Event Notification Report for August 13, 2016
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
08/12/2016 - 08/13/2016
Power Reactor
Event Number: 52177
Facility: WATTS BAR
Region: 2 State: TN
Unit: [] [2] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: MATTHEW MILLER
HQ OPS Officer: DONALD NORWOOD
Region: 2 State: TN
Unit: [] [2] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: MATTHEW MILLER
HQ OPS Officer: DONALD NORWOOD
Notification Date: 08/13/2016
Notification Time: 08:51 [ET]
Event Date: 08/13/2016
Event Time: 03:36 [EDT]
Last Update Date: 08/13/2016
Notification Time: 08:51 [ET]
Event Date: 08/13/2016
Event Time: 03:36 [EDT]
Last Update Date: 08/13/2016
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION
10 CFR Section:
50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION
Person (Organization):
SCOTT SHAEFFER (R2DO)
SCOTT SHAEFFER (R2DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 2 | N | N | 0 | Hot Standby | 0 | Hot Standby |
AUTOMATIC START OF TURBINE DRIVEN AUXILIARY FEED WATER PUMP
"On August 13, 2016 at 0330 EDT, Watts Bar Nuclear Plant Unit 2 (WBN2) was being stabilized following a pre-planned reactor trip. Both motor driven auxiliary feed water pumps and the turbine driven auxiliary feed water pump (TDAFW pump) were in operation maintaining steam generator water level 6 - 50 percent in accordance with the Reactor Trip Response Procedure.
"At 0333 EDT the TDAFW pump was secured by procedure and steam generator water level lowered to the Low Low Alarm setpoint (17 percent). The trip time delay at 0 percent power is three (3) minutes. At 0336 EDT, the TDAFW pump automatically started with steam generator water levels less than the Low Low alarm setpoint (lowest level reached was 15 percent).
"Steam generator water level was restored to the normal shutdown control band (38 percent).
"Unit 1 remains in Mode 1 at 85 percent.
"Unit 2 is stable in Mode 3 with normal shutdown power alignment. The reactor coolant system is being cooled down to 400 degrees F for a planned maintenance period, with decay heat removal via the Main Condenser Steam dumps and the AFW system.
"This event is being reported pursuant to 10 CFR 50.72(b)(3)(iv)(A).
"TVA has notified the NRC Resident Inspector."
"On August 13, 2016 at 0330 EDT, Watts Bar Nuclear Plant Unit 2 (WBN2) was being stabilized following a pre-planned reactor trip. Both motor driven auxiliary feed water pumps and the turbine driven auxiliary feed water pump (TDAFW pump) were in operation maintaining steam generator water level 6 - 50 percent in accordance with the Reactor Trip Response Procedure.
"At 0333 EDT the TDAFW pump was secured by procedure and steam generator water level lowered to the Low Low Alarm setpoint (17 percent). The trip time delay at 0 percent power is three (3) minutes. At 0336 EDT, the TDAFW pump automatically started with steam generator water levels less than the Low Low alarm setpoint (lowest level reached was 15 percent).
"Steam generator water level was restored to the normal shutdown control band (38 percent).
"Unit 1 remains in Mode 1 at 85 percent.
"Unit 2 is stable in Mode 3 with normal shutdown power alignment. The reactor coolant system is being cooled down to 400 degrees F for a planned maintenance period, with decay heat removal via the Main Condenser Steam dumps and the AFW system.
"This event is being reported pursuant to 10 CFR 50.72(b)(3)(iv)(A).
"TVA has notified the NRC Resident Inspector."
Power Reactor
Event Number: 52178
Facility: PRAIRIE ISLAND
Region: 3 State: MN
Unit: [1] [] []
RX Type: [1] W-2-LP,[2] W-2-LP
NRC Notified By: PAUL FINHOLM
HQ OPS Officer: DONALD NORWOOD
Region: 3 State: MN
Unit: [1] [] []
RX Type: [1] W-2-LP,[2] W-2-LP
NRC Notified By: PAUL FINHOLM
HQ OPS Officer: DONALD NORWOOD
Notification Date: 08/14/2016
Notification Time: 01:59 [ET]
Event Date: 08/13/2016
Event Time: 23:59 [CDT]
Last Update Date: 08/14/2016
Notification Time: 01:59 [ET]
Event Date: 08/13/2016
Event Time: 23:59 [CDT]
Last Update Date: 08/14/2016
Emergency Class: UNUSUAL EVENT
10 CFR Section:
50.72(a) (1) (i) - EMERGENCY DECLARED
10 CFR Section:
50.72(a) (1) (i) - EMERGENCY DECLARED
Person (Organization):
LAURA KOZAK (R3DO)
DARRELL ROBERTS (R3DR)
BRIAN MCDERMOTT (NRR)
BERNARD STAPLETON (IRD)
CHRIS MILLER (NRR)
LAURA KOZAK (R3DO)
DARRELL ROBERTS (R3DR)
BRIAN MCDERMOTT (NRR)
BERNARD STAPLETON (IRD)
CHRIS MILLER (NRR)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | Y | 100 | Power Operation | 100 | Power Operation |
UNUSUAL EVENT DECLARED DUE TO EXCESSIVE REACTOR COOLANT SYSTEM LEAKAGE
Prairie Island Unit 1 declared an Unusual Event at 2359 CDT on 8/13/2016 based on Reactor Coolant System (RCS) identified leakage being greater than 25 gpm. The RCS leakage was 40 gpm for three (3) minutes. The RCS leakage was stopped when letdown flow was isolated. Minimum charging flow has been established and Excess Letdown was placed in service. Prairie Island Unit 1 is currently stable and continues to operate at 100 percent power. There was no impact on Prairie Island Unit 2.
"CV-31339 (Letdown Line Containment Isolation Valve) failed closed. VC-26-1 (Regenerative Heat Exchanger Letdown Line Outlet Relief to Pressurizer Relief Tank [PRT]) lifted with 40 gallons per minute to the PRT for three (3) Minutes. Operators entered procedure 1C12.1 AOP3, Loss of Letdown Flow to VCT. Letdown was isolated per 1C12.1 AOP3, relief valve VC-26-1 reseated and leakage to the PRT stopped. Charging flow was reduced to one (1) charging pump at minimum speed (16 GPM). Excess letdown was placed in service to maintain pressurizer level between 32 - 34 percent. The cause for CV-31339 closing has not yet been determined.
"The NRC Resident Inspector has been notified."
Notified DHS SWO, FEMA Ops Center, DHS NICC. Notified FEMA National Watch and Nuclear SSA via E-mail.
* * * UPDATE FROM PAUL FINHOLM TO DONALD NORWOOD AT 0525 EDT ON 8/14/2016 * * *
"At 0329 CDT the Notice of Unusual Event was terminated based on confirmation that conditions meet all termination criteria. RCS conditions are stable. RCS leakage is less than Technical Specification limits. The current value [of RCS identified leakage] is 0.038 gpm. No classification criteria is currently met.
"The NRC Resident Inspector has been notified."
Notified R3DO (Kozak), NRR EO (Miller), and IRD (Stapleton). Notified DHS SWO, FEMA Ops Center, DHS NICC. Notified FEMA National Watch and Nuclear SSA via E-mail.
Prairie Island Unit 1 declared an Unusual Event at 2359 CDT on 8/13/2016 based on Reactor Coolant System (RCS) identified leakage being greater than 25 gpm. The RCS leakage was 40 gpm for three (3) minutes. The RCS leakage was stopped when letdown flow was isolated. Minimum charging flow has been established and Excess Letdown was placed in service. Prairie Island Unit 1 is currently stable and continues to operate at 100 percent power. There was no impact on Prairie Island Unit 2.
"CV-31339 (Letdown Line Containment Isolation Valve) failed closed. VC-26-1 (Regenerative Heat Exchanger Letdown Line Outlet Relief to Pressurizer Relief Tank [PRT]) lifted with 40 gallons per minute to the PRT for three (3) Minutes. Operators entered procedure 1C12.1 AOP3, Loss of Letdown Flow to VCT. Letdown was isolated per 1C12.1 AOP3, relief valve VC-26-1 reseated and leakage to the PRT stopped. Charging flow was reduced to one (1) charging pump at minimum speed (16 GPM). Excess letdown was placed in service to maintain pressurizer level between 32 - 34 percent. The cause for CV-31339 closing has not yet been determined.
"The NRC Resident Inspector has been notified."
Notified DHS SWO, FEMA Ops Center, DHS NICC. Notified FEMA National Watch and Nuclear SSA via E-mail.
* * * UPDATE FROM PAUL FINHOLM TO DONALD NORWOOD AT 0525 EDT ON 8/14/2016 * * *
"At 0329 CDT the Notice of Unusual Event was terminated based on confirmation that conditions meet all termination criteria. RCS conditions are stable. RCS leakage is less than Technical Specification limits. The current value [of RCS identified leakage] is 0.038 gpm. No classification criteria is currently met.
"The NRC Resident Inspector has been notified."
Notified R3DO (Kozak), NRR EO (Miller), and IRD (Stapleton). Notified DHS SWO, FEMA Ops Center, DHS NICC. Notified FEMA National Watch and Nuclear SSA via E-mail.