ML20127N676

Discusses Loss of Feedwater Transient on 850609 at Facility. AEOD Will Investigate Event & Issue Rept in 30 Days

ML20127N676
Person / Time
Site:	Davis Besse
Issue date:	06/10/1985
From:	Dircks W NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO)
To:	Asselstine, Palladino, Roberts NRC COMMISSION (OCM)
References
NUDOCS 8507020071
Download: ML20127N676 (2)

Text

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j p, NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 JUN 1 0 1385 MEMORANDUM FOR

Chairman Palladino Commissioner Roberts Commissioner Asselstine Commissioner Bernthal Commissioner Zech FROM: William J. Dircks Executive Director for Operations -

SUBJECT:

INVESTIGATION OF JUNE 9, 1985 EVENT AT DAVIS BESSE WILL BE CONDUCTED BY NRC TEA'4 About 1:30am on June 9, 1985, a loss of feedwater transient occurred at Davis Besse. The reactor tripped from 90% power on the loss of a main feedwater pump; the other feedwater pump was lost because of an inadve'rtent MSIV isolation.

Both turbine-driven auxiliary feedwater pumps failed to operate as designed.

It is understood at this time that the steam generators reached a " dry-out" condition and that the pressurizer PORV actuated. Feedwater was restored within approximately 12 minutes. Instrumentation indicated that adequate subcooling was maintained at all times.

Because this event has potential safety implications worthy of further study, I '1 ave team requestedexperts of technical AE0D to to the takesite theto:necessary(action towhat a) fact-find as to sendhappened; a small (4 member)

(b) identify the probable cause as to why it happened; and (c) make appropriate findings and conclusions which will form the basis for possible follow-on actions. The team will report directly to me and is composed of:

Dr. Ernie Rossi, Team Leader (IE), Mr. Wayne Lanning (AE0D), Mr. J. T. Beard I (NRR), and Mr. Larry Bell (Reactor Training Center, Chattanooga). This team was selected on the basis of their knowledge and experience in the fields of-operations, instrumentation and control, and reactor systems. Because the team has not completed incident investigation training, 01 is providing .

assistance regarding investigation techniques and support. The team will leave in the evening of June 10, 1985 and will be onsite early June 11, 1985.

The licensee has been requested, to the extent practical, to preserve the equipment in an "as-found" state and to have personnel and records available.

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-0 The Commission They have agreed to this request to the Regional Administrator. The team's report will constitute the single fact-finding investigation report. It is expected that the team's report will be issued no later than 30 days from now.

WWWiiam J.DirekI William J. Dircks Executive Director for Operations cc: SECY OPE OGC ACRS

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