Event Notification Report for November 01, 2020
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
10/31/2020 - 11/01/2020
Power Reactor
Event Number: 54976
Facility: Cooper
Region: 4 State: NE
Unit: [1] [] []
RX Type: [1] GE-4
NRC Notified By: James Dedic
HQ OPS Officer: Jeffrey Whited
Region: 4 State: NE
Unit: [1] [] []
RX Type: [1] GE-4
NRC Notified By: James Dedic
HQ OPS Officer: Jeffrey Whited
Notification Date: 11/01/2020
Notification Time: 09:34 [ET]
Event Date: 11/01/2020
Event Time: 05:34 [CDT]
Last Update Date: 11/01/2020
Notification Time: 09:34 [ET]
Event Date: 11/01/2020
Event Time: 05:34 [CDT]
Last Update Date: 11/01/2020
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):
GREG PICK (R4DO)
GREG PICK (R4DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | M/R | Y | 75 | Power Operation | 0 | Hot Shutdown |
MANUAL REACTOR TRIP DUE TO AN UN-ISOLABLE LEAK ON THE TURBINE HIGH PRESSURE FLUID SYSTEM
"On November 1, 2020, at 0534 CST the reactor was manually scrammed due to an un-isolable leak on the Turbine High Pressure Fluid System. Initial power level when the leak was identified was 100 percent. Power was lowered commencing at 0525 in accordance with shutdown procedures. The Reactor Operator scrammed the reactor at 0534 from approximately 75 percent power. Following the scram, Reactor vessel water level lowered to approximately -20 inches on the Wide Range Instruments, and was subsequently recovered to normal post scram range (approximately 36 inches) using the Reactor Feedwater system. Group 2 Isolation occurred due to Reactor vessel level reaching the isolation setpoint (3 inches). The plant is stable in MODE 3 and proceeding to cold shutdown. The Main Condenser remained available throughout the evolution and condenser vacuum is currently being maintained by the Mechanical Vacuum Pumps. Pressure is being controlled using the steam line drains to the main condenser.
"All control rods fully inserted and there were no complications. All systems responded as designed. The Turbine High Pressure Fluid System has been secured.
"This event is reportable under 10 CFR 50.72(b)(2)(iv)(B) due to RPS Actuation-Critical and 50.72(b)(3)(iv)(A) Valid Specified System Actuation.
"The licensee has notified the NRC Resident Inspector."
"On November 1, 2020, at 0534 CST the reactor was manually scrammed due to an un-isolable leak on the Turbine High Pressure Fluid System. Initial power level when the leak was identified was 100 percent. Power was lowered commencing at 0525 in accordance with shutdown procedures. The Reactor Operator scrammed the reactor at 0534 from approximately 75 percent power. Following the scram, Reactor vessel water level lowered to approximately -20 inches on the Wide Range Instruments, and was subsequently recovered to normal post scram range (approximately 36 inches) using the Reactor Feedwater system. Group 2 Isolation occurred due to Reactor vessel level reaching the isolation setpoint (3 inches). The plant is stable in MODE 3 and proceeding to cold shutdown. The Main Condenser remained available throughout the evolution and condenser vacuum is currently being maintained by the Mechanical Vacuum Pumps. Pressure is being controlled using the steam line drains to the main condenser.
"All control rods fully inserted and there were no complications. All systems responded as designed. The Turbine High Pressure Fluid System has been secured.
"This event is reportable under 10 CFR 50.72(b)(2)(iv)(B) due to RPS Actuation-Critical and 50.72(b)(3)(iv)(A) Valid Specified System Actuation.
"The licensee has notified the NRC Resident Inspector."
Power Reactor
Event Number: 54977
Facility: Sequoyah
Region: 2 State: TN
Unit: [1] [2] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: Zachary Patterson
HQ OPS Officer: Thomas Herrity
Region: 2 State: TN
Unit: [1] [2] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: Zachary Patterson
HQ OPS Officer: Thomas Herrity
Notification Date: 11/01/2020
Notification Time: 11:04 [ET]
Event Date: 11/01/2020
Event Time: 05:56 [EDT]
Last Update Date: 11/01/2020
Notification Time: 11:04 [ET]
Event Date: 11/01/2020
Event Time: 05:56 [EDT]
Last Update Date: 11/01/2020
Emergency Class: Non Emergency
10 CFR Section:
50.72(b)(3)(xiii) - Loss Comm/Asmt/Response
10 CFR Section:
50.72(b)(3)(xiii) - Loss Comm/Asmt/Response
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 | 100 | Power Operation | 100 | Power Operation |
| 2 | N | Y | 100 | Power Operation | 100 | Power Operation |
LOSS OF SEISMIC ASSESSMENT INSTRUMENTATION
"At 0556 EST on 11/01/2020, Sequoyah received unexpected alarms for seismological recording initiated and [Units] 1/2 Safe Shutdown Earthquake response spectra exceeded. No seismic event was felt on site, the National Earthquake Information Center was contacted to confirm there was no seismic activity, and this was also confirmed on the U.S. Geological Survey website. The alarms were determined to be invalid, and they occurred due to a failure in the seismic monitoring system. This failure results in loss of ability to assess the Emergency Action Level for Initiating Condition HU2 'Seismic event greater than Operating Basis Earthquake (OBE) levels' per procedure EPIP-1.
"If an actual seismic event occurred, HU2 could not be assessed. However, compensatory measures have been implemented and include assessing OBE criteria based on alternative criteria contained in procedure AOP-N.05 'Earthquake' which provides conservative guidance when seismic instruments are unavailable.
"This is an eight hour, non-emergency notification for an event resulting in a major loss of Emergency Assessment Capability. This event is reportable in accordance with 10 CFR 50.72(b)(3)(xiii). There is no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified."
"At 0556 EST on 11/01/2020, Sequoyah received unexpected alarms for seismological recording initiated and [Units] 1/2 Safe Shutdown Earthquake response spectra exceeded. No seismic event was felt on site, the National Earthquake Information Center was contacted to confirm there was no seismic activity, and this was also confirmed on the U.S. Geological Survey website. The alarms were determined to be invalid, and they occurred due to a failure in the seismic monitoring system. This failure results in loss of ability to assess the Emergency Action Level for Initiating Condition HU2 'Seismic event greater than Operating Basis Earthquake (OBE) levels' per procedure EPIP-1.
"If an actual seismic event occurred, HU2 could not be assessed. However, compensatory measures have been implemented and include assessing OBE criteria based on alternative criteria contained in procedure AOP-N.05 'Earthquake' which provides conservative guidance when seismic instruments are unavailable.
"This is an eight hour, non-emergency notification for an event resulting in a major loss of Emergency Assessment Capability. This event is reportable in accordance with 10 CFR 50.72(b)(3)(xiii). There is no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified."