United States Nuclear Regulatory Commission - Protecting People and the Environment

ACCESSION #: 9503160195

ITT                                           ITT Barton
                                              ITT Fluid Technology
                                              Corporation

January 20, 1995


U.S. Nuclear Regulatory Commission
Washington, D.C. 20555

ATTN:      Director, Office of Nuclear Material and Safeguards

Subject:   Interim Report of Potential Defect

Reference: Interim Report dated December 19, 1994

ITT Barton, City of Industry CA, is a supplier of basic components to the
Nuclear Power Industry.  The specific components being reported are
Indicating Switches, Models 288A and 289A.  These Indicating Switches were
qualified for safety related applications per ITT Barton Engineering
Reports R3-288A-1, dated May 1990, and R3-288A-13, dated September 1986.

In reviewing seismic test data recorded last year for ITT Barton Model
288A and 289A Indicating Switches, ITT Barton determined that these
Products may demonstrate switch contact chatter not identified during
previous nuclear qualification efforts associated with these devices.

Seismic testing documented in R3-288A-1 and R3-288A-13 included five OBE's
and one SSE at 6 G's and 12 G's respectively.  ITT Barton has completed
testing at Wyle Laboratories in Norco, CA which has confirmed the
identified potential concerns regarding switch contact chatter at elevated
seismic loadings.

This interim report is being issued to present the results of this recent
testing in a timely manner.  The attachment presents the now known switch
performance characteristics for various seismic loadings which will allow
the instrument users to evaluate their specific installations for safety
implications.  A final will be made by February 15, 1995,

If there are any questions regarding this interim notification, please
contact Jerry Anderson at (818) 961-2547.


Charles L. Perry
General Manager

Attachment

             900 South Turnbull Canyon Road, P.O. Box 1882, 
                     City of Industry, CA 91749-1882


                          10CFR21 NOTIFICATION
                           (January 20, 1995)

ITT Barton is a supplier of basic components used in safety related
applications in Nuclear Power Plants.  ITT Barton has supplied Model 288A
and 289A Differential Pressure Indicating Switches to Nuclear Power Plants
with Certification to IEEE-323/344 Qualifications which indicate there is
no switch contact chatter during seismic loadings of up to 12 G's as long
as the monitored differential pressure is at least 10% of full scale away
from the switch setpoint when the seismic event occurs.  In recently
performed unrelated testing, potential concerns regarding contact chatter
were identified which resulted in performance of additional testing on
qualified configurations of these Products.

Switch contact chatter sensitivity testing has been performed on IEEE-323
& IEEE-344 qualified versions of ITT Barton Model 288A and 289A
Differential Pressure Indicating Switches at Wyle Laboratories in Norco,
California during the first week of 1995.  This testing has again verified
that these Products are capable of surviving earthquake loadings up to 12
G's with no degradation in structural or pressure boundary integrity and
no degradation in functionality with regard to pointer accuracy, switch
setpoint change and switch deadband.  However, this testing has also
verified the recently identified concern that the contacts in the high and
low switches may chatter when subjected to elevated seismic loadings.

The occurrence of chatter and the contact opening duration has been
determined to be dependent an the switch operating forces, the switch
setpoint with respect to the monitored process condition at the time of
the event, and the acceleration level of the earthquake.  Switch
performance characteristics in the form of contact chatter duration for
various G-level loadings are presented in the following table as a
function of the distance (% of full scale) of the monitored differential
pressure from the switch setpoint at the time of the seismic event
occurrence.  This data conservatively considers instrument configurations
and switches most sensitive to chatter.

               MODEL 288A & 289A SWITCH CHATTER DURATION'S

                G         SETPOINT / POINTER POSITION (% FS)
              LEVEL       10%       15%       20%       25%

                4         None      None      None      None
                6       





 
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