Limerick Unit 2 was 'manually scrammed' from 0% power on 5/30/11 at
1150 hours0.0133 days <br />0.319 hours <br />0.0019 weeks <br />4.37575e-4 months <br /> in accordance with plant procedure OT-112 'Recirculation Pump Trip', when both the '2A' and '2B' Recirculation Pumps tripped. The cause of the pump trip is currently under investigation at this time.
At the time of the 'manual' SCRAM: The Reactor Mode Switch was in 'Startup' Mode 2. All control rods were inserted to 'full-in' position (00). Reactor Shutdown was in-progress in accordance with Plant procedure GP-3 'Normal Plant Shutdown'. No primary or secondary containment isolations occurred.
The plant is currently in HOT SHUTDOWN maintaining normal Reactor level with Control Rod Drive (CRD) hydraulic and Reactor Water Cleanup (RWCU) systems.
Licensee is investigating a potential issue with the relay logic associated with the scram bypass feature. Offsite power circuits and emergency diesel generators are operable and available. There was no increase in plant risk associated with this event.
The NRC Resident Inspector has been notified.
