Information Notice 1997-32, Defective Worm Shaft Clutch Gears in Limitorque Motor-Operated Valve Actuators

Defective Worm Shaft Clutch Gears in Limitorque Motor-Operated Valve Actuators

ML031050589
Person / Time
Site:	Beaver Valley, Millstone, Hatch, Monticello, Calvert Cliffs, Dresden, Davis Besse, Peach Bottom, Browns Ferry, Salem, Oconee, Mcguire, Nine Mile Point, Palisades, Palo Verde, Perry, Indian Point, Fermi, Kewaunee, Catawba, Harris, Wolf Creek, Saint Lucie, Point Beach, Oyster Creek, Watts Bar, Hope Creek, Grand Gulf, Cooper, Sequoyah, Byron, Pilgrim, Arkansas Nuclear, Three Mile Island, Braidwood, Susquehanna, Summer, Prairie Island, Columbia, Seabrook, Brunswick, Surry, Limerick, North Anna, Turkey Point, River Bend, Vermont Yankee, Crystal River, Haddam Neck, Ginna, Diablo Canyon, Callaway, Vogtle, Waterford, Duane Arnold, Farley, Robinson, Clinton, South Texas, San Onofre, Cook, Comanche Peak, Yankee Rowe, Maine Yankee, Quad Cities, Humboldt Bay, La Crosse, Big Rock Point, Rancho Seco, Zion, Midland, Bellefonte, Fort Calhoun, FitzPatrick, McGuire, LaSalle, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant
Issue date:	06/10/1997
From:	Slosson M Office of Nuclear Reactor Regulation
To:
References
IN-97-032, NUDOCS 9706040318
Download: ML031050589 (8)

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UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555-0001 June 10, 1997 NRC INFORMATION NOTICE 97-32: DEFECTIVE WORM SHAFT CLUTCH GEARS IN

LIMITORQUE MOTOR-OPERATED VALVE

ACTUATORS

Addressees

All holders of operating licenses or construction permits for nuclear power reactors.

Purpose

The U.S. Nuclear Regulatory Commission (NRC) Is issuing this information notice to alert

addressees to a recent discovery of a defective worm shaft clutch gear in a Limitorque SMB

Size 1 motor-operated valve actuator. The defective gear was not made by Limitorque, the

original equipment manufacturer (OEM). It is expected that recipients will review the

information for applicability to their facilities and consider actions, as appropriate, to avoid

similar problems. However, suggestions contained in this information notice are not NRC

requirements; therefore, no specific action or written response is required.

Description of Circumstances

On October 8, 1996, personnel at General Public Utilities Nuclear Corporation's Oyster Creek

facility discovered that a nonsafety-related Limitorque valve actuator in the circulating water

system failed to operate from the control room switch. The licensee determined that the

actuator failed to operate because the tripper pin had fallen out of the worm shaft clutch gear.

The actuator was sent to the original vendor, Limitorque Corporation In Lynchburg, Virginia, for root cause analysis.

Discussion

The Oyster Creek licensee procured several surplus or refurbished Limitorque actuators from

a third party company (non-OEM supplier) for use in nonsafety-related applications. Two of

the actuators failed to operate electrically because of problems with the worm shaft clutch

gear. One gear was replaced with an original Limitorque worm shaft clutch gear and

operated satisfactorily. However, in the second actuator, the worm shaft clutch gear was

replaced with a non-OEM part. Subsequently, the Oyster Creek licensee determined that the

third party supplier had replaced the original OEM worm shaft clutch gears in the actuators

with gears produced by a non-OEM replicator.

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IN 97-32 June 10, 1997 When the actuator was electrically operated from the control room, the womi shaft clutch

gear tripper pin fell out because it was not securely fastened onto the worm shaft clutch gear.

Consequently, the actuator tripper fingers were not separated as the gear rotated, and the

actuator would not operate electrically. Manual actuator operation with the hand wheel is not

affected by the loss of the tripper pin.

Limitorque examined the worm shaft clutch gear and found several examples of failure to

meet required specifications:

• The tripper pin was not staked to the worm shaft clutch gear.

• The worm shaft clutch gear lugs were not heat treated.

• The gear teeth were inappropriately shaped and not shaved.

• Other non-serious dimensional differences were also identified.

On the basis of this information, Limitorque determined that it had not manufactured the gear

and informed the NRC in a letter dated January 23, 1997. Limitorque informed the NRC that

it had discovered the non-OEM component installed in the SMB Size 1 nonsafety-related

actuator that was received from Oyster Creek for root cause analysis. The letter also stated

that Limitorque Informed its nuclear customers of record about the defective component.

When compared side by side, some of the differences in the non-OEM and OEM gear can be

readily Identified. However, if such a comparison is not available to the customer, the non- OEM part may be harder to detect. Licensees may not have sufficient information to detect

and recognize a defective worm shaft clutch gear during receipt inspection or dedication for

safety-related use.

Failure of the nonsafety-related Limitorque actuator at Oyster Creek was caused by the

tripper pin being inadequately fastened to the worm shaft clutch gear. The potential exists for

use of non-OEM parts in Limitorque actuators in safety-related applications. This information

notice is intended to alert licensees that problems can result from use of non-OEM parts, if

those parts are not manufactured to the same specifications as the OEM parts.

IN 97-32 June 10, 1997 This information notice requires no specific action or written response. If you have any

questions about the information in this notice, please contact one of the technical contacts

listed below or the appropriate Office of Nuclear Reactor Regulation (NRR) project manager.

Maree M. Slosson, Acting Dire or

Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical contacts: K. Naidu, NRR

301-415-2980

E-mail: kmenrc.gov

T. Scarbrough, NRR

301-415-2794 E-mail: tgs@nrc.gov

D. Skeen, NRR

301-415-1174 E-mail: dls@nrc.gov

Attachment: List of Recently Issued NRC Information Notices

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Attachment

IN 97-32 June 10, 1997 LIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

I

Information Date of

Notice No. Subject Issuance Issued to

97-31 Failures of Reactor 06/03/97 All holders of OLs or CPs

Coolant Pump Thermal for pressurized-water

Barriers and Check reactor plants

Valves in Foreign

Plants

97-30 Control of Licensed 06/03/97 All material and fuel

Material During Reorgan- cycle licensees

izations, Employee- Management Disagreements, and Financial Crises

97-29 Containment Inspection 05/30/97 All holders of OLs or CPs

Rule for nuclear power reactors

97-28 Elimination of Instrument 05/30/97 All holders of OLs or CPs

Response Time Testing

Under the Requirements of

10 CFR 50.59

97-27 Effect of Incorrect 05/16/97 All holders of OLs or CPs

Strainer Pressure Drop for light-water power

on Available Net Positive reactors, except those

Suction Head licensees who have per- manently ceased operations

and have certified that

fuel has been permanently

removed from the reactor

vessel

97-26 Degradation in Small- 05/19/97 All holders of OLs or CPs

Radius U-Bend Regions for pressurized-water

of Steam Generator Tubes reactors

OL = Operating License

CP = Construction Permit

IN 97-32 June 10, 1997 This information notice requires no specific action or written response. If you have any

questions about the information in this notice, please contact one of the technical contacts

listed below or the appropriate Office of Nuclear Reactor Regulation (NRR) project manager.

Marylee M. Slosson, Acting Director

Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical contacts: K. Naidu, NRR

301-415-2980

E-mail: km@nrc.gov

T. Scarbrough, NRR

301-415-2794 E-mail: tgs@nrc.gov

D. Skeen, NRR

301-415-1174 E-mail: dls@nrc.gov

Attachment: List of Recently Issued NRC Information Notices

• - See previous concurrence

Tech Editor has reviewed and concurred on 4/1/97 DOCUMENT NAME:

To receive a copy of this document. Indicate hI the box: 'C' - Copy w/o

attachment/enclosure 'E' - Copy w/attachment/enclosure 'N' - No copy

OFFICE TECH CONTS* C/PECB:DRPM* L AD/DRPM 1 1111111111 NAME KNaidu AChaffee MSlos

TScarbrough

DSkeen__ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

DATE 05/01/97 05/23/97 06/q497

04/24/97

05/08/97 OF -ICLAL RECORD COP I

[OFFICIAL RECORD COPY]

DOCUMENT NAME: 97-32.IN

KJ

I IN 97-XX

May XX, 1997 This information notice requires no specific action or written response. If you have any

questions about the information in this notice, please contact one of the technical contacts

listed below or the appropriate Office of Nuclear Reactor Regulation (NRR) project manager.

Marylee M. Slosson, Acting Director

Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical contacts: K. Naidu, NRR

(301) 415-2980

E-mail: km@nrc.gov

T. Scarbrough, NRR

(301) 415-2794 E-mail: tgs@nrc.gov

D. Skeen, NRR

(301) 415-1174 E-mail: dls@nrc.gov

Attachment: List of Recently Issued NRC Information Notices

• - See previous concurrence

OFC PECB:DRPM PSIB:DISP EMEB:DE CIEMEB:DE

NAM DHoeqf K. Naidu* T. Scarbrough* R. Wessman*

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ao 011 701 __ /74297 DATE ___________ 05101197 04124/97 04125197 OFC CIPECB:DRPM DIDRPM

NAM A. Chaffee M. Slosson

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DATE /txV97 X /97

[OFFICIAL RECORD COPY 5/-Igfq17

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DOCUMENT NAME: G:\DLSUIN97-XX.LTQ

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IN 97-XX

May XX, 1997 This information notice requires no specific action ornotice. written response. If

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one of the technical contacts listed below-or the appropriate Office of /

Nuclear React or Regulation (NRR) project manager.

Thomas T. Martin, Director

Division of Reactor Program M nagement

Office of Nuclear Reactor ulation

Technical contacts: K. Naidu. NRR

(301) 415-2980

E-mail: krn@nrc.gov

T. Scarbrough. NRR

(301) 415-2794 E-mail: tgs@nrc.gov

D. Skeen. NRR

(301) 415-1174 E-mail: dls@nrc.gov

Attachment: List of Recently Issued NRC formation Notices

• - qpp nrpvi ious concurrence

OFC PECB:DRPM- PSIB:DISP /EMEB:DE C/EMEB: DE

NAME D. Skee K.VP T. Scarbrough* R. Wessman*

DATE d5 /C5/97 I 7 04/24/97 04/25/97 OFC C/PECB:DRPM D RPM

NAME A. Chaffee M. Slosson

//97 / / /97

[OFFICIAL RECORD C Y]

DOCUMENT NAME: G: LS\IN97-XX.LTQ

.I

V> IN 97-XX

April XX, 1997 This information notice requires no specific action or written response. If

you have any questions about the information in this notice, please contact

one of the technical contacts listed below or the appropriate Office of

Nuclear Reactor Regulation (NRR) project manager.

Thomas T. Martin, Director

Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical contacts: K. Naidu, NRR

(301) 415-2980

E-mail: krn@nrc.gov

T. Scarbrough, NRR

(301) 415-2794 E-mail: tgs@nrc.gov

D. Skeen, NRR

(301) 415-1174 E-mail: dls@nrc.gov

Attachments: Figure 1 and Figure 2 - Worm Shaft Clutch Gear

List of Recently Issued NRC Information Notices

OFC lPECB:DRPM lPSJB)&ISP lEMEB:DEA C/EMB:DE

NAME D. Skee 4TU idu T. Scarbrough R. W

DATE 0o1/2f/97 jI? I /97

/ / /2'(97 /1A97 OFC C/PECB:DRPM D/DRPM

NAME A; Chaffee T. Martin

DATE / >be _/97 /97 I/

[OFFICIAL I&CRRD COPY]

DOCUMENT NAME: G:\DLS\IN97-XX.LTQ