ML20138H702

Special Rept:On 850820,173 F Temp Limit for Safety/Relief Valve Solenoids Misinterpreted as Ambient Air Temp When Intended as Metal Housing Temp.Analysis of Temp Data Indicates Solenoids Have 14 Yrs of Remaining Life

ML20138H702
Person / Time
Site:	LaSalle
Issue date:	11/18/1985
From:	Diederich G COMMONWEALTH EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
NUDOCS 8512170287
Download: ML20138H702 (1)

Text

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) LESill1 County Nucicir Station w Rural Rout) #1, Box 220 kV

\(j/ Marseilles, Illinois Telephone 61341 815/357 6761 ,

FaIO111Y R0011'lG. j November 18, 1985 mA 7  !

C Mr. James G. Keppler aI )L -

Regional Administrator HT i' Region'III U.S. Nuclear Regulatory Commission

{ FIL Ld

-799 Roosevelt Rosd Glen Ellyn, Illinois 60137

Dear Mr. Keppler:

This special report is being submitted in accordance with Technical Specif1-cations 3.7.7 Action a and 6.6.6.c and the C. W. Schroeder to J. G. Keppler letter dated December 22, 1983, regarding IaSalle Unit 1 Drywell Temperature.

The above letter established individual temperature limits for several of the key pieces of equipment in the Unit 1 dryvell. It was determined on August 20,:1985, that the 173 F temperature limit for the SRV solenoids was misinter-preted as an ambient air temperature when it in fact was intended as the metal housing temperature.

The 173 F metal housing temperature corresponds to a 150 F ambient air tempera-ture based on actual operating data. A review of all available temperature data determined that the ambient air temperature in the vicinity of the SRV solenoids exceeded the 150 F temperature limit on several occasions during

-1984. Existing data indicates temperatures above 150 F may have existed during periods of operation from January 12, 1984, to May 14, 1984; May 22, 1984, to July 11, 198h; July 17, 1984, t> July 23, 1984; and July 25, 1984, to August 30, 1984. In addition, temperatures in excess of 150 F have existed since August 8, 1985. Since no data on the temporary monitoring system is available for the period from December 27, 1984, to August 8, 1985, it is"not known how long the current high temperatures have existed. ,

A conservative analysis of all available temperature data indicated, that the SRV solenoids have a NUREG 0588 Category II remaining life of about 14 years assuming that the current high temperature conditione continue to exist.

During the present Unit _1 refueling outage, a gap in the insulation on a main steam line was found.- Hot air from the gap would have been directed toward the two sensors indicating the high temperature. The gap has been corrected.

8512170287 851110 g,.0 , A Y DR ADOCK OSO g 3 . v G. J. Diederi h Station Manager LaSalle County Station GJD/KCW/ DER /kg Enclosure [

xc: NRC Resident Inspector INPO - Records Center N V 2 51985 qp*

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