ML20071N744

Special Rept:On 940711,delta-t Channel on Chart Recorder Found to Be out-of-tolerance Due to Drifting of Analog to Digital (A/D) Converter Card.A/D Card Replaced & delta-t Channel Chart Recorder Declared Operable

ML20071N744
Person / Time
Site:	Catawba
Issue date:	07/28/1994
From:	Rehn D DUKE POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9408080184
Download: ML20071N744 (2)

Text

. .-_ _ - ..- -

.. Il I

() uke (butr Company Is . Rats Caryba %Icar Generatron Departnuent nce h nsdent 4W) Concord Road (803)ii313205 Ofhce f ork. 5C29:43 (803AT124:6 Fux DUKEPOWER July 28,1991 U. S. Nuclear Regulatory Commission ,

ATTN: Document Control Desk '

Washington, DC 20555

Subject:

Catawba Nuclear Station Docket Nos. 50-413 and 50-414 Special Report ,

Meteorological Monitoring Instrumentation System 7

Pursuant to Technical Specification 3.3.3.4, find attached a Special Report concerning the inoperability of the Meteorological Monitoring Instrumentation System.

Very truly yours, t Dik D. L. Rehn K EN/SRMETS.794 Attachment i xc: S. D. Fbneter .

Regional Administrator, Region 11 R. E. Martin, ONRR R. J. Freudenberger Senior Resident Inspector ,

i 808518k9407pg  !

s ADOCK 05000413 .

PDR I

,.- m. m .- l

s .

SPECIAL REPORT CATAWilA NUCLEAR STATION DOCKET NOS. 50-413 and 5-414 Meteorological Monitoring Instrumentation System Inoperable On July 11, 1994, during the Meteorological System weekly check, the delta-t channel on chart recorder (0EEllCR5010) was found to be out-of-tolerance.

Failure to restore the channel to operable status within the required period of seven (7) days resulted in the implementation of Action Statement a. of CNS Technical Specification 3.3.3.4.

I Work Order 94052645-01 was written on July 11, 1994, to investigate and repair the delta-t channel of this chart recordes . Troubleshooting began on July 13, 1994. Testing revealed that the Analog to Digital ( A/D) Converter card in chart recorder OEEllCR5010 was drifting. This failure was also affecting the Ambient Temperature, Dew Point Temperature, and Precipitation channel accuracies.

A replacement card was ordered from a vendor, but could not be received and installed witnin the 7 day Technical Specification Action Statement time limit.

All four of the parameters listed above are sent to the Operator Aid Computer (OAC), and are available at the display terminals. These OAC channels are i

tested by the weekly system check, and were found to be operable and within j tolerance. Therefore, all the Meteorological System channels were considered ,

to be operable due to accurate readouts being available to control room personnel .

The A/D card was replaced on July 21, 1994. A recorder channel check was performed and a Meteorological System weekly check was executed under Work Order 9405086G-01 and the delta-t channel chart recorder was declared operable.

I l

1 1

I i

. , .