ML20129F873

Special Rept 2-96-1:on 960908,DG 2A Started But Tripped. Investigation Found Six Main Bearing Temp Sensor Venting Pressure.Defective Main Bearing Sensor Replaced

ML20129F873
Person / Time
Site:	Vogtle
Issue date:	10/01/1996
From:	Mccoy C GEORGIA POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
2-96-1, LCV-0884, LCV-884, NUDOCS 9610070057
Download: ML20129F873 (2)

Text

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• -' Georgia Power Company l

• 40 inverness Conter Parkway

. Post Ottce Box 1295 Birmingham. Alabama 35201 4

Telephone 205 877 7122 C. K. McCoy GeorobNw'er Vce President, Nuclear O Vogt\e Protect the southern electrc system October 1, 1996 s

LCV-0884 Docket No. 50-425  !

t U. S. Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555 .

l Gentlemen:

VOGTLE ELECTRIC GENERATING PLANT SPECIAL REPORT 2-96-1 NON-VALID DIESEL GENERATOR FAILURE In accordance with the requirements of Vogtle Electric Generating Plant Technical Specifications (TS) sections 4.8.1.1.3 and 6.8.2, Georgia Power Company submits the enclosed special report concerning a non-valid diesel generator failure.

Sincerel ,

eel' C. K. McCoy CKM/TEW I

Enclosure:

Special Report 2-96-1 xc: Georgia Power Company ,

Mr. J. B. Beasley, Jr. l Mr. M. Sheibani j NORMS l

, i U. S. Nuclear Regulatory Commission Mr. S. D. Ebneter, Regional Administrator p/

Mr. L. L. Wheeler, Licensing Project Manager, NRR

/I Mr. C. R. Ogle, Senior Resident Inspector, Vogtle  ;

\

9610070057 961001 \

PDR ADOCK 05000425 g PDR

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. VOGTLE ELECTRIC GENERATING PLANT - UNIT 2 TECHNICAL SPECIFICATION SPECIAL REPORT 2-96-1 NON-VALID DIESEL GENERATOR (DG) FAILURE 4

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A. REQUIREMENT FOR REPORT This report is required in accordance with the Vogtle Electric Generating Plant Technical Specifications (TS), section 4.8.1.1.3, which requires that all diesel generator (DG) failures, valid or non-valid, be reported to the Commission in a special report pursuant to TS 6.8.2.

B. DESCRIPTION OF FAILURE OF DIESEL GENERATOR 2A On September 8,1996, during a refueling outage, plant personnel prepared for a l pre-maintenance run of DG2A. At 2021 EDT, DG2A was started but tripped within one minute on three different trip signals; engine bearing high temperature, turbo oil low pressure, and jacket water low pressure. An investigation found that the No. 6 main bearing temperature sensor was venting pressure and this was the cause of the event. The defective main bearing sensor was replaced. The other two trip signals alarmed due to low pressure in each of their pneumatic lines.

These lines combine with the pneumatic line of the main bearing sensor through logic elements and led to trip signals being falsely attributed to turbo oil low pressure and jacket water low pressure. The DG was restarted on September 9, 1996, at 0545 EDT, and operated successfully.

C.

SUMMARY

l The DG2A start of September 8,1996, has been determined to be a non-valid failure because the subject trip devices are bypassed during accident conditions.

Therefore, the DG's emergency start capability was not affected by the problems encountered.

DG2A has had one valid failure in the last 20 valid tests and one valid failure in the i last 100 valid tests. The test frequency for DG2A remains at once per 31 days m )

accordance with the requirements of TS table 4.8-1. l l

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