ML20234C231
| ML20234C231 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 12/31/1987 |
| From: | Tucker H DUKE POWER CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| NUDOCS 8801060154 | |
| Download: ML20234C231 (2) | |
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,4 DUKE PowEn GOMPANY I'.O.HOX 33180 CIIARLOTTE, N.O. 28242 IIALU. TUCKER Teternowz (704) 373-4S31 non russionwy WUCLEAm eBUDUCTION December 31, 1987 Document Control Desk U. S. Nuclear Regulatory Commission Washington, D. C.
20555
Subject:
Catawba Nuclear Station, Unit 1 Docket No. 50-413 Special Report Gentlemen:
Pursuant to Technical Specifications 4.8.1.1.3 and 6.9.2, please find attached a Special Report concerning a Diesel Generator 1B valid failure on December 1, 1987.
Very truly yours, Yf Hal B. Tucker JGT/1174/sbn Attachment xc:
Dr. J. Nelson Grace Regional Administrator, Region II U. S. Nuclear Regulatory Commission 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 Mr. P. K. Van Doorn NRC Resident Inspector Catawba Nuclear Station hN
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SPECIAL REPORT l
CATAWBA NUCLEAR STATION, UNIT 1 l
DIESEL GENERATOR 1B l
VALID FAILURE ON DECEMBER 1, 1987 On December 1, 1987 while performing Engineering Safeguards Testing, Unit 1 Diesel Generator 1B was started automatically from the Unit 1 Control Room.
After approximately 70 seconds the diesel tripped automatically. A work request was initiated to investigate the problem. The problem was found to be the P-3 0
b shuttle valve not operating correctly.
This is a recurring problem with the Diese] Generators. Repairs were completed on the shuttle valve and the diesel was tested satisfactory.
Further investigation was conducted by Duke Power Design Engineering personnel and Transamerica Delaval, Incorporated, personnel in order to determine an appropriate replacement for the subject shuttle valve.
It was decided that an OR gate, similar to the ones used on the Control Logic Board would perform the same function as the shuttle valve.
It was also determined that the OR Gate was a better design and more efficient component than the shuttle valve. Testing was conducted on 18 diesel using an OR Gate in place of the P-3 shuttle vale.
It was found that the OR Gate operation was superior to the shuttle valve operation. A Nuclear Station Modification was written to install the OR gates in both Unit 1 and 2 diesels at Catawba. At this time the OR gates have been installed on the Catawba diesels and no further indication of the tripping problem has been experienced since then.
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