ML20077C561

Application for Amend to License NPF-35,requesting Permanent Renewal of Voltage Based Steam Generator Tube Interim Plugging Criteria for Unit 1 Cycle 9

ML20077C561
Person / Time
Site:	Catawba
Issue date:	11/29/1994
From:	Rehn D DUKE POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20077C565	List: ML20077C561 ML20077C570 ML20077C577
References
NUDOCS 9412050224
Download: ML20077C561 (5)

Text

11 I DukeIbwer Company D. L Ron Catairba Nuclear Generunon lkrutment Vice iMident 4KK) Concord Road (S03AG13205 O!hte 1ork SC29745 (803)&113426 Fat DUKEPOWER November 29,1994 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D. C. 20555

Subject:

Catawba Nuclear Station, Unit 1 i Docket No. 50-413 Technical Specification Amendment Renewal Of Steam Generator Tube Interim Plugging Criteria for Unit 1 Cycle 9 Attached are proposed changes to the Catawba Nuclear Station Technical Specifications requesting permanent renewal of the voltage based steam generator tube interim plugging criteria for Unit 1, which was approved for Cycle 8 operation. Some additional changes to the previous Tech Specs are being made to reflect guidance given in draft NRC Generic Letter 94-XX:

" Voltage Based Repair Criteria for the Repair ofWestinghouse Steam Generator Tubes Affected by Outside Diameter Stress Corrosion Cracking" (issued for public comment in the Federal Register on August 12,1994). Catawba will use NRC accepted methodologies for calculation of Conditional Probability of Burst and Total Leak Rate during MSLB, This submittal also utilizes recent information concerning outlier tubes previously excluded in the ERPI 3/4 inch steam generator tube data base.

Catawba is committing to follow the guidance of the draft Generic Letter with three exceptions.

The exceptions are in the areas of bobbin coil calibration, periodic tube pulling, and probe wear j standard. The basis for these exceptions are explained in the Technical Justification ,

Attachment 2.

Catawba will need approval of these changes prior to startup following the End-Of-Cycle 8 refueling outage which is scheduled to begin February 12,1995. Specifically, approval will be needed prior to entry into Mode 4 on the retum to power since this is when the steam generators must be operable. Therefore, it is requested that this submittal receive timely review and approval in order to meet the schedule for the Catawba Unit 1, Cycle 9 startup. Mode 4 is currently scheduled for March 28,1995.

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l Nuclear Regulatory Commission November 14,1994 Page 2 The marked up Technical Specification pages are given on Attachment 1. Attachment 2 contains  !

the Technical Justification for these changes, and Attachment 3 contains the No Significant Hazards Analysis and EnvironmentalImpact Statement. Attachment 4 contains " Catawba - 1, Cycle 7 IPC Assessment and Projected EOC-8 SLB leakage, dated November,1994" The 1 information contained in Attachment 4 was requested by the NRC in the SER (Reference 8 of the Technical Justification) for the IPC of Cycle 8. Attachment 4 is being submitted to comply with I this request. Please note that this is a non-proprietary document. There is not a proprietary version.

Catawba requests that the NRC complete its review of the analysis of Tube Support Plate Displacement Under Steam Line Break Loads. This request is in support of this refueling outage.

Growth rates of ODSCC at hot leg tube supports for some Westinghouse D model steam generators have been high. High growth rates can be addressed and regtdatory requirements can be met, without mid-cycle outages, by the support provided by the tube support plates. The cracks, as supported by the tube support plates, will not burst under steam line break loads, and the limited support plate displacement demonstrated in the referenced WCAP, support an acceptable tube burst probability even under very conservative assumptions for crack distributions at the support plates.

WCAP-13684, Revision 1, " Analysis to Determine Relative Tube / Tube Support Plate Displacements Under Steam Line Break Loads for Catawba Unit 1 Steam Generators" (proprietary) and WCAP-13887, " Analysis to Determine Relative Tubefrube Support Plate Displacements Under Steam Line Break Loads for Catawba Unit 1 Steam Generators" (non-proprietary) was submitted to the NRC with Reference 4 of the Technical Justification.

It should be noted that the Technical Justification for this Amendment Request does not rely on this analysis, as high growth rates are not expected but it is realized that they could occur.

Pursuant to 10 CFR 50.91 (b)(1), the appropriate South Carolina oflicial is being provided a copy of this amendment request.

Very truly yours, f

Yu D. L. Rehn i

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Attachments DT/

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Nuclear Regulatoiy Commission November 14,1994 Page 3 ,

s xc: Mr. S. D. Ebaeter Regional Administrator,RegionII U. S. Nuclear Regulatory Commission ,

101 Marietta Street, NW, Suite 2900 Atlanta,GA 30323 Mr. Max Batavia, Chief Bureau ofRadiological Health South Carolina Department ofHealth & ,

Environmental Control l 2600 Bull Street Columbia,SC 29201 Mr. R. J. Freudenberger NRC Resident Inspector Catawba Nuclear Station i Mr. Robert E. Martin, Project Manager ONRR l

Mr. Ashok C. Thadni, Associate Director Inspection & Technical Assessment ONRR American NuclearInsurers c/o Dottie Sherman, ANI Library The Exchange, Suite 245 l

270 Farmington Avenue Farmington,CT 06032 M & M Nuclear Consultants l- 1166 Avenue of the Americas New York, NY 10036-2774 INPO Records Center -

Suite 1500 l 1100 Circle 75 Parkway .

Atlanta, Georgia 30339

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