ML20087H768

Significant Deficiency Rept SD-48 Re Defective Design & Const of Main Control Board Lug Wires Supplied by Reliance Electric Co.Initially Reported on 831110.Insp & Repair Program Initiated.Next Rept by Nov 1984

ML20087H768
Person / Time
Site:	Millstone
Issue date:	03/01/1984
From:	Counsil W, Sears C NORTHEAST UTILITIES
To:	Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
DS-48, F0450A, F450A, SD-48, NUDOCS 8403210161
Download: ML20087H768 (2)

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. General Offices

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HARTFORD. CONNECTICUT 06141-0270 g (203) 666-6911 March 1,1984 Docket No. 50-423 F0450A Dr. Thomas E. Murley Regional Administrator Region I U. S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406

Reference:

(1) W. G. Counsil letter to T. E. Murley, F0433A, dated December 9,1983.

Dear Dr. Murley:

Millstone Nuclear Power Station, Unit No. 3 Reporting of Potential Significant Deficiencies in Design and Corstruction:

Main Control Board Lugs (SD-48)

In a November 10,1983 telephone conversation between your Mr. T. Elsasser and our Mr. 3. Festa, Northeast Nuclear Energy Company (NNECO) reported a potential significant deficiency in the construction of Millstone Unit No. 3 as required by 10CFR50.55(e). The potential significant deficiency involves inadequate terminations of #14 AWG Tefzel and ITT Exane wire to AMP PIDG 53983-1 16-14 HD lugs in the main control board, supplied by Reliance Electric Company.

On January 16, 1984, Reliance Electric Company, with the assistance of Stone &

Webster Engineering Corporation and Northeast Utilities, initiated an inspection and repair program for all terminations of #14 AWG Tefzel and ITT Exane wire to AMP PIDG 53983-1 16-14 HD Lugs in all boards supplied by Reliance Electric Company.

The inspection criteria which Reliance Electric utilized on the AMP crimps is as follows:

o Lugs with conductors crimped only partially where the tool has compressed only a portion of the conductor at the tongue end of the barrel will be rejected.

o Lugs with conductor strands not visible inside the barrel but the crimp is within the barrel length will be rejected.

o Lugs with conductor strands visible inside the barrel but the crimp is not within the barrel length (crimp rolloff) will be rejected.

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-2 . U This rejection criteria was based on testing by Reliance Electric of samples taken from the Main Control Board in which the above configurations failed the UL-486 tensile pull test. Based on this criteria, it was concluded that the

._ integrity of the terminations exhibiting the partial or mislocated crimp on the wire barrel portion are questionable.

Using' the above criteria,' Reliance Electric documented 6,813 lugs that were rejected of an approximate 150,000 total lugs inspected. ' As of today, a total

. number of 5,682 lugs have been repaired. . An agreement was made between Reliance Electric, Stone & ; Webster Engineering Corporation, and Northeast 1 Utilities that all repair work will be performed by. Northeast Utilities and Stone

._& Webster personnel utilizing proper QA procedures. We are still in the process of replacing the remaining lugs as identified by Reliance Electric.

Throughout the inspection, Reliance Electric QA identified two other areas of concern. The first area is in regard to' lugs (16-14 AWG) that were used to terminate 20 AWG resistor leads on Cutler-Hammer Type E-30 switches and on

' Stanwick terminal blocks. .One-hundred resistor lugs.were rejected utilizing the l reject criteria. It was agreed between all parties that leads to the replacement

- resistors' will be double-backed before crimping to the lug. This double back configuration is acceptable both from an electrical and mechanical standpoint.

The second area - of concern is -in regards to lugs (16-14 AWG) that were terminated to the conductors using an ETC crimper. This type of crimp which is not exactly the same as an AMP crimp is still acceptable both from an electrical

. and mechanical standpoint.

We are in the process of revising the mild environment qualification plan (Report Number SQP-99X2087-A) to include the above two configurations. . These two configurations will be tested for tne seismic portion of IEEE-323 exactly as configured in the panels.

- We expect to be able to provide a final report on this subject by November 1984.

Very truly yours, LV.b.

W. G. Counsil

• Senior Vice President By: C. F. Sears .

Vice President Nuclear and Environmental Li.Jineering

<< .cc: Mr. R. C. DeYoung, Director Division of Inspection and Enforcement U. S. Nuclear Regulatory Commission Phillips Building

' 7920 Norfolk Avenue Bethesda, MD 20014

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