United States Nuclear Regulatory Commission - Protecting People and the Environment

Bulletin 77-05A: Electrical Connector Assemblies

                       NUCLEAR REGULATORY COMMISSION 
                    OFFICE OF INSPECTION AND ENFORCEMENT 
                          WASHINGTON, D. C. 20555 
                                     
                              November 14, 1977

                                                         IE Bulletin 77-05A 

ELECTRICAL CONNECTOR ASSEMBLIES 

Description of Circumstances: 

This Bulletin is a supplement to IE Bulletin 77-05, issued November 8, 1977,
and the two documents should be considered together. 

Bulletin 77-05 described the failure, under test conditions, of a general 
type of electrical connector. The tests were intended to simulate post-LOCA 
conditions, therefore the action requested in the Bulletin focused on the 
qualification of electrical connectors for use inside containment. 

Since issuance of Bulletin 77-05, our attention has been called to 
circumstances which indicate that the scope of the action requested should 
be expanded and therefore the response to Bulletin 77-05 should reflect the 
expanded scope. 

Electrical connectors should be qualified to perform their intended function
after having been subjected to accident conditions if they are contained in 
a system whose function is to mitigate that accident. 

The location of the connectors that must be qualified is not limited to 
those inside containment. 

Action To Be Taken By Licensees and Permit Holders: 

1.   Actions requested by Bulletin 77-05 should be expanded to include all 
     connectors in safety systems which are required to function to mitigate
     an accident where the accident itself could adversely affect the 
     ability of the system to perform its safety function. The examination 
     is not to be limited to only LOCA's nor to areas only within 
     containment. 

2.   Responses should be provided within 30 or 60 days, as appropriate, of 
     the date of this supplement. 

Approved by GAO, B180225 (R0072); clearance expires 7-31-80. Approval was 
given under a blanket clearance specifically for identified generic 
problems. 
Page Last Reviewed/Updated Tuesday, July 23, 2013