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Event Notification Report for January 03, 2021

U.S. Nuclear Regulatory Commission
Operations Center

EVENT REPORTS FOR
01/02/2021 - 01/03/2021

EVENT NUMBERS
55055
Power Reactor
Event Number: 55055
Facility: Vogtle
Region: 2     State: GA
Unit: [1] [2] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: Jamaal Merriweather
HQ OPS Officer: Lloyd Desotell
Notification Date: 01/03/2021
Notification Time: 08:33 [ET]
Event Date: 01/03/2021
Event Time: 06:45 [EST]
Last Update Date: 01/03/2021
Emergency Class: Non Emergency
10 CFR Section:
50.72(b)(3)(xiii) - Loss Comm/Asmt/Response
Person (Organization):
MARK MILLER (R2DO)
Power Reactor Unit Info
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
Event Text
NONFUNCTIONAL SEISMIC MONITORING SYSTEM

"At 1414 EST on 12/31/2020, a planned maintenance outage commenced on the Vogtle 1and 2 Seismic Monitoring System. The work was to address abnormal indications on the uninterruptable power supply, and was scheduled for an eight (8) hour duration. During the restoration activities, the system did not respond properly and has remained Non-Functional. Compensatory measures for seismic event classification were implemented in accordance with Vogtle procedures prior to removing the system from service. Based upon the troubleshooting conducted, the system is not expected to be restored within 72 hours from the start of the planned outage."

"This is an eight-hour, non-emergency notification for a loss of Emergency Assessment Capability. This event is reportable in accordance with 10 CFR 50.72(b)(3)(xiii) because the Seismic Monitoring System is the method for evaluating that an Operational Basis Earthquake (OBE) threshold has been exceeded following a seismic event in accordance with Initiating Condition 'Seismic event greater than OBE levels' and Emergency Action Level HU2. There was no impact on the health and safety of the public or plant personnel. "

"The NRC Resident Inspector has been notified."

Compensatory measures implemented include having a phone number to call to verify if an earthquake has occurred.