ML19295B992
| ML19295B992 | |
| Person / Time | |
|---|---|
| Site: | Dresden, Byron, Braidwood, Quad Cities, Zion, LaSalle  |
| Issue date: | 05/31/1978 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Brian Lee COMMONWEALTH EDISON CO. |
| References | |
| NUDOCS 8010150688 | |
| Download: ML19295B992 (1) | |
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MA5' 31 :578 Docket No 456, 50-457, 50-454, 50-455, 50-10 50-237, 50-249, 50-373, 50-374,'50-254, 50-265, 50-295 and 50-304 Comonwealth Edison Company ATTN:
Mr. Byron Lee, Jr.
7 Vice President
/ __ _' Post Office Box 767
'N Chicago, IL 60690
_. _ ~ ~_.- - Gentienen:-
Enclosed is IE Bulletin No. 78-06 which requires action by you with regard to your power reactor facilities with an operating license or a construction permit.
Should you have questions regarding this Bulletin or the actions required r - ----
of you, please contact this office.
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Sincerely.
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James C. Keppler Director
Enclosures:
_1.
List of IE Bulletins
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Issued in 1978 ec w/encia:
Mr. B. B. Stephenson, Mr. R. Cosaro, Project Station Superintendent Superintendent
/ entral Piles Mr. N. Kalivianakis, C
Station Superintendent Director, NRR/DPM Mr. N. Wandke, Station Director, NRR/ DOR Superintendent PDR Mr. L. J. Burke, Site Local PDR Project Superintendent NSIC Mr. Gunner Sorensen, Site._-
- TIC-Project Su erintendent Anthony Roisman, Esq., Attorney
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8010140 M
RITI RIII RIII
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5/30/78 oxyc w NRC Form 318A (RUI) (5-76) NRCM 02040
- U. 5. GOVERNMENT PRINTING OFFICE: 1978-253-818
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i U.S. NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT RECION III
'May 31,.1978 IE Bulletin No. 78-06 DEFECTIVE CUILER-HAMER, TYPE M RELAYS WITH DC COILS Description of Circumstances:
The Duke Power Co=pany recently reported that during a series of tests of the Emergency Power Switching Logic System at Oconee Nuclear Station, four relays in the standby buses #1 and #2 voltage sensing circuitry were found to be inoperable..The relays are identified as Cutler-Hac=er
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Type M, DC Relays, Catalog No. D23 MRD. This finding prompted 'th'e licensee to perform another test of the Emergency Power Switching Logic during which one additional relay. o_f the sa=e type and model as identified above also failed.- To date, twelve f ailures of thi's' DC relay type have occurred at Oconee Nuclear Station.
The manufacturer deter =ined that cause for fa'ilure was loss of are gap in the coil clearing contact where the normal mode of operation is to have the coil continuously energized. The purpose of this contact is to interrupt the inrush current to the pickup coil vinding in order to prevent vinding burn out. The loss of are gap in the clearing contact was caused by an abnormal amount of heat induced shrinkage of molded magnet carriers which are used in subject relays manufactured between 1971 and July of 1976. According to Cutler-Hac=er, the loss of are gap.affects the performance of only the type M relays with DC coils
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since relays with AC coils do not use the coil clearing contact feature.
The attached Cutler-Hammer Notification of Potential Product Tailure van sent to all dis'tributors of type M relays with DC coils with instructions to notify end users of the. potential problems. The notification identifies the problem and provides their reco=nended corrective action.
Action To Be Taken By Licensee:
'ith an operating license or construction DUPLICATE DOCUMENT r Type H Relays with a DC coil are safety-related systems at your Entire document previously entered into system under:
P{d9 IM%$ k ANO No. of pages:
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