Unit 1 HPCI Inoperable Due to Steam Leak

Event Number: 46644 Facility: SUSQUEHANNA Event Date: 02/25/2011

"At 2027 EST, Unit 1 HPCI system was declared inoperable due to a steam leak on HV155F002, HPCI Steam Supply Inboard Isolation Valve. Engineering evaluation determined that the valve actuator will not close the valve fully under design basis conditions, due to the impingement of steam from the valve packing region on the valve stem. The penetration flow path has been isolated and the outboard isolation valve has been deactivated. "HPCI is a single train ECCS safety system, This event results in the loss of an entire safety function which requires an 8 hour ENS notification in accordance with 10CFR50.72(b)(3)(v) and the guidance provided under NUREG-1022, rev. 2. "There are no other ECCS systems presently out of service. Unit 1 is in a 14 day LCO 3.5.1. EDG's are operable, and offsite power is normal. There is no increase in plant risk, and the licensee will notify the Pennsylvania Emergency Management Agency (PEMA). The NRC Resident Inspector has been notified.