Event Notification Report for August 26, 2013
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
08/25/2013 - 08/26/2013
EVENT NUMBERS
49308
!!!!! THIS EVENT HAS BEEN RETRACTED !!!!!
!!!!! THIS EVENT HAS BEEN RETRACTED !!!!!
Power Reactor
Event Number: 49308
Facility: COOPER
Region: 4 State: NE
Unit: [1] [] []
RX Type: [1] GE-4
NRC Notified By: FRED SCHIZAS
HQ OPS Officer: PETE SNYDER
Region: 4 State: NE
Unit: [1] [] []
RX Type: [1] GE-4
NRC Notified By: FRED SCHIZAS
HQ OPS Officer: PETE SNYDER
Notification Date: 08/27/2013
Notification Time: 04:10 [ET]
Event Date: 08/26/2013
Event Time: 23:05 [CDT]
Last Update Date: 09/05/2013
Notification Time: 04:10 [ET]
Event Date: 08/26/2013
Event Time: 23:05 [CDT]
Last Update Date: 09/05/2013
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):
BOB HAGAR (R4DO)
BOB HAGAR (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 |
POST ACCIDENT MONITORING INSTRUMENTATION POWER SUPPLIES POTENTIALLY DEGRADED
"At 2305 on 26AUG13 the Shift Manager Declared PC-ES-1A and PC-ES-1B inoperable due to a Part 21 Notification that called the operability of the equipment into question. PAM [Post Accident Monitoring] Instrumentation LCO 3.3.3.1.A and 3.3.3.1.C were entered for Functions 1 (Reactor Pressure), 3 (Containment Level), and 7 (Containment Pressure). Both divisions are potentially affected. LCO 3.3.3.1.C represents a 7 Day shutdown LCO.
"CR-CNS-2013-6096 identified a Part 21 issue associated with Foxboro Power Supply PC-ES-1A and PC-ES-1B. The Part 21 issue identifies a potential failure mechanism in which the adhesive backing on aluminum tie-wrap base used in the power supply fails and the base becomes detached from the power supply case. The nylon tie-wrap affixed to these bases becomes brittle with age and fails releasing the aluminum base to fall into the power supply where it has the potential to short out electrical equipment and fail the power supply. The equipment affected is: PC-LRPR-1A, PC-LRPR-1B, NBI-PR-2A, and NBI-PR-2B. These power supplies affect both Control Room Reg. Guide 1.97 Cat A instruments and associated PMIS/SPDS points. This instrumentation is utilized for emergency plan actions (EALs) and EOP 3A actions in addition to monitoring the previously mentioned functions. The loss of this instrumentation represents a significant loss of emergency response capability. The affected instruments are for indication only and perform no active safety functions. All of the referenced instrumentation is currently functioning as required.
"This condition has been entered into the CNS Corrective Action Program.
"A 60 day Licensee Event Report is not required for this event."
The licensee notified the NRC Resident Inspector.
* * * RETRACTION FROM DAVID MADSEN TO VINCE KLCO ON 9/5/13 AT 1854 EDT * * *
"This notification is being made to retract Event Notification EN 49308 that was reported on August 26, 2013. This EN identified Cooper Nuclear Station had equipment potentially affected by a Part 21 issue in which a potential failure mechanism of adhesive on aluminum ty-wrap bases used in two power supplies fails and the base becomes detached from the power supply case. The nylon ty-wraps affixed to these bases become brittle with age and fails, releasing the aluminum base to fall into the power supply with the potential to short out electrical equipment. These power supplies affected Post Accident Monitoring equipment that is used to monitor for Emergency Plan Actions (EALs) and EOP 3A actions. This equipment provides no active safety function and is used for indication only. The equipment affected included PC-ES-1A and PC-ES-1B and they provided divisional power to Post Accident Monitoring equipment for Reactor Pressure, Containment Level and Containment Pressure.
"Ten of the eleven aluminum cable tie holders were found to still be in place during the inspection of PC-ES-1A under WO 4972878. The one cable tie holder that was found to not be adhered was initially attached when the power supply was opened. Based on physical inspection of the removed cable ties and the installed wiring, and ten of the eleven cable tie holders being adhered upon inspection of the power supply it is concluded that this power supply remained qualified to perform its function under all design conditions in its as found configuration. The failure mechanism identified in the Part 21 required two failures. The inspection performed on PC-ES-1A only revealed the failure of one cable tie mount and not the widespread failures reported in the Part 21. Additionally, the cable ties removed from PC-ES-1A remained flexible and would not have failed during a seismic event based on engineering judgment. As such, PC-ES-1A remained capable of performing its design function. By engineering judgment PC-ES-1B also remained capable of performing its function. Therefore, there was no actual or potential major loss of emergency assessment capability per 10 CFR 50.72(b)(3)(xiii)."
The licensee notified the NRC Resident Inspector. Notified the R4DO (Gaddy).
"At 2305 on 26AUG13 the Shift Manager Declared PC-ES-1A and PC-ES-1B inoperable due to a Part 21 Notification that called the operability of the equipment into question. PAM [Post Accident Monitoring] Instrumentation LCO 3.3.3.1.A and 3.3.3.1.C were entered for Functions 1 (Reactor Pressure), 3 (Containment Level), and 7 (Containment Pressure). Both divisions are potentially affected. LCO 3.3.3.1.C represents a 7 Day shutdown LCO.
"CR-CNS-2013-6096 identified a Part 21 issue associated with Foxboro Power Supply PC-ES-1A and PC-ES-1B. The Part 21 issue identifies a potential failure mechanism in which the adhesive backing on aluminum tie-wrap base used in the power supply fails and the base becomes detached from the power supply case. The nylon tie-wrap affixed to these bases becomes brittle with age and fails releasing the aluminum base to fall into the power supply where it has the potential to short out electrical equipment and fail the power supply. The equipment affected is: PC-LRPR-1A, PC-LRPR-1B, NBI-PR-2A, and NBI-PR-2B. These power supplies affect both Control Room Reg. Guide 1.97 Cat A instruments and associated PMIS/SPDS points. This instrumentation is utilized for emergency plan actions (EALs) and EOP 3A actions in addition to monitoring the previously mentioned functions. The loss of this instrumentation represents a significant loss of emergency response capability. The affected instruments are for indication only and perform no active safety functions. All of the referenced instrumentation is currently functioning as required.
"This condition has been entered into the CNS Corrective Action Program.
"A 60 day Licensee Event Report is not required for this event."
The licensee notified the NRC Resident Inspector.
* * * RETRACTION FROM DAVID MADSEN TO VINCE KLCO ON 9/5/13 AT 1854 EDT * * *
"This notification is being made to retract Event Notification EN 49308 that was reported on August 26, 2013. This EN identified Cooper Nuclear Station had equipment potentially affected by a Part 21 issue in which a potential failure mechanism of adhesive on aluminum ty-wrap bases used in two power supplies fails and the base becomes detached from the power supply case. The nylon ty-wraps affixed to these bases become brittle with age and fails, releasing the aluminum base to fall into the power supply with the potential to short out electrical equipment. These power supplies affected Post Accident Monitoring equipment that is used to monitor for Emergency Plan Actions (EALs) and EOP 3A actions. This equipment provides no active safety function and is used for indication only. The equipment affected included PC-ES-1A and PC-ES-1B and they provided divisional power to Post Accident Monitoring equipment for Reactor Pressure, Containment Level and Containment Pressure.
"Ten of the eleven aluminum cable tie holders were found to still be in place during the inspection of PC-ES-1A under WO 4972878. The one cable tie holder that was found to not be adhered was initially attached when the power supply was opened. Based on physical inspection of the removed cable ties and the installed wiring, and ten of the eleven cable tie holders being adhered upon inspection of the power supply it is concluded that this power supply remained qualified to perform its function under all design conditions in its as found configuration. The failure mechanism identified in the Part 21 required two failures. The inspection performed on PC-ES-1A only revealed the failure of one cable tie mount and not the widespread failures reported in the Part 21. Additionally, the cable ties removed from PC-ES-1A remained flexible and would not have failed during a seismic event based on engineering judgment. As such, PC-ES-1A remained capable of performing its design function. By engineering judgment PC-ES-1B also remained capable of performing its function. Therefore, there was no actual or potential major loss of emergency assessment capability per 10 CFR 50.72(b)(3)(xiii)."
The licensee notified the NRC Resident Inspector. Notified the R4DO (Gaddy).