Event Notification Report for June 16, 2018
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
06/15/2018 - 06/16/2018
EVENT NUMBERS
53459
53459
Power Reactor
Event Number: 53459
Facility: ARKANSAS NUCLEAR
Region: 4 State: AR
Unit: [1] [] []
RX Type: [1] B&W-L-LP,[2] CE
NRC Notified By: KEVIN CASEY
HQ OPS Officer: ANDREW WAUGH
Region: 4 State: AR
Unit: [1] [] []
RX Type: [1] B&W-L-LP,[2] CE
NRC Notified By: KEVIN CASEY
HQ OPS Officer: ANDREW WAUGH
Notification Date: 06/16/2018
Notification Time: 15:56 [ET]
Event Date: 06/16/2018
Event Time: 11:21 [CDT]
Last Update Date: 06/16/2018
Notification Time: 15:56 [ET]
Event Date: 06/16/2018
Event Time: 11:21 [CDT]
Last Update Date: 06/16/2018
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS ACTUATION - CRITICAL 50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS ACTUATION - CRITICAL 50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION
Person (Organization):
NICK TAYLOR (R4DO)
BO PHAM (IRD)
MICHAEL F. KING (NRR EO)
NICK TAYLOR (R4DO)
BO PHAM (IRD)
MICHAEL F. KING (NRR EO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | M/R | Y | 2 | Startup | 0 | Hot Standby |
MANUAL REACTOR TRIP DURING STARTUP
"At 1121 CDT on June 16, 2018, Arkansas Nuclear One, Unit 1 (ANO-1) performed a manual reactor trip due to a Turbine Bypass valve failing open on reactor startup. At the time, ANO-1 was in Mode 2 at approximately 2 percent power.
"The failed Turbine Bypass valve resulted in an overcooling event and the Overcooling Emergency Operating Procedure (EOP) was entered. Main Steam Line Isolation (MSLI) automatic actuation occurred on 2 of the 4 channels of Emergency Feedwater Initiation and Control during the overcooling event in the 'B' Steam Generator. The remaining channels of MSLI were manually actuated by the control room staff from the control room. Overcooling was terminated after the closure of the Main Steam Isolation Valve (MSIV) and reactor coolant parameters were stabilized as directed by the Overcooling EOP. Additionally, Gland Sealing Steam was lost to the main turbine due to the closure of the 'B' Steam Generator MSIV and Loss of Condenser Vacuum Abnormal Operating Procedure was entered.
"This is a 4-hour non-emergency 10 CFR 50.72 (b)(2)(iv)(B) notification due to a Reactor Protection System actuation (scram) and an 8-hour non-emergency 10 CFR 50.72 (b)(3)(iv)(A) notification for safety system actuation."
All control rods fully inserted into the core during the trip. Heat removal is via the Atmospheric Dump Control valves to atmosphere.
The NRC Resident Inspector has been notified. The licensee also notified the State of Arkansas.
"At 1121 CDT on June 16, 2018, Arkansas Nuclear One, Unit 1 (ANO-1) performed a manual reactor trip due to a Turbine Bypass valve failing open on reactor startup. At the time, ANO-1 was in Mode 2 at approximately 2 percent power.
"The failed Turbine Bypass valve resulted in an overcooling event and the Overcooling Emergency Operating Procedure (EOP) was entered. Main Steam Line Isolation (MSLI) automatic actuation occurred on 2 of the 4 channels of Emergency Feedwater Initiation and Control during the overcooling event in the 'B' Steam Generator. The remaining channels of MSLI were manually actuated by the control room staff from the control room. Overcooling was terminated after the closure of the Main Steam Isolation Valve (MSIV) and reactor coolant parameters were stabilized as directed by the Overcooling EOP. Additionally, Gland Sealing Steam was lost to the main turbine due to the closure of the 'B' Steam Generator MSIV and Loss of Condenser Vacuum Abnormal Operating Procedure was entered.
"This is a 4-hour non-emergency 10 CFR 50.72 (b)(2)(iv)(B) notification due to a Reactor Protection System actuation (scram) and an 8-hour non-emergency 10 CFR 50.72 (b)(3)(iv)(A) notification for safety system actuation."
All control rods fully inserted into the core during the trip. Heat removal is via the Atmospheric Dump Control valves to atmosphere.
The NRC Resident Inspector has been notified. The licensee also notified the State of Arkansas.