ML20091R872

Forwards Interim Deficiency Rept Re Electrical Conductor Butt Splices.Topic Discussed at 840531 Prehearing Conference.Related Correspondence

ML20091R872
Person / Time
Site:	Byron
Issue date:	06/13/1984
From:	Mark Miller COMMONWEALTH EDISON CO., ISHAM, LINCOLN & BEALE
To:	Callihan A, Cole R, Smith I Atomic Safety and Licensing Board Panel
References
OL, NUDOCS 8406150301
Download: ML20091R872 (3)

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' na m )c m ,v.,u m ISHAM, LINCOLN & BEALE y COUNSRORS AT LAW C3Cf[I{3 U3hRC THREE FIRST NATIONAL PLAZA cac^=maas aa '84 JUN 15 A10:25 TELEPHONE 312 $$8-7500 WASHINGTON C,FFICE Roe TTL 0 N. 2 9 340 WILLAM G BEALE. 1885 1923 ' . "r R*- WASHINGTON. O C. 20036

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SRANCH June 13, 1984 Ivan W. Smith, Chairman Dr. A. Dixon Callihan Administrative Judge Administrative Judge Atomic Safety and Licensing Board Union Carbide Corporation U. S. Nuclear Regulatory Com- P. O. Box Y mission Oak Ridge, Tennessee 37830 Washington, D. C. 20555 Dr. Richard F. Cole Administrative Judge Atomic Safety and Licensing Board U.S. Nuclear Regulatory Commission Washington, D. C. 20555 Re: In the matter of Commonwealth Edison Company (Byron Nuclear Power Station, Units 1 and 2)

Docket Nos. 50-454 and 50-455 d &

Dear Administrative Judges:

Enclosed is a copy of letter from Commonwealth Edison Company to the Nuclear Regulatory Commission which constitutes an interim report concerning electrical conductor butt splices, a topic which was discussed at the prehearing conference on May 31, 1984.

Yours very truly, J

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/l k C l l y rne MIM:es Michael I. Miller One of the Attorneys for Commonwealth Edison Company cc Service List 0406150301 840613 PDR ADOCK 05000454 0 PDR ,

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( C /'7Chicago, Addr:ss R ply to. Post Offics Box 767 liknois 60690 l

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June 12, 1984 Mr. James G. Keppler Regional Administrator U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, IL 60137

Subject:

Byron Generating Station Units 1 and 2 Electrical Conductor Butt Splices NRC Docket Nos. 50-454 and 50-455 References (a): May 17, 1984 letter from D. L. Farrar to J. G. Keppler.

(b): May 25, 1984 letter from R. L. Spessard to Cordell Reed.

(c): June 6, 1984 letter from R. L. Spessaro to Cordell Reed.

Dear Mr. Keppler:

On May 10, 1984 Commonwealth Edison notified the NRC of a deficiency potentially reportable pursuant to 10 CFR 50.55(e) regarding butt splices in electrical conductors at Byron Station. This letter provides an interim report to satisfy the 30-day reporting requirement.

The results of the first phase of the reinspection program described in reference (a) is expected to be complete by June 20, 1984. Another interim report will be submitted at that time. For tracking purposes, this report is numbered 84-03.

Description of Defleiency Deficiencies in butt splices in electrical conductors have recently been discovered through reinspection at other nuclear plants.

To verify the acceptability of the Byron butt splices, a representative sample was inspected in March, 1984. The results were encouraging in that all of the splices were found to be generally sound. A number of splices were given a simple tug-test in the field to verify the mechanical effectiveness of the crimp. Excessive force was applied to one conductor and it parted at the splice. No problems were identified which would compromise the normal electrical load carrying capability-of the conductor. Deviations from the manufacturer's acceptance criteria were i identified, however, which could reduce the effectiveness of the electrical insulation at the splice. The results of that reinspection program are summarized in references (a) and (c).

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4 J. G'.'Keppler June 12, 1984 Analysis of Safety Implications Case-by-case engineering analyses of the butt splice 1 deficiencies are not complete as of this date. As described above,

. preliminary reviews indicate that the' deficiencies would probably have no adverse impact upon plant safety, t .

Corrective Action Taken and Results Achieved On April 5, 1984 the electrical installation. contractor-implemented new requirements for installation, inspection, and documentation of electrical butt splices. This should assure that future splices are made correctly.

i A new program of butt splice.reinspections has also bee'n undertaken as described in reference (a). We are examining previously

installed butt splices on the conductors of safety-related-instrumenta-j' . tion and control cables in panels, switchgear, motor control centers and i on both sides of electrical penetrations. :This reinspection program is.

l being conducted by the electrical contractor, Hatfield, in accordance ~

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with written procedures. As. indicated.in reference (b)Lthe NRC is closely monitoring this project.

At present over 900. butt splices'have been reinspected. .The program is about 755 complete.

'. Minor deviations from the established

{ field inspection acceptance criteria have been,found in approximately 14%

of the butt splices checked. Approximately 8% were crimped using the ,

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wrong die,'but are otherwise acceptable. About 6% of the splices have minor deficiencies such as exposed wire at the' splice or improper i

conductor. insertion into the splice.- All of the splices inspected so far have been found to be generally sound. Engineering analysis of-minorf discrepancies will determine:the safety significance of each' discrepancy. All discrepant-splices are being replaced inlaccordance with the new requirements.

! Please address further questions regarding this matter to this office.

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Very truly yours, 1

h If T. R..Tramm . .

Nuclear Licensing Administrator-

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'cc: Director.of Inspection and Enforcementi

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