PNO-V-86-001, on 860102,unusual Event Declared When Reactor Tripped on lo-lo Steam Generator Level Following Feedwater Pump Trip.Caused by Reactor Coolant Pumps Tripping on Undervoltage.Pumps Restarted in 3 to 5 Minutes

PNO-V-86-001:on 860102,unusual Event Declared When Reactor Tripped on lo-lo Steam Generator Level Following Feedwater Pump Trip.Caused by Reactor Coolant Pumps Tripping on Undervoltage.Pumps Restarted in 3 to 5 Minutes

ML20137A077
Person / Time
Site:	Diablo Canyon
Issue date:	01/03/1986
From:	Dodds R, Mendonca M NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
To:
References
PNO-V-86-001, PNO-V-86-1, NUDOCS 8601140158
Download: ML20137A077 (1)

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PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-V-86-01 Date: 1/3/86  !

I This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public ineerest significance. The information presented is as initially received without verification j or evaluation and is basically all that is known by Region V staff on this date. '

FACILITY: PACIFIC CAS & ELECTRIC COMPANY Emergency Classification ,

DIABLO CANYON UNIT DOCKET No. 50-323

__X_ Notification of Unusual Event i

> Alert '

SAN LUIS OBISPO COUNTY, CA Site Area Emergency

\ General Emergency Not Applicable i

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SUBJECT:

UNUSUAL EVENT DURING STARTUP TESTING i

During a full load rejection test on January 2, 1986 at 2:00 PM, a reactor trip was i

experienced on low-low steam generator level following a feedwater pump trip. During the ,

j transfer from the auxiliary power supply to startup power supply, the reactor coolant pumps tripped on undervoltage. The tripping of the reactor coolant pumps was declared an Unusual l j

Event in accordance with the licensee's emergency procedures. The pumps were restarted in

, about 3 to 5 minutes. The licensee's response to this event was in accordance with emergency i operating procedures and reporting requirements. The plant cooldown was stabilized and the Unusual Event was terminated at 1:35 PM. The Resident Inspector was present in the control

, room during the test, trip, and stabilization.

Reactor operation is being held up pending the licensee's evaluation of system response and 1

exact cause of reactor coolant pump trips.  !

This information is current as of 10:00 AM, January 3, 1986. '

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l CONTACT: R. T. Dodds M. Mendonca FTS 463-3720 (805) 595-2353 4

l DISTRIBUTION

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Licensee: '

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PDR (Reactor Licensees) REGION $V:, FORM 211 Resident Inspector,_. .

,;(Revised.3/14/83) i t

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PDR I&E PDR < -

PHO-V-86-OOi .

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