ML19253C448

Deficiency Rept,Sd 369-370/79-11 Re Westinghouse 7300 Series Process Comparator Card Technical Problems.Caused by Design Deficiencies.Insp of Cards Conducted & Cards Being Repaired. Corrective Actions to Be Completed by 800430

ML19253C448
Person / Time
Site:	McGuire, Mcguire
Issue date:	11/29/1979
From:	DUKE POWER CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML19253C447	List: ML19253C446 ML19253C448
References
NUDOCS 7912050594
Download: ML19253C448 (7)

Text

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DUKE POWER COMPANY MCGUIRE NUCLEAR STATION UNITS 1 AND 2 Report No.: SD 369-370/79-11 Report Date: November 29, 1979 Facility: McGuire Nuclear Station - Units 1 and 2 Identification of Deficiency: Westinghouse 7300 Series Process I & C Card Technical Problems Description of Deficiencv:

This deficiency is as described in the attached August 23, 1979 letter, NS-TMA-2124, from T. M. Anderson, Manager, Nuclear Safety Department, Westinghousg to Victor Stello, Director, Office of Inspection and Enforce-ment, U.S. Nuclear Regulatory Commission. Westinghouse reported this deficiency to the NRC as a substantial safety hazard under 10CFR21.

Analysis of Safety Implica tion:

The safety implications of this deficiency are also presented in the attached Westinghouse letter (NS-TMA-2124) .

Corrective Action:

An inspection of the Westinghouse 7300 Series Process I & C cards at McGuire has been conducted. One hundred, sixty-five (165) cards were found to be affected at Unit 1. None of the can% at Unit 2 were affected. Of the 165 Unit 1 cards 163 had pr > 1 as described on the attached Westinghouse letter. The remait: ' - o cards had problem 2. These cards are being repaired by w'estinghouse personnel and will be functionally tested by Duke. This corrective action -

will be complete by April 30, 1980, 1502 iS4 2012oooE)f-

d-E ..M.'.' ', I.l:Chl; CCT::iC.'0n PO..cr Sy5icm; m:3 P.*t% g,rt-.pr.n,-;3

. August 23, 1979 fiS-TFA-2124 Mr. '.'ictor Stello, Jr.

Director Office of Insp:ction and Enforcement U. S. Ilacicar Regulctory Commission U:shir3 tor. D.C. 20555 Mail Stop - Et-322 Subj er .. tlestinghouse 7300 Series Prccess Centrol System Dc;.: !:r. St.cile:

!!cstinghouse has made an assessmant of field reports relating to tuo (2) technical prcblems which could exist in its 73C0 S: ries Proc::s Centro.1 System.

Virginia Electric & Power Company (VCPCO) had experienced the pro-blems at its I: orth Anna Unit 1 station. The first involv s a circuit cornponar.t used in protection system comparators (bistables) v.hich was observed to have an abnormal failure rata in this application. The con-segocnce of the failure could prevent a safety signal output frca the bistable in the affected channel. The second involves the potential for a seismic-induct:d circuit malfunctior, r:hich could alter limiting setpcints for initicting cafety action by the 7300 Series systca. Although both problems are detectable during periodic system tests, the potential exists for degrtdation of redundant protection channals ' hich initiate Reactor Trip and Engineered Safeguards. On Aucust 1, 1979 and I.ugust 2, 1979 respectively, reports t:ere raade 't'o the l'RC by VEFC0 under the provisions

& of 10CfR50.55(e).

Er.ginetring changes had bean raada previcusly by the 1.'estin; house Ireu.try ~

Systems Divisior:, the manufacturer, to correct both probicms. Hac2ver, there exists en uncertainty as to the location of devices, shipped prior to the enginceying changes, which need to be replaccd or rettorhed.

Consequently, on August 21, 1979, the I?estinc_ibcu:c 1:30 S:fety Revices Ccmittee concluded that both issues constituted a Potantial Substantiel Safety Ha:ard in op: rating !!cstinghouse plcnts with 7300 Series Process Contrcl Systems and, as such, are reportable to the f;RC under Title 10CFR Part 21.

The attach : 2nt identifies all potentially offected nuclear po..er plants, and includes data 11cd technical information and corrective actions to be taken.

This intormation has already been cc:r.ir:r.icat2d to tha utility o;;ners cf th2se potentially affected plants.

Please refer any questi;ns to Dr. K. R.

Nuclear Safety Departt.;cnt. DUPLICATE DOCUMENT Entire document previously entered into system under:

79/colo #W F1 :-1:pj 1502 iS5 1. nNO AttIcht::en t . IU- /

No. of pages: (47

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