Evaluation of accident mitigation procedures with isolation condensers for LWR by reactor simulation analyses - 15370

We carried out the analysis for BWR, PWR and ABWR equipped with isolation condensers (IC) in order to find out an operating procedure to keep plant safe in a severe accident in which no active pump was operating. We used the RETRAN/MOD4 code for these analyses. The study shows that for BWR and ABWR cases, the core flooding and cooling down succeeded when IC, whose heat removal was about 2% each of 2533 MWt-BWR and 3847 MWt-ABWR thermal output, were activated after station blackout (SBO). In the case of PWR, the core cooling down through the steam generators succeeded when virtually-equipped IC whose heat removal was about 2% each of 2710 MWt-PWR thermal output, were activated. As a conclusion, we can state that the utilization of isolation condensers for BWR, PWR and ABWR in severe accident conditions with SBO decreases the risk of core meltdown