ML080440302
| ML080440302 | |
| Person / Time | |
|---|---|
| Site: | Oconee, Mcguire, Catawba, McGuire  |
| Issue date: | 02/07/2008 |
| From: | Brandi Hamilton Duke Energy Carolinas, Duke Power Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| GL-07-001 | |
| Download: ML080440302 (5) | |
Text
Duke BRUCE H HAMILTON Vice President McGuire Nuclear Station Duke Energy Corporation MG01 VP / 12700 Hagers Ferry Road Huntersville, NC 28078 704-875-5333 704-875-4809 fax bhhamilton@duke-energy. com February 7, 2008 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk 11555 Rockville Pike Rockville, MD 20852
Subject:
Duke Power Company LLC d/b/a Duke Energy Carolinas, LLC (Duke)
Oconee Nuclear Station, Units 1, 2, and 3 Docket Nos. 50-269, 50-270, 50-287 McGuire Nuclear Station, Units 1 and 2 Docket Nos. 50-369, 50-370 Catawba Nuclear Station, Units 1 and 2 Docket Nos. 50-413, 50-414 Generic Letter 2007-01, Inaccessible or Underground Power Cable Failures that Disable Accident Mitigation Systems or Cause Plant Transients Response to Request for Additional Information By letter dated May 8, 2007, Duke submitted a response to Generic Letter (GL)2007-01, "Inaccessible or Underground Power Cable Failures that Disable Accident Mitigation Systems or Cause Plant Transients." Two power cable failures meeting the criteria of this GL were reported in that letter.
On October 22, 2007, the NRC electronically sent to Duke a Request for Additional Information (RAI). The RAI stated in part that if a licensee excluded cable failures from the GL scope that were due to connection, excavation and/or maintenance activities and did not justify the exclusion, additional data must be provided. Attached is an additional power cable failure being reported since it meets the requirement of this RAI.
Please contact P. T. Vu of Regulatory Compliance at (704) 875-4302 if there are any questions.
Very truly yours, Bruce H. Hamilton Attachment 4(27 www. duke-energy, com
" I U. S. Nuclear Regulatory Commission February 7, 2008 Page 2 xc:
V. M. McCree, Acting Regional Administrator U. S. Nuclear Regulatory Commission Sam Nunn Atlanta Federal Center 61 Forsyth St., SW Atlanta, GA 30303-8931 L. N. Olshan, Senior Project Manager (ONS)
U. S. Nuclear Regulatory Commission 11555 Rockville Pike Mail Stop 0-8 G9A Rockville, MD 20852-2738 J. F. Stang, Jr., Senior Project Manager (CNS and MNS)
U. S. Nuclear Regulatory Commission 11555 Rockville Pike Mail Stop 0-8 G9A Rockville, MD 20852-2738 D. W. Rich NRC Senior Resident Inspector Oconee Nuclear Station J. B. Brady NRC Senior Resident Inspector McGuire Nuclear Station A. T. Sabisch NRC Senior Resident Inspector Catawba Nuclear Station
U. S. Nuclear Regulatory Commission February 7, 2008 Page 3 I affirm that I, Bruce H. Hamilton, am the person who subscribed my name to the foregoing, and that all the matters and facts herein are true and correct to the best of my knowledge.
Bruce H. Hamilton Subscribed and Sworn to me:
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Attachment Oconee Nuclear Station McGuire Nuclear Station Catawba Nuclear Station GL 2007-01, RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION
J GL 2007-01, RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION February 7, 2008 - Page 1 of 1 Question The U.S. Nuclear Regulatory Commission (NRC) staff has received the cable failure histories for Catawba, McGuire, and Oconee in response to Generic Letter (GL) 2007 01, "Inaccessible or Underground Power Cable Failures that Disable Accident Mitigation Systems or Cause Plant Transients."
The licensee identified power cable failures from a review of the corrective action program, work management system, and licensee event reports. The licensee included failures that satisfied the following criteria: non-connection failures, non-excavation failures, and non-maintenance-induced failures (e.g., nail puncture). Immediate cable failures caused by connection, excavation, and/or maintenance activities may be outside the scope of the GL; however, a licensee must show that the failure directly resulted from the activity alone and was not a contributing factor to a failure of an already degraded cable. In addition, latent damage from these activities leading to a subsequent cable failure is within the scope of the GL. If the licensee excluded cable failures caused by connection, excavation, and/or maintenance activities and did not justify the exclusion, provide the data for these failures as requested in GL 2007-01.
The NRC provided additional guidance on how licensees should determine which cable failures are within the scope of GL 2007 01 in the NRC letter dated April 13, 2007, from Michael J. Case (NRC) to James H. Riley (Nuclear Energy Institute) (Agencywide Documents Access and Management System (ADAMS) Accession No. ML070940311).
Answer Duke re-evaluated previous search results involving connection, excavation, and/or maintenance activities to ensure that they were properly excluded. One of these events is reported below since it meets the requirement of this RAI.
Catawba Nuclear Station Type: Crosslinked Polyethylene (XLPE) cable insulation, 3/C-#10AWG (3XJIOG2).
Manufacturer: Brand-Rex.
Date of failure: August 19, 2004.
Type of service: Normally energized, Cathodic Protection Rectifier 1 (1RECT0001), 1.42 KVA, non-safety, cable ID # 1 EUC 501. Ref. DEDB 600VAC Load List entry for MCC SMXF-F01D Load-Factor = 1.
Voltage class: Nominal system voltage 600 VAC, cable rating voltage 2000 VAC.
Years of service: Approximately 20 years.
Root causes: No formal root cause was performed. Failure was discovered during excavation.
The investigation report indicated that the subject cable was incorrectly identified as a cable planned for cutting and was cut in error. No reports indicating failure or degradation of the subject cable prior to this event were available. No information was available describing the condition or any testing of the subject cable or severed cable section. Therefore, prior degradation of the cable cannot be confirmed. Refer to PIP C-04-4053 and WR 00659570.