ML20107K620

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Final Part 21 & Deficiency Rept SD-51 Re Defect in Namco Model EA-180 Limit Switches Provided as Accessories on Valves Supplied by Pacific Valves & Fischer Controls. Initially Reported on 840131.Repairs Complete
ML20107K620
Person / Time
Site: Millstone Dominion icon.png
Issue date: 10/23/1984
From: Counsil W
NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES
To: Murley T
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
REF-PT21-84-531-000 F0588A, F588A, PT21-84-531, PT21-84-531-000, SD-51, NUDOCS 8411130215
Download: ML20107K620 (2)


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.csv .ca m we cow =- (203) 66s-5000 October 23,1984 Docket No. 50-423 F0588A 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, F0471A, dated March 1,1984.

(2) W. G. Counsil letter to T. E. Murley, F0508A, dated July 17,1984.

Dear Dr. Murley:

Millstone Nuclear Power Station, Unit No. 3 Reporting of Potential Significant Deficiencies in Design and Construction: NAMCO Model E A-180 Limit Switches (SD-51) in a January 31, 1984 telephone conversation between your Mr. T. Rebelowski and our Mr. D. B. Vali, Northeast Nuclear Energy Company (NNECO) reported a potential significant deficiency in the construction of Millstone Unit No. 3 as required by 10CFR50.55(e). Subsequently, this was followed up with another telephone conversation with your Mr. T. Elsasser on February 1,1984. We completed our evaluation of this potential problem and determined that it was a significant deficiency (see References I and 2).

The significant deficiency involved NAMCO Model EA-180 limit switches provided as accessories on valves supplied by Pacific Valves and Fisher Controls.

NAMCO determined that the splined lever shaft in some NAMCO Model EA-180 limit switches may not expand adequately to secure the operating lever when the expansion plug is tightened in the end of the shaft due to expansion plug galling.

'Ihe valves provided with the subject limit switches ,re used in safe shutdown, accident mitigation, and containment isolation syr* ;, and for safety to non-safety system isolation valves. The switches perl, functions which include valve position, status indication, and vaPr 3 operating a .:rlock signals. Thus, this condition could adversely affect the operation of Category lE circuits and equipment.

8411130215 841023 PDR ADOCK 05000423 S PDR 3

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We have completed our review to identify all valves which utilized Model EA-180 limit switches at Millstone Unit No. 3. We have determined that only Pacific Valves and Fisher Controls have supplied valves with the subject limit switches.

A list identifying these valves was provided to you in Reference (2). In addition, repair work for all of the deficient switches has been completed and certificates of conformance for the new nongalling expansion plugs received.

We consider this to be our final report closing out SD-51. We trust that the above information satisfactorily responds to your concerns.

Very truly yours, NORTHEAST NUCLEAR ENERGY COMPANY

. - I/7A/nk W. G. Counsil Senior Vice President cc: Mr. R. C. DeYoung, Director Division of Inspection and Enforcement U.S. Nuclear Regulatory Commission Phillips Building 7920 Norfolk Avenue Bethesda, MD 20014