ST-HL-AE-4300, Special Rept:On 921209,SDG 11 Was Unloaded & Declared Inoperable Due to High Exhaust Temperature.Insp & Lubrication of Remaining Sdgs in Both Units Has Been Performed to Identify Similar Freedom of Movement Problems

Special Rept:On 921209,SDG 11 Was Unloaded & Declared Inoperable Due to High Exhaust Temperature.Insp & Lubrication of Remaining Sdgs in Both Units Has Been Performed to Identify Similar Freedom of Movement Problems

ML20127B911
Person / Time
Site:	South Texas
Issue date:	01/08/1993
From:	Kinsey W HOUSTON LIGHTING & POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
ST-HL-AE-4300, NUDOCS 9301130195
Download: ML20127B911 (4)

Text

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The Light cllouston o mI.ighting p a &nPower y "'h I*' "'"I"' """" "'""*""" * *""" " ' " " " ' * *

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• January 08, 1993 ST-HL-AE-4300 File No.: G02 10CFR50 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 _

South Texas Project ,

Unit 1 Docket No. STN 50-498 Special Report Regarding a Valid Dilure of Sandby Diesel Generator #11 on December 9. 1992 Pursuant to the South Texas Project Electric Generating Station (STPEGS) Technical Specifications, liouston Lighting &

Power (llL&P) submits the attached Special Report Regarding a valid failure of Standby Diesel Generator #11 on December 9, 1992. This event did not have an adverse effect on the health and safety of the public.

If you should have any questions on this matter, please contact Mr. C. A. Ayala at (512) 972-8628 or me at (512) 972-7921.

M-W. H. Kinse , Jr.

Vice President, Nuclear Generation JMP/ag

Attachment:

Special Report Regarding a Valid Failure of Standby Diesel Generator #11 on December 9, 1992 13-10u

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9301130195 930108 i ll PDR ADOCK 05000498 I S PDR

Ilouston Lighting & Power Company ST-HL-AE-4300 South Texas Project Electric Generating Station File No.: G02 Page 2 Cc!

Regional Administrator, Region IV Rufus S. Scott Nuclear Regulatory Commission Associate General Counsel 611 Ryan Plaza Drive, Suite 400 Houston Lighting & Power Company Arlington, TX 76011 P. O. Box 61867 Houston, TX 77208 George Dick, Project Manager U.S. Nuclear Regulatory Commission INPO Washington, DC 20555 Records Center 1100 Circle 75 Parkway _

J. I. Tapia Atlanta, GA 30339-3064 Senior Resident Inspector c/o U. S. Nuclear Regulatory Dr. Joseph M. Hendrie Commission 50 Bellport Lane P. O. Box 910 Bellport, NY 11713 Bay City, TX 77414 D. K. Lacker J. R. Newman, Esquire Bureau of Radiation Control Newman & Holtzinger, P.C., STE 1000 Texas Department of Health 1615 L Street, N.W. 1100 West 49th Street Washington, DC 20036 Austin, TX 78756-3189 D. E. Ward /T. M. Puckett Central Power and Light Company P. O. Box 2121 Corpus Christi, TX 78403 J. C. Lanier/M. B. Lee _

City of Austin _

Electric Utility Department P.O. Box 1088 Austin, TX 78767 K. J. Fiedler/M. T. Hardt City Public Service. Board P. O. Box 1771 San Antonio, TX 78296 Revised 10/11/91 L4/NRC/

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l Attachment ST-HL-AE-4300 Page 1 of 2 -i South Texas Project Unit 1 Docket No. STN 50-498 i special Report Regarding a Valid Failure of Standby Diesel Generator #11 on December 9, 1992 DESCRIPTION OF EVENT:

On December 9, 1992, at 1041 hours0.012 days <br />0.289 hours <br />0.00172 weeks <br />3.961005e-4 months <br />, Unit 1 was in Mode 3 during a refueling outage. Operators were performing the Standby Diesel Generator (SDG) #11 Operability Test when the 8R cylinder exhaust temperature indicated 1050'F. The maximum allowable operating temperature of any cylinder is 980*F. The SDG was unloaded and declared inoperable due to the high exhaust temperature.

Troubleshooting indicated that the lever arm on the fuel control shaft which actuates the fuel injection pump rack was binding on the affected cylinder. The binding arm was freed using a penetrating lubricant. The lever arms on the other cylinders '

associated with SDG #11 were inspected and lubricated. Only one other cylinder had a lever arm that was experiencing binding, however, this lever arm was not completely stuck (as was the case ,

with the 8R cylinder). On December 11, 1992, SDG #11 was tested and returned to service.

CAUSE OF EVENT The cause of this event has been attributed to binding of the lever arm on the fuel control shaft which' actuates the Fuel injection pump rack causing an abnormal fuel condition. The source of the binding was due to inadequate lubrication.

Although other components of the fuel control shaft-are lubricated quarterly, the lubrication of the lever arm is not-included in preventive maintenance (PM) activities.

EVENT ANALYSIS This event has been classified as a valid failure since SDG #11 would not have been able to perform its safety function.

Although the SDGs have been analyzed to perform satisfactorily-with only la of the 20 cylinders operable, operator intervention to lock out the specific cylinder may not have occurred fast enough to prevent equipment damage.

SREPiB2*364.001

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Attachment ST-HL-AE-4300 Page 2 of 2 CORIWCTIVE ACTIONS

1) Inspection and lubrication of the remaining SDGs in both Units has been performed to identify similar freedom of movement problems.

2) SDG Preventive Maintenance activities for each SDG will be revised to require lubrication of the lever arm. The PM activities will be revised by February 26, 1993.

3) An evaluation of the SDG design will be performed to identify other components or locations not currently being lubricated which warrant lubrication. This evaluation will be completed by March 30, 1993.

6DDITIONAL INFORMATION Per STPEGS Technical Specification 4.8.1.1., there has been 1 valid failure in the last 20 valid tests of SDG #11. The number of valid failures within the la't s 100 valid tests is less than 4.

Therefore, the testing frequency for SDG #11 remains at once per 31 days.

This event has been made available to the industry via Nuclear Network. Additionally, a copy of this letter will be sent to the SDG vendor, Cooper Bessemer.

A review of the NPRDS database did not identify any other high _

exhaust temperatures for similar reasons. -

SREP)92-364,001

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