ML20086C310

Interim Deficiency Rept Re Failure of Diesel Generator Engine Exhaust Valves.Initially Reported on 750219.Caused by Procedure Error.Eaton Discontinued Roll Straightening of Valves & Substituted low-force Straightening

ML20086C310
Person / Time
Site:	Salem
Issue date:	03/17/1975
From:	Schwalje E Public Service Enterprise Group
To:	Knuth D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
Shared Package
ML20086C308	List: ML20086C310
References
10CFR-050.55E, 10CFR-50.55E, NUDOCS 8311230087
Download: ML20086C310 (2)

Text

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Public Service Electric and Gas Cornpany 80 Park Place Newark, N.J. 07101 Phone 201/622 7000 E

March 17, 1975 b

E a

t' i Dr. Donald F. Knuth, Director

U. S. Nuclear Regulatory Commission

Office of Inspection and-Enforcement 7920 Norfolk Avenue

Bethesda, Maryland 20014 '

Dear Dr. Knuth:

E DIESEL GENERATORS - EXHAUST VALVES

' NO. 1 AND 2 UNITS SALEM NUCLEAR GENERATING STATION

DOCKETS NO. 50-272 AND 50-311

? On February 19, 1975 a verbal report was made to Region 1, F 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 s in these engines. This report was in accordance with provision

[

E of 10CFR50 55(e).

g The following detail gives the background and reasoning for the i

replacement of the engine exhaust valve s :

During 1972 and 1973, Alco diesel engines, with from three to

$ six months of st vice on Canadian locomotives, began to

[ experience failure on exhaust valve s manuf actured by the Eaton Corporation. After some investigation, Alco proceeded to i

ultrasonically inspect all exhaust valves on presently in-service J engines, replacing alL valve s which showed any sign of internal

$ rupture. During this inspection, all exhaust valves on the i Salem diesels were inspected and three valves were rep la c e d .

In September 1974, 12 more valve failures occurred in. Canada P

and Australia and in each case the failed valves had been

= found free of any indications at the time of the ultrasonic '

f inspection. Alco Diesel and Eaton Corporation began an entirely i new phase of investigation in consultation with Syracuse University. The investigation determined that the rolling

process used by Eaton. Corporation to straighten the valves k

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.

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2- 3/17/75 Regulatory Comm.

To resolve the problem, Eaton has discontinued roll straightening of valves and has substituted the low-force straightening by bending procedure. All exhaust valve s 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 valve s 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.

l If you desire additional information on this subject, we will be pleased to discuss it with you.

Very truly yours,

/ E. N.-h-S h'wa lj e Manager of Quality Assurance Enginee ring & Construction Department CC Mr. J. P. O'Reilly King of Prussia, Pa.

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