ML20092L137

Forwards Justification for Interim Operation for Utilization of Westinghouse 7300 Series safety-related balance-of-plant Analog Instrumenation That Will Not Be Seimically Qualified Before Unit 1 Licensed.Nrc Approval Requested

ML20092L137
Person / Time
Site:	Byron
Issue date:	06/19/1984
From:	Tramm T COMMONWEALTH EDISON CO.
To:	Harold Denton Office of Nuclear Reactor Regulation
References
8822N, NUDOCS 8406290255
Download: ML20092L137 (2)

Text

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First NttionalEdison Pitza Chicsgo Illinois

( O 7 - Address Riply to: Post Office Box 767 (j Chicago, Illinois 60690 June 19, 1984 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555

Subject:

Byron Generating Station Units 1 and 2 Seismic Qualification of Equipment NRC Docket Nos. 50-454 and 50-455 Reference (a): May 2, 1984 letter from T. R. Tramm to H. R. Denton

Dear Mr. Denton:

This letter provides the justification for interim operation (JIO) for one item of equipment which will probably not have complete seismic-qualification at the~ time Byron 1 is licensed. Reference (a) provided JIO's for all of. the other iteras for which seismic testing will be incomplete.

Attachment A to this letter contains the JIO for safety-related Westinghouse 7300 analog instrumentation used in balance-of-plant applications. Seismic testing of this equipment has been completed by Westinghouse. The test report will not be completed until' the results have been reviewed with respect to NSSS instrumentation applications. The report is presently expected to be available by the end of 1984. If hardware changes are nccessary, they may not be completed (until the first refueling outage.

NRC approval.for' interim operation of BOP 7300 series instrumentation is requested. Please direct questiorm to this office.

One signed original and fif teen copies of this letter and the attachment are provided for NRC review.

i Very truly yours,

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T.R. Tramm Nuclear Licensing Administrator bs .

8406290255 e40619 Attachment PDR ADOCK 05000 8822N ^ -

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i Attachment A ,

Justification for Utilization of 7300 Series Safety Related Balance of Plant Analog Instrumentation Byron Except for the printed circuit cards identified belo,w, 'all printed circuit cards used for safety related functions unconditionally passed i qualification test.

The following P.C. cards experienced anomalies of mincr nature which are presented here for plant specific evaluation by plant delsgner and/or. user. Westinghouse presents the following justifications for use of these P.C. cards.

NCO, NCE, NTC, NTD Anomaly - These cards experienced contact bounce during the seismic shake. The test response spectra was of a generic nature-and much greater in magnitude and broader in peak than the '

design spectra for Byron /Braidwood. These cards operated normally after the event.

NCO, NCD, and NTC cards are not utilized at Byron for this equipment.

The NTD card is used in the main Steam Generator Pressure Relief Control System. Opening and closing control signal path for the power operated relief valves 1MS018A, B, C and D is through the NTD card and relay. During a postulated thirty second seismic event the relay contact experiences random bouncing. Effect of random bouncing is loss of signal.whenever the contact is open. Normal signal level is reestablished when the seismic event is over.

Since there are five other mechanically actuated relief valve in parallel with each MS018, valve, and since the MS018 valves will be i actuated only to establish natural circulation, the potential loss of ,

control signal for thirty seconds will be of no concern to the operation of the plant.

NCH Anomaly - After four SSEs, one in each of four directions, the NCH '

had a totalized output shift of 1.02% of output span.

-Justification - A shift of this small magnitude would not constitute failure ta) qualify especially for the fact that it required four SSEs to cause a shift of this magnitude. The card can easily be brought back ' ta) calibration after the seimsic event by readjusting

. potentiometers on P.C. card which is a normal card calibration function.

8822N

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