ML052700197

Relief Request - Reactor Vessel Closure Head Penetration Flaw Characterization Relief Request MR 02-018-2, Revision 2

ML052700197
Person / Time
Site:	Point Beach
Issue date:	01/18/2006
From:	Kobetz T Plant Licensing Branch III-2
To:	Koehl D Nuclear Management Co
Muniz A, NRR/DLPM, 415-4093
References
TAC MC7482
Download: ML052700197 (6)

Text

January 18, 2006Mr. Dennis L. KoehlSite Vice President Point Beach Nuclear Plant Nuclear Management Company, LLC 6590 Nuclear Road Two Rivers, WI 54241-9516

SUBJECT:

POINT BEACH NUCLEAR PLANT, UNIT 1 - REACTOR VESSEL CLOSUREHEAD PENETRATION FLAW CHARACTERIZATION RELIEF REQUEST MR 02-018-2, REVISION 2 (TAC NO. MC7482)

Dear Mr. Koehl:

By letter to the Nuclear Regulatory Commission (NRC) dated July 1, 2005, the NuclearManagement Company, LLC (NMC), submitted Relief Request MR 02-018-2, Revision 2 for Point Beach Nuclear Plant (PBNP), Unit 1. The relief request pertains to relief from the requirement to characterize flaws that may exist in the remnants of the control rod drivemechanism nozzle J-groove welds after the repair of a reactor vessel head penetration. Relief Request MR 02-018-2 was originally authorized on September 10, 2003. In its safety evaluation (SE) of the initial relief request, the NRC staff limited its authorization to cases wherethere was no overlap of the new Alloy 52 weld material onto any portion of the remnant J-groove weld. MR 02-018-2, Revision 1, submitted on May 13, 2004, intended by NMC to provide the technical basis for eliminating this restriction, was authorized by the NRC staff on July 16, 2004. By letter dated July 1, 2005, NMC submitted Revision 2 to Relief Request MR-02-018-2, specifically to correct an error in the reactor pressure vessel (RPV) upper head temperature for PBNP, Unit 1. The NRC staff has completed its review of Relief Request MR-02-018-2, Revision 2 asdocumented in the enclosed SE. Our SE concluded that your proposed alternative provides anacceptable level of quality and safety. Therefore, the licensee's proposed alternative is authorized pursuant to 10 CFR 50.55a(a)(3)(i) for the remainder of the operati ng cycl e #29 atPBNP, Unit 1, which ended on November 24, 2005. All other American Society of Mechanical Engineers Boiler and Pressure Vessel Code,Section XI requirements for which relief was notspecifically requested and approved in this relief request remain applicable, including third party review by the Authorized Nuclear Inservice Inspector.

D. Koehl- 2 -If you have any questions concerning this matter, please contact Mr. F. Lyon of my staff at (301) 415-2296.Sincerely, /RA/Timothy Kobetz, Acting ChiefPlant Licensing Branch III-1 Division of Operating Reactor Licensing Office of Nuclear Reactor RegulationDocket No. 50-266

Enclosure:

As stated cc w/encl: See next page D. Koehl- 2 -If you have any questions concerning this matter, please contact Mr. F. Lyon of my staff at (301) 415-2296.Sincerely, Timothy Kobetz, Acting ChiefPlant Licensing Branch III-1 Division of Operating Reactor Licensing Office of Nuclear Reactor RegulationDocket No. 50-266

Enclosure:

As stated cc w/encl: See next pageDISTRIBUTION

PUBLICRidsOgcRpTSteingass LPLIII-1 R/FRidsAcrsAcnwMailCenterRidsNrrDciCpnbRidsNrrDorlLplERidsNrrPMFLyon RidsRgn3MailCenterRidsNrrLADClarkeDORL DPRAMuniz DWeaverADAMS Accession Number: ML052700197*memo date 8/12/05

• • previously concurredNRR-028OFFICELPLIII-1/PELPLIII-1/PMLPLIII-1/LACPNB/BCOGCLPLIII-1/BC (A)NAMEAMunizCLyonDClarke**TChan*JZorn**TKobetzDATE1/13/061/17/0612/29/058/12/051/5/061/18/06OFFICIAL RECORD COPY Point Beach Nuclear Plant, Unit 1 cc:

Jonathan Rogoff, EsquireVice President, Counsel & Secretary Nuclear Management Company, LLC 700 First Street Hudson, WI 54016Mr. F. D. KuesterPresident & Chief Executive Officer WE Generation 231 West Michigan Street Milwaukee, WI 53201Regulatory Affairs ManagerPoint Beach Nuclear Plant Nuclear Management Company, LLC 6610 Nuclear Road Two Rivers, WI 54241Mr. Ken DuveneckTown Chairman Town of Two Creeks 13017 State Highway 42 Mishicot, WI 54228ChairmanPublic Service Commission of Wisconsin P.O. Box 7854 Madison, WI 53707-7854Regional Administrator, Region IIIU.S. Nuclear Regulatory Commission 801 Warrenville RoadLisle, IL 60532-4351Resident Inspector's OfficeU.S. Nuclear Regulatory Commission 6612 Nuclear Road Two Rivers, WI 54241Mr. Jeffery KitsembelElectric Division Public Service Commission of Wisconsin P.O. Box 7854 Madison, WI 53707-7854Nuclear Asset ManagerWisconsin Electric Power Company 231 West Michigan Street Milwaukee, WI 53201Michael B. SellmanPresident and Chief Executive Officer Nuclear Management Company, LLC 700 First Street Hudson, MI 54016Douglas E. CooperSenior Vice President - Group Operations Palisades Nuclear Plant Nuclear Management Company, LLC 27780 Blue Star Memorial Highway Covert, MI 49043Site Director of OperationsNuclear Management Company, LLC 6610 Nuclear Road Two Rivers, WI 54241 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATIONRELIEF REQUEST MR 02-018-2, REVISION 2 POINT BEACH NUCLEAR STATION, UNIT 1NUCLEAR MANAGEMENT COMPANY, LLCDOCKET NO. 50-266

1.0 INTRODUCTION

By letter to the Nuclear Regulatory Commission (NRC, Commission) dated July 1, 2005(Agencywide Documents Access and Management System (ADAMS) Accession No. ML051940343), Nuclear Management Company, LLC (NMC, the licensee), submitted Relief Request MR-02-018-2, Revision 2, to correct an error in the reactor pressure vessel (RPV) upper head operating temperature for Point Beach Nuclear Plant (PBNP), Unit 1. Relief Request MR 02-018-2 was originally authorized on September 10, 2003 (ADAMS Accession No. ML032310402). In its safety evaluation (SE) of the initial relief request, the NRC stafflimited its authorization to cases where there was no overlap of the new Alloy 52 weld material onto any portion of the remnant J-groove weld. MR 02-018-2, Revision 1, submitted on May 13, 2004 (ADAMS Accession No. ML041410464), intended by NMC to provide the technical basis for eliminating this restriction, was authorized by the NRC staff on July 16, 2004(ADAMS Accession No. ML041760065). By letter dated July 1, 2005, NMC submitted Revision 2 to its Relief Request MR-02-018-2, specifically to correct an error in the RPV upper head temperature for PBNP, Unit 1. Therefore, this SE will address only the effects of theincrease in RPV head operating temperature on the NRC SE dated July 16, 2004.

2.0 REGULATORY EVALUATION

Alternatives to requirements may be authorized or relief granted by the NRC purs uant to Title 10 of Code of Federal Regulations (10 CFR) 50.55a(a)(3)(i), 10 CFR 50.55a(a)(3)(ii), or 10 CFR 50.55a(g)(6)(i). In proposing alternatives or requesting relief, the licensee must demonstrate that: (1) the proposed alternatives provide an acceptable level of safety; or (2) compliance would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety; or (3) conformance is impractical for the facility. Purs uant to 10 CFR 50.55a(g)(4)(iv), inservice inspection of items may meet the requirements set forth in subsequent editions and addenda of the American Society of Mechanical Engineers (ASME)

Boiler and Pressure Vessel Code (Code) that are incorporated by reference in 10 CFR50.55a(b), subject to the limitations and modifications listed therein, and subject to Commission approval. Portions of editions or addenda may be used provided that all related requirements of the respective editions or addenda are met. In its letter dated July 1, 2005, pursuant to 10 CFR 50.55a(a)(3)(i), the licensee requested a revision to the relief authorized by the NRCstaff's SE dated July 16, 2004, from the requirements of the 1998 Edition of the ASME Code,Section XI, IWA-3300(b), IWB-3142.4, and IWB-3420, which require characterization of flaw(s) existing in the remnant of the J-groove weld(s) that will remain in service for PBNP, Unit 1, reactor vessel closure heads if a control rod drive mechanism nozzle must be partially removedand a new pressure boundary deposited over a portion of the J-groove weld remnant.

3.0 TECHNICAL EVALUATION

The NRC staff notes the revised calculations submitted by the licensee show a slightly hi ghercrack growth rate due to the higher operating temperature, resulting in a change to the calculated operating time from 1.39 effective full power years (EFPY) to 1.31 EFPY. This equates to a change from 16.68 months to 15.72 months for a net result of 0.96 month shorterduration of time until a hypothetical flaw reaches the toe of the J-groove weld in the weldoverlap region. The conservative assumptions in the revised calculations indicate that an actual flaw would require more than 1.31 EFPY to grow through the J-groove weld. PBNP, Unit 1 is not expected to accumulate greater than 1.41 EFPY prior to the plant shutdown due tooperational constraints. The delta in RPV operating temperatures is sufficiently low to not challenge the conservative assumptions in the calculations that formed part of the basis for NRC authorization of the current and previous revisions of this relief request. The NRC staffconcludes that the previously granted reliefs remain in effect for this repair situation.

4.0 CONCLUSION

The NRC staff concludes that Relief Request MR-02-018-2, Revision 2 is acceptable becausethe proposed alternative authorized in the previous revisions has not changed, the delta in RPVoperating temperatures is sufficiently low to not challenge the conservative assumptions in the calculations made to support continued safe operation, and the removal from service of the RPV head during the Autumn 2005 outage. Based on the information provided in the licensee'ssubmittal, the NRC staff concludes that the alternative proposed in MR-02-018-2, Revision 2provides an acceptable level of quality and safety. Therefore, the licensee's proposed alternative is authorized pursuant to 10 CFR 50.55a(a)(3)(i) for the remainder of operating cycle#29 at PBNP, Unit 1, which ended on November 24, 2005.All other ASME Code,Section XI requirements for which relief was not specifically requestedand approved in this relief request remain applicable, including third party review by the Authorized Nuclear Inservice Inspector.Principal Contributor: T. Steingass Date: January 19, 2006