Seal Loss-of-Coolant Accident and Recovery Actions Following Loss of Component Cooling Water

A model for the potential reactor coolant pump seal loss-of-coolant accident in a Westinghouse Electric Corporation pressurized water reactor following a loss of component cooling water (CCW) is developed based on state-of-the-art knowledge. The potential operator recovery actions in coping with a loss-of-CCW event are investigated, and an event tree is constructed to describe the possible core melt sequences. The sequence frequencies are plant specific; however, evaluations (of the sequence frequencies) demonstrate that an emergency operating procedure that clearly identifies possible recovery actions can reduce the core melt probability by two orders of magnitude.