Modelling of reactor coolant pump seal LOCA following loss of emergency service water

A model for the potential reactor coolant pump seal LOCA in a Westinghouse pressurized-water reactor following loss of cooling water (loss of component cooling water system or emergency service water system) is developed based on state-of-the-art knowledge. The core melt frequency is evaluated by constructing an event tree which includes the potential operator actions in coping with this event. The various potential core melt sequences are evaluated, and the interpretation of the results identifies the relationships between mechanical failures, the operator actions and the potential impact of good emergency operating procedures. (orig.)