ML20133H614

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Final Potential Significant Deficiency Rept SD-79 Re Interconnection Cabling for Power Supply Sys Between Westinghouse 1300 Protection Rack Sets.Initially Reported on 850408.Cables Terminated to Proper Locations
ML20133H614
Person / Time
Site: Millstone Dominion icon.png
Issue date: 07/19/1985
From: Opeka J
NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES
To: Murley T
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
F0797A, F797A, SD-79, NUDOCS 8508090421
Download: ML20133H614 (2)


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P.O. BOX 270 HARTFORD. CONNECTICUT 06141-0270 k k J C,2,$ $.*E,"cw,% (203) 665-5000 July 19,1935 Docket No. 50-423 F0797A Dr. Thomas E. Murley Regional Administrator U.S. Nuc! car Regulatory Commission Region !

631 Park Avenue King of Prussia, PA 19406

References:

(1) 3. F. Opeka to T. E. Murley, F0735A, dated May 8,1935.

(2) 3. F. Opeka to T. E. Murley, F0773A, dated June 19,1985.

Dear Dr. Murley:

Millstone Nuclear Power Station, Unit No. 3 Reporting of Potential Significant Deficiencies in Accordance with 10CFR50.55(e)

Westinghouse 7300 Protection System (SD-79)

In an April 3,1"35 telephone conversation between your Mr. T. Rebelowski and our Mr. G. M. Olsen, Northeast Nuclear Energy Company reported a potential significant deficiency in the construction of Millstone Unit No. 3 in accordance with 10CFR50.55(e). The potential significant deficiency involved the Westinghouse 7300 protection system.

As noted in Reference (1), interconnection cabling for the 24 voit DC power supply system between the 7300 protection rack sets was designed and installed as nonsafety-related cable within the same cable tray. This was determined to be a significant deficiency.

In Reference (2) we informed you that our architect-engineer, Stone & Webster Engineering Corporation was in the process of installing safety-related cable between the 7300 protection rack sets in accordance with Millstcae Unit No. 3's separation criteria, and that we would provide an update on this matter by July I S,1985.

8508090421 850719 PDR ADOCK 05000423 S PDR N

ID

. .4 Stone & Webster has completed installation of the safety-related cables between the 7300 protection racks which meets the Millstone Unit No. 3 separation criteria. NNECO has verified this configuration and terminated the cables to their proper locations within the cabinets.

As such, we consider this to be our final report for SD-79. As discussed with your Project Engineer, Mr. R. Summers, this report is being provided on July 19 rather than July 13, 1985. We trust the above information satisfactorily responds to your concerns.

Very truly yours, NORTilEAST NUCLEAR ENERGY COMPANY

3. F. Oped b 0lbt-U Senior Vice President cc: Mr. 3. M. Taylor, Director Division of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, D.C. 20555