ML20154G448

Advises That Review of Appropriate Piping Sys Completed at Plants,Per NRC Bulletin 88-008 Requirements.Insps for Action 2 Will Be Completed by 881222 for McGuire Unit 1,by 891212 for Unit 2,by 890110 for Catawba Unit 1 & 890524 for Unit 2

ML20154G448
Person / Time
Site:	Mcguire, Catawba, McGuire, 05000000
Issue date:	09/09/1988
From:	Tucker H DUKE POWER CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
IEB-88-008, IEB-88-8, NUDOCS 8809200367
Download: ML20154G448 (2)

Text

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Duke ker Company Hu R T&

PO Bat 33193 l' ice President Charlotte, NC 28242 Nuclear Production

.l (704)373-4531 1

l DUKEPOWER September 9, 1988 Document Control Desk U. S. Nuclear Regulatory Commission Washington, D. C.

20555 1

Subject:

Catawba Nuclear Station, Units 1 and 2 Docket Nos. 50-413 and 50-414 McGuire Nuclear Station, Units 1 and 2 Docket Nos. 50-369 and 50-376 NRC Bulletin No. 88-08 Gentlemen:-

Pursuant to the requirements of NRC Bulletin No. 88-08 Thermal Stresses in Piping Connected to Reactor Coolant Systems, please be advised that Duke Power personnel have completed a review of appropriate McGuire and Catawba Nuclear Stations piping systems. All systems connected to the Reactor Coolant System were reviewed to determine whether non-isolable sections of piping can be subjected to stresses from temperature stratification or temperature oscillations that could be induced by leaking valves and that were not evaluated in the design analysis of the piping.

l The subject review revealed that McGuire and Catawba safety injection piping which is linked to the normal charging piping may be subjected to thermal stresses. This piping will be inspected for thermal cycling as required por NRC Bulletin 88-08, Action 2.

Additionally, Duke Power personnel will inspect 1/2" diameter ECCS piping at the junction with the Reactor Coolant Loop piping. At McGuire and Catawba the Safety Injection and Residual Reheat Removal functions are served by separate lines and the l

Safety Injection pipe needs to only be 1-1/2" in diameter. Since thermal stratification may not occur as readily in small diameter piping due to the limited diameter distance available for thermal layers to form, the McGuire and Catawba piping is likely to be less susceptible to stratification than Farley's 6" diameter ECCS piping. However, since thermal cycling may not

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necessarily depend on stratification, the McGuire and Catawba piping will conservatively be inspected as required por NRC Bulletin 88-08, Action 2.

Duke Power Company will complete inspections required per NRC Bu110tfon 88-08, Action 2, prior tot

1) December 22, 1988 for McGuire, Unit 11 2)

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1 8809200367 880909 gDR ADOCK 0500 f

,n U. S. Nucisar Riguistory Commission je Szptember 9.-1988 Page TVo October 12, 1989 for McGuire, Unit 2 January 10, 1989 for Catawba Unit 18 and May 24, 1989 for Catawba, Unit 2.

A Report documenting the results of the inspections will be submitted within 30 days of +.he Action 2 completion date.

Very truly yours,

/ g /$, N f

H. B. Tucker JGT05.D1/lec xc G. W. Fisher J. B. Wheeler R. I. Deese C. B. Cheezen R. L. Gill C. W. Hendrix R. M. Glover D. B. Mayes T. N. Hoag J. H. Lanier P. G. LeRoy CN-815.02 N. A. Rutherford CN-801.01 R. O. Sharpe M. S. Sills W. T. Orders Resident Inspector Catawba Nuclear Station Dr. J. Nelson Grace Regional Administrator U. S. Nuclear Regulatory Commission 101 Marietta St., NW, Suite 2900 Atlanta, Georgia 30323

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