ML20086J342

AO 74-14:on 741015,inboard Main Steam Line Sample Isolation Valve Found Not Fully Closed.Caused by Setpoint Shift.Closed Valve Position Indication Limit Switch Adjusted,Valve Stroked & Proper Operation Verified

ML20086J342
Person / Time
Site:	Peach Bottom
Issue date:	10/25/1974
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Giambusso A US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20086J326	List: ML20086J325 ML20086J342 ML20086J354
References
AO-74-14, NUDOCS 8401230580
Download: ML20086J342 (2)

Text

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O O PHILADELPHIA ELECTRIC COMPANY 23O1 MARKET STREET PHILADELPHI A. PA.19101 1215) 841-4cCO October 25,197h ~

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I!r. A. Gicnbusso Deputy Director of Reactor Projects 41

/c' k ' M' United States Atomic Encrry Cce: mission Directorate of Licensing

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Washington, D.C. 20$j45 s @['i if,W7 "i h$, }. /

Dear Mr. Gianbusso:

y

Subject:

Abnomal Occurrence The following occurrence was reported to lir. Walt Baunack, A.E.C. Regicn 1 negulatcry Operations Office on October 16,197h.

E'ritten notification was nade to Mr. Janos P. O'Reilly, Region 1 f

Regalato:f Operations Office on October 16,197h. In accordarce idth Scotien 6.7.2.A of the Tcchnical Specifications, Appendix A of DPR-56 for Unit 3 Pccch Bottom Atomic ~Pouer Station, the follouing report is being subnitted to the Directorate of Licensing as an Abnomal Occurrenc c.

Reference:

Licenso Humber DPR-56 Technical Specificatien Refercnce 3 7.D Report No.: 50-278-7h-lh '

Report Date: October 25,197h t Occurrcnce Date: October 15,197h ,

Fccility: Peach Botton Atomic Pcuer Station R.D. #1, Delta, Pennsylvania 1731h Identification of Occurrer.ce:

1 Unit 3 inboard main stcan'line sample isolation valve not }

fully closed.

Conditions Prior to Occurrence:

Unit 3 reactor shutdown, reactor pressure approximately 100 psig, rcactor tcnpcrature approximately 3!;0"/, reactor ready for sta rtup.

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N 1'X & W f ut u u t .

l n m Mr. A. Gimbusso kN October 25,197h Page 2 Descriotien of Occurrcnce:

During a routine inspection of the control rocm p:ncls, en operator noticed that the inboard ncin stcom line smple isolaticn valve was indicating mid-positien. The outbcard isolation valve was irnediatel'f verifica to be in the closcd position which is the nomal positien for both isolation valves.

Dc'signation of Appercnt Cause of Occurrcr.cc:

Trip setpoint shift of the 'iclosed valve positicn indication limit switch.

Analysis of Occurrcnce:

At the time of this occurrcnce, the reactor was shutdoun and at rcduced tmpcrature and pressure. The other isolation valve in the line nas verified to be in the closed position and, as described below, tested to verify its isolation capability. Since one valve in the line was closed cnd lack tight, this occurrence has nininal safety inplications.

Corrective Action:

As required by the Technical Spccifications, a daily log of the other operable isolction valve vac iracdiately instituted, in the fom of an catablished surveillance test which verifics that the position of the other isolation valve, in the same line, is in the closed or isolatcd condition. A test was conducted to prove the isolation capability of the outboard valve. Flow thmugh the line was establishcd, cnd when the outboard isolation velve was closed, ficw cea s ed. In addition, the normal plant blocking procedures were applied to the outboard valve to ensure that the valve rcnsined in the closed or isolated condition, until the inboard isolation valve was repaired.

During the scheduled outage on October 19,197h, inspection of the valve inside the drfwell revec1cd the valve was actually fully closed. The " closed" valve position indication limit switch was adjusted, the valve stroked and proper operation verified.

Failure Data:

None l

l Verf truly youm, l (sfP M. . Cooney Asst. G ed.. Supt.

Ocneration Division cc: J. P. O'Rcilly Director, Region 1 U.S. Atonic lhergy Cc:nission