ML071620201

Summary of Telephone Conference Call Held on May 24, 2007, Between the NRC and Wolf Creek Nuclear Operating Corporation Concerning the Analysis of Service Accident Mitigation Alternatives Pertaining to the Wolf Creek Generating Station, Uni

ML071620201
Person / Time
Site:	Wolf Creek
Issue date:	07/06/2007
From:	Christian Jacobs NRC/NRR/ADRO/DLR/REBB
To:	NRC/NRR/ADRO
Logan, Dennis NRR/DLR/REBA - 415-0490
References
Download: ML071620201 (7)

Text

July 6, 2007 LICENSEE: Wolf Creek Nuclear Operating Corporation FACILITY: Wolf Creek Generating Station

SUMMARY

OF TELEPHONE CONFERENCE CALL HELD ON MAY 24, 2007, BETWEEN THE U.S. NUCLEAR REGULATORY COMMISSION AND WOLF CREEK NUCLEAR OPERATING CORPORATION, CONCERNING THE ANALYSIS OF SEVERE ACCIDENT MITIGATION ALTERNATIVES PERTAINING TO THE WOLF CREEK GENERATING STATION, UNIT 1, LICENSE RENEWAL APPLICATION The U.S. Nuclear Regulatory Commission (NRC or the staff) and representatives of Wolf Creek Nuclear Operating Corporation (WCNOC) held a telephone conference call on May 24, 2007, to discuss and clarify some of the responses provided by WCNOC to requests for additional information (RAIs) concerning the analysis of Severe Accident Mitigation Alternatives (SAMAs) for Wolf Creek Generating Station, Unit 1, license renewal application (LRA). The telephone conference call was useful in clarifying responses to RAIs previously provided by WCNOC to SAMA requests for additional information. provides a listing of the participants, and Enclosure 2 contains a listing of the SAMA questions discussed with the applicant, including a brief description on the status of the items.

The applicant had an opportunity to comment on this summary.

/RA/

Christian Jacobs, Project Manager Environmental Branch B Division of License Renewal Office of Nuclear Reactor Regulation Docket No. 50-482

Enclosures:

1. List of Participants

2. List of SAMA RAIs cc w/encls: See next page

ML071620201 OFFICE PM:REBB:DLR LA:DLR BC:REBB:DLR NAME C. Jacobs Y. Edmonds R. Franovich DATE 06/29/07 06/29/07 07/06/07 TELEPHONE CONFERENCE CALL WOLF CREEK GENERATING STATION, UNIT 1 LICENSE RENEWAL APPLICATION LIST OF PARTICIPANTS May 24, 2007 PARTICIPANTS AFFILIATIONS Christian Jacobs U.S. Nuclear Regulatory Commission (NRC)

Robert Palla NRC Bruce Mrowca Information Systems Laboratories Charlie Medenciy Wolf Creek Nuclear Operating Corporation (WCNOC)

Patrick Guevel WCNOC David Alford WCNOC Mark Ferrel WCNOC J.C. Patel WCNOC Bill Ketchum WCNOC Enclosure 1

SEVERE ACCIDENT MITIGATION ALTERNATIVE ADDITIONAL QUESTIONS REGARDING WOLF CREEK GENERATING STATION, UNIT 1 LICENSE RENEWAL APPLICATION May 24, 2007 The U.S. Nuclear Regulatory Commission (NRC or the staff) and representatives of Wolf Creek Nuclear Operating Corporation (WCNOC) held a telephone conference call on May 24, 2007, to discuss the following questions regarding responses to requests for additional information (RAIs) analysis for Severe Accident Mitigation Alternatives (SAMAs) for Wolf Creek Generating Station Unit 1, license renewal application.

1. In response to Question 1b (QU-9) it is stated that internal flooding scenarios have not been included in Probalistic Safety Assessment updates and that new internal flooding criteria may identify new human-induced floods through consideration of errors of commission. State how this could impact the SAMA analysis.

Discussion: The applicant provided clarification of their RAI response in a follow-up e-mail.

Reference response in (ADAMS under Accession No. ML071590339). Issue resolved.

2. The answer provided to Question 1b (TH-6) talks about the definition used in the Individual Plant Examination (IPE) while the Facts and Observations are focused on the Modular Accident Analysis Program (MAAP) calculation and states that the 30-minute criteria was not likely a factor in determining success or failure in many (if any) of the analyses performed for the IPE. State the issue associated with the core damage criteria used in the MAAP calculations and its impact on the SAMA evaluation.

Discussion: The applicant provided clarification of their RAI response. Issue resolved.

3. In response to Question 2b, it is stated that NUREG-1570 asserts that only 2 percent of the high pressure melt scenarios with dry steam generators (SG) would result in an induced Steam Generator Tube Rupture (SGTR) and that the applicability of percentage is predicated on the conditions that the secondary side is not depressurized and that the Reactor Coolant Pumps (RCPs) are not operated. A review of NUREG-1570 found that for cases where an RCP seal Loss of Coolant Accident (LOCA) occurs that the Thermally Induced SGTR failure probability for 3 steam generators (4 SG scenario is not available) is 1.0. State how this increased failure likelihood on RCP seal failure was accounted for in the response to Question 2b.

Discussion: The applicant provided clarification of their RAI response in a follow-up e-mail.

Reference response in (ADAMS under Accession No. ML071590339). Issue resolved.

4. In response to Question 3c, it is stated that WCGS has high temperature seal material installed in only one RCP. State the seal LOCA model used. Discuss plans for installing qualified seals in the remaining RCPs. Provide a cost-benefit assessment for installing qualified seals in the remaining RCPs, if this is not currently planned.

Enclosure 2

Discussion: The applicant clarified that they have high temperature seals in all 4 RCPs. Issue resolved.

5. In response to Question 7a, it is stated that procedures exist at WCGS to operate the turbine driven auxilary feedwater pump after battery depletion. Describe these procedures, including the instrumentation used to effectively control SG level. State the human error probability or probabilities used for this action.

Discussion: The applicant provided clarification of their RAI response. NRC understands the procedure that WCNOC is using for this turbine driven pump. Issue resolved.

6. In response to Question 6.b.ii it is stated that extending the Emergency Diesel Generator (EDG) completion time actions 24/7 would potentially place Technical Specification Amendment #163 in jeopardy. This appears to be due to the presence of a reduced base risk profile as a result of implementing the proposed alternative making the removal of an EDG more significant (Its not that an EDG outage is more significant, it is that the plants risk profile is lower making the delta risk greater). Please clarify this.

Discussion: The applicant provided clarification of their RAI response. The applicant also suggested that NRC staff re-examine information provided on Pages 30-40 of SAMA RAI response, letter ET 07-0006 (ADAMS Accession No. ML071160203). Issue resolved.

Memo to Wolf Creek Nuclear Operating Corporation from C. Jacobs dated July 6, 2007

SUMMARY

OF TELEPHONE CONFERENCE CALL HELD ON MAY 24, 2007, BETWEEN THE U.S. NUCLEAR REGULATORY COMMISSION AND WOLF CREEK NUCLEAR OPERATING CORPORATION, CONCERNING THE ANALYSIS OF SEVERE ACCIDENT MITIGATION ALTERNATIVES PERTAINING TO THE WOLF CREEK GENERATING STATION, UNIT 1, LICENSE RENEWAL APPLICATION DISTRIBUTION:

E-mail P.T. Kuo / S. Lee (RidsNrrDlr)

R. Franovich (RidsNrrDlrReba)

E. Benner (RidsNrrDlrReba)

C. Jacobs A. Williamson Bobbie.hurley@earthtech.com V. Rodriguez J. Donohew G. Pick, RIV S. Cochrum, RIV C. Long, RIV OGC (RidsOGCMailRoom)

D. Roth, OGC DLR/REBB DLR/REBA

Wolf Creek Generating Station cc:

Jay Silberg, Esq. Supervisor Licensing Pillsbury Winthrop Shaw Pittman, LLP Wolf Creek Nuclear Operating Corporation 2300 N Street, NW P.O. Box 411 Washington, DC 20037 Burlington, KS 66839 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission U.S. Nuclear Regulatory Commission Resident Inspectors Office/Callaway Plant 611 Ryan Plaza Drive, Suite 400 8201 NRC Road Arlington, TX 76011-7005 Steedman, MO 65077-1032 Senior Resident Inspector Mr. Terry J. Garrett U.S. Nuclear Regulatory Commission Vice President Engineering P.O. Box 311 Wolf Creek Nuclear Operating Corporation Burlington, KS 66839 P.O. Box 411 Burlington, KS 66839 Chief Engineer, Utilities Division Kansas Corporation Commission Kevin J. Moles, Manager 1500 SW Arrowhead Road Regulatory Affairs Topeka, KS 66604-4027 Wolf Creek Nuclear Operating Corporation P.O. Box 411 Office of the Governor Burlington, KS 66839 State of Kansas Topeka, KS 66612 Lorrie I. Bell, Project Manager Wolf Creek Nuclear Operating Corporation Attorney General P.O. Box 411 120 S.W. 10th Avenue, 2nd Floor Burlington, KS 66839 Topeka, KS 66612-1597 Ms. Julie Keys County Clerk Nuclear Energy Institute Coffey County Courthouse 1776 I Street, NW, Suite 400 110 South 6th Street Washington, DC 20006-3708 Burlington, KS 66839 Ms. Valerie Williams, Branch Director Thomas A. Conley, Section Chief Coffey County Library Radiation and Asbestos Control Burlington Branch Kansas Department of Health 410 Juniatta St.

and Environment Burlington, KS 66839 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