ML20009G441

Interim Deficiency Rept Re GE CR2490 Tandem Block Switch Assemblies,Initially Reported 810626.Corrective Action Will Consist of Tightening All Tandem Block Screws After lock-tite Has Been Applied.Completion Expected by 830501

ML20009G441
Person / Time
Site:	Perry
Issue date:	07/24/1981
From:	Davidson D CLEVELAND ELECTRIC ILLUMINATING CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
(RDC-33-(81)), 10CFR-050.55E, 10CFR-50.55E, NUDOCS 8108040264
Download: ML20009G441 (2)

Text

r THE CLEVELAND ELECTRIC ILLUMIN ATING COMPANY ILLUMINATING BLDG e PUBLIC SOUARE e CLEVEL AND. OHIO 44101 e TELEPHONE (216) 623-1350 m Mall ADDRESS- P. O BOX S000 Semng The Best Location in the Nation Dalwyn R. Davidson VICE PRESIDENT - ENGINEERING

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(b 'g July 24, 1981 \

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9.h % 2 Mr. James G. Keppler /

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U. S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137 RE: Perry Nuclear Power Plant Docket Nos. 50-440; 50-441 Interim Report on General Electric CR2490 Tandem Block Switches (RDC 33 ((81)) )

Dear Mr. Keppler:

This letter constitutes the interim report as required by 10CFR50.55(e) on the potential significant deficiency concerning CR2940 tandem block switch assemblies supplied by GE for use in the Power Generation Control Complex (PCCC). This problem was identified to Mr. McGregor of the NRC, Region III Of fice of Inspection and Enforcement on June 26, 1981 by _*

Mr. W. J. Kacer of the Cleveland Electric Illuminating Company.

Description of Deficiency The General Electric CR2940 tandem block switch assemblies contain contact blocks in which the attaching screws have shaken loose during shipment.

Vibration during a seismic event could cause the contact block to loosen sufficiently further to inhibit pruper operation of the switch. This condition was identified by General Electric to the Cleveland Electric Illuminating Company on May 20, 1981.

An inspection of the switches contained in the Unit 1 PCCC panels has been conducted identifying ten loose block assemblies. Inspection of the i Unit 2 panels will be completed following turnover of the PGCC to the Nuclear Tes t Section.

Analysis of Safety Implications The GE CR2940 switch assemblies are utilized for safety-related manual control functions. The loss of the integrity of these switch assemblies 8108040264 810724 $h /

PDR ADOCK 05000440 S PDR 68[Ogilt 29 19 87

CJ, w Mr. Keppler July 24, 1981 Page 2 could delay manual operation during an analyzed plant event such that technical specification limits could be exceeded.

Corrective Action General Electric will issue a Field Deviation Disposition Request detailing the corrective action to be taken resolving this deficiency.

Corrective action will consist of tightening all tandem block screws after lock-tite has been applied. This activity is scheduled to be completed by May 1, 1983.

Very truly yours, y

Dalwy . Davidson Vice President System Engineering and Construction DRD:kss cc: Mr. Jack Hughes NRC Resident Inspector, PNPP Mr. Victor Stello Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission Washington, DC 20555 U. S. Nuclear Regulatory Commission c/o Document Management Branch Washington, LC 20555