ML20056F251

Forwards Rev 0 to Evaluation of Reactor Vessel OD Flaw (PIP 2-M93-0717), Per GL 91-18 & Ultrasonic Exam Results of Lower Head-to-Bottom Head Weld (2RRV-W01) for McGuire Unit II Jul 1993 Reactor Pressure Vessel Exam. W/Drawing

ML20056F251
Person / Time
Site:	Mcguire
Issue date:	08/18/1993
From:	Mcmeekin T DUKE POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20056F253	List: ML20056F251 ML20056F294 ML20056F298
References
GL-91-18, NUDOCS 9308260230
Download: ML20056F251 (4)

Text

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11 1 Dde hmer Company T C McurrAn McGwrr Nuclear Gentrutwn Department Vice hwdent 12 :30 flagm Ferry R0cd(MGotA) (704)hT54800 llantersville. tic 280!S-E985 (104)8754809Dx DUKEPOWER August 18, 1993 U. S. Nuclear Regulatory Commission Attention: Document Control Desk washington, D. C. 20555 >

Subject:

McGuire Nuclear Station, Unit 2  ;

Docket No. 50-370 l Unit 2 10 year Inservice Inspection Reactor Vessel outside wall indication Dear Sir; During the current end-of-cycle 8 (EOC 8) refueling outage i for Unit 2, a longitudinal planar flaw was detected at the lower head to ring segment girth weld (WOl) on the outer wall surface of the reactor vessel. This indication was determined to exceed the allowable flaw size for acceptance by volumetric examination as specified by IWB-3510.1, of the 1980 edition of the ASME Section XI Code. In such cases, the code (IWB-3122.4) allows acceptance of the flaw indication by analytical evaluation. To this end, the indication was evaluated in accordance with the methods described in Appendix A of the 1980 edition of the ASME Section XI Code and meets the acceptance criteria specified  ;

by IWB-3600.

Please find attached (Attachment 1) a report on the evaluation of the Unit 2 reactor vessel outer wall indication. The report concludes that the Unit 2 reactor vessel is acceptable for continued service for the licensed life of McGuire Nuclear Station, Unit 2 (March 3, 2023), and '

that the following standards have been satisfied:

a) the criteria of IWB-3612; b) the primary stress limits of NB3000.

In accordance with Generic Letter 91-18, the Unit 2 reactor vessel is considered to be operable and can be returned to service. In addition, NRC review and' approval of.the evaluation report provided by attachment 1 is requested.

For_your information, Unit 2 is currently scheduled to enter mode 4 by August 28, 1993 and be at full power operation by September 7, 1993.

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i U.S. Nuclear Regulatory Commission August 18, 1993 page 2  !

I Please note that the references identified within Section 11.0, 12.2 and 12.3 of the evaluation report are not i provided. These references are available at the site for review. (

Further, Table 13.3-1 lists the transients that j were considered during the evaluation of the indication. l The report references the Westinghouse Equipment i Specification 952564 Rev. 1 as the source for the information identified within the table. Please note that  !

i the same information is also provided by Table 5.2 of the McGuire FSAR. I In support of NRC staff's review, attachment 2 provides l additional information regarding the fabrication and i inspection history of Weld WO1. The information provided by l attachment 2 is a summary of the effort in investigating the fabrication and inspection history of the weld, the actual reports regarding the fabrication and inspection of the weld are available at the site for review.

Although our efforts have yet to identify a probable cause for the indication, these efforts have not ruled out the possibility that the indication was caused by a fabrication, shipping, construction, or installation related event. All fabrication inspections of the subject weld were completed by March of 1974, and the baseline radiograph of the weld was performed on January 21, and Mhrch 20, 1972. Due to activities related to the continued fabrication of the vessel; or the shipping of the vessel; or site construction activities; or installation related activities, it is possible that the cause for the indication may have occurred after these inspections.

The baseline ultrasonic examination was performed on September 8, 1978, during the preservice examination. Due to the state-of-the-art of ultrasonic examination methods for that time period, and the technique utilized during the preservice examination, it.is likely that the baseline ultrasonic examination would not have recorded the indication.

As a final note, additional inspections of the indication will be performed as required by IWB-3122.4(b) and in  ;

accordance with IWB-2420(b) and (c).  !

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U. S._ Nuclear Regulatory Commission August 18, 1993 page 3 Please contact Paul Guill at (704) 875-4002 if there are any questions regarding this submittal.

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Very truly yours,

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)1/c hh' ' - l T. C. McMeekin f:

xc: Mr. S. D. Ebneter Regional Administrator, Region II j U. S. Nuclear Regulatory Commission l 101 Marietta Street, NW, Suite 2900 l Atlanta, Georgia 30323 Mr. George F. Maxwell l Senior NRC Resident Inspector, McGuire  !

McGuire Nuclear Station i l

t Mr. Victor Nerses, Project-Manager j L Office of Nuclear Reactor Regulation i U. S. Nuclear Regulatory Commission j l One White Flint North, Mail Stop 9H3 i Washington, D.C. 20555 Mr. Nick Economos

. U. S. Nuclear Regulatory Commission, Region II l 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 1'

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ATTACHMENT 1 I 1

DUKE POWER COMPANY ,

MCGUIRE NUCLEAR STATION l EVALUATION OF REACTOR VESSEL OD FLAW  !

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