ML20154L145
| ML20154L145 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 05/17/1988 |
| From: | Tucker H DUKE POWER CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| NUDOCS 8805310179 | |
| Download: ML20154L145 (2) | |
Text
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DUKE POWER GOMPANY
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l May 17, 1988 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D. C.
20555
Subject:
Catawba Nuclear Station, Unit 1 Docket No. 50-413 Special Report Gentlemen:
Pursuant to Technical Specification 3/4.8.1.1.3, please find attached Revision 1 to the Special Report which was submitted on April 6, 1988 concerning a Diesel Generator 1A valid failure,-and three invalid failures. Duke Power personnel has determined that start attempt number 627, which was originally classified as an invalided failure, should be changed to a valid failure as indicated in the enclosed revision.
Very truly yours, Y S Tclut g Hal B. Tucke JGT/22/sbn Attachment xc Dr. J. Nelson Grace, Regional Administrator U
S. Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 Mr. P. K. Van Doorn NPC Resident Inspector Catawba Nuclear Station 1
8805310179 880517 PDR ADOCK 05000413 S
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~A SPECIAL REPORT, REVISION 1 CATAWBA NUCLEAR STATION, UNIT 1 W O DIESEL GENERATOR 1A VALID FAILURE ON MARCH 7, 1988 AND TWO INVALID FAILURES ON MARCH 8, 1988 While performing the operability verification of Diesel Generator (D/G) 1A on
' March 7, 1988, the D/G failed to reach the required 441 RPM within 11 seconds during start number 623 at 1005 hours0.0116 days <br />0.279 hours <br />0.00166 weeks <br />3.824025e-4 months <br />. High differential pressure across the fuel oil pump strainers and oil filters prompted the issuance of Standing Work
. Requests 5402, 5404, 6921, and 9004. The strainers and filters for D/G 1A were replaced by 1500 hours0.0174 days <br />0.417 hours <br />0.00248 weeks <br />5.7075e-4 months <br /> on that day. This is the third Valid Failure in the last 100 Valid Starts on D/G 1A and the first in the last-20 Valid Starts. The surveillance interval remained at 31 days following this Valid Failure, which is in accordance with Technical Specifications Surveillance 4.8.1.1.2.
Invalid Test Start numbers 624, 625, and 626 were performed to troubleshoot. Start number 623.
Valid Failure Start number 627 was performed on Msrch 7, 1988, at 1955 hours0.0226 days <br />0.543 hours <br />0.00323 weeks <br />7.438775e-4 months <br /> to verify operability by loading the D/G. The D/G started properly and loaded to 5700 KW but tripped on overcurrent protection after exhibiting varying excitation voltage.
Invalid Failure Start numbers 628 and 629 were performed to troubleshoot the overcurrent trip on Start number 627. The D/G started but would not load due to loss of generator excitation. Work Request 27213 OPS was initiated and identified a shorted rectifier diode (CR61 in the excitation circuit which was subsequently replaced.
Valid Success Start number 630 was performed on March 8, 1988, at 1535 hours0.0178 days <br />0.426 hours <br />0.00254 weeks <br />5.840675e-4 months <br /> following replacement of the rectifier diode.
D/G 1A was unavailable for 29 hours3.356481e-4 days <br />0.00806 hours <br />4.794974e-5 weeks <br />1.10345e-5 months <br />, 30 minutes as a result of these problems. Unit 1 was in Power Operation during the period D/G 1A was unavailable. D/G 1B was verified operable as well as offsite power as required by Technical Specifications.
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