The evaluation of the RCS Injection Strategy by an Active Safety Injection Pump during SBLOCA

In the Advanced Power Reactor Plus (APR+) reactor design, which is a GEN III+ reactor based on the proven APR1400, has been developed and obtained design approval in August 2014. The APR+ already adopted a passive auxiliary feedwater system (PAFS) for enhancing the safety and the core could be continuously cool down during transient without electricity. The iPOWER is an advanced pressurized water reactor (PWR) that incorporates the passive safety features such as the passive emergency cooling system (PECCS) and the passive containment cooling system (PCCS). The accident could be mitigated without operator's action or any electric sources in iPOWER. In this study, the results show that safety injection by ASIP is effective for 2inch break SBLOCA to avoid ADS-4 actuation. The core is cooled down until the RCS pressure reach to IRWST injection pressure according to the PECCS actuation regardless of the PAFS operation during SBLOCA. Without ADV stage 4 open, operation methods by using ASIP are suggested. If 2 ASIP could be operated in 40 min during SBLOCA, SBLOCA could be mitigated. These are limited preliminary test results however they could be used to support the development of the iPOWER operation strategy and applied to the design of non-safety active pump in typical plant operation