ML20086J479

Telecopy AO 74-6:on 740915,instrument Piping to Main Steam Line High Flow Differential Pressure Indicator Switches on Main Steam Line B Found Reversed.Caused by Piping Reversed in Instrument Piping Tray During Installation

ML20086J479
Person / Time
Site:	Peach Bottom
Issue date:	09/16/1974
From:	Ullrich W PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20086J477	List: ML20086J475 ML20086J479
References
AO-74-6, NUDOCS 8401240032
Download: ML20086J479 (2)

Text

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/S-337- //Sc i PHIIAIELIHIA EIECEIC COMPANY hach Botton Atomic Ibver Station /Qh

-Delta, Penngylvania September 16,197h Mr. James P. O'Railly, Director thited States Atantic Energy Ccamission Directorate of Begulatory Operations 631 Bark Avenue King of Pnssia, Pennsylvania ISh06 arbject: Abnormal Occurrenec 2L-Bour Notification Confirming J. E. Wine.enried's phone conversation with Mr. Walt Baunack, A.B.C. Region 1 Regulatory Operations Office on September 16,197h.

Reference:

License Ember IPR-56 Technical Specification Reference 3 2.A ~

Report No.: 50-278-7h-6 Report Date: September 16, 197h Occurrence Date: Septer.ber 15,197L Pacility: Peach Bottom Ator:ic Power Station R.D.1, Delta. Pennsylvania 1*(31h Identification of Occurrence:

Instmnent piping to the Unit 3 Main Steam Line High Flow Differential Pressure Indicator suitches (DPIS) on the "B" Main Steam line was revareed.

Conditions Prior to Ocm.m; Reactor operating at apprminately 25% power. Startup testing in progress.

Description of Occurrence:

During a reutine inspecticn of the plant the operator noted all four DPIS on the "B" Main Stena line won reading downscale while the IPIS on the other main steam lines were reading slightly upscale.

Designation of Apparent Cause of Csswoe 2e piping was reversed in the instrument piping tray daring installation.

Analysis of Occurrence .

Se reversed differential rendered the four high f2cw switches unable to respond to a high flow condition in the "B" sain steam line. 'Dms, a l Noup I 's isolation due to a 'B'sain stoma line rupture would have been prevented. Bis is the first time the nactor has been at this poser level and themfore tbs first time that significant steam f2cv el=wmt differential pressure has been availableito verify cornet operation of these switches. e401240032 740925 c $; .,

PDR ADOCK 05000278 S PDR

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g,ggi,, gggg Both Eain Staan Isolation Valves (ESIV) in the "B" steam line were shut.

Instrument piping at the instansent rack was re-piped to produce the proper differential to the IFIS. Surve411me tests were perfoneed on all fear DPIS to verify operability and setpoints. Se 'B' steam line IGIT's

. :~ L : =,+, c' ,y, were re-open ith the resultant proper indi on on all four DPIS. . ' '

, s . The 12 DPIS e three other' main steam li re all checked and found to be operating properly.

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, s Very truly yours,

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W. T. Ullrich, Superi endent --

Peach Bottom Atomic Power Station-n

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