The corium masses in the lower head

The corium masses in the lower head without HA injection is furnished in Table 4and their evolution in Fig. 17. It is evident that break size has not played a significant contribution on the corium mass in cases without HA. Total corium mass accumulated in the lower head was 87.12 tons for 850 mm break. In this case formation of corium mass is dictated predominately by higher decay heat (Fig. 18) as core heat up takes place at early stage of the transient (50 s). In case of 150 mm break, core heat up starts at around 611 s and the corium mass is dictated largely by decay power as compared to oxidation power (Fig. 19). The core heatup for 50 mm break is much delayed (3956 s) and the corium mass is generated from equal contribution of oxidation power and low decay power (Fig. 20).