ML20216J836

PNO-78-146:on 780817,turbine Trip from 90% Power Was Initiated by High Water Level in Moisture Separator.Four Main Steam Valves Opened to Relieve Sys Pressure.One of Four Valves Failed to Reseat Until Sys Pressure Reached 300 Psig

ML20216J836
Person / Time
Site:	Browns Ferry
Issue date:	08/18/1978
From:	Klingler G, Nolan F, Sniezek J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
To:
References
PNO-78-146, NUDOCS 9804220008
Download: ML20216J836 (1)

Text

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PRELIMINARY NOTIFICATION 8 -

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August 18, 1978 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE -- PNO-78-146 This preliminary notification constitutes EARLY notice of an event of POSSIBLE safety or public interest significance. The information presented is as initially received without verification or evaluation and is basically all that is known by IE staff as of this date.

FACILITY: Tennessee Valley Authority Browns Ferry, Unit No. 3 l Docket No. 50-296 Athens, Alabama

SUBJECT:

PRIMARY SYSTEM BLOWDOWN l 1

At 10:37 PM on August 17, a turbine trip from 90% power was initiated by high water level in the moisture separator. This resulted in a reactor ,

isolation and scram. Four main steam relief valves opened to relieve '

system pressure. One of the four valves failed to reseat until system l pressure reached 300 psig. Pressure built back to 850 psig when one '

relief valve again lifted. Pressure was again reduced and at 300 psig,  % i apparently two other relief valves lifted. The reactor will remain "

l shutdown to replace the faulty relief valves.

(" The Technical Specification limiting cooldown rate to 100 degrees F/hr may have been exceeded. A thermal transient analysis is in progress.

l There was no release of radioactivity to the environment. l i

Media interest is expected, the licensee is expected to issue a news '

release. NRC is considering a press release. A Region II inspector is l onsite. The State of Alabama has been notified.

Region II (Atlanta) received notification of this occurrence by telephone l

from the plant superintendent at 9:15 AM on August 18. This information I

is current as of 10:00 AM on August 18.

Contact:

GKlingler, IE x28019 FNolan, IE x28019 JSniezek, IE x28019 i Distribution: Transmitted H St 4.'/ f .

l Chairman Hendrie Commissioner Bradford S. J. Chilk, SECY l Commissioner Kennedy Commissioner Ahearne C. C. Kammerer, CA Commissioner Gilinsky (ForDistribution)

Transmitted: MNBB 4.' 3d P Bldg 4! S '7 L. V. Gossick, EDO H. R. Denton, NRR J. G. Davis, Region IE [

-2f dld S. H. Hanauer, ED0 J. J. Fouchard, PA SS Bldg 8.'## (MAIL)

N. M. Haller, MPA C. V. Smith, miSS 0. G. Abston, 01A R. G. Ryan, OSP

,[ R. Minogue, SD g j H. K. Shapar, ELD ,, .

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9804220008 78081e PRELIMINARY NOTIFICATION gI%v PDR I&E PNO-78-146 PDR

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