United States Nuclear Regulatory Commission - Protecting People and the Environment

Information Notice No. 87-44, Supplement 1: Thimble Tube Thinning in Westinghouse Reactors

                                 UNITED STATES
                          NUCLEAR REGULATORY COMMISSION
                      OFFICE OF NUCLEAR REACTOR REGULATION
                             WASHINGTON, D.C.  20555

                                 March 28, 1988


Information Notice No. 87-44, SUPPLEMENT 1:  THIMBLE TUBE THINNING IN
                                                 WESTINGHOUSE REACTORS


Addressees: 

All holders of operating licenses or construction permits for nuclear power 
reactors that employ a Westinghouse nuclear steam supply system (NSSS). 

Purpose: 

This notice is provided as a supplement to Information Notice No. 87-44 to 
alert recipients of additional information regarding thinning of the incore 
neutron monitoring system thimble tubes.  It is expected that recipients will 
review the information for applicability to their facilities and consider 
actions, as appropriate, to avoid similar problems.  However, suggestions 
contained in this information notice do not constitute NRC requirements; 
IN 87-44
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