ML19031C066
| ML19031C066 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 03/17/1975 |
| From: | Schwalje E Public Service Electric & Gas Co |
| To: | Knuth D NRC/IE |
| References | |
| Download: ML19031C066 (2) | |
Text
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Public Service Electric and Gas Company 80 Park Place Newark, N.J. 07101 Phone 201 /622-7000 March 17, 1975 Dr. Donald F. Knuth, Director U. S. Nuclear Regulatory Commission Office of Inspection and Enforcement 7920 Norfolk Avenue Bethesda, Maryland 20014
Dear Dr. Knuth:
DIESEL GENERATORS -
EXHAUST VALVES NO. 1 AND 2'UNITS SALEM NUCLEAR 9_Elil.E-Rf\\.TING STATION DOCKETS NO. ~AND 50-311 On February 19, 1975 a verbal report was made to Region 1, Office of Inspection and Enforcement advising that, based on operating experience elsewhere, the manufacturer of the Alco diesel engines for Salem was to replace all the exhaust valves in these engines.
This report was in accordance with provision of 10CFR50.55(e).
The following detail gives the background and reasoning for the replacement of the engine exhaust valves:
During 1972 and 1973, Alco diesel engines, with from three to six months of service on Canadian locomotives, began to experience failure on exhaust valves manufactured by the Eaton Corporation.
After some investigation, Alco proceeded to ultrasonically inspect all exhaust valves on presently in-service engines, replacing all valves which showed any sign of internal rupture.
During this inspection, all exhaust valves on the Salem diesels were inspected and three valves were replaced.
In September 1974, 12 more valve failures occurred in Canada and Australia and in each case the failed valves had been found free of any indications at the time of the ultrasonic inspection.
Alco Diesel and Eaton Corporation began an entirely new phase of investigation in consultation with Syracuse University.
The investigation determined that the rolling process used by Eaton Corporation to straighten the valves introduced internal stresses in excess of 50,000 psi tensile at the fracture location.
It was also determined that these stresses could be eliminated by substituting a low-force proce-dure of straightening by bending in lieu of the roll straightening.
?'if The Energy People 95-2001 (400M) 5-73
U.S. Nuclear Regulatory Comm.
2 -
3/17/75 To resolve the problem, Eaton has discontinued roll straightening of valves and has substituted the low-force straightening by bending procedure.
All exhaust valves in the Salem diesels are to be removed by Alco and replaced with valves manufactured with the newly adopted process.
We believe that Alco Diesel and Eaton have adequately investi-gated this problem and have made the necessary changes to their manufacturing process to insure that the exhaust valves will meet all requirements of service.
Replacing the exhaust valves at Salem eliminates the potential for diesel failure due to exhaust valve failure.
The intake valves in these engines are of a different design from the exhaust valves and have performed satisfactorily in service without failure.
The replacement of the exhaust valves in the Salem engines is expected to be completed by May 1, 1975.
If you desire additional information on this subject, we will be pleased to discuss it with you.
CC Mr. J. P. O'Reilly King of Prussia, Pa.
Very truly yours, A-~
E. N. S ~hwa lj e V'
Manager of Quality Assurance Engineering & Construction Department