ML20059D244
| ML20059D244 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 08/24/1990 |
| From: | Tucker H DUKE POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9009060167 | |
| Download: ML20059D244 (3) | |
Text
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Duke Mrr Correazy Hu !! han PO flax 33198 iice Prnident Charlotte, N C 224 Nuclear kductwn (TM)3734531 DUKEPOWER i
August 24, 1990 U.S. Nuclear Regulatory Commission Attn Document Control Desk Washington, D.C.
20555
Subject:
Catawba Nuclear St' tion Docket No. 50-413 j
Special Report Gentlement Purcuant to Technical Specifications 6.9.2 and 4.8.1.1.2(d), please find attached a Special Report concerning the cathod!c protection system for the Unit 1 Diesel Cencrator Fuel Storage Tank pipes.
Very truly yours, m
AkI
- 11. B. Tucker M1111/
Attachment xc Mr. S. D. Ebneter Regional Administrator, RII U. S. Nuclear Regulatory Commission 101 Marietta Street, NW, Suite 2900 Atlanta, 'leorgia 30323
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Dr. K. N. Jabbour Office of Nuclear Regulation U. S. Nuclear Regulatory Commission 3
One White Flint North O s, O c y Washington, D. C.
20555 Mr. W. T. Orders i
NRC Resident Inspector Catawba Nuclear Station p0 i
9009060167 900824 0
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(DR ADOCK 05000413 '
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l-SPECIAL REPORT PIR-1-C90-0261 CATHODIC PROTECTION SYSTEM TECH. SPEC. 3.8.1.l(g), 4.8.1.1.2(d)
On July 25, 1990, the Cathodic Protection System was declared inoperable after the system did not pass the acceptance criteria of the sixty (60) day surveillance.
Failure to restore the system to operable status within the required period of ten days resulted in implementing action statement "g" of CNS Technical Specification 3.8.1.1 and 6.9.2.
P On July 15, 1990, while performing'the sixty (60) day i
surveillance on Rectifier #7 (Unit 1 D/G Fuel Storage Tank Cathodic Protection) the reading for Test Station TS-36 was found to be below the acceptance criteria indicating inadequate cathodic protection of the D/G Fuel Storage Tank Piping. The system was declared inoperable and Design Engineering was contacted.
On August 2,1990 station NPD and Design Engineering personnel tested the system by checking for proper voltage on the anodes associated with Rectifier #7. During this testing, one (1) prepackaged anode was found to have no voltage supplied to it indicating a cut or broken power cable. Following the testing, it was determined that one or more of the following could cause the low reading at Test Station TS-36.
1)
The loss of voltage at prepackaged anode # 5 2)
Deterioration of Test Station'TS-36 3)
Deterioration of existing anodes Based on the above, the following action has been taken or i
is planned:
1)
Restore voltage to prepackaged anode # 5 within the next sixty (60) days.
2)
Adjusted the output voltage of Rectifier #6 which l
is located in close proximity to Rectifier #7 to the highest voltage setting available. This action helped increase the voltage potential at Test Station TS-36 by approximately 25 millivolts.
3)
Based on data obtained from Ebasco Services, an upgrade to the Cathodic Protection System will be implemented under Station Modification Number
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5
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o (NSM) CN-50385/00 in 1991. Sixteen (16) anode wells will be added to the Lube oil and Fuel oil system to ensure adequate cathodic protection.
Additionally a new rectifier will be mounted beside existing Rectifier # 7 and six (6) new Test Stations will be installed.
4)
As an interim measure a Standing Work Request (SWR) will be generated to check the voltage potential at Test Station TS-36 on a weekly basis until corrective actions have been taken to restore the system to an operable condition.
Even though the system presently is not meeting the acceptance criteria, the system is providing adequate protection to the D/G Fuel Storage Tanks and the fuel tank pipes. In addition, corrosion deterioration on the pipes is a long term process and poses no immediate concerns.
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