Event Notification Report for December 25, 2022
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
12/24/2022 - 12/25/2022
EVENT NUMBERS
56347
56347
Power Reactor
Event Number: 56347
Facility: Calvert Cliffs
Region: 1 State: MD
Unit: [2] [] []
RX Type: [1] CE,[2] CE
NRC Notified By: Ervin Lyson
HQ OPS Officer: Adam Koziol
Region: 1 State: MD
Unit: [2] [] []
RX Type: [1] CE,[2] CE
NRC Notified By: Ervin Lyson
HQ OPS Officer: Adam Koziol
Notification Date: 02/09/2023
Notification Time: 15:40 [ET]
Event Date: 12/25/2022
Event Time: 06:37 [EST]
Last Update Date: 02/09/2023
Notification Time: 15:40 [ET]
Event Date: 12/25/2022
Event Time: 06:37 [EST]
Last Update Date: 02/09/2023
Emergency Class: Non Emergency
10 CFR Section:
50.73(a)(1) - Invalid Specif System Actuation
10 CFR Section:
50.73(a)(1) - Invalid Specif System Actuation
Person (Organization):
Cahill, Christopher (R1DO)
Cahill, Christopher (R1DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 2 | N | Y | 100 | Power Operation | 100 | Power Operation |
60-DAY OPTIONAL TELEPHONIC NOTIFICATION OF INVALID ACTUATION OF EMERGENCY DIESEL GENERATOR (EDG)
The following information was provided by the licensee via email:
"This 60-day optional telephone notification is being made in lieu of an LER [Licensee Event Report] submittal as allowed by 10 CFR 50.73(a)(1). This notification is made pursuant to the reporting requirements specified in 10 CFR 50.73(a)(2)(iv)(A) for an invalid actuation of one of the systems listed in 10 CFR 50.73(a)(2)(iv)(B). At approximately 0637 EST on December 25, 2022, the 2B EDG inadvertently started and ran unloaded without a valid undervoltage or safety injection actuation signal. It was determined that this condition was caused by the failure of the emergency start button due to age-related degradation. The button is normally held depressed (closed) by the glass enclosure in standby. To start the EDG using the Emergency Start Button, the button is released (open) when the glass enclosure is broken, which sends a start signal to the EDG. During troubleshooting, the resistance across the button contacts was measured at zero volts DC, indicating the button had failed to an open state causing the EDG to start. The button fell apart when the glass enclosure was removed. The actuation was not initiated in response to actual plant conditions, it was not an intentional manual initiation, and there were no parameters satisfying the requirements for initiation of the emergency diesel generator."
The NRC Resident Inspector has been notified.
The following information was provided by the licensee via email:
"This 60-day optional telephone notification is being made in lieu of an LER [Licensee Event Report] submittal as allowed by 10 CFR 50.73(a)(1). This notification is made pursuant to the reporting requirements specified in 10 CFR 50.73(a)(2)(iv)(A) for an invalid actuation of one of the systems listed in 10 CFR 50.73(a)(2)(iv)(B). At approximately 0637 EST on December 25, 2022, the 2B EDG inadvertently started and ran unloaded without a valid undervoltage or safety injection actuation signal. It was determined that this condition was caused by the failure of the emergency start button due to age-related degradation. The button is normally held depressed (closed) by the glass enclosure in standby. To start the EDG using the Emergency Start Button, the button is released (open) when the glass enclosure is broken, which sends a start signal to the EDG. During troubleshooting, the resistance across the button contacts was measured at zero volts DC, indicating the button had failed to an open state causing the EDG to start. The button fell apart when the glass enclosure was removed. The actuation was not initiated in response to actual plant conditions, it was not an intentional manual initiation, and there were no parameters satisfying the requirements for initiation of the emergency diesel generator."
The NRC Resident Inspector has been notified.