ML20085G429

AO BFAO-7318W:on 730929,during Startup Testing,Hpci Invertor Power Supply Fuse Failed.Cause Under Investigation.Fuse Replaced

ML20085G429
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-7318W, NUDOCS 8308290083
Download: ML20085G429 (2)

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" - TENNESSEE VALLEY AUTHO AITY ;~'~F's 77 'O CHATTANOOGA, TENNESSEE  ! j 37401  :.J ~.~ m

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L=,7l y-y, [;M October 5, 1973 SE"M'ES!.'e%

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Mr. John F. O' Leary, Director

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Office of Regulation t. .

U.S. Atomic Jnercy Corliscion _, ,

Wachington, DC 205! 45 '

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Dour Mr. O' Leary:

TJI!I!ESSEE VALLEY AiTEORITY - EP.CEG FERRY :!UCLSAR PU iT U:ilT 1 -

DCCFET !!O. 50-259 - FACILITY OPERATI iG LICE.!SE DPR flCICFlVJ, CCCURRE::CE Fi'?CdT EFAC-731b'.!

The purroce of this raport is to provide details of the EPCI inverter pcVer cupply fuse failure which occurred on Septe:nber 29, 1973, at Brovnc Ferry liuclear Plant.

D2cerintion of tne Incident At 10:20 a.n. ca Septcuber 29 during ctnrtup' testin6; with the reactor at 600 psig, a fuce failed in the EPCI inverter power supply. The '

itse was replaced and the HTCI voc operable within one minute. The HFCI vac not in operation at the time of the failure nor is there any known plant operation or action vnich centributed to this failure.

Invectiration and Corrective Action This occurrence is similar to a previous failure reported to you cn September 18 as EFAO-739W. Following that occurrence, General Electric Company and Topa:: Electronics, the inverter manufacturer, modified the inverter by replacing the Zl!609 500V breasover voltage SCR's with ZN690 6007 breakover voltage SCR's and addin6 a GE MOV-V 250 Uh0 filtering network to the input to protect againct voltage spikes. On ,

September la the nodified inverter was inctallcJ and had been operating l catisfnetorily until thic fuce failure. Iio increaced curveillance is considered necescary cince failure is aanunciated in the main control roo.'t . The power cupply hac been operating caticfactorily cince the 8308290083 731005 PDR ADOCK 05000259 S PDR

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Mr. Jchn F. O' Leary October 5, 1973 l l

Trl:EE:SSEE VALLEY AUTECRITY - IRC'.0:S FERRY I!UCIEAR PL/J:T U:!IT 1 -

DOCKET !!O. 50-259 - FACILITY GPEMTI:!G LICZ:ISE DPR AE::031AL CCCURh2:!CE Tu:FOIC LFAC-7318W fuce vac replaced on September 29 The cause of tne failure and poccible corrective cetion is under continuing invectigation. 1."nea a resolution ic reached, you will be udviced.

Very truly ycure, TEi!!!ESSEE VALE Y A!?fEC3ITY 4.

$ Ah u Y! .GDN E. F. Tho:nas Director of Power Productica CC: Mr. I!crman C. !:oceley, Director Region II Eegulut,ory Operationc Office, USAEC 230 Pecch ,ree Street, :~4.

Atlaata, Georcit. 30333 s

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