ML20205J337

Forwards Request for Addl Info Re Wolf Creek Generating Station IPEEE & 971208 Response to RAI from NRC Re Ipeee. RAI & Schedule for Response Were Discussed with T Harris on 990405

ML20205J337
Person / Time
Site:	Wolf Creek
Issue date:	04/06/1999
From:	Thomas K NRC (Affiliation Not Assigned)
To:	Maynard O WOLF CREEK NUCLEAR OPERATING CORP.
References
TAC-M83696, NUDOCS 9904090326
Download: ML20205J337 (6)

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April 6,1999 Mr. Otto L. Maynard President and Chief Executive Officer Wolf Creek Nuclear Operating Corporation Post Office Box 411 Burlington, Kansas 66839

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION (RAl) REGARDING WOLF CREEK GENERATING STATION (TAC NO. M83696)

Dear Mr. Maynard:

The NRC staff has reviewed the Wolf Creek Generating Station individual Plant Examination of External Events (IPEEE) and the December 8,1997, response to a request for additional information from the NRC regarding the IPEEE. As a result of the review, the staff has that additionalinformation is needed to complete the review. The information needed is detailed in the enclosure.

To assist the NRC staff in meeting its review schedule, we request that you respond to the RAI within 60 days of receipt of this letter. The RAI and schedule for your response were discussed with Mr. Tony Harris of your staff on April 5,1999.

If you have any questions, please contact me at (301) 415-1362.

Sincerely, ORIG. SIGNED BY Kristine M. Thomas, Project Manager, Section 2 Project Directorate IV & Decommissioning Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-482 DISTRIBUTION:

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• • • • • April 6, 1999 l

Mr. Otto L. Maynard President and Chief Executive Officer Wolf Creek Nuclear Operating Corporation Post Office Box 411 Burlington, Kansas 66839

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION (RAI) REGARDING WOLF CREEK GENERATING STATION (TAC NO. M83696) l l

Dear Mr. Maynard:

l The NRC staff has reviewed the Wolf Creek Generating Station Individual Plant Examination I of Extemal Events (IPEEE) and the December 8,1997, response to a request for additional information from the NRC regarding the IPEEE. As a result of the review, the staff has determined that additionalinformation is needed to complete the review. The information needed is detailed in the enclosure.

To assist the NRC staff in meeting its review schedule, we request that you respond to the RAI within E0 days of receipt of this letter. The RAI and schedule for your response were discussed with Mr. Tony Harris of your staff on April 5,1999.

If you have any questions, please contact me at (301) 415-1362.

Sincerely, 1

WW Kristine M. Thomas, Project Manager, Section 2 ,

Project Directorate IV & Decommissioning i Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-482

Enclosure:

Request for Additional Information cc w/ encl: See next page l

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Wolf Creek Generating Station cc w/r.ncl:

Jay Silberg, Esq. ' Chief Operating Officer Shaw, Pittman, Potts & Trowbridge Wolf Creek Nuclear Operating Corporation 2300 N Street, NW P. O, Box 411 Washington, D.C. 20037 Burlington, ~ Kansas 66839 Regional Administrator, Region IV Supervisor Licensing U.S. Nuclear Regulatory Commission Wolf Creek Nuclear Operating Corporation 611 Ryan Plaza Drive, Suite 1000 P.O. Box 411 Arlington, Texas 76011 Burlington, Kansas 66839 Senior Resident inspector U.S. Nuclear Regulatory Commission U.S. Nuclear Regulatory Cornrrission Resident inspectors Office P. O. Box 311 8201 NRC Road Burlington, Kansas 66839 Steedman, Missouri 65077-1032 Chief Engineer Utilities Division Kansas Corporation Commission j 1500 SW Arrowhead Road l Topeka, Kansas 66604-4027 l Office of the Got r nor i State of Kansas i Topeka, Kansas 66612 Attomey General j Judicial Center 301 S.W.10th 2nd Floor Topeka, Kansas 66612 County Clerk Coffey County Courthouse

- Burlington, Kansas 66839 Vick L. Cooper, Chief Radiation Control Program Kansas Department of Health and Environment Bureau of Air and Radiation Forbes Field Building 283 Topeka, Kansas 66620

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IPEEE SUPPLEMENTAL REQUEST FOR ADDITIONAL INFORMATION WOLF CREEK NUCLEAR OPERATING CORPORATION WOLF CREEK GENERATING STATION DOCKET NO. 50-482 Seismic Evaluation Wolf Creek Nuclear Operating Corporation's (WCNOC) letter of May 20,1994, stated that it intended to perform a reduced-scope seismic examination at Wolf Creek instead of a Seismic l

Level I probabilistic risk assessment for the seismic portion of the IPEEE. The rationale was i that the seismic hazard information contained in NUREG-1488, " Revised Livermore Seismic l Hazard Estimates for 69 liuclear Power Plant S tes East of the Rocky Mountain," has confirmed that the seismic hs=rd at most Eastem United States plants is low, comparable to the 1989 Livermore seismic hazard results at 10 sites which were binned as reduced-scope plants in NUREG-1407. In the stars response dated August 15,1994, it was stated that the staff was in the process of assessing whether restructuring of the seismic IPEEE program was warranted and that the staff was not able to approve WCNOC's revised approach at that time. The staff I further stated that it would provide a final response to WCNOC's May 20,1994, letter upon l completion of its evaluation of the Lawrence Livermore estimates and related NEl white paper, i

which was expected to be completed by the end of 1994. Following this evaluation, there were additional intomal and extemal reviews related to Supplement 5 to Generic Letter 88-20 which was issued on September 9,1995. This generic letter notified all operating licensees about the

! modifications in the recommended scope of the seismic IPEEE based on the staff's review of

" o.i 41488 and provided guidance to licensees who might wish to voluntarily modify their l

v /io.c ly committed seismic IPEEE programs. However, the NRC did not change the binning I o; ao plants (i.e., for those plant sites classified as focused-scope plants, they were to remain in ht bin), and the rationale for not changing the binning was provided in the appendix to Supplement 5. Consequently, the staff's review of WCNOC's IPEEE submittalin the seismic area has cont,istantly treated Wolf Creek as a focused-scope plant, and the RAls were crafted j in such a way that the information requested, if provided appropriately, would enable the staff to draw the conclusion that the IPEEE intent has been met for Wolf Creek in the seismic area.

To resolve this issue, conference calls between WCNOC staff and NRC staff were held on January 27 and February 25,1999, to discuss the following two approaches: (1) demonstrate l that the Wolf Creek site should be placed in the reduced-scope bin based on seismic hazard l considerations, or (2) address the stars questions related to evaluating the Wolf Creek site as I l

a focused-scope plant. There are two possible attematives to this latter approach as discussed

! further below.  !

For the first approach, WCNOC would have to submit additional Information demonstrating that the seismic hazard at the Wolf Creek site is comparable to orlower than any one of the sites currently being pleosd in the reduced-scope bin in NUREG-1407. As disensed during the ENCLOSURE

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j' conference calls, such an evaluation was performed by the licensee of the Farley pl ant. The submittal documenting the evaluation was reviewed by the NRC staff, and it was agreed that g l the information provided jusSfied placing Farley in the reduced-scope bin. '

For the second approach, there are two attematives to addressing Wolf Creek as a focused-scope plant. The first is to perform the analyses identified in the initial RAI and discussed again below. The second altemative, as suggested by WCNOC staff in the conference calls, is to provide informatbn justifying the use of the Callaway plant focused-scope assessment to demonstrate that, similarly to Callaway, there are no seismic vulnerabilities at Wolf Creek. In either case, you should consider the following discussion.

l The response provided in WCNOC's letter of December 8,1997, was not adequate for the staff

' to complete its eva'uation of the Wolf Creek IPEEE. In particular, as requested in RAI # 3, WCNOC did not provide (1) an example of a bounding anchorage evaluation, and (2) the guidance used by the seismic review team (SRT) and the procedure used to screen out anchorages for each equipment category of Section 3.5 of the IPEEE submittal. Also, as  ;

requested in RAI # 4, WCNOC did not provide an evaluation of USl A-45 for the 0.3g RLE as requested in NUREG-1407. Furthermore, as raquested in RAI # 5, WCNOC did not provide seismic capacities for those equipment items that have demands exceeding the design basis, in i order to verify the judgments made during the walkdown screening.

Thus, the staff's remaining concems focus o i the following three areas: (1) the RWST,(2) the portion of the turbine bu'Iding that contains tl' s emergency safety feature 4kV power line with related equipment and ownponents, and (3)ihe screening out of certain anchorages without adequate bases.

WCNOC may choose to perform a plant-specific analysis for Wolf Creek to determine the seismic capacities for the components identified below, or, as suggested in the February 25, 1999 conference call, WCNOC may use the results obtained from the seismic IPEEE assessment at Callaway to demonstrate that the Wolf Creek plant would be expected to behave similarly under seismic conc'itions and that no vulnerabilities would be expected as was determined for Callaway. At indicated during the call, both plants are SNUPPS plants and nearly identical seismic anal)ses and designs were used for both plants. Therefore, in order to justify the comparison with Collaway, information would be needed supporting the claim that the plant designs are nearly identical, and where there are deviations, those deviations should be identified, and their impact on seismic risk should be assessed.

I If WCNOC chooses to do a plant-specific seismic' assessment, the results of the evaluation should be provided for each of tae items listed below.

1. . Capacity calculations for the RWST including all failure modes and anchorage.

2. A description of the guidance used by the SRT, the procedure it used, and the basis for screening out emergency service water (ESW) pump anchorages in the ESW pump house.

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3. (a) A list of all s afe shutdown equipment, and any other equipment modeled in the IPE, which oither is physically located in the turbine building, or depends on control or m)tive power from electrical components (e.g., switchgear or cables) that are located in the turbine building.

(b) The horizontal and vertical location of this equipment in relationship to the )

turbine building itself, and other equipmsnt in the building.

(c) Capacity calculations including anchcrage capacities for this equipment.

(d)' Seismic evaltiation work sheets, phe ;os and calculations associated with this equipment in order to show the basis for screening, and (e) A description of how Seismic II/I co isiderations were treated during the walkdown, and the walkdown findin 3s for this equipment.

If, instead, WCNOC chooses to make reference to the Callaway seismic results, WCNOC should confirm that the Wolf Creek plant informat on pertinent to the items listed above apply equally to Wolf Creek as to Callaway, or discuss any deviations to demonstrate that they do not invalidate the comparison of t*,c hvo plants.

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