ML20041B792

Final Deficiency Rept Re Failures of J-13 Relays.Vendor Rept Indicates That Coil Failure Was Possibly Caused by Application of Excessive Input Voltage.Control Circuits Will Be Revised to Eliminate Control Voltage

ML20041B792
Person / Time
Site:	Zimmer
Issue date:	02/11/1982
From:	Borgmann E CINCINNATI GAS & ELECTRIC CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
10CFR-050.55E, 10CFR-50.55E, QA-1629, NUDOCS 8202250207
Download: ML20041B792 (2)

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1-i THE CINCINNATI GAS & ELECTRIC COMPANY C

CINCIN NATt. OHIO 452o1 February 11, 1982

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E. A. 90RGMAN N SENIOR VtCE PRESIDE NT 4

l U. S. Nuclear Regulatory Commission Region III I

799 Roosevelt Road Glen Ellyn, Illinois 60137 Attention:

Mr. J. G. Keppler M-J.?f I

Director S-RE:

WM. H. ZIMMER NUCLEAR POWER STATION - UNIT I ij 4

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't 10CFR50.55(c) - ITEM E FAILURES OF J-13 y,

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t' *4 RELAYS - DOCKET No. 50-358, CONSTRUCTION

1. Mio ['l PERMIT CPPR-88, W.O. #57300 JOB E-5590 - FILE

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CC' NO. NRC ITEM E-12 N A, N

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,- \\ b' Gentlemen:

This letter constitutes a final report concerning the deficiency of the sub-ject relays initially reported under the requirements of 10CFR50.55(e).

Most of the relays of this type used at Zimmer are either not continuously energized (therefore not subject to coil burnout) or not performing essential functions. However, relays of this type that are continuously energized and per-form essential safety functions are used in the following systems at Zimmer:

1.

Nuclear Steam Supply Shutoff System (NB) 2.

Drywell Pneumatic System (IN) 3.

Primary Containment Ventilation System (VP)

^4 These relays operate upon loss of voltage, initiate an alarm in the control room and remove control power from the magnetic starters. The failures of these j

relays on DC circuits have been from open circuited coils. The relays were returned to the vendor in November 1980 and an analysis was received on August 10, 1981.

The report from the vendor indicates that the. probable cause of coil failure was due to the application of excessive input voltage. We feel that an overvoltage condition does not exist at Zimmer. This also was addressed in our previous report, QA-1550, dated December 30, 1981.

i 8202250207 820211 gDRADOCKOSOOOg kggg

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o Mr. J. G. Keppler Director Region III February 11, 1982 QA-1629 Page 2 We have not received the second report from the vendor in response to our i

request for a re-examination of the failed coils. However, verbal discussions i

held with the vendor indicate that this matter will not be resolved to our liking and that the cause of the failure of these relays cannot be determined. Therefore, to insure the safety of the plant's operation, we will revise the control circuits in which these relays are continuously energized and performing essential functions either 1) eliminate the function which removes the contro1 voltage or 2) bypass the contact except during surveillance testing. Thus, these relays will operate to initiate an alarm in the control room only.

We trust that the above will fulfill the requirements of a final report under 4

10CFR50. 55 (e).

Very truly yours, THE CINCINNATI GAS & ELECTRIC COMPANY lk w

E. A. BORGMANN SENIOR VICE-PRESIDENT WPC:ac cc:

NRC Resident Inspector Attn:

W. F. Christianson NRC Office of Inspection & Enforcement Washington, D.C.

20555 l

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