ML18219C184

Response to IE Bulletin No. 77-01 Entitled, Pneumatic Time Delay Relay Setpoint Drift.

ML18219C184
Person / Time
Site:	Cook
Issue date:	05/31/1977
From:	Dolan J American Electric Power Service Corp
To:	James Keppler NRC/RGN-III
References
IEB-77-001
Download: ML18219C184 (4)

Text

AMERICAN ELECTRIC POWER Sr.i vi ct Co>P0I ati on 2 Droatlttnty, ¹to Fork, N. F. I000$

(2/d) 422 4800 JOIIh'. DOLhII Senior Ecccuticc 1 t cc Prccidcnt Enginccring 4 Conttruction May 31, 1977 Donald C. Cook Nuclear Plant Unit Nos. 1 and 2 Docket Nos. 50-315 and 50-316 DPR No. 58 CPPR'No. 61 Mr. Z. G." Keppler, Regional Director U.S. Nuclear Regulatory Commission Office of Inspection and Enforcement Region XXX 799 Roosevelt Road Glen Ellyn, Illinois 60137

Dear Mr. Keppler:

This letter is in response to your letter of April 29, 1977, which transmitted to us IE Bulletin No. 77-01 entitled, "Pneumatic Time Delay Relay Setpoint Drift. " You requested us, if we have been notified of the potential problem to describe actions taken regarding

, by the manufacturer, corrective measures to identify and resolve any setpoint drift.

problems with the XTE time delay relays. You also requested us to provide the basis for concluding that'xisting pneumatic time delay relays are functioning as required, or provide plans to assure satis'factory operation.

Ne have not received notification of any deficiencies in pneumatic time delay relays prior to the receipt of IE Bulletin No. 77-01. There are no XTE pneumatic time delay relays in use at the Donald C. Cook Nuclear Plant.

JUN G 1g7P

gr. J. G. Keppler Nay 3l, l977 time delay relays used in safety systems are Elastic Stop Nut "Agastat" series 7000 relays. These relays have a repeat accuracy of + 5%. No evidence of drift in excess of the specified 5% has been detected. All critical timing circuits make allowance for the 5% tolerance.

Yours very truly, ohn E. Dolan Senior Ex cutive Vice president Engineering and Construction JED:mam CC R. C. Callen P. W. Steketee R. Walsh G. Charnoff R. J. Vollen R. S. Hunter R. W. Jurgensen Bridgman

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