ML19322C362
| ML19322C362 | |
| Person / Time | |
|---|---|
| Site: | Crane, Davis Besse  |
| Issue date: | 09/26/1977 |
| From: | Jonathan Evans TOLEDO EDISON CO. |
| To: | |
| References | |
| TASK-TF, TASK-TMR NUDOCS 8001160898 | |
| Download: ML19322C362 (1) | |
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,,,_,T TO: United States Nuclear Regulatory Cocmission Office of Inspection and Enforecacnt
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Region Atto: Tom Tambling
SUBJECT:
Reportable Occurrence SFRCS Actuation with Resultant Reactor Trip and SFAS Actuation
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I Davis-Ecsse No. I Reactor in Mode 1 Operation Power 280 MHT - Ioad 90 WE
(. At._2134 hours..on September. ~24',(1977) the Reactor Operator noticed Main Feed Pucp No. 2 Speed decreasing and received a low level alara on No. 2 Ol3G.
At 2135 hours0.0247 days <br />0.593 hours <br />0.00353 weeks <br />8.123675e-4 months <br />. he received. a low steam generator level SFRCS trip.. The.,
- Teactor was manually tripped at 2136 due to increasing pressurizer., level -
and at the same time the. pressurizer electromagnetic-relief lifted. Unknown to the operator the electromagnetic relief failed to reclose result.ing in a decrease of RCS pressure and
. resultant SFAS actuation at.1600 pounds osig. As a result of the electromagnetic relief staying open and the quench tank cooling being isolated by the SFAS actuation, the quench tank pressure increased and the rupture disc ruptured.
When the operator realized the electromagnetic relief was not closed, the isolation valve was shut and RCS pecssute stabilized.
High pressure.inj ection. which was. initiated by NAS was maintained id operation =
j to assist returning the RCS pressure and pressud:ce level to nor:nal.
The main stea:n isolation valves were reopened a :1 the nonaal Plant cooldown was started.
Tom Tambling, NRC Region III, telephoned at 103. hours on Septecher ~25,1977.
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ack Evans Station Superintendent Davis-Besse-Nuclear Power Station Toledo Edison Company soo11so##
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