ML070930659
| ML070930659 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek  |
| Issue date: | 04/11/2007 |
| From: | Veronica Rodriguez NRC/NRR/ADRO/DLR |
| To: | Garrett T Wolf Creek |
| rodriguez v m, ADRO/DLR/RLRB, 415-3703 | |
| References | |
| Download: ML070930659 (7) | |
Text
April 11, 2007 Mr. Terry J. Garrett Vice President Engineering Wolf Creek Nuclear Operating Corporation P.O. Box 411 Burlington, KS 66839
SUBJECT:
REQUESTS FOR ADDITIONAL INFORMATION FOR THE REVIEW OF THE WOLF CREEK GENERATING STATION, UNIT 1, LICENSE RENEWAL APPLICATION
Dear Mr. Garrett:
By letter dated September 27, 2006, Wolf Creek Nuclear Operating Corporation submitted an application pursuant to 10 CFR Part 54, to renew the operating license for Wolf Creek Generating Station, Unit 1, for review by the U.S. Nuclear Regulatory Commission (NRC or the staff). The staff is reviewing the information contained in the license renewal application and has identified, in the enclosure, areas where additional information is needed to complete the review.
These requests for additional information were discussed with Lorrie Bell, and a mutually agreeable date for the response is within 30 days from the date of this letter. If you have any questions, please contact me at 301-415-3703 or e-mail VMR1@nrc.gov.
Sincerely,
/RA/
Verónica M. Rodríguez, Project Manager License Renewal Branch B Division of License Renewal Office of Nuclear Reactor Regulation Docket No. 50-482
Enclosure:
Requests for Additional Information cc w/encl: See next page
ML070930659 OFFICE LA:DLR PM:RLRB:DLR BC:RLRB:DLR NAME SFigueroa VRodríguez RAuluck DATE 03/4/07 04/10/07 04/11/07
WOLF CREEK GENERATING STATION (WCGS), UNIT 1 LICENSE RENEWAL APPLICATION (LRA)
REQUEST FOR ADDITIONAL INFORMATION (RAI)
Nickel Alloy Aging Management Program RAI B.2.1.34-1 The Nickel Alloy Aging Management Program (AMP) was submitted prior to the performance of pre-mitigation weld inspections for the application of weld overlays on pressurizer connections with dissimilar metal butt welds at WCGS. The pre-mitigation inspection performed in 2006 identified extensive circumferential cracking at three dissimilar metals welds associated with surge, relief, and safety nozzles. The staff requests that the applicant revise this AMP to incorporate information pertaining to the dissimilar metals butt weld inspection activities and findings. The revised AMP should: (1) discuss program enhancements incorporated as a result of the inspections, (2) provide information regarding the mitigation and preventive actions, taken or planned, to reduce the susceptibility of Alloy 600/82/182 components to primary water stress corrosion cracking (PWSCC), (3) discuss the inspection frequency and method of inspection of components susceptible to PWSCC covered under the scope of this program, and (4) provide justification that the AMP will provide reasonable assurance that PWSCC will be detected on a timely manner.
In addition, the staff requests that the applicant update the AMP Updated Safety Analysis Report (USAR) supplement to reflect all changes made to the program.
RAI B.2.1.34-2 PWSCC of components made of Alloy 600/82/182 in pressurized power reactors (PWR) is an emerging material degradation issue. The industry has initiated augmented inspections and mitigation of susceptible components to ensure safe operation of the affected plants. Recent inspection findings of extensive circumferential cracking of Alloy 82/182 dissimilar metal welds at WCGS has raised concerns regarding the adequacy of the inspection scope and schedule based on industry initiatives. In addition, discussions with the industry to resolve the staffs comments and recommendations to the inspection program delineated in the Materials Reliability Program (MRP)-139, Primary System Butt Weld Inspection and Evaluation Guideline, is continuing. Therefore, to ensure that the program is acceptable for implementation during the period of extended operation and that it will manage the effects of aging in accordance with 10 CFR 54.21(a)(3), the staff requests that the applicant commit to continue to participate in industry initiatives (such as the Westinghouse Owners Group and the Electric Power Research Institute MRP.) The program inspection requirements of Alloy 600/82/182 components must be consistent with the latest version of the NRC accepted industry guidance, generic communications, orders, and applicable regulatory requirements delineated in 10 CFR 50.55a. In addition, the staff requests that the applicant submit the AMP inspection plan for NRC review and approval at least 24 months prior to entering the period of extended operation.
RAI B.2.1.34-3 By letter dated October 12, 2005, the NRC staff provided comments and recommendations to the Nuclear Energy Institute (NEI) pertaining to the guidance provided in MRP-139 for the inspection and evaluation of Alloy 82/182 butt welds. This initiative is continuing and a resolution has not been reached. The staff requests that the applicant identify any exceptions that WCGS plans to take to the NRCs comments and recommendations provided to the NEI. If WCGS plans to take exceptions, the staff requests that the applicant provide its technical justification.
RAI B.2.1.34-4 By letter dated July 27, 2004, Wolf Creek Nuclear Operating Corporation (WCNOC) responded to NRC Bulletin 2004-01, Inspection of Alloy 82/182/600 Materials Used in the Fabrication of Pressurizer Penetrations and Steam Space Piping Connections at Pressurized Water Reactors. The staff requests that the applicant confirm that WCGS is not taking any exception to the guidance provided in this bulletin. If exceptions are identified, the applicant should address and justify them, especially those in the following areas: (1) percentage of inspection coverage to be achieved at each location, and (2) performance of an extent-of-condition evaluation, sample expansion, and non-destructive examinations if circumferential cracking is found. In addition, in view of the extensive PWSCC found at WCGS, the staff requests that the applicant discuss any enhancements made to the WCGS inspection plan for those components addressed in Bulletin 2004-01.
RAI B.2.1.34-5 NRC Bulletin 2003-02, Leakage from Reactor Pressure Vessel Lower Head Penetrations and Reactor Coolant Pressure Boundary Integrity, requested information from PWR licensees regarding the reactor coolant pressure boundary integrity associated with the reactor pressure vessel lower head penetrations. WCNOC did not discuss augmented inspection plans for these components in its response to this bulletin nor in its description of the AMP. In view of the extensive PWSCC found at WCGS, the staff requests that the applicant discuss the inspection plan for the components addressed in Bulletin 2003-02, and provide justification for its adequacy.
RAI B.2.1.34-6 The LRA states that the reactor coolant system (RCS) pressure boundary, RCS non-pressure boundary, and ESF locations are included within the scope of this AMP. The staff requests that the applicant identify the components associated with these locations and its corresponding inspection plan. In addition, the staff requests that the applicant identify any Alloy 600/82/182 components not covered within the scope of this program and the reasons for their exclusion.
RAI B.2.1.34-7 The detection of aging effects program element states that this AMP utilizes various visual, surface and volumetric inspections and examination techniques for early detection of PWSCC in Alloy 600 components. However, it does not specify whether the equipment, method and personnel used for these inspections meet the ASME Code Section XI requirements. The staff requests that the applicant revise the LRA to clarify this statement.
RAI B.2.1.34-8 The monitoring and trending program element states that relative risk rankings for Alloy 600 locations are included as part of this AMP. The staff requests that the applicant address how the relative risk rankings will be used in the inspection of Alloy 600/82/182 components and whether this ranking methodology was approved by the NRC.
RAI B.2.1.34-9 The corrective actions program element states that Corrective actions may be used as tracking and documentation records for changes in plant thought processes and to identify potential improvement in programs from benchmarking activities. The staff requests that the applicant provide details and examples to clarify this statement.
Letter to T. Garrett from V. Rodriguez, dated April 11, 2007 DISTRIBUTION:
SUBJECT:
REQUESTS FOR ADDITIONAL INFORMATION FOR THE REVIEW OF THE WOLF CREEK GENERATING STATION, UNIT 1, LICENSE RENEWAL APPLICATION HARD COPY DLR RF E-MAIL:
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Wolf Creek Generating Station cc:
Jay Silberg, Esq.
Pillsbury Winthrop Shaw Pittman, LLP 2300 N Street, NW Washington, DC 20037 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-7005 Senior Resident Inspector U.S. Nuclear Regulatory Commission P.O. Box 311 Burlington, KS 66839 Chief Engineer, Utilities Division Kansas Corporation Commission 1500 SW Arrowhead Road Topeka, KS 66604-4027 Office of the Governor State of Kansas Topeka, KS 66612 Attorney General 120 S.W. 10th Avenue, 2nd Floor Topeka, KS 66612-1597 County Clerk Coffey County Courthouse 110 South 6th Street Burlington, KS 66839 Thomas A. Conley, Section Chief Radiation and Asbestos Control Kansas Department of Health and Environment Bureau of Air and Radiation 1000 SW Jackson, Suite 310 Topeka, KS 66612-1366 Vice President Operations/Plant Manager Wolf Creek Nuclear Operating Corporation P.O. Box 411 Burlington, KS 66839 Supervisor Licensing Wolf Creek Nuclear Operating Corporation P.O. Box 411 Burlington, KS 66839 U.S. Nuclear Regulatory Commission Resident Inspectors Office/Callaway Plant 8201 NRC Road Steedman, MO 65077-1032 Kevin J. Moles, Manager Regulatory Affairs Wolf Creek Nuclear Operating Corporation P.O. Box 411 Burlington, KS 66839 Lorrie I. Bell, Project Manager Wolf Creek Nuclear Operating Corporation P.O. Box 411 Burlington, KS 66839 Mr. James Ross Nuclear Energy Institute 1776 I Street, NW, Suite 400 Washington, DC 20006-3708