Closeout of IE Bulletin 79-28: Possible Malfunction of NAMCO Model EA180 Limit Switches at Elevated Temperatures.

摘要

Documentation is provided in the report for the closeout of IE Bulletin 79-28 regarding the possible malfunction of NAMCO Model EA180 limit switches in safety-related systems at elevated temperatures. Closeout is based on the implementation and verification of four (4) required actions by holders of operating licenses or construction permits for nuclear power facilities. Evaluation of utility responses and NRC/Region inspection reports indicates that the bulletin is closed for all of the 119 facilities to which it was issued for action. It is concluded from the results that although the potential problem was widespread, supporting documentation shows that the bulletin concern has been resolved.