ML20128A921

Deficiency Rept SD-79 Re Westinghouse 7300 Protection Sys Interconnection Cabling Installed as nonsafety-related. Initially Reported on 850408.Redesign of Cable Runs in Progress.Next Rept Will Be Submitted by 850718

ML20128A921
Person / Time
Site:	Millstone
Issue date:	06/19/1985
From:	Opeka J, Sears C NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES
To:	Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
F0773A, F773A, SD-79, NUDOCS 8507030067
Download: ML20128A921 (2)

Text

IV l'g gg NORTHEAST UTILITIES General Offices

• Selden Street, Berlin, Connecticut Usfi7[ssu EsYiNaw P.O. BOX 270 not aneww~

HARTFORD CONNECTICUT 06141-0270 L L J [ C ,7,,2, ",~', (203) 665-5000 June 19,1985 Docket No. 50-423 F0773A  !

Dr. Thomas E. Murley Regional Administrator U. S. Nuclear Regulatory Commission Region 1 631 Park Avenue King of Prussia, PA 19406

Reference:

J. F. Opeka to T. E Murley, F0735A, dated May 8,1985.

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 8,1985 telephone conversation between your Mr. T. Rebelowski and our Mr. G. 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.

Interconnection cabling between the 24 volt DC power supply system and the 730f' orotection rack sets was designed and installed as nonsafety-related cable wit *he same cable tray. Since the 24 volt DC is used as an auctioneered back. ;ower supply for the 26 volt DC power supply, the cabling should have been safety-related and installed in accordance with Millstone Unit No. 3's cable separation criteria. Hence, this represents a significant deficiency in the final design for Millstone Unit No. 3.

Our architect-engineer, Stone & Webster Engineering Corporation, has re-designed the cable runs for the interconnection of the 24 volt DC power supplies.

Stone & Webster is in the process of installing safety-related cable with the 7300 protection rack in accordance with Millstone Unit No. 3's separation criteria.

This new configuration has not been completed to date. As such, we are not able 8507030067 850619 \g PDR ADOCK 05000423 S PDR

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4 to provide a final report at this time. We will provide an update on this matter by July 18,1985.

Very truly yours, i

NORTHEAST NUCLEAR ENERGY COMPANY

d. .b J. F. Opeka Senior Vice President L

. By: C. F. Sears Vice President cc: Mr. 3. M. Taylor, Director Division of Inspection and Enforcement U. S. Nuclear Regulatory Commission Washington, D. C. 20535 l

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