ML20069K812

Interim Significant Deficiency Rept SD 413-414/83-05 Re Allen Set Screws Backing Out of Worm Shaft Clutch on Limitorque Actuators.Initially Reported on 830318.Defective Parts Replaced w/Lok-Tite

ML20069K812
Person / Time
Site:	Catawba
Issue date:	04/15/1983
From:	Tucker H DUKE POWER CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
10CFR-050.55E, 10CFR-50.55E, NUDOCS 8304260495
Download: ML20069K812 (2)

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• ~ e-DUKE POWER GOMPANY P.O. box 33189 CHARLOTTE, N.C. 28242 HAL B. TUCKER ren.epuoxz

== rar-ar (704)373 4 s3 sversam roonvenow April 15, 1983 Mr. James P. O'Reilly, Regional Administrator m U. S.' Nuclear Regulatory Commission u Region 11 g ,2 101 Marietta Street, NW, Suite 2900 ;o z T; Atlanta, Georgia 30303 y jO U

Re: Catawba Nuclear Station  :::. 'S Units 1 and 2 E3 Docket No. 50-413 and 50-414

• C .

~ *-

Dear Mr. O'Reilly:

Pursuant to 10 CFR 50.55e, please find attached Significant Deficiency Report .

SD 413-414/83-05.

Very truly yours, gA <

Hal B. Tucker RiiG/phy Attachment cc: Director INP0 Records Center Office of Inspection and Enforcement Suite 1500 U. S. Nuclear Regulatory Commission 1100 circle 75 Parkway i Washington, D. C. 20555 Atlanta, Georgia 30339 l

Mr. P. K. Van Doorn Mr. Robert Guild, Esq.

l NRC Resident Inspector . Attorney-at-Law Catawbn. Nuclear Station P. O. Box 12097 Palmetto Alliance i 2135 Devine Street I Columbia, South Carolina 29205 l

h ND;.

1 g rc t r i l 8304260495 830415 PDR ADOCK 05000413 S pop f5 &

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Duke Power Company

' Catawba Nuclear Station Significant Deficiency Report Number: SD 413-414/83-05 Report Date: April 15, 1983 Facility: Catawba Nuclear Station Units 1 and 2 Identification of Deficiency: NCI number 16293, dated February 17, 1983, identified allen set screws backing out of the worm shaft clutch on Limitorque actuators. The deficiency was identified on Limitorque model number SBD-3, supplied by Westinghouse per Duke Power Design Specification CNS-1205.00-0008 and Mill Power Order A-98524.

Initial Report

• Initial report was made to Mr. A. Ignatonis, Region II NRC, on March 18, 1983 by Messrs. W. O. Henry and J. K. Berry, Duke Power Company.

Description of Deficiency: Allen set screws in the affected shaft clutches had been secured by. center punching material adjacent to the allen screws.

Spot checks of the clutches revealed that in some cases center punching was not close enough to the screws for securing. This allowed several screws to begin backing out. Limitorque actuators using a similar gear and clutch arrangement are models SMB l-3, SBD l-3 and SB l-3 with 3600 rpm AC, or 1800 rpm DC current motors.

Analysis of Safety Implications: Valves 1&2NIO54A, 1&2NIO65B, 1&2NIO76A and 1&2NIO88B are low pressure accumulator tank discharge isolation valves. Valves 1&2 nil 83B are residual heat removal header to hot leg injection isolation valves.

Screws. backing completely out of the clutch could become lodged between the worm shaft gear and motor pinion gear. This could preclude these active valves from completing their safety function.

Corrective Action: Defective parts have been removed from service in all actuators affected. Allen set screws in replacement parts were secured with Lok-Tite. Duke is reviewing similar valve applications at other Nuclear Stations and will notify the NRC should any deficiencies be identified.

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