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Event Notification Report for December 21, 2017

U.S. Nuclear Regulatory Commission Operations Center Event Reports For 12/20/2017 - 12/21/2017 ** EVENT NUMBERS ** 53132 53133 Power Reactor Event Number: 53132 Facility: WATTS BAR Region: 2 State: TN Unit: [1] [2] [ ] RX Type: [1] W-4-LP,[2] W-4-LP NRC Notified By: JUSTIN GALLAGHER HQ OPS Officer: VINCE KLCO Notification Date: 12/20/2017 Notification Time: 18:18 [ET] Event Date: 12/20/2017 Event Time: 10:40 [EST] Last Update Date: 12/20/2017 Emergency Class: NON EMERGENCY 10 CFR Section: 50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION Person (Organization): ERIC MICHEL (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 Event Text SYSTEM ACTUATIONS DUE TO OPENING OF FEEDER BREAKER TO SHUTDOWN BOARD "On December 20, 2017, at 1040 Eastern Standard Time (EST), the Watts Bar Nuclear Plant (WBN) 1B-B 6.9kV Shutdown Board (SDBD) normal feeder breaker opened. The loss of voltage to the 1B-B SDBD resulted in the start of the 1B-B Motor Driven Auxiliary Feedwater (MDAFW) pump, the Unit 1 Turbine Driven Auxiliary Feedwater (TDAFW) pump, and the start of all four Emergency Diesel Generators (EDGs). Power was restored to the 1B-B 6.9 kV SDBD when it loaded on to its associated EDG. "Following initial investigation, the 1B-B 6.9 kV SDBD was transferred to its alternate offsite power source, Common Station Service Transformer (CSST) C at 1217 EST. At 1230 EST, the 1B-B 6.9 kV SDBD alternate feeder breaker opened. The loss of voltage to the 1B-B SDBD did not result in the restart of the 1B MDAFW pump, the Unit 1 TDAFW pump, or EDGs; this equipment remained running from the earlier event. Power was restored to the 1B-B 6.9 kV SDBD when it loaded on to its associated EDG. "Restoration of normal offsite power to the 1B-B SDBD was completed at 1654. "Other than several common Unit Technical Specifications having not been met, Unit 2 was not operationally impacted by the transfer of the 1B-B Shutdown Board to onsite power and remains in Mode 1 at 100% power. "This report is made per 10 CFR 50.72(b)(3)(iv)(A). "NRC Resident Inspector has been notified." The licensee investigation continues for the cause of the event. Power Reactor Event Number: 53133 Facility: COOPER Region: 4 State: NE Unit: [1] [ ] [ ] RX Type: [1] GE-4 NRC Notified By: TERRELL HIGGINS HQ OPS Officer: MARK ABRAMOVITZ Notification Date: 12/20/2017 Notification Time: 21:22 [ET] Event Date: 12/20/2017 Event Time: 15:59 [CST] Last Update Date: 12/20/2017 Emergency Class: NON EMERGENCY 10 CFR Section: 50.72(b)(3)(xiii) - LOSS COMM/ASMT/RESPONSE Person (Organization): GREG PICK (R4DO) 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 ALERT SYSTEM OUT OF SERVICE "During review of the documentation for the 11/16/17 outage of the NOAA/NWS [National Oceanographic and Atmospheric Administration/National Weather Service] tower, it was identified that there was also record of a trouble ticket being issued on 11/19/17 for the NOAA/NWS tower. Further discussions with the National Weather Service determined that the tower did experience an outage on 11/19/17 which affected the ability to activate EAS [Emergency Alert System]/Tone Alert Radios. Final determination that the EAS/Tone Alert Radios were affected during this outage was made at 1559 [CST], which was the time that the National Weather Service sent the e-mail to the EP [Emergency Planning] Manager and EP Offsite Coordinator with notification that activation of the EAS/Tone Alert Radios was affected during the outage. This is considered to be a major loss of the Public Prompt Notification System capability, and is reportable under 10CFR 50.72(b)(3)(xiii). "The transmission outage was on 11/19/2017 0853 until 1100 but CNS [Cooper Nuclear Station] was not notified until 1559 on 12/20/2017. "The NRC Senior Resident has been informed"

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