05000312/LER-1982-004, Forwards LER 82-004/03L-0.Detailed Event Analysis Submitted

Forwards LER 82-004/03L-0.Detailed Event Analysis Submitted

ML20042A897
Person / Time
Site:	Rancho Seco
Issue date:	03/04/1982
From:	Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT
To:	Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
Shared Package
ML20042A898	List: 05000312/LER-1982-004, Forwards LER 82-004/03L-0.Detailed Event Analysis Submitted 05000312/LER-1982-004-03, /03L-0:on 820209,reactor Protection Sys Channel C Pressure Transmitter Read 15 Psi High.Caused by Calibr of Transmitter During Artificial Cooling of Ambient Temp by Emergency Cooler.Input Buffer Amp Bias Changed
References
NUDOCS 8203240252
Download: ML20042A897 (2)

LER-1982-004, Forwards LER 82-004/03L-0.Detailed Event Analysis Submitted

Event date:
Report date:
3121982004R00 - NRC Website

text

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esuun SACRAVENTO MUNICIPAL UTILITY DISTRICT O 6201 S Street, Box 15830, Sacramento, California 95813; (916) 452-3211 ftarch 4, 1982 a

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.33 R H ENGELKEN, REGIONAL ADfi!NISTRATOR M

2 REGION V 0FFICE OF INSPECTION & ENFORCEftENT N

N U S NUCLEAR REGULATORY COPit!SSION

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In accordance with Rancho Seco Nuclear Generatii@ Station Technical Specifications Section 6.9.4.2a and Regulatory Guide 1.16 Section C.2.b(1), the Sacramento Municipal Utility District is submitting the following 30-day report for Reportable Occurrence 82-04.

On January 30, 1982 because of instrument drift problems the Reactor Protection System (RPS) Channel C pressure transmitter was replaced with a spare Westinghouse pressure transmitter ffodel 59PH.

On February 9,1982 the "C" channel was reported to be reading approximately 15 psi higher than its associated channels. This was the same shift as reported in LER 81-57.

Subsequent investigations revealed that the "C" tranmitter had been calibrated while the emergency coolers were running.

The location of the transmitter is directly in the path of the discharge of the coolers. These cor;1ers were being run to cool the containment atmosphere while maintenance personnel were in the building. When the unit was started up, the coolers were turned off, lhus the ingtrumentsawigsambienttemperaturechangefromanestimated 60 F to over 120 F.

Engineering calculation showed that this would account for the shift.

As a result, a work request was written to adjust the RCS Channel C input buffer amp bias to compensate for the temperature induced zero shift. This has been accoinplished and the transmitter is at the present time within acceptable limits of operation.

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R. H. Engelken March 4, 1982 Operations will also restrict the non-emergency use of this dooler to prevent abnormal temperature induced zero shift in this trans-mitter. A review of other transmitter locations revealed that none of the other transmitters is located such that similar problems will occur.

No transients resulted from this event nor was public or plant safety affected.

J hnb. Mattir.ioe k Assistant General Manager and Chief Engineer cc:

I&E Washington (30)

MIPC(3)

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