ML20090H015
| ML20090H015 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 03/04/1992 |
| From: | Tuckman M DUKE POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9203130228 | |
| Download: ML20090H015 (3) | |
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{&1)h.%$.Ylllb Dlfd t W hi'lM I3 (W1)M31Jt:6ht DUKC POWCfl March 4,1992 U. S. Nuclear Regulatory Commission A1TN: Document Control Desk Washington, DC 20555
Subject:
Catawba Nuclear Station Unit 2 Docket No. 50-414 Special lteport Cathodic P.utection System inoperable -
Pursuant to Technl<.al Specification 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 January 27,1992 and remained inoperable for more than 10 days.
Very truly yours, Ud Mi h M. S. Tuckman CRUSR22492. CAT Attachment xe: S. D. libneter Regional Administrator, Region II R.11. Martin, ONItR W. T. Orders Senior Resident inspector 4
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U. S. Nuclear Regulatory Commission March 4,1992 l' age 2 bxc: R. C. Futrell R. l.. Gill T. R. Gill s
W. R. McCollum l'. T. Vu C. R. lewis K. E. Nicholson Group File: CN 801.01 Corporate Records: 801.01 -
SPECIAL llEPORT CATAWilA NUCLEAR STATION UNIT 2 CATI {0DIC PitOTECTION SYSTEM INOPERA111.E On January 27,1992 the Cathodic Protection System for Catawba Nuclear Station Unit 2 was declared inoperable due to a fault in the voltage transformer associated with Itectiner 3, The faulted transformer resulted in a circuit breaker trip which isolated power to the rectifier. The cause of the transformer failure in Rectifier 3 was hard to determine because the transformer was badly burned. The most probable root cause of the failure is insulation degradation Icading to a turn to turn winding fault.
Purchase requisitions were written to order a new transformer and silicon diode rectiner bridges. An additional transformer was also ordered to place in stock should another one fail in the future. _ Rectiner 3 was repaired and declared operable on February 24,1992i Even though Rectifier 3 was not in service from January 27,1992 to February 24,1992, corrosion deterioration of the piping is a long term process and did not pose a threat during this period of inoperability, j