The emergency core cooling system (ECCS) in a pressurized water reactor (PWR) is designed to provide the required coolant flow to removes the decay heat from the reactor core during a postulated loss of coolant accident (LOCA) scenario, bringing the system to the cold shutdown condition.


A set of screens are typically installed in the reactor containment to protect the ECCS components from possible damage induced by the LOCA-generated debris, created during the accident and transported through the containment floor into the sump by the water flow. 

The Generic Safety Issue (GSI) 191 addresses the concerns associated with the generation of the debris during a LOCA in light water reactors (LWR), its transport in the containment from the generation site to the sumps trainers, and the potential effects that such debris cause to the safety injection performances (in particular to the injection pumps) and to the core cooling capabilities that may be altered by the amount of debris that may bypass the sump strainers.

The thermal-hydraulic team has actively contributed to the GSI-191 resolution project, developing computational and experimental capabilities and supporting the nuclear power industry with thermal-hydraulic analyses of different aspects of the issue.

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Photo for Experimental Activity

The thermal-hydraulics group has been performing experimental studies as a part of resolution of Generic Safety Issue 191 (GSI-191), Assessment of Debris Accumulation on PWR Sump Performance.  Read More

Photo for Computations

The team has developed standardized models of the primary system and reactor containment with system codes largely used in analysis of LWR transients.  Read More