Deterministic analysis of emergency AC power recovery during SB-LOCA along with LOOP accident in Bushehr nuclear power plant

The availability of current AC electrical power is essential for the safe operation and accident recovery of commercial nuclear power plants. Loss of offsite power (LOOP) considers as one of the significant post-Fukushima accidents. When the onsite diesel generators are not recovered in the power plant, the accident encounters with station blackout (SBO) situation. In this study, the emergency AC power recovery is investigated during SB-LOCA along with LOOP accident for 25 mm, 50 mm, and 100 mm breaks with RELAP5 thermal-hydronic. Likewise, in evaluating the emergency power recovery scenario, the power plant's recovery in the first and second hours has been investigated. The results showed that in the first hour of emergency power recovery, the reactor is not reached the core damage threshold in all three breaks. Meanwhile, in the second hour of emergency power recovery for 25 mm and 50 mm, the reactor core reaches to core damage threshold before the emergency diesel generators are activated. Therefore, the results show that in SB-LOCAs with a lack of emergency power recovery, there is a chance to recover emergency power and safety systems at least until the first hour.