United States Nuclear Regulatory Commission - Protecting People and the Environment

ACCESSION #: 9505010161

Reciprocating Products Division
150 Lincoln Avenue
Grove City, PA 16127-1898
412 458-8000

April 21, 1995                                    Cooper Energy Services

Our Ref: QCG-10134

Document Control Desk
U.S.  Nuclear Regulatory Commission
Washington, D.C.  20555

Dear Sir:

In accordance with the requirements of the Nuclear Regulatory Commission
Title 10, Chapter 1, Code of Federal Regulations, Part 21, Cooper-
Bessemer Reciprocating Products Division, a division of Cooper
Industries, hereby notifies the Commission of a potential design defect
of the KSV emergency diesel generator (EDG) system.

There exists a potential problem with the cooling water system for the
mechanical governor.  On January 29, 1995, Niagara Mohawk, Nine Mile
Point Unit 2, experienced a governor failure on Division 1 EDG due to
overheating of the governor.  Subsequently, the governor removed from
Division II EDG also encountered this same failure during failure mode
testing at the governor manufacturer due to overheating of the mechanical
governor.  Further information about this failure is contained in Niagara
Mohawk, Nine Mile Point, Deviation/Event Report 2-95-0192.

Testing of the failed mechanical governor at the governor manufacturer
with representatives of both Niagara Mohawk and Cooper Bessemer present,
revealed that the root cause of the failures was: 1] A low or no flow
condition during low cooling water flow conditions, 2] Too small (3/8")
and/or long water tubing runs, 3] low differential pressure across the
intercoolers (the source of cooling water for the governor cooling
system).  The cooling system for the mechanical governor was designed and
supplied by Cooper-Bessemer.

The only EDG's in service with this mechanical governor cooling design

          UTILITY                       ENGINE SERIAL NO.

Niagara Mohawk                               7190, 7191
Commonwealth Edison - Byron Station          7169, 7174, 7175, 7176

All other KSV-EDG's have either been previously modified or have
dissimilar designs for governor cooling.

Cooper-Bessemer** (Registered Trademark) o Enterprise** (Trademark) o
Penn** (Trademark) o Ajax**  (Registered Trademark) o Superior**
(Registered Trademark)

April 20, 1995
Page 2

Although immediate modification of the cooling system piping
configuration has resulted in adequate cooling to the governor, the
recommended long term action required to correct the governor oil cooling
system is:

     o    Connect the oil cooler tubing to the end of the left bank
          engine jacket water inlet and outlet headers.  This will
          control oil viscosity at all operating and standby conditions.

For specific design information about this system change, please contact
John M. Horne, Manager Nuclear and Analytical Engineering at 412-458-

Our investigation into this matter was completed on April 18, 1995.  If
you have further questions concerning this report, please contact John R.
Schneider, Manager, Assurance Manager at 412-458-3434.



J. D. Mowery
Vice President and General Manager


cc:  E. E. Roper - CES/GC
     B. R. Sedelmyer - CES/GC
     D. T. Blizzard - CES/GC
     J. M Horne - CES/GC
     A. D. Gillette - CES/GC
     J. R. Schneider - CES/GC
     J. A. Kinnard - CES/GC
     File: K5fa34

April 20, 1995
Page 3

Copies to:

     Mr. Walter Haass - NRC             Mr. Dave Baran
     One White Flint North              Byron Nuclear Power Station
     Mailstop 9D4                       4450 North German Church Rd.
     Washington, DC 20555               Bryon, IL 61010

     Mr. Elmer Hernandez
     Commonwealth Edison co.
     Byron Nuclear Power Station
     4450 North German Church Rd.
     Byron, IL 61010

     Mr. Dave Gustafson
     Commonwealth Edison Co.
     Braidwood Nuclear Power Station
     Tech Staff Electrical Shop
     Route 1 Box 84
     Braceville, IL 60407

     Mr. Terry O'Brien
     Commonwealth Edison Co.
     1400 Opus Place
     Downers Grove, IL 60515

     Mr. Terry Vandevoort
     Commonwealth Edison Co.
     Zion Generating Station
     101 Shiloh Blvd.
     Zion, IL 60099

     Ms. Kathleen Russo
     Niagara Mohawk Power Corp.
     Nine Mile Rd.  - Unit 2
     P. O. Box 63
     Lycoming, NY 13093

     Mr. Lenny Schiavone
     Niagara Mohawk Power Corp.
     301 Plainfield Rd.
     North Syracuse, NY 13212

     Mr. Arthur Killinger
     MPR Associates Inc.
     320 King Street
     Alexandria, VA 22314-3238


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