Event Notification Report for September 02, 2016
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
09/01/2016 - 09/02/2016
!!!!! THIS EVENT HAS BEEN RETRACTED !!!!!
!!!!! THIS EVENT HAS BEEN RETRACTED !!!!!
Power Reactor
Event Number: 52218
Facility: WOLF CREEK
Region: 4 State: KS
Unit: [1] [] []
RX Type: [1] W-4-LP
NRC Notified By: LARRY HAUTH
HQ OPS Officer: STEVEN VITTO
Region: 4 State: KS
Unit: [1] [] []
RX Type: [1] W-4-LP
NRC Notified By: LARRY HAUTH
HQ OPS Officer: STEVEN VITTO
Notification Date: 09/02/2016
Notification Time: 11:29 [ET]
Event Date: 09/02/2016
Event Time: 08:08 [CDT]
Last Update Date: 10/21/2016
Notification Time: 11:29 [ET]
Event Date: 09/02/2016
Event Time: 08:08 [CDT]
Last Update Date: 10/21/2016
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(2)(i) - PLANT S/D REQD BY TS
10 CFR Section:
50.72(b)(2)(i) - PLANT S/D REQD BY TS
Person (Organization):
GREG WARNICK (R4DO)
GREG WARNICK (R4DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | Y | 100 | Power Operation | 0 | Hot Standby |
TECHNICAL SPECIFICATION REQUIRED SHUTDOWN
"While operating in MODE 1 at 100 percent rated thermal power and placing Excess Letdown in service for Reactor Coolant System (RCS) leak detection, RCS operational leakage exceeded 1 gpm [gallon per minute] unidentified leakage as identified by performing RCS Water Inventory Balance using the Nuclear Plant Information System Computer. This required the entry into Technical Specification (TS) Limiting Condition of Operation (LCO) 3.4.13 Condition B at 0808 [CDT] on 9/2/16. The associated action is to place the unit into Mode 3 in 6 hours. Trending of containment sump level indicates the leakage is inside containment with the exact location within containment unknown. Containment inspection is being performed to try and identify the source of Reactor Coolant System leakage. NRC Resident Inspector has been notified. Re-alignment of the Letdown System back to its normal arrangement has subsequently reduced RCS leak rate to 0.521 gpm at 0652 CDT on 9/2/16.
"Unusual or Not Understood - Leak Location is not known at this time."
Maximum leak rate recorded was 1.358 gpm. The leak was first discovered at 08/31/16 at 1519 CDT.
Safety Related Equipment not operational - Reactor Vessel Level Indicating System (TS 3.3.3).
* * * RETRACTION AT 1101 EDT ON 10/21/2016 FROM LARRY HAUTH TO JEFF HERRERA * * *
"Wolf Creek Nuclear Operating Corporation is retracting the 10 CFR 50.72(b)(2)(i) notification based on subsequent review of the event. The calculation of unidentified leak rate which triggered entry into the Mode 3 Required Action Statement was performed immediately after placing RCS Excess Letdown in service. An evaluation of the leak rate calculation determined that the leak rate was invalid due to performance of the RCS water inventory balance during non-steady state operating conditions. This was contrary to the requirements of TS Surveillance Requirement 3.4.13.1, as this test was performed while charging and letdown flows were being stabilized following the alignment of excess letdown. A walk down of the Excess Letdown system while in-service determined no leakage. Subsequent RCS water inventory balances performed with Excess Letdown in service under steady state operating conditions while in Mode 3 at normal operating pressure and temperature determined the maximum calculated unidentified leak rate was 0.675 gpm.
"After the plant entered Mode 3 a non-RCS pressure boundary leak was identified during equipment walk downs on a seal weld from the reactor vessel head core exit thermocouple nozzle assembly 77.
"The leakage did not impact the ability to shut down the unit. No TS limits were exceeded during this event.
"Therefore, the plant shutdown to investigate and correct leakage past the seal weld of a threaded connection does not meet the reporting requirements of 10 CFR 50.72.
"The NRC Resident Inspector has been notified."
Notified the R4DO (Kramer).
"While operating in MODE 1 at 100 percent rated thermal power and placing Excess Letdown in service for Reactor Coolant System (RCS) leak detection, RCS operational leakage exceeded 1 gpm [gallon per minute] unidentified leakage as identified by performing RCS Water Inventory Balance using the Nuclear Plant Information System Computer. This required the entry into Technical Specification (TS) Limiting Condition of Operation (LCO) 3.4.13 Condition B at 0808 [CDT] on 9/2/16. The associated action is to place the unit into Mode 3 in 6 hours. Trending of containment sump level indicates the leakage is inside containment with the exact location within containment unknown. Containment inspection is being performed to try and identify the source of Reactor Coolant System leakage. NRC Resident Inspector has been notified. Re-alignment of the Letdown System back to its normal arrangement has subsequently reduced RCS leak rate to 0.521 gpm at 0652 CDT on 9/2/16.
"Unusual or Not Understood - Leak Location is not known at this time."
Maximum leak rate recorded was 1.358 gpm. The leak was first discovered at 08/31/16 at 1519 CDT.
Safety Related Equipment not operational - Reactor Vessel Level Indicating System (TS 3.3.3).
* * * RETRACTION AT 1101 EDT ON 10/21/2016 FROM LARRY HAUTH TO JEFF HERRERA * * *
"Wolf Creek Nuclear Operating Corporation is retracting the 10 CFR 50.72(b)(2)(i) notification based on subsequent review of the event. The calculation of unidentified leak rate which triggered entry into the Mode 3 Required Action Statement was performed immediately after placing RCS Excess Letdown in service. An evaluation of the leak rate calculation determined that the leak rate was invalid due to performance of the RCS water inventory balance during non-steady state operating conditions. This was contrary to the requirements of TS Surveillance Requirement 3.4.13.1, as this test was performed while charging and letdown flows were being stabilized following the alignment of excess letdown. A walk down of the Excess Letdown system while in-service determined no leakage. Subsequent RCS water inventory balances performed with Excess Letdown in service under steady state operating conditions while in Mode 3 at normal operating pressure and temperature determined the maximum calculated unidentified leak rate was 0.675 gpm.
"After the plant entered Mode 3 a non-RCS pressure boundary leak was identified during equipment walk downs on a seal weld from the reactor vessel head core exit thermocouple nozzle assembly 77.
"The leakage did not impact the ability to shut down the unit. No TS limits were exceeded during this event.
"Therefore, the plant shutdown to investigate and correct leakage past the seal weld of a threaded connection does not meet the reporting requirements of 10 CFR 50.72.
"The NRC Resident Inspector has been notified."
Notified the R4DO (Kramer).
!!!!! THIS EVENT HAS BEEN RETRACTED !!!!!
!!!!! THIS EVENT HAS BEEN RETRACTED !!!!!
Power Reactor
Event Number: 52219
Facility: MCGUIRE
Region: 2 State: NC
Unit: [1] [] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: DANIEL BARKER
HQ OPS Officer: STEVEN VITTO
Region: 2 State: NC
Unit: [1] [] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: DANIEL BARKER
HQ OPS Officer: STEVEN VITTO
Notification Date: 09/02/2016
Notification Time: 23:33 [ET]
Event Date: 09/02/2016
Event Time: 19:22 [EDT]
Last Update Date: 09/04/2016
Notification Time: 23:33 [ET]
Event Date: 09/02/2016
Event Time: 19:22 [EDT]
Last Update Date: 09/04/2016
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(xiii) - LOSS COMM/ASMT/RESPONSE
10 CFR Section:
50.72(b)(3)(xiii) - LOSS COMM/ASMT/RESPONSE
Person (Organization):
JONATHAN BARTLEY (R2DO)
JONATHAN BARTLEY (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 |
SPENT FUEL POOL AREA RADIATION MONITOR LOST SIGNAL
"Unit 1 Spent Fuel Pool Area Radiation Monitor (1EMF17) lost signal resulting in off scale high indications. Subject EMF provides alarm functions and indication which are used for assessment of EAL classifications. Failure response conducted per applicable Alarm Response Procedures and subsequent actions performed per applicable license commitment required actions. Temporary dose rate monitor has been set up for area monitoring with alarm setpoint commensurate with subject EMF. Issue entered into corrective action program and prioritized to restore subject EMF to functional status within required 30 days."
The licensee notified the NRC Resident Inspector.
* * * RETRACTION FROM PHILIP BALES TO STEVEN VITTO AT 2323 EDT ON 9/4/2016 * * *
"This notification is being made to retract event EN 52219, which was reported on September 2, 2016. Upon further investigation, the loss of radiation monitor 1EMF17 did not prevent the evaluation of all EALs [Emergency Action Level] for the associated emergency initiating conditions. Additionally, it has been determined 1EMF17 is not utilized for performing radiological assessments.
"Therefore, no actual or potential major loss of emergency assessment capability existed per 10 CFR 50.72(b)(3)(xiii). This is consistent with NUREG 1022, Rev. 3, Supplement 1 and NEI 13-01, Rev. 0. The NRC Resident Inspector will be notified of the retraction."
Notified R2DO (Bartley).
"Unit 1 Spent Fuel Pool Area Radiation Monitor (1EMF17) lost signal resulting in off scale high indications. Subject EMF provides alarm functions and indication which are used for assessment of EAL classifications. Failure response conducted per applicable Alarm Response Procedures and subsequent actions performed per applicable license commitment required actions. Temporary dose rate monitor has been set up for area monitoring with alarm setpoint commensurate with subject EMF. Issue entered into corrective action program and prioritized to restore subject EMF to functional status within required 30 days."
The licensee notified the NRC Resident Inspector.
* * * RETRACTION FROM PHILIP BALES TO STEVEN VITTO AT 2323 EDT ON 9/4/2016 * * *
"This notification is being made to retract event EN 52219, which was reported on September 2, 2016. Upon further investigation, the loss of radiation monitor 1EMF17 did not prevent the evaluation of all EALs [Emergency Action Level] for the associated emergency initiating conditions. Additionally, it has been determined 1EMF17 is not utilized for performing radiological assessments.
"Therefore, no actual or potential major loss of emergency assessment capability existed per 10 CFR 50.72(b)(3)(xiii). This is consistent with NUREG 1022, Rev. 3, Supplement 1 and NEI 13-01, Rev. 0. The NRC Resident Inspector will be notified of the retraction."
Notified R2DO (Bartley).