We still don’t know what tripped the control rods on Constellation Energy’s Ginna nuclear reactor on the shores of Lake Ontario near Rochester, NY on Wednesday; the nuke remains down.
Staff reports for Democrat and Chronicle.com yesterday, No estimate on when Ginna nuclear plant will be back online,
The Ginna nuclear power plant in Wayne County remained shut down Friday afternoon, 48 hours after it went off line unexpectedly due to a generator problem.
No estimate was available of when the plant would go back into service, said Maria Hudson, spokeswoman for Constellation Energy Nuclear Group, the plant’s Baltimore-based owner.
“We’re continuing with our repairs,” she said.
The 581-megawatt plant on the Lake Ontario shoreline, the largest in the Rochester area, ceased producing electricity Wednesday afternoon when its huge generator shut down. That triggered the automatic insertion of control rods into the plant’s nuclear reactor.
Officials said a protective electrical relay in the generator was not set correctly, an error that caused the generator to go off line as it was undergoing a test on Wednesday.
Power Reactor Event Number: 49214 Facility: GINNA
Region: 1 State: NY
Unit:  [ ] [ ]
RX Type:  W-2-LP
NRC Notified By: TOM FOUTS
HQ OPS Officer: PETE SNYDER
Notification Date: 07/24/2013
Notification Time: 17:46 [ET]
Event Date: 07/24/2013
Event Time: 14:19 [EDT]
Last Update Date: 07/24/2013
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(2)(iv)(B) – RPS ACTUATION – CRITICAL
50.72(b)(3)(iv)(A) – VALID SPECIF SYS ACTUATION
ANTHONY DIMITRIADIS (R1DO)
Unit SCRAM Code RX CRIT Initial PWR Initial RX Mode Current PWR Current RX Mode 1 A/R Y 100 Power Operation 0 Hot Standby
AUTOMATIC REACTOR TRIP FROM FULL POWER
“At 1419 EDT on 7/24/2013, the reactor tripped due to a reactor protection system (RPS) actuation signal from a turbine trip, which was caused by a generator trip. All control rods inserted on the trip and reactor coolant system (RCS) pressure is currently 2235 psig and stable with RCS temperature stable at 547 degrees F. Decay heat is being removed by steam dumps [to the main condenser] and auxiliary feedwater which auto started as expected.
“The cause of the generator trip is under investigation. The plant will remain in Mode 3 until the cause of the trip is determined.
“The plant notified the NRC Resident Inspector.”