ML030990040
| ML030990040 | |
| Person / Time | |
|---|---|
| Site: | Mcguire, Catawba, McGuire  |
| Issue date: | 04/08/2003 |
| From: | Rani Franovich NRC/NRR/DRIP/RLEP |
| To: | Tuckman M Duke Energy Corp |
| References | |
| Download: ML030990040 (9) | |
Text
April 8, 2003 Mr. M. S. Tuckman Executive Vice-President Nuclear Generation Duke Energy Corporation P.O. Box 1006 EC07H Charlotte, NC 28201-1006
SUBJECT:
COMMITMENT TO IMPLEMENT THE FINAL VERSION OF THE INTERIM STAFF GUIDANCE GOVERNING THE TREATMENT OF FUSE HOLDERS FOR RENEWAL OF MCGUIRE AND CATAWBA OPERATING LICENSES
Dear Mr. Tuckman:
By a letter dated June 13, 2001, Duke Energy Corporation (Duke) submitted an application to the U.S. Nuclear Regulatory Commission (NRC) for renewal of the McGuire, Units 1 and 2, and Catawba, Units 1 and 2, operating licenses for up to an additional 20 years. In a letter dated November 7, 2002, the NRC staff requested Duke to commit to implement, at McGuire and Catawba, the final resolution of an interim staff guidance (ISG) document governing the treatment of fuse holders for license renewal that was being developed at that time. In a letter dated November 18, 2002, Duke responded to the staffs request accordingly and committed to implement the final version of the fuse holder ISG by June 12, 2021 (for McGuire, Units 1 and 2), and December 6, 2024 (for Catawba, Units 1 and 2).
On January 6, 2003, the staff issued its safety evaluation report (SER) to document the findings of the safety review of the license renewal application (LRA) and supporting documentation for McGuire, Units 1 and 2, and Catawba, Units 1 and 2. The commitment is documented in Section 2.5.2.2 and Appendix D of the SER.
In a letter to Mr. Alan Nelson, of the Nuclear Energy Institute, and to Mr. David Lochbaum, of the Union of Concerned Scientists, dated March 4, 2003, the staff issued the final fuse holder ISG document (ADAMS Accession No. ML030690492). A copy of the ISG is enclosed for your convenience. The staff requests that Duke review the enclosed ISG and confirm, by official correspondence, its plans to implement this guidance by June 12, 2021 (for McGuire, Units 1 and 2), and December 6, 2024 (for Catawba, Units 1 and 2).
M. S. Tuckman If you have any questions regarding this matter, please contact me at 301-415-1868.
Sincerely,
/RA/
Rani Franovich, Project Manager License Renewal and Environmental Impacts Program Division of Regulatory Improvement Programs Office of Nuclear Reactor Regulation Docket Nos.: 50-369, 50-370, 50-413, and 50-414
Enclosure:
As stated cc w/encl: See next page
M. S. Tuckman If you have any questions regarding this matter, please contact me at 301-415-1868.
Sincerely,
/RA/
Rani Franovich, Project Manager License Renewal and Environmental Impacts Program Division of Regulatory Improvement Programs Office of Nuclear Reactor Regulation Docket Nos.: 50-369, 50-370, 50-413, and 50-414
Enclosure:
As stated cc w/encl: See next page DISTRIBUTION:
See next page Coordinated with OGC (S. Uttal)
Document Name: C:\\ORPCheckout\\FileNET\\ML030990040.wpd OFFICE PM:RLEP:DRIP LA:RLEP:DRIP SC:RLEP:DRIP PD:RLEP:DRIP NAME RFranovich YEdmonds (Ltr. Only)
SLee PTKuo DATE 4/8/2003 4/8 /2003 4/8 /2003 4/8/2003 OFFICIAL RECORD COPY
DISTRIBUTION: Letter to Mr. Michael S. Tuckman, Dated: April 8, 2003 HARD COPY RLEP RF R. Franovich E-MAIL:
PUBLIC W. Borchardt D. Matthews F. Gillespie RidsNrrDe R. Barrett E. Imbro G. Bagchi K. Manoly W. Bateman J. Calvo C. Holden P. Shemanski H. Nieh G. Holahan H. Walker S. Black B. Boger D. Thatcher G. Galletti C. Li J. Moore R. Weisman M. Mayfield A. Murphy W. McDowell S. Smith (Srs3)
T. Kobetz C. Munson RLEP Staff R. Martin C. Patel R. Haag C. Julian
McGuire & Catawba Nuclear Stations, Units 1 and 2 cc:
Ms. Lisa F. Vaughn Legal Department (PBO5E)
Duke Energy Corporation 422 South Church St.
Charlotte, NC 28201-1006 County Manager of Mecklenburg County 720 East Fourth St.
Charlotte, NC 28202 Mr. Michael T. Cash Regulatory Compliance Manager Duke Energy Corporation McGuire Nuclear Site 12700 Hagers Ferry Rd.
Huntersville, NC 28078 Anne Cottingham, Esquire Winston and Strawn 1400 L Street, NW Washington, DC 20005 Senior Resident Inspector c/o U. S. Nuclear Regulatory Commission 12700 Hagers Ferry Rd.
Huntersville, NC 28078 Mr. Peter R. Harden, IV VP-Customer Relations and Sales Westinghouse Electric Company 6000 Fairview Rd., 12th Floor Charlotte, NC 28210 Dr. John M. Barry Mecklenburg County Department of Environmental Protection 700 N. Tryon St.
Charlotte, NC 28202 County Manager of York County York County Courthouse York, SC 29745 Mr. Richard M. Fry, Director Division of Radiation Protection North Carolina Department of Environment, Health, and Natural Resources 3825 Barrett Dr.
Raleigh, NC 27609-7721 Ms. Karen E. Long Assistant Attorney General North Carolina Department of Justice P. O. Box 629 Raleigh, NC 27602 Mr. C. Jeffrey Thomas Manager - Nuclear Regulatory Licensing Duke Energy Corporation 526 South Church St.
Charlotte, NC 28201-1006 NCEM REP Program Manager 4713 Mail Service Center Raleigh, NC 27699-4713 Mr. T. Richard Puryear Owners Group (NCEMC)
Duke Energy Corporation 4800 Concord Rd.
York, SC 29745 Mr. Gary Gilbert Regulatory Compliance Manager Duke Energy Corporation 4800 Concord Rd.
York, SC 29745 North Carolina Municipal Power Agency Number 1 1427 Meadowwood Blvd.
P. O. Box 29513 Raleigh, NC 27626-0513 Piedmont Municipal Power Agency 121 Village Dr.
Greer, SC 29651 Saluda River Electric P. O. Box 929 Laurens, SC 29360 North Carolina Electric Membership Corporation P. O. Box 27306 Raleigh, NC 27611 Senior Resident Inspector 4830 Concord Rd.
York, SC 29745 Lou Zeller Blue Ridge Environmental Defense League P.O. Box 88 Glendale Springs, NC 28629 Paul Gunter Nuclear Information &
Resource Service 1424 16th Street NW, Suite 404 Washington, DC 20036 Don Moniak Blue Ridge Environmental Defense League Aiken Office P.O. Box 3487 Aiken, SC 29802-3487 Mr. Kevin Cox The Huntersville Star P. O. Box 2542 Huntersville, NC 28070 Mr. Robert L. Gill, Jr.
Duke Energy Corporation Mail Stop EC-12R P. O. Box 1006 Charlotte, SC 28201-1006 Mr. Henry J. Porter, Assistant Director Division of Waste Management Bureau of Land & Waste Management S.C. Dept of Health and Environ. Control 2600 Bull St.
Columbia, SC 29201-1708 Mr. L. A. Keller Duke Energy Corporation 526 South Church St.
Charlotte, NC 28201-1006 Mr. Gregory D. Robison Duke Energy Corporation Mail Stop EC-12R 526 S. Church St.
Charlotte, NC 28201-1006 Mary Olson Nuclear Information & Resource Service Southeast Office P.O. Box 7586 Asheville, NC 28802 Mr. Alan P. Nelson Nuclear Energy Institute 1776 I Street, N.W., Suite 400 Washington, DC 20006-3708
INTERIM STAFF GUIDANCE (ISG)-5 ON THE IDENTIFICATION AND TREATMENT OF ELECTRICAL FUSE HOLDERS FOR LICENSE RENEWAL Staff Position Consistent with the requirements specified in 10 CFR 54.4(a), fuse holders (including fuse clips and fuse blocks) are considered to be passive electrical components. Fuse holders would be scoped, screened, and included in the aging management review (AMR) in the same manner as terminal blocks and other types of electrical connections that are currently being treated in the process. This staff position only applies to fuse holders that are not part of a larger assembly, but support safety-related and non safety-related functions in which the failure of a fuse precludes a safety function from being accomplished [10 CFR Part 54.4(a)(1) and (a)(2)].
Examples are fuses that are used as protective devices to ensure the integrity of containment electrical penetrations when they are challenged by electrical faults, or as isolation devices between Class 1E and non-Class 1E electrical circuits to ensure that the safety function is not compromised as a result of faults in the non-Class 1E circuits. An appropriate aging management program (AMP) should be adopted to manage the effects of aging where necessary.
Rationale The intended functions of a fuse holder are to provide mechanical support for the fuse and to maintain electrical contact with the fuse blades or metal end caps to prevent the disruption of the current path during normal operating conditions when the circuit current is at or below the current rating of the fuse. Fuse holders perform the same primary function as connections; they provide electrical connections to specified sections of an electrical circuit to deliver rated voltage, current, or signals. The intended functions of fuse holders meet the criteria of 10 CFR 54.4(a) and are performed without moving parts or without a change in configuration or properties as described in 10 CFR 54.21(a)(1)(i). The staff concludes that fuse holders are passive, long-lived electrical components within the scope of license renewal and subject to an AMR. However, fuse holders inside the enclosure of an active component, such as switchgear, power supplies, power inverters, battery chargers, and circuit boards, are considered to be piece parts of the larger assembly. Therefore, under 10 CFR 54.21, fuse holders that are parts of a larger assembly are considered outside the scope for license renewal.
For license renewal purposes, fuse holders/blocks are classified as a specialized type of terminal block because of the similarity in design and construction. Terminal blocks are passive components subject to an AMR for license renewal. However, like fuses, terminal blocks located inside the enclosure of an active component are considered to be piece parts of the larger assembly and, thus, are outside the scope of license renewal. The fuse holders are typically constructed of blocks of rigid insulating material, such as phenolic resins. Metallic clamps are attached to the blocks to hold each end of the fuse. The clamps can be spring-loaded clips that allow the fuse ferrules or blades to slip in, or they can be bolt lugs, to which the fuse ends are bolted. The clamps are typically made of copper.
Operational experience, as discussed in NUREG-1760 (Aging Assessment of Safety-Related Fuses Used in Low-and Medium-Voltage Applications in Nuclear Power Plants), identified fuse holders as experiencing a number of age-related failures. Aging stressors such as vibration, thermal cycling, electrical transients, mechanical stress, fatigue, corrosion, chemical contamination, or oxidation of the connecting surfaces can result in fuse holder failure. On this basis, fuse holders (including both the insulation material and the metallic clamps) are subject to both an AMR and AMP for license renewal. Typical plant effects observed from fuse holder failures due to aging have resulted in: challenges to safety systems, cable insulation failure due to over-temperature, failure of a containment spray pump to start, a reactor trip, etc. Therefore, managing age-related failures of fuse holders would have a positive effect on the safety performance of a plant. Information Notices 91-78, 87-42, and 86-87 provide examples that underscore the safety significance of fuse holders and the potential problems that can arise from age-related fuse holder failures.
GALL AMP for Fuse Holders Fuse holders, are considered as electrical connections and, thus, are subject to GALL XI.E1 Electrical Cables and Connections Not Subject to 10 CFR 50.49 Environmental Qualification Requirements. However, the AMP for fuse holders needs to include the following aging stressors, if applicable: fatigue, mechanical stress, vibration, chemical contamination, and corrosion. Where environments or operating conditions preclude such aging effects (e.g., fuse holders not subject to vibration from rotating machinery), they need not be addressed by the AMP. GALL XI.E1 is based on only a visual inspection of accessible cables and connections.
Visual inspection, alone, may not be sufficient to detect the aging effects from fatigue, mechanical stress, vibration, or corrosion on the metallic clamps of the fuse holder. Other methods of aging detection may be necessary. Alternatively, plant modifications or administrative controls that have been made, which preclude these types of aging effects from occurring, would eliminate the need for an additional AMP (i.e., the GALL XI.E1 program will be adequate).