RBG-27313, Part 21 Rept Re Defect in safety-related Limitorque Valve Operators.Initially Reported on 880114.Defective Lugs Replaced W/Correctly Sized Lugs & Rev of Procedures Underway to Include Insp of Lug Size on Motor Leads

Part 21 Rept Re Defect in safety-related Limitorque Valve Operators.Initially Reported on 880114.Defective Lugs Replaced W/Correctly Sized Lugs & Rev of Procedures Underway to Include Insp of Lug Size on Motor Leads

ML20149E046
Person / Time
Site:	River Bend
Issue date:	01/19/1988
From:	Deddens J GULF STATES UTILITIES CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
REF-PT21-88, REF-PT21-88-005-000 PT21-88-005-000, PT21-88-5, RBG-27313, NUDOCS 8802100191
Download: ML20149E046 (4)

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l 1-* .s j GULF STATES UTILITIES " OMPANY RNER SEND STU10N PO$f OFFICE BOX 220 $1 FRANCISVILLI.LOVistANA 70775 AREA CODE 604 635 6094 346 8651 January 19, 1988 RBC- 27313 File Nos. G9.5, G9.25.1.2 Regional Administrator ' @[?IllW/[s[f'

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m U.S. Nuclear Regulatory Commission l' l Region IV  : JAN29 M 611 Ryan Plaza Drive, Suite 1000 I ,

Arlington, TX 76011 O

Gentlemen:

River Bend Station - Unit 1 Docket No. 50-458 Pursuant to the requirements of 10CFR21.21(b)(2), Gulf States Utilities Company (GSU) is submitting this written report of a defect in safety-related Limitorque valve operators at River Bend Station. Initial notification of this defect was provided by telephone on January 14, 1988 to Mr. Glen Madsen of the NRC-Region IV from Mr. Rick J. King of GSU. t The attached report provides the information required by 10CFR21.21.

Sincerely, Vl n J. C. Deddens Senior Vice President River Bend Nuclear C: cup JCD/J

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(RH/UNL/ch a 1) o$$ Attachment 00""

00 cc: Director

$c Office of Nuclear Regulatory Regulation g U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Q

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f ca NRC Resident Inspector P.O. Box 1051

$$ St. Francisville LA 70775 coa.tn Mr. Pat McQuillian Limitorque Corporation P.O. Box 11318 j,, -

g Lynchburg, VA 24506-1318 jf

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ATTACHMENT Gulf States Utilities Ccapany River Bend Station - Unit 1 Report of a Defect Per 10CFR21.21

1. Name and address of individual (s)"informing the NRC.

Written notification is provided by this report from Mr. J.C. Deddens, !

Senior Vice President.

Address: Gulf States Utilities Post Office Box 220 St. Francisville, LA 70775

2. Identification of the facility, the activity or the basic component supplied for the facility or activity within the United States which l fails to comply or contains a defect.

l The defect was found in five safety-related valve operators at River l Bend Station - Unit 1. The valves which were found to contain the  :

defect were three main steam shutoff valves (Mark Nos. IB21*MOVF098A, j B,C) and two feedwater isolation valves (Mark Nos. IB21*MOVF065A and IFWS*MOV7A).

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3. Identification of the firm constructing or supplying the basic component which fails to comply or contains a defect.

The wire lugs were contained in valve operators supplied during initial  !

construction of River Bend Station by Limitorque Corporation.

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4. Nature of the defect or failure to comply and the safety hazard which  !

is created by the defect or failure to comply.

During functional testing of main steam shutoff valve, 1B21*MOVF098B, the valve failed to fully close. The motor operator experienced a high current surge and tripped its motor overload heater. During investigation, two motor leads were found burned and separated from the

, wire lugs. The third lug was easily pulled from the wire lead after removing heat shrink insulation. The lugs were found to be oversized for the motor lead conductors. Also, while performing maintenance on feedwater isolation valve, IFWS*MOV7A, a lug on one motor lead was found to be oversized for the conductor and not crimped.

The lugs were marked "T&B Navy 23-30 E-6" and were sized for use with a

1. 5-6 AWG conductor. The motor leads were #10 stranded conductor.

Further investigation found that both valves used Limitorque SMB-4 operators with terminal blocks that had one-quarter inch diameter terminal screws. The lugs were the correct size for the one-quarter i

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-.. - ai inch screw, 6ut -not the cerrect size for the conductor. This is the only size of Limitorque operator ar 4RBS 't. hat uses a quarter-inch terminal screw. /

All safety related SMB-4 operators were inspected to determine lug size. Of a total of ten operatorp in safety related service, five were found with oversized Irgs and were deemed to be unreliable although

, chey passed surveillances requirenents. The logs were repaired by .

replacing them withc'orrectly sized lugs.  !

The lugs could potentially cause the valves to fail to operate when required, ast was the case during the testing of IB21*MOVF0988, a main steam shutoff valve used in conjunction with main steam isolation valve

- posit'he 4 leakage control system (MSIV-PLCS) to limit leakage from the main steam lines to the environment following an accident. Failure of these valvef' to close would cause 'the outboard division of MSIV-PLCS to be inoparable. The feedwater isolation valves are used to isolate one feedwater intet line to the/ reactor vessel. These valves, along with the penetration valve leakag'e control system (PVLCS), are used to limit leakage from the. feedwater line following an accident. The potential failure of these. valves to cicoe would cauce PVLCS to be inoperable for one feedwater line.' If these ' events o c cu c-::d following a loss of coolant accident, Ioakage control systems vould not function properly, ,

potentially leading' to radipactive releases to the environment. '

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5. The date on which the informecion

of the defect or failure to comply was obtained.  ;

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The initial condition was fou'nd on December 7, 1987 as reported in Condition Report CR 37-1640. / Subsequent evaluation determined the condition to be reportable pe; {0CFR21 on January 14, 1988. .

6. In the case "vf a basic component which contains a defect or fails to ,

comply, the number and location of all the components in use at, i supplied for, or being supplied for one or more facilities or activities subject to the regulations of 10CFR21. i

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. l A total of ten Limitorque SMB-4 operators are used in safety related applicaqions at River Bend Station. The function of those valves containing i the defect is given in Sections 2 and 4 above.

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7. The correctize action wht:b has been, or will be taken; the name of the

' ihdividual or organization responsible for the action; and the length of time that has been or vill be taken to complete the action.

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GSU has replaced the defective lugs with correctly sized lugs. This l s work was performed by Maintenance Work Orders 118783, 113618, and 111336. This corrective action was completed on December 12, 1987. In i addition, receipt inspection of Limitorque motor operators is being I revised to includL inspection of lug size on motor leads eo prevent r

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reoccurence of this condition. Revision of procedures controlling this activity will be completed by February 29, 1988.

GSU believes the condition is only applicable to SMB-4 operators.

However, due to potential generic concerns with applicability of this condition to other size Limitorque motor operators, CSU will also inspect a sample of other operator sizes. This sampling program will be performed per MIL-STD-105D and will be completed prior to start up following the second refueling outage.

8. Any advice related to the defect or failure to comply about the facility, activity or basic component that has been, is being, or will be given to purchasers or licensees.

Not applicable.