Information Notice No. 79-23, Emergency Diesel Generator Lube Oil Coolers

IN79023 

                               UNITED STATES 
                       NUCLEAR REGULATORY COMMISSION 
                          WASHINGTON, D. C. 20555 
                                     
                            September 25, 1979 

MEMORANDUM FOR:     B. H. Grier, Director, Region I 
                    J. P. O' Reilly, Director Region II 
                    J. G. Keppler, Director, Region III 
                    K. V. Seyfrit, Director, Region IV 
                    R. H. Engelken, Director, Region V 

FROM:               Norman C. Moseley, Director, Division of Reactor 
                      Operations Inspection, IE 

SUBJECT:            Information Notice No. 79-23, EMERGENCY DIESEL 
                    GENERATOR LUBE OIL COOLERS 

The enclosed information notice should be dispatched September 26, 1979 to 
all power reactor facilities holding operating licenses and construction 
permits. 


                                        Norman C. Moseley, Director 
                                        Division of Reactor Operations 
                                          Inspection 
                                        Office of Inspection and Enforcement

Enclosures: 
1.   Information Notice No. 79-23
2.   Draft Transmittal Letter 

CONTACT:  H. A. Wilber, TP 
          49-28180 
.

(Draft letter to all power reactor facilities with operating licenses and 
construction permits.)  

                                           Information Notice No. 79-23 

Gentlemen: 

The enclosed Information Notice provides information with regard to failures
of lube oil coolers for emergency diesel generators. 

                                        Sincerely, 


                                        Signature 
                                        (Regional Director) 

Enclosures: 
1.   Information Notice 79-23 
2.   List of IE Information 
       Notices Issued in the 
       Last Six Months 
.

                                                  Accession No: 7908220121 
                                                  SSINS:  6870             

                              UNITED STATES 
                      NUCLEAR REGULATORY COMMISSION 
                   OFFICE OF INSPECTION AND ENFORCEMENT 
                          WASHINGTON, D.C. 20555 
                                     
                            September 26, 1979 

                                           Information Notice No. 79-23 

EMERGENCY DIESEL GENERATOR LUBE OIL COOLERS 

Within a two week time span (August 27 to September 11, 1979), the tube 
sheets failed in the Arkansas Nuclear One (ANO) Unit 1 lube oil coolers for 
both of the Unit 1 Emergency Diesel Generators. The introduction of water 
into the diesel lube oil system resulted in trips of both diesels during 
surveillance testing. The diesels were not considered capable of sustained 
operation. 

Investigation by the licensee has indicated cracks around the outer 
periphery of the tube sheets. The exact failure mode has not been assessed; 
however, the licensee has replaced the Emergency Diesel lube oil coolers for 
both diesels with a cooler of different design. The original lube oil 
coolers had tube sheets which were one-eighth (1/8) inch in thickness and 
the tubes were soldered in place. Epoxy was also used as a sealer on the 
tube (water side) of the lube oil cooler. The new coolers have one-half 
(1/2) inch tube sheets and the tubes are rolled. 

The ANO, Unit 1 Emergency Diesel Generators were purchased in 1970 and were 
manufactured by the Electromotive Division of General Motors Corporation. 
The lube oil coolers (Model Number D-191700) were manufactured by Young 
Radiator Corporation. 

This information is provided as an early notification of a possible 
significant matter. It is expected that recipients will review the 
information for possible applicability to their facilities. No specific 
action or response is requested at this time. If further NRC evaluations so 
indicate, an IE Circular or Bulletin will be issued to recommend or request 
specific licensee actions. If you have questions regarding this matter, 
please contact the Director of the appropriate NRC Regional Office.