Information Notice No. 86-65: Malfunctions of ITT Barton Model 580 Series Switches During Requalification Testing

                                                            SSINS No.: 6835 
                                                            IN 86-65       

                                UNITED STATES
                           WASHINGTON, D.C. 20555

                               August 14, 1986

Information Notice No. 86-65:   MALFUNCTIONS OF ITT BARTON MODEL 580 
                                   SERIES SWITCHES DURING REQUALIFICATION 


All nuclear power reactor facilities holding an operating license or a 
construction permit. 


This notice is provided to alert recipients to a potentially significant 
safety problem pertaining to malfunctions of ITT Barton Model 580 Series 
indicating switches under accident conditions. It is expected that 
recipients will review the information for applicability to their facilities 
and consider actions, if appropriate, to preclude malfunctions occurring at 
their facilities. However, suggestions contained in this notice do not 
constitute NRC requirements; therefore, no specific action or written 
response is required. 

Description of Problem: 

On April 14, 1986, NRC was notified by ITT Barton Instruments Company of the
defect in accordance with 10 CFR Part 21. According to the report, during 
requalification testing of ITT Barton Model 580 Series indicating switches 
under loss-of-coolant accident conditions, switch malfunctions occurred when
the chamber temperature was raised to 340F. The symptoms of the 
malfunctions were: 

     -    In three of the five instruments tested, one or both of the 
          switches failed to operate (no change in switch state) when input 
          pressure to the instrument was varied. 

     -    Switch set-point shift in excess of the allowable 10 percent 
          occurred on two of the instruments. 

When the chamber temperature was lowered to room ambient, all of the 
switches changed state when input pressure was varied; however, the switch 
setpoint shifts which occurred at temperature were permanent. 

The initial report indicated that the failure was due to a specific 
component used, a Honeywell Snap-Acting Switch, part number IISM 403. A 
subsequent report indicated that, as a result of additional testing, it was 
determined that there is also a deflection of the instrument case 
which affects the position of the snap switch and the setpoint. Furthermore, 
the deflection can result in failure of case seal integrity. 


                                                            IN 86-65 
                                                            August 14, 1986 
                                                            Page 2 of 2    

ITT Barton has indicated that they are evaluating case/seal redesigns and a 
realistic date for completion of retesting would be April 15, 1987. 

In previous tests, the instruments performed successfully when subjected to 
220F after aging, irradiation, and seismic testing. 

This information notice is being issued to ensure that all nuclear power 
plant end-users have been notified of this problem. 

A contact at ITT Barton Instruments Company knowledgeable of this problem 

          John P. Doyon
          Manager, Sales and Service
          (818) 961-2547 extension 456

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

                                   Edward L. Jordan Director 
                                   Division of Emergency Preparedness 
                                     and Engineering Response 
                                   Office of Inspection and Enforcement 

Technical Contact:  Eric Weiss, IE
                    (301) 492-9005

                    Pentti Koutaniemi, IE
                    (301) 492-9428

Attachments: List of Recently Issued IE Information Notices 

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