ML20069E667

Interim Deficiency Rept 83-01 Re Significant Deviation from Performance Specs for Riley Temp Switches in Leak Detection Sys.Initially Reported on 830215.Two Units Returned to GE for Evaluation.Temp Module Resolution Expected by Apr 1983

ML20069E667
Person / Time
Site:	LaSalle
Issue date:	03/16/1983
From:	Schroeder C COMMONWEALTH EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
10CFR-050.55E, 10CFR-50.55E, 6209N, 83-01, 83-1, NUDOCS 8303220145
Download: ML20069E667 (2)

Text

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/ Commonivealth Edison

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7 Addrass Rrply to: Post Office Box 767 y ,- Chicago. Illinois 60690 March 16, 1983 Mr. James G. Keppler, Director Directorate of Inspection and Enforcement - Region III U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, IL 60137

Subject:

LaSalle County Station, Unit 2 10CFR50.55(e) Notification 83-01, Interim Report, Riley Temperature Indicating Switches NRC Docket No. 50-374

Dear Mr. Keppler:

Commonwealth Edison notified your of fice on February 15 of a reportable deficiency in accordance with 10CFR50.55(e) concerning significant deviation from performance specifications for the Riley temperature switches installed in the leak detection system. (Model 86 VEFFF for the differential temperature devices and model 86 PEGF for the ambient instruments).

During Unit 1 startup testing of the Leak Detection System (LDS), inconsistencies in the reading of the Riley temperature indicating switches (modules) were noted in that indications were different from expected temperatures by up to 160F.

As part of our corrective action, two units were returned to General Electric, San Jose, for their evaluation of the failure mode. In addition, Riley visited LaSalle to investigate the problem and has established that the problem does exist by tests perfornied on-site and duplicated at Riley's facilities.

The cause of the erroneous temperature indication caused by the temperature offset is due to the development of a voltage drop across the thermocouple line resistance which partially offsets the thermocouple EMF.

Further, the manufacturer believes they have found the solution to why the modules are inconsistent in their readings and are modifying their current calibration procedure to correct the problem. This procedure will be ready for use on or about 3/18/83.

9303220145 830316 MAR 17 683 PDR ADOCK 05000374 S PDR A a?

J. G. Keppler March 16, 1983 Final resolution of the temperature module problem is expected by the end of April 1983. A final report will be issued at that time.

If you or your staff have any questions concerning this activity, please contact us at this office.

Very truly yours, S flLl% 3 C. W. Schroeder Nuclear Licensing Administrator 1m cc: Director of Inspection and Enforcement, Washington, D.C.

NRC Resident Inspector - LSCS 6209N l