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Event Notification Report for January 18, 2018

U.S. Nuclear Regulatory Commission
Operations Center

EVENT REPORTS FOR
01/17/2018 - 01/18/2018

EVENT NUMBERS
53176

Power Reactor
Event Number: 53176
Facility: SUMMER
Region: 2     State: SC
Unit: [1] [] []
RX Type: [1] W-3-LP,[2] W-AP1000,[3] W-AP1000
NRC Notified By: MICHAEL MOORE
HQ OPS Officer: HOWIE CROUCH
Notification Date: 01/18/2018
Notification Time: 17:03 [ET]
Event Date: 01/18/2018
Event Time: 12:02 [EST]
Last Update Date: 01/18/2018
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION
Person (Organization):
GERALD MCCOY (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
Event Text
EMERGENCY DIESEL GENERATOR ACTUATION DUE TO LOSS OF ONE OF TWO OFFSITE POWER SUPPLIES

"This event is being reported in accordance with 10 CFR 50.72(b)(3)(iv)(A) as an event that resulted in a valid actuation of the Emergency Diesel Generator.

"On January 18, 2018 at 1202 EST, V.C. Summer Nuclear Station (VCSNS) lost one of its two redundant offsite power supplies. The loss of the 115kV power supply created an undervoltage condition on the normal incoming Engineered Safety Features power supply to safety related bus 1DA. The 'A' Emergency Diesel Generator started and loads sequenced as designed. The 'A' Residual Heat Removal pump started but did not inject any water into the Reactor Coolant System. The 'A' Emergency Feedwater Pump started and ran for approximately 2 minutes. Other plant equipment and systems also responded as expected.

"The loss of the 115kV power supply occurred due to an issue with a component in a switchyard, external to VCSNS. The cause of the event is still under investigation.

"All loads have been transferred back to the offsite 115kV power supply at 1318 EST. The diesel generator was secured at 1321 EST, reset and is ready to auto-start.

"The NRC Resident Inspector has been notified."