ML20094F485

Potential Significant Deficiency Rept Re Namco Model EA-180 Limit Switches Provided as Accessories on Valves Supplied by Pacific Valves & Fisher Controls.Initially Reported on 840131.Next Rept Expected by 841023

ML20094F485
Person / Time
Site:	Millstone
Issue date:	07/17/1984
From:	Counsil W, Sears C NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES
To:	Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
F0508A, F508A, NUDOCS 8408100064
Download: ML20094F485 (3)

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.i, ... . c0 (203) 666-6911 July 17,1984 Docket No. 50-423 F0508A 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, FO471 A, dated March 1, 1984.

Dear Dr. Murley:

Millstone Nuclear Power Station, Unit No. 3 Reporting of Potential Significant Deficiencies in Design and Construction: NAMCO Model EA-180 Limit Switches (SD-51)

In a January 31, 1984 telephone conversation between your Mr. T. Rebelowski and our Mr. D. B. Vail, 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.

The potential 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. A preliminary review performed by NUSCO Engineering determined that this potential significant deficiency could adversely impact the operation of Category lE circuits and equipment. We are now providing you with additional information regarding these limit switches.

The valves provided with the subject limit switches are used in safe shutdown, accident mitigation, and containment isolation systems, and for safety to non-safety system isolation valves. 'ihe switches perform functions which include valve position, status indication, and valve operating interlock signals.

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4 We are currently aware that there are eight (8) valves provided by Pacific Valves with the subject switches. These affected valves are as follows:

3RHS*MV8701B RCS to RHR 3RHS*MV8702A RCS to RHR 3SIL*MV8812B RHR Suction from RWST 3SIH*MV8813 SI Pumps to RWST 3RSS*MV8837A Recirc Pump A to Cold Leg of RCS 3RSS*MV8837B Recirc Pump B to Cold Leg of RCS 3RSS*MV8838A Recirc Pump C to Cold Leg of RCS 3RSS*MV8838B Recirc Pump D to Cold Leg of RCS We are also aware that there are twelve (12) valves provided by Fisher Controls with the subject switches. These affected valves are as follows:

31AS* PV15 Containment Instrument Air Supply Pressure 3CDS*CTB38A Chilled Water Containment Trip 3CDS*CTB38C Chilled Water Containment Trip 3CDS*CTB39A Chilled Water Containment Trip 3CDS*CTB39B Chilled Water Containment Trip 3CCP*AOV10A Tr. A Nonsafety Header Supply ! solation 3CCP*A0V10B Tr. B Nonsafety Header Supply Isolation 3CCP* AOVl9A Tr. A Nonsafety Header Supply Isolution 3CCP*AOVl9B Tr. B Nonsafety Header Supply Isolation 3CCP*AOVl94A Tr. A Nonsafety Header Supply isolation 3CCP*AOV194B Tr. B Nonsafety Header Supply isolation 3FPW*CTV48 Containment Fire Protection Water Isolation We have received a list of the date codes of the deficient switches from NAMCO. Stone & Webster Engineering Corporation is in the process of reviewing this list against all other Model EA-180 limit switches which will be used at Millstone Unit No. 3. Once the remainder of the deficient switches have been identified, new nongalling expansion plugs will be procured from NAMCO and the affected switches repaired.

We are not able to provide you with a final report at this time. Our next report regarding this matter will be provided to you by October 23,1984.

Very truly yours, NORTHEAST NUCLEAR ENERGY COMPANY W h byn W. G. Counsil Senior Vice President L hMILL BY: C. F. Sears Vice President Nuclear and Environmental Engineering

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I cc: Mr. R. C. DeYoung,- Director Division of Inspection and Enforcement U.S. Nuclear Regulatory Commission Phillips Building 7920 Norfolk Avenue Bethesda, MD 20014 4

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