AP1000 station blackout study with and without depressurization using RELAP5/SCDAPSIM

The maximum core surface temperature is 3096 K and 3236 K for the high pressure and low pressure case; leading to maximum hydrogen generation rate of 0.87 and 9.22 kg/s with total hydrogen generated is 747 and 425 kg respectively. Significant differences in the damage progression have been observed for the two cases. Results also reinforced the fact that surge line fails before vessel failure in case of high pressure scenario.