ML20097G598

Special Rept:On 920501,determined That Voltage Output from Rectifier 10 in Cathodic Protection Sys Well Below Acceptance Criteria.Caused by Defect in Connection Between Test Leads & Test Probe.Test Equipment Modified

ML20097G598
Person / Time
Site:	Catawba
Issue date:	06/10/1992
From:	Tuckman M DUKE POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9206170148
Download: ML20097G598 (2)

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Duke Pouer Cortipany Catwba kclear Generateen Department hce imident 4800 Concord Road (803)R314:05 Olike hrk SC 9715 (803)M14C6 fu

DUl(E POWER June 10,1992 U. S. Nuclear Regulatory Commission A*ITN: Document Control Desk Washington, DC 20555

Subject:

Catawba Nuclear Station, Unit 1 Docket No. 50-413 Special Report Cathodic Protection System Inoperable Pursuant to Technical Specifications 3.8.1.1 ACTION statement "g" and 6.9.2, find attached a Special Report concerning the inoperability of the Cathodic Protection System for Catawba Unit 2. The system was declared inoperable on May 1,1992 and remained inoperable for more than 10 days.

Very truly yours, N-M. S. Tuckman CRUSR61092. CAT l

Attachment xc: S. D. Ebaeter Regional Administrator, Region II R. E. Martin, ONRR W. T. Orders Senior Resident Inspector-l I

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SPECIAL REPORT l'

CATAWBA NUCLEAR STATION UNIT 1

! CATIIODIC PROTECTION SYSTEM INOPERABLE 4

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. On May 1,1992, fastrumentation and Electrical (IAE) technicians performed a routine

surveillance on the Unit 1 Cathodic Protection System which detennined that the ' voltage output from rectifier #10 was well below the acceptance criteria, The technicians then proceeded to the alternate test method, a mitivolt drop test, which called for the rectifier to be turned off. The milivolt drop test did not meet the acceptance criteria. At this point, the Cathodic Protection System was declared inopemble because it could not meet the -

surveillance mquirements.

The technicians discussed the. surveillance results with the component engineer and

, concluded that the test equipment was faulty.- New test equipment was made available from the Engineering Gmup on May 13, 1992.- This new test equipment verified the inaccuracy of the station test equipment. The new test equipment determined that the rectifier was:

within the acceptance criteria as specified in the Technical Specifications. The Cathodic

, Protection System was declared operable on May !3,-1992.

The test equipment failure was due to a manufacturer deficiency in the connection between the test leads and the test probe. To prevent this problem from reoccurring, Catawba j Nuclear Station test equipment has been modified to enhance the connection from the test i lead to the test probe.

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