ML20085G435

AO BFAO-7317W:on 730927,RCIC Sys Flow Indicator FI-71-1A Indicated Negative Steamflow.Caused by Crossed High & Low Pressure Instrument Lines.Instrument Lines Reversed.All Lines Will Be Checked

ML20085G435
Person / Time
Site:	Browns Ferry
Issue date:	10/05/1973
From:	Eric Thomas TENNESSEE VALLEY AUTHORITY
To:	Oleary J US ATOMIC ENERGY COMMISSION (AEC)
References
AO-BFAO-7317W, NUDOCS 8308290087
Download: ML20085G435 (2)

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TENNEGSEE CHAi i ANCOGA, VALLEY AUTHORIT/ nn /7 j:"~\

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[n-,lcy (M L_dl October 5, 1973 ANN nuo.

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5' .. ru m Mr. John F. O'Icary, Direetor -[ Y Directorate of Liccesing  ;

Office of Regulaticn x" U.S. Atomic Enerce Ccnission -

' y' k'achington, DC 20545 -

Dear Mr. O' Leary:

TE:E!ESSLE VALI2Y AUTECRITY - EROZ;S FERRY NUCLEAR PIM'T UMIT 1 -

DOCK 0T :;0 50-259 - F1CILITY OPERATING LICE:iSE DPR EOR'1AL CCCURRE: CE PsPORT IFAO-7317U The purpoce cf this report is to provide details concerning the discovery of reverced inctrument sencing lines on RCIC turbine cteamline high flow differential pressure cwitch PdlS-71-1A cn Septembe r 27, 1973, at Erovas Ferry I;uclear Plant. This occurrence was reported by telegran cn September 23 to the Region II Directorate of Regulatory Ope:ations, Atlanta, Georgin.'

Deccrintion of the Incident Daring tecting of the RCIC syctea at 150-psig reactor pressure, a negative steauflow vac observed on flow indicator FI-71-1A. The reactor was scramed by an unrelated cause during the test and remained shut down until the problen was recolved.

Investigation end Corrective Action Investigation revesled that the high- and low-pressure instInment lines from the RCIC ster = flow orifice were crocced. Also, investigation revealed that steanline high flow switch PdIS-71-1A was conaected to thece caue instrument linec, therefore rendering it incperable.

Instrument lines to the redundant flew indicator and stec~ aline high flow cuitch were fcund correctly inctalled.

The switch is part of the icolation logic for the RCIC system. Two days before the cecurrence, this switch and the redundant switch in the other trip cystem were functionally tested and found to operate properly. Since only cne of the two channels is required operable, the isolation logic vould have performed its intendeci function if required. ,/

8308290087 731005 /

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i Mr. John F. O'Icary October 5, 1973 l TE INESSEE VALIl2 /GTEORITY - ERC'.niS FERRY !!UCIEAR FIJJif UNIT 1 -

ICCl2T IiO. 50-259 - FACILITY CPERATIHG LICE!!SE DPR IJst:0miAL '

, CCCUILE:!CE REPORT EFAO-7317J 1

The instrument lines were reverced at the instrument panel and the i

flow indientor observed to read upscale during a subsecuent RCIC tect.

All instrument lines to differential preccure instrumeats in the l technical specifications vill be checked for correct inctallatioa cither by physical inspection or by obcervation of instrunent response during operation.

Very truly yours, I

TE:MESSEE VAT.T.EY AUTEORITY

! A i 4 l . .d w '

E. F. Thomas Director of Fover P_mduction .

i j CC: Mr. I;orman C. Moseley, Director p 3

Region II Ragulatory Operationc Office, US/.EC

230 Peachtre Street,

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j Atlcata, Georgia 30303 i

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