United States Nuclear Regulatory Commission - Protecting People and the Environment

Information Notice No. 89-57: Unqualified Electrical Splices in Vendor-Supplied Environmentally Qualified Equipment

                                  UNITED STATES
                          NUCLEAR REGULATORY COMMISSION
                             WASHINGTON, D.C.  20555

                                  July 26, 1989

                                   VENDOR-SUPPLIED ENVIRONMENTALLY 
                                   QUALIFIED EQUIPMENT


All holders of operating licenses or construction permits for nuclear power 


This information notice is being provided to alert addressees to a potential 
problem involving unqualified electrical splices in vendor-supplied environ-
mentally qualified (EQ) equipment.  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; therefore, no 
specific action or written response is required.

Description of Circumstances:

On June 5, 1989, the licensee for the Cooper Nuclear Station (CNS) reported to 
the NRC the finding of unqualified splices within conduits on vendor-supplied 
instrument racks.  The racks contain wire junction boxes and Barton differen-
tial pressure indicating switches (DPISs).  A piece of flexible conduit runs 
between the junction box and a condulet mounted on the DPIS (See Attachment 
1).  The flexible conduits vary in length from 2 to 10 feet.  The unqualified 
splices consisted of wirenuts, insulated butt crimps, or Scotch tape splices.  
This problem was discovered during an unrelated walkdown inspection that was 
being performed as part of an instrument upgrading process for Regulatory 
Guide 1.97, "Instrumentation for Light-Water-Cooled Nuclear Power Plants to 
Assess Plant and Environs Conditions During and Following an Accident."  The 
racks were manufactured by HUICO Incorporated of Pasco, Washington, and 
supplied as a unit by the General Electric Company during initial plant 


The only wiring performed by the licensee during initial plant construction 
was that from the field to the rack-mounted junction boxes.  During previous 
EQ walkdown inspections of plant equipment, the licensee inspected the 
junction boxes only to verify the existence of qualified wiring.  The licensee 
did not inspect the cable terminations in the DPISs because such an inspection 

.                                                                 IN 89-57
                                                                 July 26, 1989
                                                                 Page 2 of 2

have affected the EQ integrity of the DPISs and because only a short run of 
wire was involved.  It was assumed that the qualified wire in the junction 
boxes continued to the DPIS terminal strips, but unqualified splices were 
found instead.  These splices were not indicated on any plant drawings. 

The licensee performed a 100-percent walkdown inspection of all instrument 
racks and believes that the problem is confined to approximately seven racks.  
A review of maintenance records indicated that about four of the DPIS instru-
ments were replaced.  As this replacement only involved disconnection of leads 
at the terminal strip located inside the instrument, the unqualified splices 
remained undetected.  The results of the licensee's investigation indicate 
that the unqualified splices are restricted to the specific instrument racks  
manufactured by HUICO.  The investigation also indicates that the unqualified 
splices existed in the conduits when the racks were delivered to CNS.

No specific action or written response is required by this information notice.
If you have any questions about this matter, please contact the technical 
contact listed below or the Regional Administrator of the appropriate regional 

                              Charles E. Rossi, Director
                              Division of Operational Events Assessment
                              Office of Nuclear Reactor Regulation

Technical Contact:  Thomas F. Stetka, Region IV
                    (817) 860-8247

1.  Figure 1, "Typical Junction Box and Barton Switch Arrangement"
2.  List of Recently Issued NRC Information Notices  

.                                                            Attachment
                                                            IN 89-57 
                                                            July 26, 1989 
                                                            Page 1 of 1

                             LIST OF RECENTLY ISSUED
                             NRC INFORMATION NOTICES
Information                                  Date of 
Notice No._____Subject_______________________Issuance_______Issued to_________

89-56          Questionable Certification    7/20/89        All holders of OLs
               of Material Supplied to the                  or CPs for nuclear
               Defense Department by Nuclear                power reactors. 

89-45,         Metalclad, Low-Voltage        7/6/89         All holders of OLs
Supp. 1        Power Circuit Breakers                       or CPs for nuclear 
               Refurbished With Substandard                 power reactors. 

89-55          Degradation of Containment    6/30/89        All holders of OLs
               Isolation Capability by a                    or CPs for nuclear
               High-Energy Line Break                       power reactors. 

89-54          Potential Overpressurization  6/23/89        All holders of OLs
               of the Component Cooling                     or CPs for nuclear
               Water System                                 power reactors. 

89-53          Rupture of Extraction         6/13/89        All holders of OLs 
               Steam Line on High                           or CPs for nuclear 
               Pressure Turbine                             power reactors. 

88-46,         Licensee Report of            6/8/89         All holders of OLs
Supp. 3        Defective Refurbished                        or CPs for nuclear
               Circuit Breakers                             power reactors. 

89-52          Potential Fire Damper         6/8/89         All holders of OLs
               Operational Problems                         or CPs for nuclear
                                                            power reactors. 

89-51          Potential Loss of Required    5/31/89        All holders of OLs
               Shutdown Margin During                       or CPs for nuclear
               Refueling Operations                         power reactors. 

88-88,         Degradation of Westinghouse   5/31/89        All holders of OLs
Supp. 1        ARD Relays                                   or CPs for nuclear
                                                            power reactors. 

89-50          Inadequate Emergency          5/30/89        All holders of OLs
               Diesel Generator Fuel                        or CPs for nuclear
               Supply                                       power reactors. 
OL = Operating License
CP = Construction Permit 

Page Last Reviewed/Updated Friday, May 22, 2015