ML20207G400
| ML20207G400 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 12/01/1977 |
| From: | Klingler G, Sniezek J, Whitt K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| To: | |
| References | |
| PNO-77-214, NUDOCS 9903120066 | |
| Download: ML20207G400 (1) | |
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PRELIMINARY NOTIFICATION
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December 1,1977
' PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-77 214 This areliminary notification constitutes EARLY notice of an event of
_POSS13LE 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 on this date.
t Facility: Toledo Edison Company, Davis-Besse 1 (DN 50-346)
(Ottawa County, Ohio)
Sub.iect:
REACTOR SCRAM FROM A DROPPED CONTROL R00 i
.. At 10:24 p.m. on November '29,1977, while.~operatina at 40% power, a controi rod dropped into the reactor core. To compensate for the resulting reduction in power, the integrated control system withdrew other control rods. Due to the apparent overcompensation of the integrated control system, the reactor tripped from an overpower condition (overpower trip set at 50%).
j When the reactor scrammed, the operator inadvertently tripped the gene ator j
breakers, and by doing so prevented the normal transfer of plant loads to the startup transformers. This temporary power interruption caused the diesel generators to start, however, the No. 1 diesel tripped on overspeed.
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The licensee has initiated an investigation into the causes of the diesel generator overspeed trip and the dropped control rod The length of outage j
is dependent on th'e 'results of the investigation, however, a minimum of two days will be required to performed the outage work.
The State of Ohio has been notified by Region III.
No press releases by the licensee or RIII are planned at this. time. An inspector is at the site.
RIII (Chicago) received notification of this occurrence by telephone 1
from the Operating Superintendent at 8:30 a.m., November 30, 1977.
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u og This report represents an up-to-date status of plant conditions as of O\\
fEc 4:00 p.m., November 30, 1977.
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Contact:
KWhitt IE x28019 GKlingler IE x28019 JSniezek, IE x 28180
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/o Distribution:
Transmitted H St//T/
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Chairman Hendrie Commissioner Bradford 3
hCommissionerKennedy S. J. Chilk, SECY C. C. Kammerer, CA
' b Commissioner Gilinsky (ForDistribution)
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Transmitted: MNBB/// 73 P Bldg //.'b E. Volge gu, IE o
L. V. Gossick, ED0 E. G. Case, NRR Region ; L
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S. H. Hanauer, ED0 1 4 1 ~
J. J. Fouchard, PA SS Bldg f f N (MAIL)
R. Hartfield, MIPC C. V. Smith, NMSS R. J. McTiernan, 0IA l
R. G. Ryan, OSP R. Minogue, SD H. K. Shapar Elp i
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