ML20024H235

Special Rept:On 910422,diesel Generator 2A Failed to Reach Required 441 RPM within 11 Seconds Due to Mispositioned Fuel Oil Strainer.Operators to Be Trained on Incident & Strainers to Be Inspected More Frequently

ML20024H235
Person / Time
Site:	Catawba
Issue date:	05/21/1991
From:	Tuckerman M DUKE POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9105300299
Download: ML20024H235 (2)

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ouxcpowEn May 21,1991 U. S. Nuclear Regulatory Commission A*ITN: Document Centrol Desk Washington, DC 20555

Subject:

Catawba Nuclear Station, Unit 2 Docket No. 50-414 Special Report Valid Failure of Diesel Generator 2A Pursuant to Technical Specification 4.8.1.1.3 and 6.9.2, find attached a Special Report concerning the Unit 2 Diesel Generator A (D/G 2A) valid failure that occurred on April 22,1991.

Very truly yours,

%.s. % k 1

M. S. Tuckman CRUSR52291 Attachment xc:

S. D. Ebneter j

Regional Administrator, Region II J

R. E. Martin, ONRR W. T. Orders Senior Resident Inspector p

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SPECIAL REPORT DUKE POWER COMPANY CATAWBA NUCLEAR STATION DIESEL GENERATOR 2A VALID FAILURE DUE TO FUEL OIL STRAINER VALVE MISPOSITIONING AND FUEL OIL STRAINER CLOGGING While performing operability verification on Diesel Generator (D/G) 2A per PT/2/A/4350/02A_on April 22,1991, the D/G failed to reach the required 441 RPM within 11 seconds. The failure occurred on start number 650 at 2341 hours0.0271 days <br />0.65 hours <br />0.00387 weeks <br />8.907505e-4 months <br />. This is the third valid failure in the last 100 valid starts on D/G 2A and the first valid failure in the last 20 valid starts. The surveillance interval remains 31 days following this valid failure. This is in accordance with Technical Specification 4.8.1.1.2 Table 4.8.1.

Following the failure, the fuel oil strainer selector valve was found to be in an intermediate

- position. The valve was returned to its proper position and D/G 2A was successfully started per OP/2/A/6350/02 on April 23,1991 at 0320 hours0.0037 days <br />0.0889 hours <br />5.291005e-4 weeks <br />1.2176e-4 months <br />. The D/G was unavailable for 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> and 39 minutes. Work request 48351 OPS was initiated and subsequently indicated both fuel oil strainers were partially clogged. The fuel oil strainer selector valve position and the partially clogged fuel oil strainers combinec to provide a fuel oil flow restriction that would not allow the diesel to reach 441 RPM within 11 seconds. In an effort to reduce the potential for this type of failure, operators will be trained on this incident and on the operation of this type of selector valve. Additionally, fuel oil strainers are being inspected more frequently, and a fuel oil polishing system is scheduled to be implemented between Unit 2 End of Cycle 4 and Unit 2 End of Cycle 5.

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