Event Notification Report for March 24, 2020
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
03/23/2020 - 03/24/2020
Power Reactor
Event Number: 54603
Facility: BRUNSWICK
Region: 2 State: NC
Unit: [1] [] []
RX Type: [1] GE-4,[2] GE-4
NRC Notified By: WILLIAM ROBERTS
HQ OPS Officer: BETHANY CECERE
Region: 2 State: NC
Unit: [1] [] []
RX Type: [1] GE-4,[2] GE-4
NRC Notified By: WILLIAM ROBERTS
HQ OPS Officer: BETHANY CECERE
Notification Date: 03/24/2020
Notification Time: 16:02 [ET]
Event Date: 03/24/2020
Event Time: 12:05 [EDT]
Last Update Date: 03/24/2020
Notification Time: 16:02 [ET]
Event Date: 03/24/2020
Event Time: 12:05 [EDT]
Last Update Date: 03/24/2020
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(2)(i) - PLANT S/D REQD BY TS 50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION
10 CFR Section:
50.72(b)(2)(i) - PLANT S/D REQD BY TS 50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION
Person (Organization):
MARK MILLER (R2DO)
MARK MILLER (R2DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | Y | 22 | Power Operation | 0 | Hot Shutdown |
TECHNICAL SPECIFICATION-REQUIRED SHUTDOWN DUE TO UNIDENTIFIED LEAKAGE
"At 1205 Eastern Daylight Time (EDT) on March 24, 2020, a Technical Specification-required shutdown was initiated on Unit 1 due to indication of a leak in the drywell. Technical Specification Action 3.4.4.A, Unidentified Reactor Coolant System (RCS) leakage increase not within limit, requires RCS leakage to be reduced to within limits within 8 hours.
"It was expected that the leakage would not have been reduced to within limits within the required Technical Specification completion time; therefore, this event is being reported in accordance with 10 CFR 50.72(b)(2)(i).
"Reactor water level reached low level 1 (LL1) following the reactor shutdown. The LL1 signal causes Group 2 (i.e., floor and equipment drain isolation valves), Group 6 (i.e., monitoring and sampling isolation valves), and Group 8 (i.e., shutdown cooling isolation valves) isolations. The LL1 isolations occurred as designed; the Group 8 valves were closed at the time of the event. Due to the valid Primary Containment Isolation System (PCIS) actuation, this event is also being reported in accordance with 10 CFR 50.72(b)(3)(iv)(A).
"Unit 2 is not affected by this event.
"There was no impact on the health and safety of the public or plant personnel.
"The NRC Resident Inspector has been notified."
"At 1205 Eastern Daylight Time (EDT) on March 24, 2020, a Technical Specification-required shutdown was initiated on Unit 1 due to indication of a leak in the drywell. Technical Specification Action 3.4.4.A, Unidentified Reactor Coolant System (RCS) leakage increase not within limit, requires RCS leakage to be reduced to within limits within 8 hours.
"It was expected that the leakage would not have been reduced to within limits within the required Technical Specification completion time; therefore, this event is being reported in accordance with 10 CFR 50.72(b)(2)(i).
"Reactor water level reached low level 1 (LL1) following the reactor shutdown. The LL1 signal causes Group 2 (i.e., floor and equipment drain isolation valves), Group 6 (i.e., monitoring and sampling isolation valves), and Group 8 (i.e., shutdown cooling isolation valves) isolations. The LL1 isolations occurred as designed; the Group 8 valves were closed at the time of the event. Due to the valid Primary Containment Isolation System (PCIS) actuation, this event is also being reported in accordance with 10 CFR 50.72(b)(3)(iv)(A).
"Unit 2 is not affected by this event.
"There was no impact on the health and safety of the public or plant personnel.
"The NRC Resident Inspector has been notified."
Power Reactor
Event Number: 54605
Facility: SOUTH TEXAS
Region: 4 State: TX
Unit: [1] [2] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: MICHAEL CHANDLER
HQ OPS Officer: KERBY SCALES
Region: 4 State: TX
Unit: [1] [2] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: MICHAEL CHANDLER
HQ OPS Officer: KERBY SCALES
Notification Date: 03/24/2020
Notification Time: 17:15 [ET]
Event Date: 03/24/2020
Event Time: 10:46 [CDT]
Last Update Date: 03/24/2020
Notification Time: 17:15 [ET]
Event Date: 03/24/2020
Event Time: 10:46 [CDT]
Last Update Date: 03/24/2020
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):
RAY KELLAR (R4DO)
RAY KELLAR (R4DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | N | 0 | Defueled | 0 | Defueled |
| 2 | N | Y | 100 | Power Operation | 100 | Power Operation |
SPECIFIED SYSTEM ACTUATION - AUTO START EMERGENCY DIESEL GENERATORS
"At 1046 CDT on 3/24/2020, with Unit 1 defueled and Unit 2 in Mode 1 at 100 percent power, the South Texas Project (STP) South switchyard electrical bus was deenergized. This resulted in a loss of power to Standby Transformer 2 which was supplying power to the Engineered Safety Features (ESF) 4160v busses for Unit 1 A- and C-Trains, and Unit 2 B-Train. Emergency Diesel Generators (EDGs) 11, 13, and 22 automatically started in response to the undervoltage condition.
"The cause for the loss of the South switchyard electrical bus was an error in relay testing in the switchyard.
"This event is reportable under 10 CFR 50.72(b)(3)(iv)(A) as an event that resulted in the valid actuation of emergency AC electrical power systems (50.72(b)(3)(iv)(B)(8)) as well as the Unit 1 A- and C-Train and Unit 2 B-Train Reactor Containment Fan Coolers (50.72(b)(3)(iv)(B)(7)) and Unit 2 B-Train Auxiliary Feedwater pump (50.72(b)(3)(iv)(B)(6)).
"There was no impact on the health and safety of the public or plant personnel.
"The NRC Resident Inspector has been notified."
"At 1046 CDT on 3/24/2020, with Unit 1 defueled and Unit 2 in Mode 1 at 100 percent power, the South Texas Project (STP) South switchyard electrical bus was deenergized. This resulted in a loss of power to Standby Transformer 2 which was supplying power to the Engineered Safety Features (ESF) 4160v busses for Unit 1 A- and C-Trains, and Unit 2 B-Train. Emergency Diesel Generators (EDGs) 11, 13, and 22 automatically started in response to the undervoltage condition.
"The cause for the loss of the South switchyard electrical bus was an error in relay testing in the switchyard.
"This event is reportable under 10 CFR 50.72(b)(3)(iv)(A) as an event that resulted in the valid actuation of emergency AC electrical power systems (50.72(b)(3)(iv)(B)(8)) as well as the Unit 1 A- and C-Train and Unit 2 B-Train Reactor Containment Fan Coolers (50.72(b)(3)(iv)(B)(7)) and Unit 2 B-Train Auxiliary Feedwater pump (50.72(b)(3)(iv)(B)(6)).
"There was no impact on the health and safety of the public or plant personnel.
"The NRC Resident Inspector has been notified."