Transient Analysis of Loss of All AC Power While on Shutdown Cooling for WH 2-Loop Nuclear Power Plant

The analysis was performed to provide useful insights for operator guidelines to maintain critical safety functions during SBO for shutdown modes. For Shutdown State A, if the SG PORV is manually opened at 4,000 sec by operator and secondary external injection by operator was provided at 5hours, the core boiling is not expected and core is cooled well. For Shutdown State C, if RWST gravity feed by operator is provided at 4,000 sec, the core is not uncovered and core is cooled well. This study would be useful for improving a strategy to cope with loss of all AC power while on shutdown cooling. The purpose of this study is to provide strategies for maintaining core cooling and protecting the reactor core in the event of complete loss of all AC power while on Residual Heat Removal (RHR) cooling. In this study, in order to comprehend the Fukushima accident, the transient analysis was performed to provide insights into mitigating strategies for SBO while on a shutdown state using the RELAP5/MOD3.3 code