PNO-II-86-020, on 851031,bushings Were Installed During Outage Following Engine Failure in Diesel Generator of Plant Unit 2

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PNO-II-86-020:on 851031,bushings Were Installed During Outage Following Engine Failure in Diesel Generator of Plant Unit 2
ML20212E672
Person / Time
Site: North Anna Dominion icon.png
Issue date: 03/05/1986
From: Brownlee V, Ignatonis A
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:
References
PNO-II-86-020, PNO-II-86-20, NUDOCS 9711040018
Download: ML20212E672 (1)


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. L e '4rch 5, 1986 l ,

y s ELIMINARYNOTIFINATIONOFEVENTORUNUSUALOCCURRENCEPNO-II-86-2(0 I This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or putdic interest significance. The information is as initially received without verifi-cation or evaluation, and is basically all that is known by the Region !! staff on this date.

FACILITY: Virginia Electric & Power Company Licensee Emergency Classification:

North Anna Unit 2 ._ Notification of Unusual Event Docket No. 50-339 Alert Mineral, Virginia Site Area Emergency General Emergency X Not Applicable

SUBJECT:

DEGRADATION OF DIESEL GENERATOR BUSHINGS i

Virginia Power has informed Region 11 that an inspection of one of the two emergency diese! pnera.~. - of North Anna Unit 2 has found excessive degradation of some piston pin bushings. Eleven of the 24 bronze bushings show such characteristics as excessive elongation and deformed ends. The maximum elongation noted was .02-inch as compared with an elongati . v.' .20-inch which caused a previous engine failure.

These bushings were installed during an outage in October 1985 following engine failure in

! this particular diesel generator. The machine's total run time since then has been about l

g\0 hours,

presentatives of Fairbanks-Morse, the diesel generator manufacturer, are on site to

(" investigate these findings. Based on preliminary data, these vendor representatives attribute the bushing deformation to engine overload, possibly caused by such , factors as excessive number of fast starts, unequal firing pressure, timing, and electrical overload of the generator. This diesel generator has had three to four fast starts since the October 1985 cutage. The unit's other diesel generator is scheduled for inspection in about two weeks.

North Anna Unit 2 has been out of service for refueling and modifig(Nns sip February

20. Unit l's diesel generators were inspected and overhauled dudhg an o@ge in November and December of 1985. The total run time for each Unit I diesel geneopftWr isfgtds than eight hours. Unit 1 is now operating at 100 percent power.

p@ #g Region II has informed the Office of Nuclear Reactor Regulation of thjs*9 matter, and both the region and NRR are monitoring Virginia Power's follow-up actions).' Region 11 also has informed the Commonwealth of Virginia.

Virginia Power is prepared to respond to meola inquiries. 9

&y This information is current as of 4 p. m. (EDT) today.

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Contact:

A. Ignatonis, 242-5563 V. Brownlee, 242-5583 f, i

'J 9711040018 860305 PDR I&E PNO-II-86-020 PDR