Demonstration of adequacy of passive in-bundle ECC injection of AHWR

Emergency Core Cooling System (ECCS) of a reactor is designed for postulated Loss-of-Coolant-Accident (LOCA). Such an accident may occur due to a leakage or breakage in the main heat transport system of the reactor which is beyond the capacity of make-up systems. In Advanced Heavy Water Reactor (AHWR), in-bundle injection of emergency coolant is proposed. Unlike conventional header/plenum injection systems (as in PWRs and PHWRs) or top spray system (as in BWRs), in-bundle injection aims to deliver the emergency coolant directly to the fuel cluster in case of a LOCA. Though very promising, this concept has not been widely used in water cooled reactors. This necessitates conducting experiments for establishing the efficacy of this method of injection. The paper presents the results of such experiments on in-bundle ECC in a fuel cluster simulating the AHWR fuel cluster.