ML20195D236
| ML20195D236 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 05/09/1986 |
| From: | Tucker H DUKE POWER CO. |
| To: | Grace J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| REF-PT21-86-202-000 PT21-86-202, PT21-86-202-000, NUDOCS 8606020217 | |
| Download: ML20195D236 (2) | |
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httS Duxe POWER GOMPANY P.O. Box 33180 CIIAHLOTTE, N.C. 28242
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IIAL II. TUCKER ruternown 1
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May 9, 1986 Dr. J. Nelson Grace, Regional Administrator U. S. Nuclear Regulatory Commission Region 11 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 Re: Catawba Nuclear Station, Unit 1 Docket No. 50-413 i
Dear Dr. Grace:
Pursuant to Technical Specification 4.8.1.1.3 and 6.9.2. please find attached a Special Report concerning the valid failure of Diesel Generator IA which occurred on April 11, 1986.
Very truly yours,
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Hal B. Tucker RWO: sib Attachment ec: Director Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission Washington, D. C.
20555 NRC Resident Inspector Catawba Nuclear Station 8606020217 G60509 ADOCK 0500 3
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SPECIAL REPORT Diesel Generator LA Valid Failure on 04-11-86 As required by Technical Specification 4.8.1.1.3 and Station Directive 2.8.1, the following information concerns'. the valid failure which occurred on Diesel Generator (D/G) 1A on April 11, 1986. This valid failure was the fourth failure within the last 100 valid tests'for the Unit 1 Diesel _
Generators (this includes the four valid failures).
This failure occurred ef ter the 1A D/G had run for one hour at fu11 ' load (be tween 5600 & 5750 kw).
This test was being performed to satisfp the requirements of the operations operability periodic test. When the one hour run had been completed, the operator began to redace the load on the 1A D/G.
As the load was being reduced, several components in the diesel generator control panel failed which resulted in the loss of~the generator field. The components which failed were 3 silicon controlled.rectiftere and one diode. At this time, the cau)e of these component failures is unknoen. However, an investigation is b4ing ' conducted to determine the root cauae of this failure.
To correct the malfunction, personnel replaced the faulty compononts and the 1A D/G was restarted and verified opdrable. The 1A D/G was declared inoperable at 0035 on April 11, 1986 and saa nubsequently declared operable at 0830 on April 12, 1986. Therefore, 'the 1A D/G was out of service for 31 hours3.587963e-4 days <br />0.00861 hours <br />5.125661e-5 weeks <br />1.17955e-5 months <br /> and 55 minutes. Af ter this failure occurred, the testing interval was 3 dayr which in '
in accor: lance with section C.2.d.4 of Regul6 tory Guide 1.108 (Periodic Testing cf Diesel Generator Units Used Ac Onsite Electric Power Systems at Nuclear Power,Plante) Revision 1.
However, on April 28, 1986 the number of failures within the last.100-valid tests was reduced to 3.
Therefore, the present testing intervaj is 7 days which is in accordance with section C.2.d.3 of 4
Regulatory Guide 1.108' Revision 1.
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