ML20211M923

Part 21 & Deficiency Rept Re Warped Geared Limit Switch Rotors Supplied by Limitorque Corp.Initially Reported on 870205.Internal Occurrence Description Rept Initiated. Limitorque Corp Will Provide Itemization of Affected Plants

ML20211M923
Person / Time
Site:	Rancho Seco
Issue date:	02/10/1987
From:	Julie Ward SACRAMENTO MUNICIPAL UTILITY DISTRICT
To:	Martin J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
References
REF-PT21-87, REF-PT21-87-034-000 IEB-85-003, IEB-85-3, JEW-87-119, PT21-87-034-000, PT21-87-34, NUDOCS 8702270389
Download: ML20211M923 (2)

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$suun "YP SACRAMENTO MUNICIPAL UTIUTY DISTRICT O P 15830, Sacramento CA 95852-1830,(916) 452-3211 A fig S STEM SERVING THE HEART OF CALIFORNIA february 10, 1987 8 JEW 87-119 NI//q J. B. Martin, Regionai Administrator Region V Office of Inspection and Enforcement Attn: Deument Control Desk U. S. t(Lclear Regulatory Comission 1450 Maria Lane, Suite 210 Walnut Creek, CA 94596 DOCKET NO. 50-312 Rancho Seco Nuclear Generating Station Unit #1 License No. OPR-54 10 CFR 21 REPORT, LIMITORQUE GEARED LIMIT SWITCH ROTORS WARPED

Dear Mr. Martin:

In accordance with 10 CFR 21.21(b)(2), the Sacramento Municipal Utility District hereby submits a written report documenting the notification made by Mr. C. Stephenson of the District to Mr. L. Miller of Region V Nuclear Regulatory Comission (NRC) on february 5,1987 concerning warped geared limit switch rotors supplied by Limitorque Corp., Lynchburg, Virginia.

During the motor operated valve (MOV) refurbishment program initiated by IE Bulletin 85-03, seven (7) out of a group of fifty (50) fibrite (brown color) geared limit switch rotors were discovered to be warped sufficiently to prevent limit switch adjustments. The warped fibrite geared limit switch rotor was detected on January 16, 1987 during the replacement of a rotor on the limit switch gear box. Electrical maintenance personnel installed a new fibrite rotor onto a limit switch gear box and proceeded to rotate the limit switch rotor with a drill motor during bench testing to ensure engagement of the gears. They observed that the rotor was not making contact with the

" fingers" due to an axial bend in the rotor.

The entire shipment of fifty (50) fibrite limit switch rotors was checked for warpage. Seven (7) of the fifty (50) were warped severely enough to prevent limit switch adjustments. The shipment was purchased under Purchase Order No. RS 90625.

An internal Occurrence Description Report was initiated on January 16, 1907 requesting the Plant Review Comittee (PRC) to review the warped rotors for possible 10 CFR 21 reportability. On february 3,1987 the PRC recomended that a 10 CFR 21 Report be submitted to the NRC pursuant to 10 CFR 21.4(d)(1).

07022 ] h $ hPDR 12 PDH h-/ f'C i O g

RANCHO SECO NUCLEAR GENERATING STATION C 14440 Tmn Cities Road, Herald, CA 95638 9799;(209) 333 2935

i Mr. Martin February 14 1987 District maintenance procedures were in place, prior to the discovery of the warped rotors, that prevented the installation of a defective component into an operating system.

The District considers Limitorque Corporation to be better qualified to provide the NRC an itemization of those facilities which may be affected by this defect.

If there are any questions concerning this report, please contact Mr. Ron W. Colombo at Rancho Seco Nuclear Generating Station.

Sincerely,

(

Jo n E. Ward Deputy General Manager, Nuclear cc: Director I&E NRR

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