ML20086L160

Ao:On 731101,four Oxygen Analyzer Sys Isolation Valves SV 2978B & D & 2671F & G Found Inoperable.Caused by Buildup of Dirt & Rust on Valve Internals.Valves Dismantled,Parts Cleaned or Replaced & Reassembled

ML20086L160
Person / Time
Site:	Peach Bottom
Issue date:	11/09/1973
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Giambusso A US ATOMIC ENERGY COMMISSION (AEC)
References
NUDOCS 8402070432
Download: ML20086L160 (2)

Text

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PHILADELPHIA ELECTRIC COMPANY 2301 MARKET STREET

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November 9,1973 D'Ti!-?n a/.r, ,

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Mr. A. Giambusso Deputy Director of Reactor Projects United States Atomic Energy Commission Directorate of Licensing Washington, D. C. 20545

Reference:

Peach Bottom Atomic Power Station - Unit 2 Facility Operating License DPR-44 Docket No. 50-277

Subject:

Abnormal Occurrence During a routine surveillance test performed on November 1, 1973, four oxygen analyzer system isolation valves, S.V.-29788, S.V.-2978D, S.V.-2671F, S.V.-2671G, were found to be inoperable. This was reported to Mr.

Eldon Brunner, A.E.C. Region 1, Regulatory Operations Office on November 2, 1973 Investigation An investigation into the cause of failure indicated that the valves were operating properly electrically, but were mechanically failing to close because of a build-up of dirt and rust on the valve internals. Most of the sample piping in this system is stainless steel except for a small section through .the dry-well penetrations.

s Corrective Action The manual block valves upstream of the inoperable solenf ad valves were immediately closed following the performance of the surveillance testing.

The sticky valves were dismantled; the internal parts cleaned and/or replaced, and I then reassembled. The test performed on pthese rebuilt valves was satisfactory.

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8402070432 731109 3 s PDR ADOCK 05000271

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COPY SENT REGION h 82Q3 A

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The subject valves will be placed on an increased testing frequency. Engineering has been asked to review the system design in light of these failures and suggest permanent solutions to prevent reoccurrence.

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Safety Implications The solenoid valves which were found to be inoperable are required to close on primary containment isolation. There are two valves in series in each line from the drywell to the sampling station. The four failures noted were in separate lines. The other valve in series with the inoperable valves would have isolated the line successfully had an isolation signal been present. Since the sample lines would have isolated properly during a containment isolation, there is no safety implication associated with these f ailures.

t Very truly yours, ,

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. M M. J Cooney /

i Asst. Gent . Superintendent Generation Division MJCtjb cc .. Mr. J. P. O'Reilly Director, Region i United States Atomic Energy Commission 631 Park Ave.

King of Prussia, PA 19406

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