ENS 49308
ENS Event | |
|---|---|
04:05 Aug 27, 2013 | |
| Title | Post Accident Monitoring Instrumentation Power Supplies Potentially Degraded |
| Event Description | 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.
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). |
| Where | |
|---|---|
Cooper  Nebraska (NRC Region 4) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | |
| Time - Person (Reporting Time:+0.08 h0.00333 days <br />4.761905e-4 weeks <br />1.09584e-4 months <br />) | |
| Opened: | Fred Schizas 04:10 Aug 27, 2013 |
| NRC Officer: | Pete Snyder |
| Last Updated: | Sep 5, 2013 |
| 49308 - NRC Website
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Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 577902025-06-30T21:41:00030 June 2025 21:41:00
[Table view]10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of the Public Primary Alert Notification System ENS 576832025-04-28T15:26:00028 April 2025 15:26:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of OFF-SITE Communication ENS 572202024-07-09T09:55:0009 July 2024 09:55:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Communications Capabilities ENS 559812022-07-07T21:01:0007 July 2022 21:01:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of National Warning System Tower ENS 557152022-01-27T16:38:00027 January 2022 16:38:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Meteorlogical Data Acquisition System ENS 542322019-08-19T14:39:00019 August 2019 14:39:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Public Prompt Notification System ENS 539412019-03-16T16:00:00016 March 2019 16:00:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Tone Alert Radio Transmission Tower ENS 532612018-03-14T22:11:00014 March 2018 22:11:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Emergency Notification Tone Alert Radio System ENS 531332017-12-20T21:59:00020 December 2017 21:59:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Emergency Alert System Out of Service ENS 530742017-11-16T02:07:00016 November 2017 02:07:00 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release, 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Public Prompt Notification System Capability ENS 527682017-05-23T13:30:00023 May 2017 13:30:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Meteorological Tower Primary and Backup Communication Equipment ENS 527652017-05-19T13:05:00019 May 2017 13:05:00 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release, 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Nonfunctional Radio Transmission Tower Affects Tone Alert Radios ENS 522792016-10-04T20:30:0004 October 2016 20:30:00 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release, 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Cooper Nuclear Station Loss of Tone Alert Radios ENS 522622016-09-25T14:15:00025 September 2016 14:15:00 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release, 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Cooper Nuclear Station Loss of Tone Alert Radios ENS 520702016-07-07T11:10:0007 July 2016 11:10:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Tone Alert Radio System Tower ENS 518872016-04-27T13:23:00027 April 2016 13:23:00 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release, 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Tone Alert Radio System Tower ENS 516172015-12-22T01:55:00022 December 2015 01:55:00 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release, 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Tone Alert Radio System Tower ENS 515582015-11-21T00:08:00021 November 2015 00:08:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Meteorological Tower Out of Service ENS 512362015-07-16T04:32:00016 July 2015 04:32:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Emergency Assessment Capability Due to Meteorological Tower Software Failure ENS 509472015-04-02T06:49:0002 April 2015 06:49:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Meteorological System Due to Lightning Strike ENS 503922014-08-22T11:45:00022 August 2014 11:45:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Assessment Capability Because the Meteorological Tower Computer Failed ENS 501612014-05-31T16:36:00031 May 2014 16:36:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Emergency Tone Alert Radio Transmitter Not Functional ENS 501052014-05-11T13:02:00011 May 2014 13:02:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of the Meteorological Tower Computer System ENS 495002013-11-05T07:00:0005 November 2013 07:00:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Technical Support Center Out of Service for Planned Maintenance ENS 493082013-08-27T04:05:00027 August 2013 04:05:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Post Accident Monitoring Instrumentation Power Supplies Potentially Degraded ENS 490622013-05-23T15:19:00023 May 2013 15:19:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Temporary Loss of Meteorological Monitoring System During Planned Maintenance ENS 484302012-10-22T11:42:00022 October 2012 11:42:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Partial Loss of Emergency Assessment Capability ENS 484052012-10-13T08:20:00013 October 2012 08:20:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Portions of Onsite Telephone Systems Not Responding Normally ENS 483012012-09-12T13:06:00012 September 2012 13:06:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Technical Support Center Out of Service for Planned Maintenance ENS 482302012-08-24T18:32:00024 August 2012 18:32:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Partial Loss of Reactor Building Emergency Assessment Capability ENS 479032012-05-07T17:39:0007 May 2012 17:39:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Tone Alert Radio System Outage ENS 477782012-03-28T16:30:00028 March 2012 16:30:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Tone Alert Radios Out of Service for Planned Maintenance ENS 477532012-03-19T06:19:00019 March 2012 06:19:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss Public Prompt Notification Capability ENS 458562010-04-19T06:58:00019 April 2010 06:58:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Tsc Emergency Ventilation System Discovered Non-Functional While Placing a Clearance ENS 449372009-03-27T05:00:00027 March 2009 05:00:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Troubleshooting Emergency Offsite Facility Communications ENS 438702007-12-28T02:04:00028 December 2007 02:04:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Spds Capability for Greater than One Hour ENS 438562007-12-20T13:00:00020 December 2007 13:00:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Various Systems at Eof Due to Local Telephone System Partial T1 Failure ENS 438352007-12-11T16:19:00011 December 2007 16:19:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of 11 Alert and Notification Sirens Due to Severe Ice Storm ENS 430762007-01-04T23:43:0004 January 2007 23:43:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness High Range Effluent Radiation Monitors Declared Inoperable Due to Common Cause Failure ENS 429942006-11-16T06:09:00016 November 2006 06:09:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Spds Unavailible Due to Planned Maintenance ENS 415882005-04-11T22:04:00011 April 2005 22:04:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Public Prompt Notification Capability ENS 408782004-07-16T18:45:00016 July 2004 18:45:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness the Plant Lost Public Prompt Notification Capability ENS 407412004-05-11T15:55:00011 May 2004 15:55:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Emergency Assessment Capability Due to Loss of Normal Power to Tsc 2025-06-30T21:41:00 | |