ML20069K294

Interim Significant Deficiency Rept 82-06 Re Sheared Pinion Keys in Limitorque Motor Operators Supplied by Westinghouse. Initially Reported on 820901.Keys Replaced.Westinghouse Will Provide Date for Completing Corrective Action

ML20069K294
Person / Time
Site:	Beaver Valley
Issue date:	10/07/1982
From:	Wollever E DUQUESNE LIGHT CO.
To:	Haynes R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
10CFR-050.55E, 10CFR-50.55E, 2NRC-2-036, 2NRC-2-36, NUDOCS 8210260143
Download: ML20069K294 (4)

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2NRC-2-036 m (412) 787 - 5141 (412)923 - 1960 Telecopy (412) 787-2629 Nuclear Construction DMsion Robinson Plaza, Building 2. Suite 210 October 7 ' 1982 Pittsburgh, PA 15205 United States Nuclear Regulatory Commission Region I 631 Park Avenue King of Prussia, PA 19406 ATTENTION: Mr. R. Haynes Administrator

SUBJECT:

Beaver Valley Power Station - Unit No. 2 Docket No. 50-412 Limitorque Motor Key Failures Significant Deficiency Report No. 82-06 Gentlemen:

This interim report is in reference to sheared pinion keys in Limitorque motor operators supplied by Westingheuse Nuclear Energy Systems (WNES) for the safety injection system. Duquesne Light Company notified the Region I office that an evaluation under 10CFR50.55(e) was underway on September 1, 1982.

The sheared pinion keys have been replaced in the operators already identified to have this problem in Beaver Valley Unit No. 2. WNES will provide a date for implemeatation of the corrective action to remedy the deficiencies. Pursuant to the requirements of 10CFR50.55(e), an interim report is submitted, and it is presently anticipated that a subsequent report on this subject should be submitted to the Region I office by May 20, 1983.

DUQUESNE LIGHT COMPANY By n , ..

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E. ft Woolevbr Vice President JMM/wjs Attachment ec: Mr. R. DeYoung, Director, Office of Inspection and Enforcement (w/a) (3)

NRC Document Control Desk (w/a)

Mr. G. Walton, NRC Resident Inspector (w/a)

Ms. E. Doolittle, Project Manager (w/a)

SUBSCRIBLD AND SWORN TO BEFORE ME THIS 7 DAY OF [0I" , 1982.

ALAN B. BAN AS. NOTARY PUBilC f- '

ROBikSON InP., ALLEGHENY COUNTY UY COMISSION EXPIRES april 12, Iggs "V

1otary Public

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United Strtes Nuclear R3gulatory Commission prga 2 COMMONWEALTH OF PENNSYLVANIA )

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COUNTY OF ALLEGH'ENY )

On this ~7 day of d(, [. , /93 2., before me, ll-AA/

d 8A A/Af , a Notary Public in an'd for said Commonwealth and County, per-sonally appeared E. J. Woolever, who being duly sworn, deposed, and said that (1) he is Vice President of Duquesne Light, (2) he is duly authorized to execute and file the foregoing Submittal on behalf of said Company, and (3) the statements set forth in the Submittal are true and correct to the best of his knowledge, information and belief.

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ALAN B. BAN AS. h0TAty PUBllC N0848304 inP.. AllEGHENf COUNTY MY C0051$$f 0N EXPlRES APRit 12.1986 Meetw! Pennsylvania Association of Notaries

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Beevar Valley Power Station - Unit No. 2 Duquesne Light-Company Interim Report No. 1 on Limitorque Motor Key Failures

1. Summary In complying with the resolution to NRC IE Bulletin 81-02, "Limitorque" operators on valves supplied by Westinghouse Nuclear Energy Systems (WNES) were reworked at the BVPS-2 jobsite. During disassembly and *nspection, six of ten valves with SB-0-25 operators were found to contain sheared pinion keys. These keys are used to. secure the pinion gear to the motor shaft which transmits torque to the operator. The affected valves are located in the safety injection system (SIS) and function during the recirculatian phase of safety injection.

2. Immediate Action Taken WNES was informed about the sheared keys and these were replaced with new keys supplied by WNES. WNES also filed a 10CFR21 report with the Director of NRC's Region III Office of Inspection and Enforcement. Duquesne Light Company notified the Region I Office on September 1, 1982, that an evalu-ation concerning potential reportability of the problem under 10CFR50.55(e) was underway.

3. Description of Deficiency The affected valves are:

WNES WNES Limitorque Operator Motor Item Valve ID Location # Operator Type Serial # Serial #

1 10GM72FB 8811A SB-0-25 ft-lb 245153 ID710787-VB 2 10GM72FB 8811B SB-0-25 ft-lb 245150 ID710787-VB 3 10GM72FB 8887A SB-0-25 ft-lb 245152 ID710787-VB 4 10GM72FB 8887B SB-0-25 ft-lb 245151 ID710787-VB 5 14GM7?FB 8809A SB-0-25 ft-lb 248019 ID710787-VB 6 14GM72FB 8809B SB-0-25 ft-lb 248020 ID710787-VB These valves were shop tested to WNES requirements prior to shipment and were not operated after delivery at the site.

A metallurgical evaluation of the failed pinion keys, performed by WNES, indicated that they were of a low carbon steel rather than an available hardened alloy. Prior to identification of the sheared pinion keys at BVPS-2, modifications / inspections of SB-0-25 operators were made by WNES at 32 other plants and only one sheared pinion key was found; however, hardness checks were not made. The possibility of sheared pinion keys was previously identified for Limitorque Model SMB-4 motor operators in Information Notice 81-08.

4. Analysis of Safety Implication As a result of the failure of a pinion key, the open or closed position of the motor operated valves cannot be determined during valve operation. If

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the failure was not detected, this would adversely affect the safety of operation of the plant. Items 1 and 2 are required to provide a recircu-lation path from the recirculation pumps to the . low head safety injection

-discharge header. Items 3 and 4 provide separation of flow paths during recirculation. Items 5 and 6 provide redundant flow paths from the re-fueling water storage tank to the suction of the low head safety injection pumps. All of these functions are critical to the intended safety function of the SIS. ,

In correspondence dated August 9, 1982, WNES indicated that, due to a lack of specific information on pinion key material,other Limitorque motor operators in their scope of supply may be affected. WNES is investigating the scope of this problem with Limitorque.

5. Corrective Action to Remedy Deficiencies WNES is investigating with Limitorque to determine whether other operator models could be affected by improper pinion key material.

As discussed in Section 2 of this report, the sheared pinion keys have been replaced in the operators already identified to have this problem in BVPS-2.

6. Additional Reports WNES will provide a date when a listing of other affected valves will be available and a date for implementation of the corrective action to remedy the deficiencies. Duquesne Light Company will issue another report, interim or final, when further details concerning the corrective action are availabic. It is expected that this report will be issued to Region I Office by May 20, 1983.

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