ML20086J303

Telecopy AO 74-15:on 741015,drywell Purge Isolation Valves AO-3505 & AO-3520 Observed Cycling W/Valve Control Switch in Closed Position.Caused by Component Failure.Corrective Action to Be Determined After Investigation

ML20086J303
Person / Time
Site:	Peach Bottom
Issue date:	10/17/1974
From:	Ullrich W PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20086J293	List: ML20086J289 ML20086J303 ML20086J315
References
AO-74-15, NUDOCS 8401230560
Download: ML20086J303 (1)

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17314 Oc tober 17, 1974 t.

lir. . James P. O'Reilly, Director - . . - - -

United States Atonic Energy Coc:=ission Directorate of Regulatory Operations 631 Park Avenue King of Prussia, Pennsylvania 19406 -

Subj ec t :

Abnorml Occurrence 24-Hour Notification --

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Reference:

License Number DPR-56 Technical Specification Ref erence 3.7.D 1 and 3.7.D.2 Repwn,+ --%073u?4-13 __

Repor t Da t e: October 16, 1974 - - -

---Oecurrence Da te:

October 15, 1974 --

Facility: Peach Lottom Atomic Power Station R.D. 1. Delta, Pennsylvania 17314 Identification of Occurrence: -

Drywell purge isolation valve A0-3505 and A0-3520 were observed egli,g (fron the closed position to slightly of f its seat to closed) with the valve control switch in the closed position.

Conditions Prior to Occurrence: -

Reactor shutdown. Pricary syotes pressurized to approxicately 100 psig. ILuicu=

i power level achieved prior to occurrence vas approximately 50%.

Description of Occurrence:

The air actuated 2-vay valves Nhich are part of the isolation valve pneunatic control) developed a small air leak which caused the isolation valvos to cycle. 2

$$ st Designa t ion of Apparent Cause of Occurrence: __

Co=ponent failure. $FAE r

Analysis of Occurrence:

Cycling of these valves could essentially cause a leak from the dryvell to the secondary contaitrient building. Because of the long interval between cycles, no significant Icakage is believed to have occurred.

Corrective Action:

All other isolation valves of similar design vere checked for abnornal operation.

Only the two valves reported above were found to be cycling. (Total nu.nber of valves per plant is eleven).

The two valves vero f ailed in the isolated condition (closed) and a tc=porary air supply vas installed to the valve boot sca l . An investigation is being conducted to determine corrective action to be taken. A local leak showed rate zero test was conducted between the isolation valves and the results leakage.

840123 Failure Data: hDR Aph00 ohg None. ,

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