05000348/LER-1978-061-03, /03L-0 on 780905:failure of 1-2A Diesel Generator to Respond to Voltage/Speed Control in Auto Due to Failure of Motorized Potentiometer(Failed Diodes)Causing the 125V DC Supply Fuses to Blow

/03L-0 on 780905:failure of 1-2A Diesel Generator to Respond to Voltage/Speed Control in Auto Due to Failure of Motorized Potentiometer(Failed Diodes)Causing the 125V DC Supply Fuses to Blow

ML20147B318
Person / Time
Site:	Farley
Issue date:	10/02/1978
From:	Hairston W ALABAMA POWER CO.
To:
Shared Package
ML20147B297	List: 05000348/LER-1978-061, Forwards LER 78-061/03L-0 05000348/LER-1978-061-03, /03L-0 on 780905:failure of 1-2A Diesel Generator to Respond to Voltage/Speed Control in Auto Due to Failure of Motorized Potentiometer(Failed Diodes)Causing the 125V DC Supply Fuses to Blow
References
LER-78-061-03L, LER-78-61-3L, NUDOCS 7810100072
Download: ML20147B318 (1)

LER-1978-061, /03L-0 on 780905:failure of 1-2A Diesel Generator to Respond to Voltage/Speed Control in Auto Due to Failure of Motorized Potentiometer(Failed Diodes)Causing the 125V DC Supply Fuses to Blow

Event date:
Report date:
3481978061R03 - NRC Website

text

NRC FORM 366 U. S. NUCLEAR REGULATORY COMMISSION (7-77 )

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LICENSEE EVENT REPORT CONTROL BLOCK: l l

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8 00 61 DOCK ET NUMB E H 68 b9 EVENT DATE 74 7b REPORT DATE 80 EVENT DESCRIP110N AND PROBABLE CONSEQUENCES h 10121 l on 9/5/78 while being started for maintenance, the 1-2A diesel nenerator would not I

[ _o l 3 l l respond to voltage or speed (frequency) adjustments in auto.

T/S 3.8.1.1 requires I

lo14IIthat two separate independent diesel generator sets be operable. The 1-2A diesel l

lo isl [ generator was declared inoperable at 0835 on 9/5/78, and was returned to an operable I

l o lo i l status at 1300 on 9/5/78.

T/S 3.8.1.1 action statement requirements were met.

The I

l o ] 7 l l health and safety of the general public _were not af fected.

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SYST E M

CAUSE

CAUSE COMP.

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CODE TYPE N O.

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40 41 42 43 44 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS h l1 l O l l The f ailure of the 1-2A diese1~ generator to respond to voltage / speed control in auto l

_.1iiil Iwas due to the failure of a motor-operated potentiometer (failed diodes) which caused I g, i. ; l the 125V DC supply fuses to blow. The motor operated potentiometer was repaired and I

j j 3 [3; l reinstalled, and the fuses were replaced.

The 1-2A diesel generator was satisf actorily!

[3 l4l l tested per FNP-1-STP-28.1.

A similar occurrence was reported in LER 78-060/03L-0.

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PERSONNE L INJU IES NUMBtR

DESCRIPTION

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7 8 9 11 12 80 LOSS OF OR DAMAGE TO F ACillTV TYPE DE SCRIP 7 TON l1 [ 9 l l Z l@l NA l

1 8 9 10 B0 NRC USE ONLY l 2101 l N f@l ESCRIPT10 9 ISSUg NA l

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W. G. Hairston, III (205) 899-5156 2

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