ML20132B208

Special Rept:On 850813,valid Failure of Diesel Generator 1B Occurred.Caused by Failure of Static Voltage Regulator,Three Silicon Controlled Rectifiers & Two Diodes in Control Panel. Components Replaced.Generator Restarted.Part 21 Related

ML20132B208
Person / Time
Site:	Catawba
Issue date:	09/12/1985
From:	Tucker H DUKE POWER CO.
To:	Grace J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
REF-PT21-85-424-000 PT21-85-424, PT21-85-424-000, NUDOCS 8509260126
Download: ML20132B208 (3)

Text

DuxE POWEn GOMPANY P.O.IM)K M)llM)

CHAMI,OTTP., N.O. 2449 4 9 HALH. TUCKER nasp. sown

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September 12, 1985 Dr. J. Nelson Crace Regional Administrator U.S. Nuc1 car Regulatory Comission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323

Reference:

Catawba Nuclear Station, Unit 1 Docket No. 50-413

Dear Dr. Grace:

Pursuant to Technical Specifications 4.8.1.1.3 and 6.9.2, please find attached a Special Report concerning the valid failure of Diesel Cencrator 1B which occurred on August 13, 1985.

Very truly yours.

Hal B. Tucker RWO:smh Attachment 8509260126 850912 gDR ADOCM 0 3 1 \

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l Dr. J. Nelson Grace, Regional Administrator September 12, 1985 Page 2

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. cc: Director Office of Inspection and Enforcement

! U.S. Nuclear Regulatory Commission j Washington, D.C. 20555

, NRC Resident inspector Catawba Nuclear Station 1

i Palmetto Alliance

! 2135 Devine Street i Columbia, South Carolina 29205

) 4 Mr. Jesse L. Riley Carolina Environmental Study Group 854 Henley Place j Charlotte, North Carolina 28207

) Robert Guild, Esq.

P. O. Box 12097 j Charleston, South Carolina 29412

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SPECIAL REPORT l

l Diesel Generator 1B Valid Failure 4

i i As required by Technical Specification 4.8.1.1.3 and Station Directive 2.8.1 the following information concerns the valid i failure which occurred on D/G 1B on August 13, 1985. This '

valid failure was the second failure within the last 33 valid tests for the Unit 1 Diesel Generators. Please note that as of August 13, 1985, the 1A and 1B Diesel Generators had only completed 33 valid tests (this includes both valid failures).

1 The failure occurred while the IB D/G was running in the unloaded l condition to allow for the calibration of the visicorder. During the test, several components in the diesel generator control panel failed which resulted in the loss of the generator field. The l

! components which failed were the static voltage regulator, three  !

silicon controlled rectifiers (SCR) and two diodes. At this time. [

the cause of these component failures is unknown. To correct the

, malfunction, personnel replaced the faulty components and the IB j D/G was restarted and verfied operable. The IB D/G was declared inoperable at 1610 on 8/13/85 and was subsequently declared

! operable at 0237 on 8/16/85. Therefore, the IB D/G was out of service for 58 hours6.712963e-4 days <br />0.0161 hours <br />9.589947e-5 weeks <br />2.2069e-5 months <br /> and 27 minutes. At this time, the Surveil-d lance Testing interval is 14 days which is in accordance with Section C.2.d.2 of Regulatory Guide 1.108 (Periodic Testing of Diesel Generator Units used as onsite Electric Power Systems at Nuclear Power Plants) Revision 1.

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