United States Nuclear Regulatory Commission - Protecting People and the Environment


LICENSEE: ITT INDUSTRIES                     

SITE: ITT INDUSTRIES                        EN NUMBER:31570

DOCKET:                                  EVENT DATE: 01-10-97

RX TYPE:                                 EVENT TIME: 16:07

VENDORS:                                NOTIFY DATE: 01-10-97

EMERGENCY CLASS: N/A  REGION: 4 STATE: CA      TIME: 16:07

OPS OFFICER: JOHN MacKINNON           

10 CFR SECTION: CDEG  21.21(c)(3)(i)      DEFECTS/NONCOMPLIANCE



A SITUATION HAS BEEN DISCOVERED (IN THE BARTON MODEL 753 GAGE    

PRESSURE ELECTRONIC TRANSMITTERS) THAT ITT BARTON BELIEVES MAY   

REPRESENT A SUBSTANTIAL HAZARD IN SOME OF THESE INSTRUMENTS THAT 

ITT HAS MANUFACTURED. THIS HAZARD IS SULFUR INDUCED CORROSION OF 

THE #40 AWG COPPER STRAIN GAGE LEAD WIRES AND THE BERYLLIUM      

COPPER LINK CLIP.                                                

                                                                 

ITT INDUSTRIES (ITT BARTON) LOCATED AT 900 S. TURNBULL CANYON    

RD., P.O BOX 1882, CITY OF INDUSTRY, CA. NOTIFIED WESTINGHOUSE   

ENERGY CENTER LOCATED AT 4350 NORTHERN PIKE, MONROVILLE, PA. OF  

THIS POTENTIAL 10 CFR PART 21 NOTIFICATION ON 01/10/97.          

                                                                 

ITT BARTON SUPPLIES MODEL 753 GAGE PRESSURE ELECTRONIC           

TRANSMITTERS TO THE COMMERCIAL NUCLEAR POWER INDUSTRY FOR USE IN 

SAFETY RELATED APPLICATIONS THROUGH WESTINGHOUSE NUCLEAR ENERGY. 

A SITUATION HAS BEEN DISCOVERED THAT ITT BARTON BELIEVES MAY     

REPRESENT A SUBSTANTIAL SAFETY HAZARD IN SOME OF THESE           

INSTRUMENTS THAT THEY HAVE MANUFACTURED. THIS SITUATION INVOLVES 

SULFUR INDUCED CORROSION OF THE #40 AWG COPPER STRAIN GAGE LEAD  

WIRES AND THE BERYLLIUM COPPER LINK CLIP. UNTIL RECENTLY, ITT    

BARTON WAS NOT ABLE TO ASCERTAIN THE SOURCE OF THE SULFUR        

CONTAMINATION AND BELIEVED THAT THE LIMITED OCCURRENCES OF THIS  

PROBLEM ORIGINATED OUTSIDE THE FACTORY.                          

ITT BARTON UNCOVERED THAT THE CORK GASKET USED WITH THE BOURDON  

TUBE TRANSDUCER HOUSING CAUSED CORROSION OF COPPER AND COPPER    

ALLOY PARTS. IN ADDITION, INTERVIEWS WITH INSTRUMENT ASSEMBLY    

PERSONNEL UNCOVERED A SITUATION WHICH INDICATED THAT SOME LINK   

ADJUST  ASSEMBLIES USED IN THE MODEL 753 TRANSMITTER MAY HAVE    

BEEN CONTAMINATED WITH DOW CORNING MOLYKOTE (MOLYBDENUM          

DISULFIDE). CORRECTIVE ACTIONS IMPLEMENTED IN THE FACTORY        

INCLUDED REMOVAL OF ALL GASKETS OF CONCERN, SUBSTITUTION OF A    

GASKET MADE FROM A MORE STABLE MATERIAL, ASSEMBLY PROCEDURE      

UPGRADES, OPERATOR TRAINING, AND CLEANING OF ALL EXISTING LINK   

ADJUST ASSEMBLIES.                                               

THE EXISTENCE OF THE SULFUR INDUCED CORROSION CAN BE SEEN IN AN  

OPERATING INSTRUMENT IN THE FORM OF ABNORMAL DRIFT(i.e., DRIFT IN

EXCESS OF NORMALLY EXPERIENCED DRIFT FOR THE PARTICULAR UNIT     

MONITORED OVER A PERIOD OF DAYS AT STEADY STATE CONDITIONS). THE 

DIRECTION OF THE STRAIN GAGE LEAD WIRE CORROSION DRIFT CAN BE    

HIGH OR LOW DEPENDING ON THE CORROSION RATE APPLICABLE TO THE    

COMPRESSION OR TENSION STRAIN GAGE LEADS. LINK CLIP DRIFT        

DIRECTION IS ALWAYS NEGATIVE. THE ELECTRICAL LEAD CORROSION DRIFT

IS CAUSED BY THE INCREASE IN RESISTANCE OF THE CIRCUIT AS THE    

CORROSION REDUCES THE DIAMETER OF THE LEAD WIRES WHILE THE LINK  

CLIP CORROSION DRIFT IS CAUSED BY MATERIAL STRETCHING AS THE LINK

CLIP THICKNESS IS REDUCED. THERE IS NO DIFFERENCE BETWEEN A      

SAFETY RELATED AND A NON SAFETY RELATED MODEL 753 WITH RESPECT TO

THIS CORROSION CONCERN. THIS CONCERN IS LIMITED TO THE MODEL 753 

TRANSMITTER BECAUSE OF THE USAGE OF THE SULFUR CONTAMINATED      

COMPONENTS.                                                      

                                                                 

NUCLEAR POWER PLANTS OF CONCERN ARE: 1) SOUTH CAROLINA ELECTRIC &

GAS (V.C. SUMMER ), 2) DUQUESNE LIGHT (BEAVER VALLEY), AND       

PACIFIC GAS & ELECTRIC (DIABLO CANYON).                          



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