ML20044G132

Responds to Violations Noted in Insp Repts 50-498/93-08 & 50-499/93-08.Disputes Violations.Rhr Suction Isolation MOVs Correctly Determined Operable & MOVs Demonstrated to Have Acceptable Thrust by Movats Testing at End of Outage 1

ML20044G132
Person / Time
Site:	South Texas
Issue date:	05/18/1993
From:	Rosen S HOUSTON LIGHTING & POWER CO.
To:	NRC OFFICE OF ENFORCEMENT (OE), NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
EA-93-047, EA-93-47, ST-HL-AE-4453, NUDOCS 9306020065
Download: ML20044G132 (4)

Text

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The Light companys Houston Lighting & Power uth esas Prvject Dectric Generating Station P. O. Box 289 Wadswonh. Texas 77483 May 18, 1993 ST-HL-AE-4453 File No.: G02.04 10CFR2.201 Director, Office of Enforcement U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 South Texas Project Units 1 and 2 Docket Nos. STN 50-498; STN 50-499 Reply to Notice of Violation for Inspection Report 93-08: Enforcement Action 93-047 Houston Lighting & Power Company (HL&P) has reviewed the Notice of Violation and submits the attached reply to Violation II, the violation not assessed a civil penalty. HL&P's replies to violations I.A. and I.B., violations that were assessed a civil penalty, are being submitted to the NRC in a separate letter.

HL&P denies that the violation occurred. Details of the denial are provided in the Attachment to this letter.

If you have any questions, please contact C. A. Ayala at (512) 972-8628 or me at (512) 972-7138.

.. L. Rosen Vice President, Nuclear Engineering DNB/sr

Attachment:

Reply to Notice of Violation, Violation II 1

Pnd/A048 Proicca Manager on Behalf of the Panicipants in the South Texas Project

,fpi/ i

,j 9306020065 DR 930518 I' ADOCK 05000498 PDR

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-: lkuston Lighting & Power Company  !

South Texas Project Electric Generating Station ST-HL-AE-4453 File No. : G02.04  :

Page 2 .

1 c: ,

Regional Administrator, Region IV Rufus S. Scott-  ;

Nuclear Regulatory Commission Associate-General Counsel  ;

611 Ryan Plaza Drive, Suite 400 -Houston Lighting & Power Company _' j Arlington, TX 76011 P. O. Box 61867

' Houston, TX 77208  ;

Project Manager .

U.S. Nuclear Regulatory Commission Institute of Nuclear Power _.  :

Washington, DC 20555 Operations -_ Records ~ Center  !

1100 Circle 75 Parkway, #1500 J. I. Tapia Atlanta, GA 30339-3064 i Senior Resident Inspector j c/o U. S. Nuclear Regulatory Dr. Joseph M. Hendrie  !

Commission 50.Bellport. Lane P. O. Box 910 Bellport,.NY_ 11713 i Bay City, TX 77414 .;

D. K. Lacker .

j

-J. R. Newman, Esquire Bureau of Radiation ~ Control Newman & Holtzinger, P.C., STE 1000' Texas Department of Health i 1615 L Street, N.W. 1100 West'49th Street- ..

Washington, DC '20036 Austin, TX_ 78756-3189 D. E. Ward /T. M. Puckett U.S. Nuclear RegulatorylDoma.  ;

Central Power and Light Company Attn: . Document Control Desk' .j P. O. Box 2121 Washington, D.C. 20555  !

Corpus Christi, TX 78403  ;

J. C. Lanier/M. B. Lee

-City of Austin  :

Electric Utility Department 721 Barton Springs Road j Austin, TX. 78704  ;

K. J. Fiedler/M. T. Hardt

i City Public Service P. O. Box 1771 San Antonio, TX 78296  :

1 1

IR\93-111.002 l

i Attachment 1 ST-HL-AE-4453 Page 1 of 2 Reply to Notice of Violation, Violation II {

I. Statement of Violation II:

10 CFR 50, Appendix B, Criterion XVI, states, in part, that measures shall be established to assure that conditions adverse to quality are promptly identified and corrected. l i

Contrary to the above, on February '2, 1993, the licensee f

determined that five STP Unit 1 Residual Heat Removal suction isolation motor-operated valves had incurred torque loadings of up to 253% of the actuator qualified limit for up to 50 cycles, a condition adverse to quality, but failed to identify ,

the full scope of the deficiency and take adequate corrective i action. Specifically, the licensee concluded that the valves i were operable based on valve internal inspections conducted  :

during the previous outage, which recorded " excessive" wear on the worm gear (a component vulnerable to the effects of high torque). The licensee developed no justification or basis  !

consistent with the recommendations of the actuator vendor or information published by or for the users of motor-operated ,

valves in the nuclear power industry for the continued  ;

application of torque values in excess of the qualified limit.

i This is a Severity Level IV violation (Supplement I).

II. Houston Liahtina & Power Position:

HL&P denies that the cited violation occurred. Specifically, HL&P contends that the Residual Heat Removal (RHR) . suction isolation motor-operated valves (MOVs) were correctly determined operable and that the basis and justification for the operability determination was adequate.

In retrospect, HL&P admits that, although adequate, the basis of the operability determination could have been more fully,-

and more clearly documented. In the future, MOV operability i determinations will - be guided by the use of a recently developed MOV operabil'ty Checklist. The use of this  !

checklist should assure that the basis and justification of subsequent operability determinations are consistent and clearly documented. ,

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[

taws-ni.on ,

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Attachment 1  ;

ST-HL-AE-4453 Page 2 of 2 ,

l Reply to Notice of Violation. Violation II III. Reason for Denial:

HL&P maintains that the operability determination performed on ,

February 2, 1993 was correct and adequate because of the following: ,

1. The MOVs operated successfully in the overtorqued ,

condition since the Spring 1990 refueling outage (1RE02).

A minimal number of cycles were anticipated prior to the next outage (1RE05), when the MOVs were scheduled to be ,

reworked.

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2. The MOV actuators were disassembled and inspected during l the Fall 1992 fourth refueling outage (1RE04). Although wear was noted, the wear was determined not to require  ;

immediate corrective action.

3. The MOVs had been demonstrated to have acceptable thrust by Motor Operated Valve Actuator Test System (MOVATS) testing at the end of 1RE04. The acceptable thrust values showed that the MOVs would have performed their intended safety function.

4. Operability of the MOVs is not directly affected by overtorquing the actuator. Over'orque could cause accelerated wear of the mechanicaa components in the actuator. Accelerated wear could reduce the " life" of the actuator, but the accelerated wear does not necessarily render the MOV inoperable.

HL&P believes that the above listed information, when considered collectively, provided adequate basis and justification to support the determination on February 2, 1993, that the Unit 1 RHR MOVs were operable.

IV. Additional Information:

The overtorque conditions on the Unit 1 RHR MOVs have been corrected. The review of the Unit 2 RHR MOV test packages identified one MOV with a slight overtorque condition, which has also been corrected.

IR\93 111.002