Impact of External Injection from FLEX Equipment during LOCA in APR1400

During accident scenarios at nuclear power plants, which include the loss of coolant inventory, it is essential to restore the core cooling capability. Normally, this is achieved by Emergency Core Cooling System (ECCS). However, if this system is depleted or not available, one of the means of restoring core cooling is by providing a supply of emergency cooling water from external source directly into Reactor Pressure Vessel (RPV) using The Diverse and Flexible Coping Strategies (FLEX) or so called FLEX equipment. The aim of this article is to find out the impact of external injection on state of core degradation during Loss-Of-Coolant Accident (LOCA) scenario. Another aim of this study is to determine the FLEX deployment time, after which the external injection is no longer able to prevent RPV failure.