United States Nuclear Regulatory Commission - Protecting People and the Environment

Information Notice No. 79-03, Limitorque Valve Geared Limit Switch Lubricant

IN79003 

                             February 6, 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:               N. C. Moseley, Director, ROI:IE 

SUBJECT:            Information Notice No. 79-03, LIMITORQUE VALVE GEARED
                    LIMIT SWITCH LUBRICANT 

The subject Information Notice is transmitted for issuance on February 9, 
1979. The Information Notice should be issued to all power reactor 
facilities with an operating license or a construction permit. Also enclosed 
is a draft copy of the transmittal letter for this purpose. 

The subject document was changed to an Information Notice from the proposed 
draft Circular transmitted to you for comment. The change was made in 
response to contents on the proposed Circular. No inspection followup is 
necessary since this issuance is for information only. 


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

Enclosures:
1.   Information Notice No. 79-03
2.   Draft Transmittal Letter 

CONTACT:
C. J. DeBevec, IE 
49-28180 
.

(Draft letter to all power reactor facilities with an operating license or a 
construction permit) 

                                           Information Notice No. 79-03 

Addressee: 

This Information Notice is provided as an early notification of a possibly 
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 the matter, 
please contact the Director of the appropriate NRC Regional Office. 


                                        Signature 
                                        (Regional Director) 

Enclosures: 
1.   Information Notice No. 79-03 
2.   List of IE Information Notices 
       Issued in 1979 
.

                             UNITED STATES 
                      NUCLEAR REGULATORY COMMISSION 
                   OFFICE OF INSPECTION AND ENFORCEMENT 
                          WASHINGTON, D.C. 20555 
                                     
                             February 9, 1979 

                                           Information Notice No. 79-03 

LIMITORQUE VALVE GEARED LIMIT SWITCH LUBRICANT 

Description of Circumstances: 

At Commonwealth Edison reactors excessive failure rates of the Limitorque 
valve geared limit switches were being experienced. Investigation revealed 
that the failure mode was a drying out and hardening of the Beacon 325 
lubricant. Once hardening takes place, the brass gears within the limit 
switch become immobile and destroy themselves when an attempt is made to 
operate the valve. 

The Limitorque Corporation has recommended Mobilgrease 28 as a replacement 
grease for switch applications where the temperature exceeds 140 degrees 
Fahrenheit. Tests conducted by Mobil and Limitorque Corporation indicate 
that Mobilgrease 28, in addition to having a superior temperature rating, 
will satisfy the same environmental conditions and meet the same 
qualification parameters as Beacon 325. 

All licensee and construction permit holders should consider conducting a 
review to determine if Beacon 325 lubricant is being used in geared limit 
switches in environments conducive to drying out and subsequent hardening of
the lubricant. 

If conditions are found to be conducive to failures, consideration should be
given to replacing the grease with a more suitable grease. 

This information is provided as an early notification of a possibly 
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. 

Enclosure: 
List of IE Information Notices 
  Issued in 1979 

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