ELV-03478, Special Rept 2-92-1:on 920205,DG 2B Declared Inoperable Due to Negative Reactive Power.Cause Undetermined.Engine Being Tested Each Wk While Monitoring Equipment Connected to Capture Any Info Useful in Investigation of Cause

Special Rept 2-92-1:on 920205,DG 2B Declared Inoperable Due to Negative Reactive Power.Cause Undetermined.Engine Being Tested Each Wk While Monitoring Equipment Connected to Capture Any Info Useful in Investigation of Cause

ML20090E035
Person / Time
Site:	Vogtle
Issue date:	03/02/1992
From:	Mccoy C GEORGIA POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
2-92-1, ELV-03478, ELV-3478, NUDOCS 9203090192
Download: ML20090E035 (2)

Text

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~ic, Geotg:a Paer caupany -

- 40 inwtnew Center Pmkwu Post O!fre Bos 1295

- g - 8 mungham Alatuma 3520 t g Tele phone 205 877 7122 -

C,K.McCoy GCOf('ill power v ce Presdent Nudem Vap Praygt Ut' 5D(A"sPtn fittM SWJefw March 2,-1992 ELV-03478 001225 Docket No. 50-425 U. S. Nuclear Regulatory Comnission ATTN: Document Control Desk

. Washington, D. C.- 20555 Gentlemen:

V0GTLE ELECTRIC GENERATING PLANT SPECIAL REPORT VAllD DIESEL GENERATOR FAllVRE in accordance with the requirements of the Vogtle Electric Generating Plant Technical Specifications, sections 4.8.1.1.3 and 6.8.2, Georgia Power Company hereby- submits the enclosed Special Report concerning a valid diesel generator failure.

Sincerely, C. K. McCoy CKM/NJS/gsb

Enclosure:

Special Report 2-92-1 xc: Georoia Power Comoany Mr. W. B. Shipman Mr; M. Sheibani NORMS-

- U. S. Nuclear Reoulatory Commission Mr. S. D. Ebneter, Regional Administrator Mr. D. S. Hood, Licensing Project Manager, NRR Mr. B. R. Bonser, Senior Resident Ir:spector, Vogtle 000rS:

9203090192.920302 -

PDR S-A90CK 05000425 . // '

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PDR /

4 .-

V0GTLE ELECTRIC GENERATING PLANT - UNIT 2 TECHNICAL SPECIFICATION SPECIAL REPORT 2-92-1 DIESEL GENERATOR 2B VALID FAILURE A. REQ'JIREMENT FOR REPORT This report is required in accordance with Technical Specification (TS) 4.8.1.1.3, which requires all diesel generator (DG) failures, valid or nonvalid, to be reported to the Commission in a Special Report pursuant to TS 6.8.2.

B. DESCRIPTION OF EVENT On February 5, 1992, at 0945 EST, DG 2B was started for a monthly surveillance test per TS requirements. At 1000 EST, the DG output breaker was closed in order to connect the DG to the grid, but reactive power indicated negative 4200 kVARs and the output breaker was opened. The DG was declared inoperable at 1002 EST.

A brief investigation found no other abnormalities. Based on this and previous similar events (LER 50-425/1991-003) when negative reactive power had been intermittently indicated, personnel decided to continue the planned testing. The output breaker was again closed, and reactive power indicated normal, positive values. With personnel monitoring performance narameters, DG 2B operated while tied to the grid for over 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> before the output breaker was reopened. At 122' EST, the output breaker was again closed so that personnel could monitor breaker operation. It was rnopened at 1229 EST, with no anomalies noted, and the DG was stopped at 1234 EST. Following a review of the testing, DG 2B was declared operable at 1706 EST. During this period, DG 28 was inoperable for 7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br /> and 4 minutes.

Although the cause for the negative reactive power remains undetermined, engineering personnel are reviewing drawings associated with the DG excitation system and consulting with-the vendor in an attempt to diagnose this continuing problem. If a probable cause cannot be determined, physical inspections of these circuits will be made against the design drawings during the upcoming Spring 1992 refueling outage. Additionally, the engine is now being tested each week while monitoring equipment is connected in order to capture any inforination useful to the investigation into the cause of the failure. This monitoring during-testing will continue until the upcoming refueling outage.

C.

SUMMARY

This event is classified as a valid failure per Regulatory Guide 1.108, Section C.2.e. There hase been 2 valid failures in the last 20 valid tests of DG 2B and a total of 3 valid failures in 69 valid tests. The test frequency has been increased to once per 7 days in accordance with TS table 4.8-1.

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