ML20024B777

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Final Deficiency Rept 83-03 Re Medium Voltage Circuit Breakers of Same Type Installed at Limerick Which Inadvertently Closed After Completion of Spring Charging Due to Slipped Close Latch,Discussed in Brown Boveri 830524 Ltr
ML20024B777
Person / Time
Site: Limerick, LaSalle, 05000000
Issue date: 07/07/1983
From: Schroeder C
COMMONWEALTH EDISON CO., CONSOLIDATED EDISON CO. OF NEW YORK, INC.
To: James Keppler
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20024B778 List:
References
10CFR-050.55E, 10CFR-50.55E, 6902N, 83-03, 83-3, NUDOCS 8307110371
Download: ML20024B777 (5)
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. / '1 Commonwealth Edison j One First Nation 11 Ptiza, Chicago, llhnois

( [/ Address R; ply to: Post Office Box 767 x / Chicago Illinois 60690 July 7, 1983 Mr. James G. Keppler, Regional Administrator

- Region III U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, IL 60137

Subject:

LaSalle 10 CFR 50.55(eCounty) Station Units Report No. 1 andFinal 83-03, 2 i Report - Medium Voltage Circuit Breakers NRC Docket Nos. 50-373 and 50-374 Reference (a): May 24, 1983, letter from Mr. J.E.

l Murray of Brown Boveri Electric, Inc.

l to Mr. J.R. Gilliom.

Dear Mr. Keppler:

Commonwealth Edison Company notified Mr. Roger Walker of NRC Region III on June 13, 1983, of a possible defect with the ESF Divisions I and II 4 KV circuit breakers. This notification was made in accordance with 10 CFR 50.55(e), and this final report fulfills the 30 day reporting requirement of that regulation.

Description of Deficiency In a letter dated May 24, 1983, Brown Boveri Electric, (formerly ITE) notified Commonwealth Edison af a problem that Philadelphia Electric Company had with an ITE type HK circuit breaker. The breaker inadvertently closed following completion of the spring charging because the close latch slipped. At the end of th'e charging cycle the closing springs drives the close latch roller against the close latch, and the shock caused the latch to slip on the breaker. They corrected this problem by adding a light spring to the close latch in the breaker operating mechanism. This spring reduces the shock and the clearances in the close latch and associated linkages.

The ESF Divisions I and II 4KV circuit breakers at LaSalle are ITE type 5HK350, and Brown Boveri stated that they omitted this spring in the production of these beakers between June, 1975, and June, 1977.

Since the 4KV switchgears were delivered either during or immediately after this time period, we requested the station to inspect the breakers so that we could determine if this deficiency was applicable to LaSalle.

The station found that most of the safety related ITE type HK circuit breakers were manufactured during this time period. The attached lists indicate the production date for each breaker.

l 8307110371 830707 DR ADOCK 0500037 g[ $ gg M Mar

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J. G. Keppler July 7, 1983 Analysis of Safety Implications If an ESF Division I or II 4KV circuit breaker closes inadver-tently, the Claus IE power system for that divi,sion could fail, especially upon loss of of f-site AC Power. Closure of a breaker for a non-ESF load after the diesel generator had been automatically connected to the ESF bus would overload the diesel generator. Also, an inadvertent closure of a diesel generator output breaker will damage the generator.

Corrective Action LaSalle Station will install the close anti-shock spring to each ITE type HK circuit breaker that does not have one. The schedule for completing this work on each unit is prior to start up after the first refueling outage. The parts are expected to be delivered in September.

We do not believe that immediate corrective action is required because this problem has only occurred on one ITE type HK breaker to date and has not occurred at LaSalle.

If there are any further questions regarding this matter, please contact this office.

Very truly yours, WW r/7/o C. W. Schroeder Nuclear Licensing Administrator 1m cc: Director of Inspection and Enforcement - Washington, D.C.

NRC Resident Inspector - LSCS 6902N

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Unit 1 Switchgears 4160V Switch9ear 141Y ESF Division I Rated Production Breaker Continuous Nominal Cubicle Date Type Current (A) MVA 1 9/75 SHK 3000 350 2 N/A N/A N/A N/A 3 9/75 5HK 1200 350 4 9/75 5HK 1200 350 5 9/75 SHK 1200 350 ,

6 9/75 SHK 1200 350 7 9/75 SHK 1200 350 8 9/75 5HK 1200 350 9 9/75 SHK 1200 350 10 9/75 5HK 3000 350 11 9/75 SHK 1200 350 12 9/75 5HK 1200 350 13 9/75 5HK 1200 350 14 4/78 5HK 1200 350 4160V Switchgear 142Y ESF Division II Rated Production Breaker Continous Nominal Cubicle Date Type Current (A) MVA 1 10/75 5HK 3000 350 2 N/A N/A N/A N/A 3 10/75 SHK 1200 350 4 10/75 SHK 1200 350 5 10/75 SHK 1200 350 6 10/75 SHK 1200 350 7 10/75 5HK 1200 350 8 10/75 5HK 1200 350 9 10/75 SHK 1200 350 10 10/75 5HK 3000 350 11 10/75 SHK 1200 350 12 10/75 SHK 1200 350 13 10/75 5HK 1200 350 14 4/78 SHK 1200 350 1

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Unit 2 Switchgears 4160V Switchgear 241Y ESF Division I Rated Production Breaker Continuous Nominal

, Cubicle Date Type Current (A) MVA 0 1/76 SHK 1200 350 1 2/76 SHK 1200 350 2 2/76 SHK 1200 350 3 12/75 SHK 3000 350 4 1/76 SHK 1200 350 5 2/76 SHK 1200 350 6 4/78 SHK 1200 350 7 2/76 SHK 1200 350 8 1/76 5HK 1200 350 9 2/76 SHK 1200 350 10 1/76 SHK 1200 350 11 N/A N/A N/A N/A i 12 12/75 5HK 3000 350 4160V Switchgear 242Y ESF Division II Rated Production Breaker Continous Nominal Cubicle Date Type Current (A) MVA i

1 4/78 -SHK 1200 350 2 2/78 SHK 1200 350 3 2/76 5HK 1200 350 4 2/76 5HK 1200 350 5 2/76 5HK 3000 350 6 2/76 SHK 1200 350 7 2/76 5HK 1200 350 8 2/76 5HK 1200- 350 1.

t 9 2/76 5HK 1200 350 10 2/76 5HK 1200 350 11 2/76 5HK -1200 -350 12 2/76 SHK- 1200 350

.13 N/A N/A N/A N/A 14 2/76 5HK 3000 350 3215L 8

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BBC BROWN BOVERI Brown Boveri Electric, Inc. 84S Manufacturer of I-T-E Electncal Power Equipment OUM2-May 24, 1983 i j ) \. ' ,

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Conmonwealth Edison Campany P.O. Box 767 h f.

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Chicago, Illinois 60690 jb Attention: Mr. J.R. 11 ,Manker [

Statfort clear,Ehgineering Departnent

Subject:

IaSalle County Station Medium Voltage Metal-Clad Switchgear Your P.O. No. 167530 Centlemen:

Recently, the Philadelphia Electric Company filed an interim report with the N.R.C. identifying a problem with the close latch on cne of approxirrately 150 Type EE circuit breahors we furnished at their Limerick Generating Station.

You have this type of circuit breaker at your LaSalle County Station.

Although you were probably notified of this by the N.R.C., we are forwarding a copy of our response with attachments.

Since we have so many Type IE circuit breakers in Nuclear Plants, we are forwarding this respcnse to all custaners who took delivery of circuit breakers prior to June 1977, after which an anti-shock spring was added to the close latch.

Please distribute this infonration to the responsible parties in your organiza-tion and to the appropriate personnel at LaSalle County Station.

Yours very truly, BRCNN BOVERI ELECTRIC, INC.

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James E. Murray ilf CMf '

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Executive Sales Engineer s

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Sperry Univec Mare,8600 W. Bryn Mawr Avenue, Suite 710S, Chicago. It.60631 * (312) 6934510 l

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