ML20235W411
| ML20235W411 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 02/24/1989 |
| From: | Tucker H DUKE POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 8903130030 | |
| Download: ML20235W411 (3) | |
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. Duke her Company
~ He R Tucker
. PO. Box 33198 Vice President Charlotte, N.C 28242 ~
' Nuclear Production (704)373-4531 1
1 DUKEPOWER.
February 24,'1989 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 6.9.2, please find: attached a Special Report concerning a Unit 1 Diesel Generator 1B valid failure-during'the monthly operability test on January 27, 1989.
. Very truly yours,
- H. B. Tucker JGT/2/SR89-8 Attachment xc: Mr. M. L. Ernst Acting Regional Administrator, Region II U. S. Nuclear Regulatory Commission 101 Marietta St., NW, Suite 2900 Atlanta, Georgia 30323 Mr. W. T. Orders NRC Resident Inspector Catawba Nuclear Station L
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. CATAWBA NUCLEAR STATION, UNIT 1 SPECIAL REPORT DIESEL GENERATOR 1B VALID FAILURE DURING MONTHLY OPERABILITY TESTING OF ENGINE ON' JANUARY 27, 1989 A valid failure (start' No. 859) of Unit 1 Diesel Generator (D/G) 1B occurred on January' 27, 1989 at 1515 hours0.0175 days <br />0.421 hours <br />0.0025 weeks <br />5.764575e-4 months <br /> while D/G 1B was at 100% load. D/G 1B was on a monthly operability test schedule at the time of this valid failure. There have been.no valid failures in the past.20 valid starts and 3 valid failures in the past.100 valid starts for D/G 1B.
Following. fast start No. 859, the operator loaded IB diesel generator to 5750 KW.
He checked the electrical indications, moved to the engine control panel to recheck the pressure / temperature indications, and then proceeded to check the lube oil sump tank level instrumentation. On the way.to.the sump tank, he observed light smoke above and coming from the left bank turbocharger. He called the maintenance. representative that was working in the room on the air compressor to check out'the smoke with him. While they were _looking at the turbocharger to determine where the smoke.was. coming from and what was causing the smoke / vapors, the smoke / vapors flashed'into flames. The operator unloaded and shutdown the engine; the maintenance' man got a CO2 extinguisher to put out the fire. The fire was put out simultaneous with engine shutdown. The duration of the fire was approximately.1. minute. The fire'was reported out to the control room and to the-Fire Brigade Captain. Very light smoke and pungentLacrid vapors continued to emanate from the insulation on the left bank turbocharger. When the fire was verified out, the Fire Brigade Captain authorized ventilating the diesel room.
The maintenance engineer assigned responsibility examined both turbocharger trying to determine what could have been burning. The odor in the room was not that of burnt or burning lube oil or fuel oil. At first observation it seemed the insulation had caught fire but insulation is not supposed to burn with a flame. Past experience indicated that insulation on fire darkens and smolders and causes no other problem.
f The insulation was carefully removed one piece at a time. Each piece was examined as it was removed as well as the metal that it had been in contact with.
With the exception of the piece of insulation that was around the exhaust pipes that go into the turbocharger, all the insulation from the left bank hood exhibited varying degrees of breakdown. Additionally, the back panel, where the highest heat is recorded, was saturated with an oily like substance. This i
substance was seen in other locations on the left bank exhaust hood but to a l.
lesser extent. Further, the vapors had condensed on all the metal button backs
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that are a part of the insulation mounting or anchoring system. The turbocharger
-exhaust hood had the resin / oil like substance all over it.
All the insulation was carefully removed, piece by piece, from the right bank turbocharger. No effects from the exhaust heat were evident on any piece of insulation removed from the right bank turbocharger.
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The IA engine was examined to see what kind of insulation was installed. None had been installed at this time.
Personnel responsible for insulation installation were informed not to apply any insulation until further notice.
The residue from the insulation that was on the-left bank turbocharger exhaust.
hood was wiped off. Permission was requested and granted to test the 1B engine.
As a precaution, fire protection equipment was moved into place. The engine was started and allowed to idle.
Personnel looked for leaks and anything unusual.
Time was allowed for the residue to vaporize from the exhaust hood. After 10 minutes at idle, load was incrementally applied over a period of 20 minutes to full load. Full load was maintained for approximately 15 minutes. The last 5 minutes of the run showed no smoke indications, thus no residue-remained. The load was removed and the engine was cooled down and shut down.
The monthly operability test was conducted on the 1B diesel generator on January 27, 1989 with satisfactory results. The IB diesel generator was declared operable. The IB unavailability time for this failure was 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />.
The difference between the previous 1B diesel generator runs and start No. 859 was that there was no insulation installed. The previous run, (the operability test), had immediately followed the break-in runs following maintenance. This is done so that any leaks that might. exist can be seen.
It also allows us to see that the smoke / vapor are from the oily hand prints and thread lubricant'used during maintenance and not from something more serious. Then the insulation is installed. The new insulation was installed on 1B during the time that maintenance was being held on 1A diesel generator.
Prior to this event, the Unit 2 D/G's have successfully completed numerous full load runs without experiencing any insulation problem.
The insulation removed from the left bank turbocharger as well as the right bank was sent to the Duke Power Applied Science Laboratory for a complete analysis and evaluation of the material and the residues found.
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