ML20086J391

AO 74-11:on 741004,RCIC Steam Line Drain Valve Failed to Close.Caused by Piece of Weld Slag Wedged in Below Seat Stem Guide.Valve Disassembled & Cleaned

ML20086J391
Person / Time
Site:	Peach Bottom, Oyster Creek, Pilgrim, 05000000
Issue date:	10/14/1974
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Giambusso A US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20086J393	List: ML20086J391 ML20086J395 ML20086J403 ML20086J425
References
AO-74-11, NUDOCS 8401230632
Download: ML20086J391 (2)

Text

q O O l PHILADELPHIA ELECTRIC COMPANY  !

l l 2301 MARKET STREET l -

PHILADELPHIA. PA.19101 i

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12153841 4000 .

I October 14, 1974

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Mr. A. Giambusso ,

Deputy Director of Reactor Projects ,

United States Atomic Energy Conmission  %..fi./ S ,3 Directorate of Licensing *. ' ;3 Washington, D.C. 20545 ".; /[ "  ;

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Dear Mr. Giambusso:

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Subject:

Abnormal Occurrence . -. g N' The following occurrence was reported to Mr. Walt Baunack, A.E.C. Region 1 Regulatory Operations Office on October'4, 1974.

Written notification was made to Mr. James P. O'Reilly, Region 1 Regulatory Operations Office on October 4, 1974. In accordance with Section 6.7.2.A of the Technical Specifications, Appendix A of DPR-56 for Unit 3 Peach Botton Atomic Power Station, the following report is being submitted to the Directorate of Licensing as an Abnormal Occurrence:

Reference:

License Number DPR-56 Technical Specification References 3.5.D.1, 3.5.D.2, 3.7.D.2., plus Tablu 3.7.1 Report No.: 50-278-74-11 Report Date: October 14, 1974 Occurrence Date: October 4, 1974 Facility: Peach Bottom Atomic Power Station R.D. 1, Delta, Pennsylvania 17314 Identification of Occurrence:

RCIC steam line drain valve failure to close.

Conditions Prior to Occurrence:

Reactor was operating at approximately 1% power with primary coolant pressure of-150 psig. RCIC operability testing in progress.

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Mr. A. Giambusso October 14, 1974 fx Page 2 O- u Description of Occurrence: .

During surveillance testing of the RCIC system during a plant startup, the inner RCIC steam line drain valve ( AO-3-13 -34 )

failed to close.

Desionation of Apnarent Cause of Orcurrence:

A piece of wold slag had entered the valve and became wedged in the below seat stem guide, preventing the valve from closing.

Analysis of Occurrence:

The RCIC main steam line drain system is equipped with a drain pot, a steam trap and two air operated isolation. valves in series. Water which condenses in the main steam line is passed through two air operated isolation valves in series to the main condenser. Both of these isolation valves close automatically on RCIC initiation. Since only one valve was affected by this occurrence, system operability was not affected.

Corrective Action:

After removing the RCIC system from service and initiating the required surveillance tests , the valve was disassembled and thoroughly cleaned. The disc and seat were machined to remove indentations caused by the foreign object and then lapped. The valve was reassembled, leak tested and returned to service.

Failure Data:

No previous failures of this type have occurred.

Very truly yours,

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M./.[Goney[gr y Let [~

y Asd't Gen'l Superintendent Generation Division cc: Mr. J. P. O'Reilly Director Region 1 United States Atomic Energy Commission 631 Park Avenue King of Prussia, PA 19406 L

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