ML17266A274

LER 80-050/03L-0:on 800904,while Power Supplies for Control Element Assemblies 42 & 44 Were in Parallel,Both Dropped. Probably Caused by Voltage Spike

ML17266A274
Person / Time
Site:	Saint Lucie
Issue date:	10/03/1980
From:	Pace P FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML17209A216	List: ML17209A215 ML17266A274
References
LER-80-050-03L, LER-80-50-3L, NUDOCS 8010100314
Download: ML17266A274 (3)

Text

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SUFFUCR Ia iS 44 CCMFCNCNT MANVFACTV>>lCR 41 o While chan in the 15V ower su 1 for CEA 42 CEA 44 dro ed ossibl due to a voltage spike. Due to a failure of the plant PA system, maintenance personnel were not notified that CEA 44 dropped and they continued removin the ower su 1 for CEA 42. Thi ed t t occurrence of the dual rod drop.

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REPORTABLE OCCURRENCE 335-80-50 LICENSEE EVENT REPORT PAGE TWO ADDITIONAL CAUSE DESCRIPTION When the 15V power supply for CEA 42 was removed while paralleled, the upper gripper hold voltage for CEA 42 was supplied from the coil power programmer for CEA 44. When operators attempted to with- .

draw CEA 44 the normal sequencing of the coil power programmer interiupted power to the upper gripper for CEA 42. This caused CEA 42 to drop.

This occurrence probably could have been reduced'to a single rod drop if better communications between the control room and maintenance had been established. This would have allowed the equipment status to be verified quickly. Lessons learned regarding the importance of communi-cations and emphasis on the details of the CED system are being incorporated into the training program.