ML19242A665

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RO 79-091/01T-0 on 790725:followup Rept on Discovery That Component W-104 Dual Peripheral Driver in 7,300 Series Signal Comparator Cartds Could Fail,Causing Associated Bistable to Fail in Unsafe Mode
ML19242A665
Person / Time
Site: North Anna Dominion icon.png
Issue date: 07/26/1979
From:
VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
NUDOCS 7908030367
Download: ML19242A665 (1)


Text

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, y,. . w a . rin. toc u.xj i t ecr Ccmparg 3.o m A. .. a l't taer stedhn, unit w i Npp 4 (T%7*

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! Tvi f fear Repartable Eent JUL 2 01979 ,,

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I Event : Fabre cG Tgpe NAL 9,4ynl Ccupctra-tcr

Cards

} LER/RO 7()-Ocl3/oiT-C

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il ve Ar_nverect hat it is poscable Gor tha "

I jaoc, pco sectes shgocd ccmparator (NAL) CardC to 9c

$ causing the cosecriated bistable to possib\g Sc

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s Scn \ in an unsc6e b, ode-en y '

The cause oG this prob \em is tha.t compene.

Q W-loy(Duni rLcipheral briver plus 2. NPt4 Output Tconsistors) on the MAL card somekimes Cd' ds n-i, srom char ted ccndition &rebg perCormicg ded Sunckion .prevenbing Ehe .bishtk TEs inten 1

fj, Vepco Instrume ,t Npartment has Initiated N

[N (( revieu 09 the historg 09 NAL card 9adures.

u u co The tMit is presenb\g operaking in Moci, ca i Fj ll Fubtre correckIVe ac.tions cdll be. cleberni

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bg the Gindings 09 the M A L Cord Go~ dure historg revieu.

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