Experimental Demonstration of AHWR Safety During Prolonged Station Black Out

Fukushima accident has raised a strong concern and apprehension about the safety of a nuclear reactor failing to remove the decay heat following an extreme event. After Fukushima accident, the reactor designers worldwide analyzed the safety margin of the existing and new generation nuclear power plants for such an event. Advanced heavy water reactor (AHWR), designed in India, was also analyzed for even more severe conditions than occurred at Fukushima. AHWR equipped with several passive systems showed its robustness against this type of scenarios. However, several new passive systems were incorporated in AHWR design for maintaining the integrity of the reactor at least for 7 days as a grace period. A passive moderator cooling system (PMCS) and a passive endshield cooling system (PECS) were among the newly introduced safety system in AHWR. An experimental test facility simulating the prolonged station blackout (SBO) case in AHWR has been designed and built. Experiments have been performed in the test facility for simulated conditions of prolonged SBO. The current study shows the performance of AHWR during prolonged SBO case through simulation in the integral test facility. The results indicate that AHWR design is capable of removing decay heat for prolonged period without operator interference.