An Extended Thermosyphon Cooling System for APR-1400 Reactor Design

Advanced Power Reactor (APR-1400) is a Generation III + Pressurized Water Reactor (PWRs) and has gained popularity among energy mix community. APR-1400 features enhanced safety limits to prevent a “Fukushima-type” accident scenario for a duration up to 8 h. This work proposes a system that enhances APR 1400 passive cooling (Thermosyphon Cooling System, TCS) capabilities to guarantee at least double the coping time before core meltdown. TCS provides enough cooling to the reactor core in the case of loss of offsite power, known as Station Black-Out (SBO) accident. This work invites to use the In-containment Refueling Water Storage Tank (IRWST) to further extend the APR1400 capability to passively cool the reactor core after an SBO accident. This work is designed and tested by 3Keymaster simulator platform developed by Western Service Corporation. Simulation has modified the existing model of APR1400 in the simulator by adding pipes, valves and heat exchanger. Results show the system will cool the reactor core for almost 18 h after the SBO accident. The system works initially in parallel with steam generators then it continues cooling the reactor core for extra 18 h resulting in providing more time for restoring the on-site power sources and preventing core meltdown.