Automatic Reactor Trip Due to Turbine Trip Initiated by Loss of Stator Cooling Water
Ft. Calhoun station automatically tripped due to a loss of turbine load. The turbine tripped due to loss of stator cooling water. Maintenance was in progress on the stator cooling system when inventory was lost and low pump discharge pressure caused an automatic turbine trip and reactor trip. All systems operated as expected. Ft. Calhoun station is shutdown and stable in mode 3 at this time.
All control rods fully inserted into the core and decay heat is being removed using the normal condenser steam dump system.
The licensee has notified the NRC Resident Inspector.
Nine Mile Point, Unit 1, License Amendment Request Pursuant to 10 CFR 50.90: Adoption of NFPA 805, Performance-Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants (2001 Edition) - Response to NRC Rai. Part
Manual Reactor Trip Due to Loss of Generator Stator Cooling Water
At 1951 CDT on March 20, 2013, Byron Unit 2 Reactor was manually tripped due to the loss of all Generator Stator Cooling Water. 2BEP-0, 'Reactor Trip or Safety Injection Unit 2' was entered and a transition was made to 2BEPES 0.1, 'Reactor Trip Response Unit 2.' The auxiliary feedwater pumps automatically actuated upon the expected low steam generator level. Upon the trip, it was noted that a Digital Rod Position Indication System Urgent Failure occurred with a General Warning on Control Rod position M12. Indication for the Train 'B' Reactor Trip breaker was lost. All Control Rods inserted upon Reactor trip and the Train 'B' Reactor trip breaker was locally verified open.
The plant is in its normal shutdown electrical lineup. No safeties or reliefs lifted during the event. There was no impact on unit-1.