B10809, Final Significant Deficiency Rept SD-25 Re Failure of Pinion Gear Shear Keys in Limitorque Mode SB-0 Motor Operated Valves.Initially Reported on 820903.Westinghouse Will Replace Pinion Keys on All SB-0 Series Motor Operators

Final Significant Deficiency Rept SD-25 Re Failure of Pinion Gear Shear Keys in Limitorque Mode SB-0 Motor Operated Valves.Initially Reported on 820903.Westinghouse Will Replace Pinion Keys on All SB-0 Series Motor Operators

ML20079Q823
Person / Time
Site:	Millstone
Issue date:	06/10/1983
From:	Counsil W NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES
To:	Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
10CFR-050.55E, 10CFR-50.55E, B10809, SD-25, NUDOCS 8306200396
Download: ML20079Q823 (2)

Text

i Gml Omen e Selen Sunt, Belin, Connecticut NORTHEAST UTILITIES q j,,7Z*g" ",*,"," P.O. BOX 270

.am na on.co H ARTFORD. CONNECTICUT 06141-0270 L g y yve ao e cow = (203) 666-6911 June 10,1983 Docket No. 50-423 B10809 Dr. Thomas E. Murley Region 1 Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406

References:

(1) W. G. Counsil letter to R. C. Haynes, Millstone Nuclear Power Station, Unit No. 3, Reporting of Potential Significant Deficiencies in Design and Construction: Failure of Pinion Gear Shear Keys in Limitorque Model SBO (SD-25), dated September 3,1982.

(2) W. G. Counsil letter to R. C. Haynes, Millstone Nuclear Power Station, Unit No. 3, Reporting of Potential Significant Deficiencies in Design and Construction: Failure of Pinion Gear Shear Keys in Limitorque Model SBO (SD-25), dated October 6,1982.

(3) W. G. Counsil letter to R. C. Haynes, Millstone Nuclear Power Station, Unit No. 3, Reporting of Potential Significant Deficiencies in Design and Construction: Failure of Pinion

, Gear Shear Keys in Limitorque Model SBO (SD-25), dated l November 24,1982.

l I

Dear Sir:

Millstone Nuclear Power Station, Unit No. 3, Reporting of Potential Significant Deficiencies in Design and Construction: Failure of Pinion Gear Shear Keys in Limitorque Model SBO (SD-25)

! In Reference (1), Northeast Nuclear Energy Company (NNECO) reported a potential significant deficiency concerning failure of pinion gear shear keys in Limitorque Model SBO motor operated valves as required by Title 10, Code of l Federal Regulations Part 50, Paragraph 55(e). References (2) and (3) provided interim reports on our progress toward resolving the deficiency.

j Westinghouse and Limitorque have completed an extensive investigation of this j issue, and Westinghouse has determined that the potential for sheared keys is limited to Westinghouse Electro-Mechanical Division (WEMD) manufactured 9306200396 830610 f4 PDR ADOCK 05000423 S PDR t'. '

g/ i 0 6

valves equipped with Limitorque Model SB-O-25 motor operators.

Although it has been determined that the unique circumstances resulting in key failure affect only SB-O-25 motor operators in WEMD manufactured valves, WEMD has elected to replace the pinion keys on all SB series motor operators

, on WEMD manufactured valves.

WEMD valves ordered under the NSSS contract for Millstone Unit No. 3 are currently being manufactured at WEMD. These valves will have replacement pinion keys installed prior to shipment, which will resolve this deficiency.

This letter constitutes our final report closing out all items related to SD-25.

We trust the above information satisfactorily responds to your concerns.

Very truly yours, NORTHEAST NUCLEAR ENERGY COMPANY

/ - / 71J W. G. Counsil '

Senior Vice President

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