Event Notification Report for February 08, 2025
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
02/07/2025 - 02/08/2025
EVENT NUMBERS
57537
57537
Power Reactor
Event Number: 57537
Facility: Browns Ferry
Region: 2 State: AL
Unit: [1] [2] [3]
RX Type: [1] GE-4,[2] GE-4,[3] GE-4
NRC Notified By: Eric Steel
HQ OPS Officer: Ernest West
Region: 2 State: AL
Unit: [1] [2] [3]
RX Type: [1] GE-4,[2] GE-4,[3] GE-4
NRC Notified By: Eric Steel
HQ OPS Officer: Ernest West
Notification Date: 02/09/2025
Notification Time: 00:28 [ET]
Event Date: 02/08/2025
Event Time: 22:48 [CST]
Last Update Date: 02/13/2025
Notification Time: 00:28 [ET]
Event Date: 02/08/2025
Event Time: 22:48 [CST]
Last Update Date: 02/13/2025
Emergency Class: Unusual Event
10 CFR Section:
50.72(a) (1) (i) - Emergency Declared 50.72(b)(2)(iv)(B) - RPS Actuation - Critical 50.72(b)(3)(iv)(A) - Valid Specif Sys Actuation 50.72(b)(2)(xi) - Offsite Notification
10 CFR Section:
50.72(a) (1) (i) - Emergency Declared 50.72(b)(2)(iv)(B) - RPS Actuation - Critical 50.72(b)(3)(iv)(A) - Valid Specif Sys Actuation 50.72(b)(2)(xi) - Offsite Notification
Person (Organization):
Suggs, LaDonna (R2DO)
Franovich, Michael (NRR)
Miller, Mark (R2 RA)
Erlanger, Craig (NSIR)
Crouch, Howard (IR)
Suggs, LaDonna (R2DO)
Franovich, Michael (NRR)
Miller, Mark (R2 RA)
Erlanger, Craig (NSIR)
Crouch, Howard (IR)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | Y | 100 | Power Operation | 100 | Power Operation |
| 2 | N | Y | 89 | Power Operation | 89 | Power Operation |
| 3 | A/R | Y | 67 | Power Operation | 0 | Hot Shutdown |
EN Revision Imported Date: 2/14/2025
EN Revision Text: NOTIFICATION OF UNUSUAL EVENT DUE TO SMOKE IN UNIT 3 TURBINE BUILDING
The following information was provided by the licensee via phone and email:
"On 2/8/2025, at 2248 CST, Browns Ferry Unit 3 experienced a main generator fault causing Unit 3 to experience an automatic reactor scram. Smoke was observed in multiple areas that required greater than 15 minutes to verify that no fire occurred. Browns Ferry declared a Notification of Unusual Event (NOUE), Emergency Action Level HU4, [at 2310] and completed the applicable notifications. The fault causing the main generator trip is still under investigation.
"A loss of power to the 3EA and 3EB 4KV shutdown boards resulted in a valid actuation of the 3A and 3B emergency diesel generators (EDGs) which successfully re-energized the boards as designed. During the scram response, there was a valid actuation of the primary containment isolation system (PCIS) groups 2, 3, 6, and 8. Upon receipt of these signals, all components actuated as required. Local offsite fire assistance was requested based on the initial indications but was not required. Operators responded and stabilized the plant. Units 1 and 2 were not affected.
"This event requires a 4-hour non-emergency report per 10 CFR 50.72(b)(2)(iv)(B), any event or condition that results in actuation of the reactor protection system (RPS) when the reactor is critical except when the actuation results from and is part of a pre-planned sequence during testing or reactor operation.
"This event requires a 4-hour non-emergency report per 10 CFR 50.72(b)(2)(xi), any event or situation, related to the health and safety of the public or onsite personnel, or protection of the environment, for which a news release is planned or notification to other government agencies has been or will be made.
"This event requires an 8-hour non-emergency report per 10 CFR 50.72(b)(3)(iv)(A), any event or condition that results in valid actuation of any of the systems listed in paragraph (b)(3)(iv)(B): 1) reactor protection system (RPS) including: reactor scram or reactor trip, 2) general containment isolation signals affecting containment isolation valves in more than one system or multiple main steam isolation valves (MSIVs), 8) emergency AC electrical power systems, including: EDGs.
"All safety systems operated as expected. At no time was public health and safety at risk. The NRC Resident Inspector has been notified"
Notified DHS SWO, FEMA Operations Center, CISA Central, FEMA NWC, CWMD Watch Desk (email), DHS NRCC THD Desk (email), and DHS Nuclear SSA (email).
The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:
Browns Ferry Unit 3 intentions are to proceed to mode 4. Offsite power has been restored, and both the 3A and 3B EDGs have been secured. The NOUE was terminated on 2/9/2025, at 0110 CST.
* * * UPDATE ON 2/13/2025 AT 1549 EST FROM CHASE HENSLEY TO SAMUEL COLVARD * * *
"Browns Ferry Nuclear Plant (BFN) is updating EN 57537 to retract the Notification of Unusual Event (NOUE), emergency action level (EAL) HU4, at 0028 EST on February 9, 2025, based on the following additional information.
"In accordance with the emergency preparedness implementing procedures, BFN reported a condition that was determined to meet EAL HU4, initiating criteria number 1. These criteria, in part, applies if a fire is not extinguished within 15 minutes of a report from the field and the fire was within any table H2 plant area.
"The field report of heavy smoke was received at 2256 CST, and the NOUE was declared 14 minutes later at 2310 CST in anticipation of exceeding the 15-minute time requirement of HU4. Upon entry by the site fire brigade, it was determined that no fire existed and was reported to the shift manager at 2311 CST which was 15 minutes after the first report of smoke was received.
"The basis for retraction of the initial emergency notification is that this event did not meet the definition of a fire, and the lack thereof was confirmed within 15 minutes. The NOUE had been conservatively declared based on the amount of smoke observed at the time from an unknown source; however, a fire was not identified through any fire alarm or observation of flame or heat. Additionally, the report that no fire existed was received within 15 minutes of the smoke report but after the NOUE was declared.
"The remaining events that were reported in EN 57537 as a 4-hour non-emergency report in accordance with 10 CFR 50.72(b)(2)(iv)(B) as an actuation of the reactor protection system (RPS) when the reactor is critical, a 4-hour nonemergency report per 10 CFR 50.72(b)(2)(xi), any event or situation, related to the health and safety of the public or onsite personnel, or protection of the environment, for which a news release is planned or notification to other government agencies has been or will be made, an 8-hour non-emergency report per 10 CFR 50.72(b)(3)(iv)(A), any event or condition that results in valid actuation of any of the systems listed in paragraph (b)(3)(iv)(B): 1) reactor protection system (RPS) including: reactor scram or reactor trip, 2) general containment isolation signals affecting containment isolation valves in more than one system or multiple main steam isolation valves (MSIVs), 8) emergency AC electrical power systems, including: EDGs, are still applicable and require no additional update at this time."
Notified R2DO (Penmetsa)
EN Revision Text: NOTIFICATION OF UNUSUAL EVENT DUE TO SMOKE IN UNIT 3 TURBINE BUILDING
The following information was provided by the licensee via phone and email:
"On 2/8/2025, at 2248 CST, Browns Ferry Unit 3 experienced a main generator fault causing Unit 3 to experience an automatic reactor scram. Smoke was observed in multiple areas that required greater than 15 minutes to verify that no fire occurred. Browns Ferry declared a Notification of Unusual Event (NOUE), Emergency Action Level HU4, [at 2310] and completed the applicable notifications. The fault causing the main generator trip is still under investigation.
"A loss of power to the 3EA and 3EB 4KV shutdown boards resulted in a valid actuation of the 3A and 3B emergency diesel generators (EDGs) which successfully re-energized the boards as designed. During the scram response, there was a valid actuation of the primary containment isolation system (PCIS) groups 2, 3, 6, and 8. Upon receipt of these signals, all components actuated as required. Local offsite fire assistance was requested based on the initial indications but was not required. Operators responded and stabilized the plant. Units 1 and 2 were not affected.
"This event requires a 4-hour non-emergency report per 10 CFR 50.72(b)(2)(iv)(B), any event or condition that results in actuation of the reactor protection system (RPS) when the reactor is critical except when the actuation results from and is part of a pre-planned sequence during testing or reactor operation.
"This event requires a 4-hour non-emergency report per 10 CFR 50.72(b)(2)(xi), any event or situation, related to the health and safety of the public or onsite personnel, or protection of the environment, for which a news release is planned or notification to other government agencies has been or will be made.
"This event requires an 8-hour non-emergency report per 10 CFR 50.72(b)(3)(iv)(A), any event or condition that results in valid actuation of any of the systems listed in paragraph (b)(3)(iv)(B): 1) reactor protection system (RPS) including: reactor scram or reactor trip, 2) general containment isolation signals affecting containment isolation valves in more than one system or multiple main steam isolation valves (MSIVs), 8) emergency AC electrical power systems, including: EDGs.
"All safety systems operated as expected. At no time was public health and safety at risk. The NRC Resident Inspector has been notified"
Notified DHS SWO, FEMA Operations Center, CISA Central, FEMA NWC, CWMD Watch Desk (email), DHS NRCC THD Desk (email), and DHS Nuclear SSA (email).
The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:
Browns Ferry Unit 3 intentions are to proceed to mode 4. Offsite power has been restored, and both the 3A and 3B EDGs have been secured. The NOUE was terminated on 2/9/2025, at 0110 CST.
* * * UPDATE ON 2/13/2025 AT 1549 EST FROM CHASE HENSLEY TO SAMUEL COLVARD * * *
"Browns Ferry Nuclear Plant (BFN) is updating EN 57537 to retract the Notification of Unusual Event (NOUE), emergency action level (EAL) HU4, at 0028 EST on February 9, 2025, based on the following additional information.
"In accordance with the emergency preparedness implementing procedures, BFN reported a condition that was determined to meet EAL HU4, initiating criteria number 1. These criteria, in part, applies if a fire is not extinguished within 15 minutes of a report from the field and the fire was within any table H2 plant area.
"The field report of heavy smoke was received at 2256 CST, and the NOUE was declared 14 minutes later at 2310 CST in anticipation of exceeding the 15-minute time requirement of HU4. Upon entry by the site fire brigade, it was determined that no fire existed and was reported to the shift manager at 2311 CST which was 15 minutes after the first report of smoke was received.
"The basis for retraction of the initial emergency notification is that this event did not meet the definition of a fire, and the lack thereof was confirmed within 15 minutes. The NOUE had been conservatively declared based on the amount of smoke observed at the time from an unknown source; however, a fire was not identified through any fire alarm or observation of flame or heat. Additionally, the report that no fire existed was received within 15 minutes of the smoke report but after the NOUE was declared.
"The remaining events that were reported in EN 57537 as a 4-hour non-emergency report in accordance with 10 CFR 50.72(b)(2)(iv)(B) as an actuation of the reactor protection system (RPS) when the reactor is critical, a 4-hour nonemergency report per 10 CFR 50.72(b)(2)(xi), any event or situation, related to the health and safety of the public or onsite personnel, or protection of the environment, for which a news release is planned or notification to other government agencies has been or will be made, an 8-hour non-emergency report per 10 CFR 50.72(b)(3)(iv)(A), any event or condition that results in valid actuation of any of the systems listed in paragraph (b)(3)(iv)(B): 1) reactor protection system (RPS) including: reactor scram or reactor trip, 2) general containment isolation signals affecting containment isolation valves in more than one system or multiple main steam isolation valves (MSIVs), 8) emergency AC electrical power systems, including: EDGs, are still applicable and require no additional update at this time."
Notified R2DO (Penmetsa)