Event Notification Report for August 10, 2003
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
08/09/2003 - 08/10/2003
EVENT NUMBERS
40054
Power Reactor
Event Number: 40054
Facility: BROWNS FERRY
Region: 2 State: AL
Unit: [] [2] []
RX Type: [1] GE-4,[2] GE-4,[3] GE-4
NRC Notified By: DAVID TIDWELL
HQ OPS Officer: GERRY WAIG
Region: 2 State: AL
Unit: [] [2] []
RX Type: [1] GE-4,[2] GE-4,[3] GE-4
NRC Notified By: DAVID TIDWELL
HQ OPS Officer: GERRY WAIG
Notification Date: 08/11/2003
Notification Time: 05:04 [ET]
Event Date: 08/10/2003
Event Time: 23:31 [CDT]
Last Update Date: 08/11/2003
Notification Time: 05:04 [ET]
Event Date: 08/10/2003
Event Time: 23:31 [CDT]
Last Update Date: 08/11/2003
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION
10 CFR Section:
50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION
Person (Organization):
STEPHEN CAHILL (R2)
STEPHEN CAHILL (R2)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 2 | N | Y | 100 | Power Operation | 100 | Power Operation |
AUTOMATIC START OF EMERGENCY DIESEL GENERATORS DURING BUS TRANSFER FOR MAINTENANCE
"Unit 1/2 A and B Diesel Generators auto started on Undervoltage while attempting to transfer Shutdown Bus 1 to Alternate supply, the alternate supply breaker failed to close, resulting in a momentary undervoltage condition on the Shutdown Bus and 4160V Shutdown Boards A & B. Shutdown Bus 1 was reenergized by reclosure of the Normal feeder breaker. The Diesel Generators did not tie onto the board due to the voltage returned to normal prior to the DG obtaining rated speed and voltage when the operator reclosed the normal supply breaker. SBGT [Standby Gas Treatment] & CREV [Control Room Emergency Ventilation] auto started and Refuel Zone ventilation isolated due to a failure of Unit 1 Refuel Zone Rad monitor; Unit 2 Reactor Zone ventilation isolated due to a momentary loss of I & C 'A'.
"This event is reportable as an 8 hour report per 10CFR50.72(b)(3)(iv)(A) as 'Any event or condition that results in valid actuation of any of the systems listed in (b)(3)(iv)(B), specifically Emergency AC Electrical power systems, including: Emergency Diesel Generators (EDGs).'
"This is also reportable per 10CFR50.73(a)(2)(iv)(A) for the above conditions as a 60 day written report."
The licensee reported that affected ventilation systems and electrical systems have been returned to a normal configuration with the exception of the shutdown bus "43 switch" [in normal supply]. All Emergency Diesel Generators are operable and in standby. Offsite electrical power supply to the station is in a normal configuration.
The licensee has notified the NRC Resident Inspector.
"Unit 1/2 A and B Diesel Generators auto started on Undervoltage while attempting to transfer Shutdown Bus 1 to Alternate supply, the alternate supply breaker failed to close, resulting in a momentary undervoltage condition on the Shutdown Bus and 4160V Shutdown Boards A & B. Shutdown Bus 1 was reenergized by reclosure of the Normal feeder breaker. The Diesel Generators did not tie onto the board due to the voltage returned to normal prior to the DG obtaining rated speed and voltage when the operator reclosed the normal supply breaker. SBGT [Standby Gas Treatment] & CREV [Control Room Emergency Ventilation] auto started and Refuel Zone ventilation isolated due to a failure of Unit 1 Refuel Zone Rad monitor; Unit 2 Reactor Zone ventilation isolated due to a momentary loss of I & C 'A'.
"This event is reportable as an 8 hour report per 10CFR50.72(b)(3)(iv)(A) as 'Any event or condition that results in valid actuation of any of the systems listed in (b)(3)(iv)(B), specifically Emergency AC Electrical power systems, including: Emergency Diesel Generators (EDGs).'
"This is also reportable per 10CFR50.73(a)(2)(iv)(A) for the above conditions as a 60 day written report."
The licensee reported that affected ventilation systems and electrical systems have been returned to a normal configuration with the exception of the shutdown bus "43 switch" [in normal supply]. All Emergency Diesel Generators are operable and in standby. Offsite electrical power supply to the station is in a normal configuration.
The licensee has notified the NRC Resident Inspector.