ML19284A403

LER 79-014/03L-0 on 790202:pressurizer Level Indicator Indicated High Over Allowable Range.Caused by Voltage Drift in Associated Level Transmitter.Appropriate Channel Placed in Trip Condition & Transmitter Recalibr

ML19284A403
Person / Time
Site:	North Anna
Issue date:	02/28/1979
From:	Cartwright W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML19284A398	List: ML19284A396 ML19284A403
References
LER-79-014-03L, LER-79-14-3L, NUDOCS 7903060244
Download: ML19284A403 (2)

Text

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Virginia Electric and Pouer Company ihrth Anaa Powr s tat ion, Unit #1

Attachment:

Page 1 of 1 Docket No. 50-338 Report No. LER-79-14/03L-0 Description of Event:

On 2-2-79 while investigating indication error in the pressurizer level transmitters it was found that LI-1459 indicated 3.5% high over the range O to 100%. This is contrary to the allowable range listed in table 3.3-4 item 1.d of T.S. 3.3.2.1. Action statement number 14 in table 3.3-3 was taken and steps were taken to recalibrate the level transmitter LI-1459.

I'robable Consequences of Event The pressurizer level channels are used to generate both a Reactor Trip signal on high 1cvel and Safety Injection, Turbine Trip and Feedwater Isola-tion on low level in coincidence with low pressure. Both actions require a minimum of two operable channels. The 3.5% high error in LI-1459 was in the conservative direction for the Reactor Trip signal but was outside the allow-able range for the Safety Injection signal. The health and safety of the general public was not endangered as the affected channel was placed in tripped condition as required by action step 14 of Table 3.3-3.

Cause of Occurrence The cause of the high indication on LI-1459 was due to voltage drift in the level transmitter LI-1459.

Immediate Corrective Action:

Placed affected channel in tripped condition and recalibrated the level transmitter LI-1459 satisfactorily. Returned transmitter to service.

Scheduled Corrective Action No further action required.

Actions Taken To Prevent Recurrence No further action required.