96 h

Fig. 5. Distribution of temperature field in corium pool (a) 24 h, (b) 96 h

Fig. 6. Heat flux density of corium pool under different calculation durations

Fig. 7. Average velocity and average temperature of corium pool

Fig. 8. Soild volume fraction of corium in corium pool (a) 4 h, (b) 12 h, (c) 24 h, (d) 96 h