ML20084L225

Final Potential Significant Deficiency Rept SD-55 Re GE AKR-30 & AKR-50 Breakers W/Improperly Mfg electro-mechanical Trip Units in Dc Distribution Panel Boards.Initially Reported on 840330.Corrective Actions Completed

ML20084L225
Person / Time
Site:	Millstone
Issue date:	04/27/1984
From:	Counsil W NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES
To:	Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20084L226	List: ML20084L225 ML20084L237
References
F0432A, SD-55, NUDOCS 8405140392
Download: ML20084L225 (2)

Text

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NORTIMAST UTILITIES '"' "'"" Selden Shut, Bedin, Connemt w coaecicw ton ne mna ""

P.O. BOX 270 ClE[7,7"" H ARTFORD. CONNECTICUT 06141-0270 L g g aca

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April 27,1984 Docket No. 50-423 FA32A Dr. Thomas E. Murley Regional Administrator Region i U.S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406

Reference:

(1) D. Dixon (General Electric) to R. C. DeYoung (NRC), dated April 21,1983.

Dear Dr. Murley:

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

General Electric AKR-30 and AKR-50 Breakers (SD-55)

In a March 30, 1984 telephone conversation between your Mr. T. Rebelowski and our Mr. R. E. Lefebvre, 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 Generai Electric AKR-30 and AKR-50 breakers with electro-mechanical trip units which may have been improperly manufactured, as addressed in Reference (1) (attached). These breakers are located in the DC distribution panel boards.

The problem was discovered on the Millstone Unit No. 3 breakers while they were at the General Electric service shop for calibration, and were the breakers which prompted the reporting of this generic problem to the NRC.

General Electric has informed us that this defect has been corrected on all of the Millstone Unit No. 3 AKR-30 and AKR-50 breakers, however, we are awaiting final, written confirmation from General Electric on this. Pending receipt of this correspondence, we ccasider this to be our final report closing out all items related to SD-55. We trust that the above information satisfactorily responds to your concerns.

Very truly yours, NORTHEAST NUCLEAR ENERGY COMPANY 8405140392 840427 PDR ADOCK 05000423 , , .

(, M S PDR W. G. Counsil Senior Vice President 1

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cc: Mr. R.' C. DeYoung, Director -

Division of Inspection and Enforcement U.S. Nuclear Regulatory Commission Phillips Building 7920 Norfolk Avenue Bethesda, MD 20014 i

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