ML080530067

Request for Additional Information for the Review of the Wolf Creek Generating Station (Wcgs), License Renewal Application

ML080530067
Person / Time
Site:	Wolf Creek
Issue date:	02/28/2008
From:	Tam Tran NRC/NRR/ADRO/DLR
To:	Garrett T Wolf Creek
Tran T, NRR/RPB2, 415-3617
References
Download: ML080530067 (5)

Text

February 28, 2008

Mr. Terry Garrett Vice President, Engineering

Wolf Creek Nuclear Operating Corporation P.O. Box 411 Burlington, KS 66839

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION FOR THE REVIEW OF THE WOLF CREEK GENERATING STATION, LICENSE RENEWAL APPLICATION

Dear Mr. Garrett:

By letter dated September 27, 2006, Wolf Creek Nuclear Operating Corporation (WCNOC) submitted an application pursuant to 10 CFR Part 54, to renew the operating license NPF-42 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. Further requests for additional information may be issued in the future.

Items in the enclosure were discussed with Ms. Lorrie Bell; and a mutually agreeable date for the response is within 30 days from the date of this letter or no later than April 1, 2008. If you have any questions, please contact me at 301-415-3617 or by e-mail at TXT1@nrc.gov. Sincerely, /RA/ Tam Tran, Project Manager Project Branch 1 Division of License Renewal Office of Nuclear Reactor Regulation Docket No. 50-482

Enclosure:

As Stated

cc w/encl: See next page

ML080530067 OFFICE LA:DLR PM:RPB1:DLR BC:RPB1:DLR NAME YEdmonds T. Tran L. Lund DATE 02/27/08 02/27/08 02/28/08 WOLF CREEK GENERATING STATION, UNIT 1 LICENSE RENEWAL APPLICATION REQUESTS FOR ADDITIONAL INFORMATION Metal Fatigue Analyses

Follow-up RAI for 4.3-1 The applicant's responses provided in letters dated October 3, and 17, 2007, did not address the staff's concerns as stated in RAI 4.3-1. The October 3, 2007, letter stated that 1D transfer functions were developed for HL surge line nozzle and the charging nozzles in the vicinity of the nozzle to pipe welds. It went on to state that the development of the transfer functions takes full advantage of the local geometry and symmetry. However, the staff finds no axis of symmetry at the nozzle corners. Further, at the nozzle to pipe welds, the loading is not symmetric if thermal stratification is present. Therefore, the validity of transfer functions developed by using "1-D peak stress" is not applicable at these locations. In order to enable the staff to make a

determination on this issue, the applicant is requested to perform an environmentally-assisted fatigue analysis and provide results to the NRC Staff of a 3-D finite element analysis using an industry-accepted computer code, such as ANSYS. The analysis should cover nozzle corners with geometrical discontinuities and at locations where thermal stratification loading is significant. This analysis shall follow the rules of American Society of Mechanical Engineers Boiler and Pressure Vessel Code Section III, Subsection NB-3200, requiring the use of six stress components to define the stress state and determine the alternating stress intensities.

Follow-up RAI for 4.3-3

Wolf Creek Generating Station's (WCGS) commitment closure letter (ET 08-007), dated January 25, 2008, does not address the following commitments on Page 14 of the October 3, 2007, letter (ET 07-0046):

(1) Since WCGS implemented the modified operating procedure (MOP) prior to 1995, it is reasonable to suspect that heat-ups during PERIOD1 would have more insurge/outsurge cycles than PERIOD2. WCNOC agrees with this assertion, and will commit to updating the baseline to account for this factor. The baseline will be increased based on the expected number of additional insurge/outsurge cycles that would be accumulated in a pre-MOP environment.

(2) In a follow-up discussion, the reviewers further noted that the cumulative usage factors back-projection did not consider the relative severity of charging and letdown transients. - However, in the revised baseline, Wolf Creek will explicitly consider the differential contribution of fatigue for each category of charging event.

The January 25, 2008, letter did not close commitments made by WCGS in the October 3, 2007, letter as quoted above. Please provide additional calculations and discussions to address the committed actions regarding the additional insurge/outsurge cycles and the differential contribution of fatigue for each category of charging event.

Letter to Wolf Creek from T. Tran, dated February 28, 2008 DISTRIBUTION

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION FOR THE REVIEW OF THE WOLF CREEK GENERATING STATION, LICENSE RENEWAL APPLICATION HARD COPY: DLR R/F E-MAIL: PUBLIC SSmith (srs3)

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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 PO 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. 10 th Avenue, 2nd Floor Topeka, KS 66612-1597

County Clerk Coffey County Courthouse

110 South 6 th 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 PO Box 411 Burlington, KS 66839

Supervisor Licensing

Wolf Creek Nuclear Operating Corporation PO 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 PO Box 411 Burlington, KS 66839 Lorrie I. Bell, Project Manager

Wolf Creek Nuclear Operating Corporation PO Box 411 Burlington, KS 66839 Mr. Gordon A. Clefton Nuclear Energy Institute

1776 I Street, NW, Suite 400 Washington, DC 20006-3708