TXX-3567, Deficiency Rept Re Defective Governor Drive Coupling on Diesel Generators.Initially Reported on 820912.Drive Coupling Elements Will Be Replaced W/Neoprene Since Isoprene Rapidly Deteriorates & Ultimately Fails
| ML20063M758 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 09/08/1982 |
| From: | Gary R TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | Madsen G NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, TXX-3567, NUDOCS 8209160093 | |
| Download: ML20063M758 (2) | |
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TEXAS UTILITIES GENERATING COMInNY 2(NH HHYAN TOWEli
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September 8, 1982 l
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- =wLIjQ f j Mr. G. L. Madsen, Chief Reactor Projects Branch 1 U. S. Nuclear Regulatory Commission Office of Inspection and Enforcement 611 Ryan Plaza Drive, Suite 1000 Docket Nos. 50-445 Arlington, TX 76012 50-446 COMANCHE PEAK STEAM ELECTRIC STATION DEFECTIVE GOVERNOR DRIVE COUPLINGS FILE N0. 10110 l
Dear Mr. Madsen:
In accordance with 10 CFR 50.55(e), we are submitting the attached report of actions taken to correct a deficiency regarding defective governor drive couplings on the diesel generators. We had previously informed your Mr. R. G.
Taylor of the deficiency on August 12, 1982.
Supporting documentation is available at the CPSES site for your Inspector's review.
Very truly yours, hk C,b,w y R. J. Gary RJG:eaq l
Attachment
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cc:
NRC Region IV - (0 + 1 copy)
Director, Inspection and Enforcement - (15 copies) c/o Distribution Services Branch, DDC, ADM.
U. S. Nuclear Regulatory Commission Washington, DC 20555 l
f 8209160093 820908 PDRADOCK05000g 7
6
o TXX-3567 September 8, 1982 ATTACHMENT DEFECTIVE GOVERN 0R DRIVE COUPLINGS DESCRIPTION OF DEFICIENCY The supplier (Delaval) has identified a material deficiency in the governor drive couplings of the standby diesel generators. The material, an isoprene suitable for ambient applications, rapidly deteriorates and ultimately fails when subjected to the high temperature, oil atmosphere encountered in the engine gear case. While the couplings are " fail-safe" and will mechanically lock in the event of failure of the element, sufficient frequency instability exists in the engines to possibly actuate the engine auxiliary systems. Under these conditions, the availability of the standby diesel generators can not be assured.
SAFETY IMPLICATIONS Had the deficiency gone undetected, the failure of the governor drive couplings could render the standby diesel generators inoperable prohibiting the controlled safe shutdown of the plant.
CORRECTIVE ACTION Based upon the recommendations of the supplier and manufacturer (Koppers), the drive coupling elements will be replaced with neoprene which is suitable to the application.
DATE OF IMPLEMENTATION The replacement elements have been received at CPSES. Unit 1 elements will be installed by November 1, 1982. Unit 2 elements will be replaced during start-up as the installation can not be accomplished without prior oil flush and turning of the engine.
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