Event Notification Report for November 26, 2017
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
11/25/2017 - 11/26/2017
EVENT NUMBERS
53092
Power Reactor
Event Number: 53092
Facility: WATTS BAR
Region: 2 State: TN
Unit: [] [2] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: BRIAN MCILNAY
HQ OPS Officer: MICHAEL BLOODGOOD
Region: 2 State: TN
Unit: [] [2] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: BRIAN MCILNAY
HQ OPS Officer: MICHAEL BLOODGOOD
Notification Date: 11/26/2017
Notification Time: 16:16 [ET]
Event Date: 11/26/2017
Event Time: 12:25 [EST]
Last Update Date: 11/26/2017
Notification Time: 16:16 [ET]
Event Date: 11/26/2017
Event Time: 12:25 [EST]
Last Update Date: 11/26/2017
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(2)(iv)(A) - ECCS INJECTION
10 CFR Section:
50.72(b)(2)(iv)(A) - ECCS INJECTION
Person (Organization):
LADONNA SUGGS (R2DO)
LADONNA SUGGS (R2DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 2 | N | N | 0 | Cold Shutdown | 0 | Cold Shutdown |
UNPLANNED EMERGENCY CORE COOLING SYSTEM (ECCS) INJECTION DURING A PLANNED SAFETY INJECTION TEST
"On November 26, 2017, at 1225 Eastern Standard Time (EST), the Watts Bar Nuclear Plant (WBN) Unit 2 experienced an unplanned ECCS discharge to the Unit 2 Reactor Coolant System (RCS) while de-pressurized, in Mode 5, with the Pressurizer vented to the Pressurizer Relief Tank. ECCS injection via the Boron Injection flow path occurred during planned Safety Injection system Engineered Safety Features Actuation System (ESFAS) testing. The Boron Injection flow path should have been isolated and should not have resulted in any injection flow to the Unit 2 RCS. Since the injection was not a part of the pre-planned test this is reportable under 10 CFR 50.72(b)(2)(iv), System Actuation.
"All other systems responded as expected in accordance with the ESFAS testing procedure. The unintended ECCS injection flow was isolated and flow through the Boron Injection path was verified to be stopped at 1232 EST. The Unit 2 Pressurizer level and pressure remained below any limits and no safety limits were challenged.
"NRC Resident Inspector has been notified."
"On November 26, 2017, at 1225 Eastern Standard Time (EST), the Watts Bar Nuclear Plant (WBN) Unit 2 experienced an unplanned ECCS discharge to the Unit 2 Reactor Coolant System (RCS) while de-pressurized, in Mode 5, with the Pressurizer vented to the Pressurizer Relief Tank. ECCS injection via the Boron Injection flow path occurred during planned Safety Injection system Engineered Safety Features Actuation System (ESFAS) testing. The Boron Injection flow path should have been isolated and should not have resulted in any injection flow to the Unit 2 RCS. Since the injection was not a part of the pre-planned test this is reportable under 10 CFR 50.72(b)(2)(iv), System Actuation.
"All other systems responded as expected in accordance with the ESFAS testing procedure. The unintended ECCS injection flow was isolated and flow through the Boron Injection path was verified to be stopped at 1232 EST. The Unit 2 Pressurizer level and pressure remained below any limits and no safety limits were challenged.
"NRC Resident Inspector has been notified."