ML19242A864

LER 79-044/03L-0 on 790706:while Performing Reactor Low Water Level 1 Channel Calibr,Switch 1 Found Out of Tolerance Low.Caused by Instrument Drift.Instrument Recalibr & Returned to Svc

ML19242A864
Person / Time
Site:	Brunswick
Issue date:	08/03/1979
From:	Tollison A CAROLINA POWER & LIGHT CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML19242A854	List: ML19242A853 ML19242A864
References
LER-79-044-03L, LER-79-44-3L, NUDOCS 7908060501
Download: ML19242A864 (1)

Text

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i o I :' ' [Whi le .per forming _PT 1.1.4PCu_ Reactor Low Water Level il Channel Calibration, a 3 [B21-LIS-N017B, switch I was found to be out of tolerance low. The required value is l 4 l [~> d 12.5 inches of _ water and the as found value was 10.6 inches o f wa t . . r io t LTechnical Specifications 2.2.1. 6.9.1.9a l Ia lo l I __ _ ___ J !a i l o l s L _ __..___._. _ - _ _ _ . . ._ _ - _ . . _ _ _ ea a . Am ,E LE Io o [I A l( 1) Qj } Z_j i) [ I l N l S l T l R [l{jh j() lZlh

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o The only reason determined was instrument drift. The ins trument was recalibrated and l L ii_J Ireturned to service. A plant modification has been eritten to replace the bi-stable I j, [ switches with analog ins trumen tatic,n during the 1980 refueling outage. This new l

   ,  ,          l in s t rumen t a tion is auch more stable and should greatly redue                                                                                                                                           the drift problems now                                              l 2          [being encountered.                                                                                                                                                                                                                                                                l a '                                                                                                                          m so F                                                                                              >

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                                                           ,           ,                      A. C. Tollison, Jr.

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