ML20086H052

AO 75-71:on 751030,drywell Oxygen Analyzer Sample Sys Outer Isolation Valve SV-3978B Failed.Caused by Dirt on Seat & in Body of Valve.Valve Internals & Seat Cleaned.Valve Disc, Piston Rings & Bonnet O-ring Replaced

ML20086H052
Person / Time
Site:	Peach Bottom
Issue date:	11/07/1975
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Boyd R Office of Nuclear Reactor Regulation
Shared Package
ML20086H055	List: ML20086H052 ML20086H056
References
AO-75-71, NUDOCS 8401130374
Download: ML20086H052 (2)

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./* b Q PHILADELPHIA ELECTRIC COMPANY g .M.7f),

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November 7,1973 g Mr. Roger S. Boyd, Acting Director Division of Reactor Licensing Office of Nuclear Reactor Regulations United States Nuclear Regulatory Commission Washington, D.C. 20555

Dear Mr. Boyd:

Subiect: Abnormal Occurrence The following occurrence was reported to Mr. Walt Baunack, Region 1, Office of Inspection and Enforcement, Uni ted Sta tes Nuclear Regulatory Commission, on October 30, 1975. ' Written notification was made to Mr. James P. O'Reilly, Office of ' Inspection and Enforcement, Region 1, United States tJucicar Regulatory Commission on October 31, 1975 In accordance wi th Section 6.7.2.A of the Technical Specifica-tions, Appendix A of DPR-56 for Unit 3 Peach Bottom Atomic Power Station, the following report is being submitted to the Directorate of Reactor Licensing as an Abnormal Occurrence.

Reference:

License Number DPR-56 Technical Specification

Reference:

4.7.D.1 Report No.: 50-278-75-71 Report Date: November 7,1975 Occurrence Date: October 30, 1975 Faci li ty: Peach Bottom Atomic Power Station R.D. #1, Del ta, Pennsylvania 17314 Identification or Occurrence:

Failure of the drywell 02 Analyzer ' Sample System Outer Isolation Valve (SV-39788) .

Conditions Prior to Occurrence:

Uni t 3 at 56% power.

Description of Occurrence:

4 During a routine surveillance test this outboard isolation valve failed to fully close.

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Mr. Roger S. Boyd 50-278-75-71 -

November 7,1975 Page 2 Designetion of Apparent Cause of Occu rence:

Disassembly of the valve revealed dirt on the seat and in the body uf the valve, preventing tight seating.

Analysi s of Occurrence:

The safety implication of this occurrence is minimal, be-cause the inner isolation valve SV-3671B was found to operate satisfactorily. In addition, the upstream manual isolation valve was closed until the valve was repaired and retested.

Corrective Action:

The valve internals and seat were c1 caned. The valve disc, piston rings, and bonnet 0-ring were replaced. The valve was leak tested and f ound satisf actory.

Failure Data:

Similar failures were reported as Abnormal Occurrence Report 50-278-75-11 and also on November 9,1973 Very truly yours,

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// JL&)L (y-M. p. Cooney <

Superintendent Generation Division - Nuclear cc: Mr. J. P. O'Reilly Director, Region i Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406 r

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