Information Notice No. 89-14:Inadequate Dedication Process for Commercial-Grade Components which could lead to Common Mode Failure of a Safety System

                                  UNITED STATES
                          NUCLEAR REGULATORY COMMISSION
                             WASHINGTON, D.C  20555

                                February 16, 1989

                                   GRADE COMPONENTS WHICH COULD LEAD TO COMMON
                                   MODE FAILURE OF A SAFETY SYSTEM


All holders of operating licenses or construction permits for nuclear power 


This information notice is being provided to alert addressees to potential 
problems resulting from an error made by a vendor in supplying a commercial-
grade component of the wrong size and an inadequate dedication process by the 
licensee.  It is expected that recipients will review the information for ap-
plicability 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 July 7, 1988, during surveillance testing of the auxiliary feedwater pumps 
at the Rancho Seco station, the outboard packing on the dual-drive auxiliary 
feedwater pump overheated.  The packing was replaced four times during the fol-
lowing month because it overheated during surveillance or post-maintenance 
testing.  The licensee then installed a packing supplied by a different vendor 
which was satisfactorily tested on August 14, 1988.


A review of these events by the licensee showed that the last four sets of 
packing supplied by the vendor were dimensionally incorrect and were installed 
in the pump without any verification of the actual dimensions.  This type of
problem has particularly significant safety implications because of the poten-
tial to cause a common mode failure of a safety system.  The packing was 
procured as commercial grade and upgraded for safety-related application by a 
review of the packing's critical characteristics.  Size was one of the 
critical character-istics.  However, the vendor considered the inside and 
outside diameters to be proprietary information, and this restriction 
contributed to the licensee's failure to perform an independent verification 
of the dimensions.  The licensee verified the size by looking at the invoice 
for the packing and at the vendor's technical information.  The vendor's error 
could not be detected by this level 

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                                                            Page 2 of 2

of verification.  The documentation matched the purchase order; however, the 
replacement packing was of the wrong size.  In one of the four failures 
reported, inadequate maintenance testing failed to uncover the vendor's error.  
The packing did not overheat because the pump was not operated long enough.  
The packing over-heated during subsequent operation of the pump. 

Calculations by the licensee showed that in the event of a complete packing 
failure, the pump still would have fulfilled its safety function.  However, 
the use of inadequately dedicated commercial-grade parts in nuclear facilities
significantly increases the probability that safety-related systems may not 
perform their intended function.

The licensee intends to take additional precautions to accurately verify 
critical characteristics of components before dedication.  For instance, 
the dimensions of the packing will now be measured directly and compared 
to the shaft size.  The licensee is also planning to increase the running 
time for post-maintenance testing. 

This event shows the importance in the dedication process to upgrade 
components from commercial grade to safety-related applications of licensees 
independently verifying the vendor's documentation.  The event also 
demonstrates the necessity of adequate post-maintenance equipment testing. 

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:  Daniele Oudinot, NRR
                    (301) 492-1174

Attachment:  List of Recently Issued NRC Information Notices

                                                            IN 89-14
                                                            February 16, 1989
                                                            Page 1 of 1

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

89-13          Alternative Waste Management  2/8/89         All holders of NRC
               Procedures in Case of Denial                 specific licenses.
               of Access to Low-Level Waste
               Disposal Sites

89-12          Dose Calibrator Quality       2/9/89         All NRC medical
               Control                                      licensees.

89-11          Failure of DC Motor-Operated  2/2/89         All holders of OLs
               Valves to Develop Rated                      or CPs for nuclear
               Torque Because of Improper                   power reactors.
               Cable Sizing

89-10          Undetected Installation       1/27/89        All holders of OLs
               Errors In Main Steam Line                    or CPs for BWRs.
               Pipe Tunnel Differential
               Temperature-Sensing Elements
               at Boiling Water Reactors.

89-09          Credit for Control Rods       1/26/89        All holders of OLs
               Without Scram Capability                     or CPs for test and
               in the Calculation of the                    research reactors.
               Shutdown Margin

89-08          Pump Damage Caused by         1/26/89        All holders of OLs
               Low-Flow Operation                           or CPs for nuclear
                                                            power reactors.

89-07          Failures of Small-Diameter    1/25/89        All holders of OLs
               Tubing in Control Air, Fuel                  or CPs for nuclear
               Oil, and Lube Oil Systems                    power reactors.
               Which Render Emergency Diesel
               Generators Inoperable

89-06          Bent Anchor Bolts in          1/24/89        All holders of OLs
               Boiling Water Reactor                        or CPs for BWRs 
               Torus Supports                               with Mark I steel 
                                                            torus shells. 
OL = Operating License
CP = Construction Permit 

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