United States Nuclear Regulatory Commission - Protecting People and the Environment

Bulletin 76-03: GE Type STD Relays

                      NUCLEAR REGULATORY COMMISSION 
                    OFFICE OF INSPECTION AND ENFORCEMENT    IEB 76-03 
                         WASHINGTON, D. C. 20555            3/15/76  
                                                            2 pages  

Inspection and Enforcement Bulletin (IEB) 
Number 76-03, March 15, 1976 

RELAY MALFUNCTIONS - GE TYPE STD RELAYS 

DESCRIPTION OF CIRCUMSTANCES: 

A malfunction of a General Electric (GE) Type 12STD15B5A Relay occurred 
recently in a safety related load center at Joseph M. Farley Station. The 
relay malfunction was due to radio frequency interference from an activated 
transceiver. This malfunction tripped the circuit breakers to isolate the 
associated transformer which resulted in the removal of the incoming power 
to the 600 volt load center. Three other users of these devices have 
reported STD relay malfunctions due to radio frequency interference. In 
addition, there have been several cases of failed shorted components on the 
STD relay amplifier card which resulted in relay malfunction. The STD type 
relay may be installed in similar applications at BWR or PWR facilities. The 
relays involved were initially marketed in 1968. 

Portions of a GE service letter containing information about these relays 
are attached to this bulletin. Further instructions regarding repair 
procedures can be obtained from the GE Service Engineering Department, 
Philadelphia. 

ACTION TO BE TAKEN BY LICENSEES AND PERMIT HOLDERS: 

For all power reactor facilities with an operating license or construction 
permit: 

1.   If you have received the attached GE service letter, describe what 
     action you have taken regarding the recommended action to update your 
     existing STD relays identified in the enclosed GE letter. 

2.   If you have not received the attached GE service letter, describe what 
     action you plan to take if relays of the type and model described in 
     the enclosed GE letter are in use or planned for use in safety related 
     systems. 
.

                                                            IEB 76-03  
                                                            3/15/76  
                                                            page 2 

ACTION TO BE TAKEN BY LICENSEES AND PERMIT HOLDERS (continued) 

Reports for facilities with operating licenses should be submitted within 30
days after receipt of this bulletin, and reports for facilities with 
construction permits should be submitted within 60 days after receipt of 
this bulletin. Your report should also include the date when the above 
actions were or will be completed. 

Reports should be submitted to the Director of the NRC Regional Office and a 
copy should be forwarded to the NRC Office of Inspection and Enforcement, 
Division of Reactor Inspection Programs, Washington, D. C. 20555. 

Approval of NRC requirements for reports concerning possible generic 
problems has been obtained under 44 U.S.C. 3152 from the U. S. General 
Accounting Office (GAO Approval B-180255(R0072), expires 7/31/77) 

ATTACHMENT: 
Extract from General Electric Service Letter: 
  STD RELAYS 
  TRANSFORMER DIFFERENTIAL RELAY 
Page Last Reviewed/Updated Tuesday, July 23, 2013