Part 21 Report - 1997-010
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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