Event Notification Report for May 20, 2023
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
05/19/2023 - 05/20/2023
EVENT NUMBERS
56531
56531
Power Reactor
Event Number: 56531
Facility: Browns Ferry
Region: 2 State: AL
Unit: [1] [] []
RX Type: [1] GE-4,[2] GE-4,[3] GE-4
NRC Notified By: Chris Wilson
HQ OPS Officer: Ian Howard
Region: 2 State: AL
Unit: [1] [] []
RX Type: [1] GE-4,[2] GE-4,[3] GE-4
NRC Notified By: Chris Wilson
HQ OPS Officer: Ian Howard
Notification Date: 05/20/2023
Notification Time: 07:45 [ET]
Event Date: 05/20/2023
Event Time: 03:15 [CDT]
Last Update Date: 05/20/2023
Notification Time: 07:45 [ET]
Event Date: 05/20/2023
Event Time: 03:15 [CDT]
Last Update Date: 05/20/2023
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
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS Actuation - Critical 50.72(b)(3)(iv)(A) - Valid Specif Sys Actuation
Person (Organization):
Miller, Mark (R2DO)
Miller, Mark (R2DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | A/R | Y | 80 | Power Operation | 0 | Hot Shutdown |
AUTOMATIC REACTOR SCRAM
The following information was provided by the licensee via phone and email:
"On 5/20/2023 at 0315 CDT, Browns Ferry Unit 1 was at 80 percent reactor power performing, 'Turbine control valve fast closure turbine trip and RPT [recirculation pump trip] initiate logic testing'. During performance of this test, Unit 1 received a full reactor scram. An investigation is in progress to determine the cause of the scram. All systems responded as expected, and Unit 1 is stable at zero percent power in mode 3.
"All control rods fully inserted into the core. Main steam isolation valves remained open with main turbine bypass valves controlling pressure. Reactor feedwater pumps remained in service to control reactor water level. Primary containment isolation signals groups 2, 3, 6, and 8 were received with expected system actuations.
"This event is reportable 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'.
"The event is also reportable within 8 hours per 10 CFR 50.72(b)(3)(iv)(A), 'Specified System Actuation'.
"The NRC Resident has been notified."
The following information was provided by the licensee via phone and email:
"On 5/20/2023 at 0315 CDT, Browns Ferry Unit 1 was at 80 percent reactor power performing, 'Turbine control valve fast closure turbine trip and RPT [recirculation pump trip] initiate logic testing'. During performance of this test, Unit 1 received a full reactor scram. An investigation is in progress to determine the cause of the scram. All systems responded as expected, and Unit 1 is stable at zero percent power in mode 3.
"All control rods fully inserted into the core. Main steam isolation valves remained open with main turbine bypass valves controlling pressure. Reactor feedwater pumps remained in service to control reactor water level. Primary containment isolation signals groups 2, 3, 6, and 8 were received with expected system actuations.
"This event is reportable 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'.
"The event is also reportable within 8 hours per 10 CFR 50.72(b)(3)(iv)(A), 'Specified System Actuation'.
"The NRC Resident has been notified."