United States Nuclear Regulatory Commission - Protecting People and the Environment


ACCESSION #:  9701150043  



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                                        ITT Barton

ITT Industries                          900 S.  Turnbull Canyon Rd.

     AUTOMOTIVE                         P.O.  Box 1882

     DEFENSE & ELECTRONICS              City of Industry, CA 91749-1882

     FLUID TECHNOLOGY                   Tel: (818)961-2547

                                        Fax: (918) 333-7241

January 10, 1997



Westinghouse Energy Center

4350 Northern Pike

Monroeville, Penn.  15146-2886



Attention:     Mr.  Ray Kelchner 

               Manager Quality Assurance



Subject:       10CFR21 Notification on Model 753 Gage Pressure Electronic

               Transmitters.



Dear Mr.  Kelchner;



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.  The attached POTENTIAL

10 CFR PART 21 NOTIFICATION is ITT Barton's official notification that a

situation has been discovered that ITT Barton believes may represent a

substantial safety hazard in some of these instruments that we have

manufactured.



ITT Barton sells the Model 753 through Westinghouse, however, the

utilities identified as being involved in our failure analysis efforts

are being notified directly regarding this concern.  Those utilities are;



     South Carolina Electric & Gas (V.C.  Summer Nuclear Plant)

     Duquesne Light (Beaver Valley Nuclear Plant)

     Pacific Gas & Electric (Diablo Canyon Nuclear Plant)



Regarding any additional information and status of this notification,

please do not hesitate to contact the undersigned.



Regards;





Ted Holdredge 

Quality Manager 

ITT Industries 

ITT Barton

phone: (818) 961-2547 

fax    (818) 937-0418

(doc.  NRC2)



   Check us out on Industry Net at http://www.industry.net/itt.barton





cc:



U.S.  Nuclear Regulatory Commission

South Carolina Electric & Gas, (V,C, /Summer Nuclear Plant)

Duquesne Light, (Beaver Valley Nuclear Plant)

Pacific Gas & Electric, (Diablo Canyon Nuclear Plant)



D.  Evarts, General Manager, ITT Barton

R.  Krechmery, Director of Engineering, ITT Barton

A.  Lussier, Director of Operations, ITT Barton

M.  Larson, ITT Barton Nuclear & Government Product Engineering

J.  Incontri, ITT Barton, Director of Marketing

S.  Noji, ITT Barton Consumer Affairs





POTENTIAL 10 CFR PART 21 NOTIFICATION

(January 10, 1997)



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 we 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.



There was an incident involving sulfur induced corrosion of strain gage

lead wires circa 1983 where a number of Model 753 transmitters were

returned from the Diablo Canyon Nuclear Plant.  Because the source of the

sulfur contamination could not be uncovered and because only Diablo

Canyon reported the incident, it was believed to be an out of factory

related situation.



In 1994, two Model 753 transmitters were returned from the V.  C.  Summer

Nuclear Plant for failure analysis because of excessive drift concerns. 

These units had been repaired previously and had failed again after only

about nine months where the units had been in storage.  This failure

analysis, much like the 1983 investigation, identified the failure to be

caused by sulfur induced corrosion and could not uncover the source of

the sulfur contamination.  The units were repaired and returned to the

customer where, after some storage time, The units failed again (third

time) for the same reason.



In 1996, another Model 753 transmitter was returned from the Beaver

Valley Nuclear Plant for excessive drift concerns.  This instrument was

found to have suffered a failure as a result of sulfur induced corrosion

of the beryllium copper link clip between the bourdon tube and the strain

gage beam.  When two more Model 753 transmitters were returned by a non-

power customer after less than one year of out of factory life for drift

concerns, which were identified to be caused by sulfur induced corrosion

of the strain gage lead wires, ITT Barton initiated another investigation

into the problem in order to ascertain the source of the sulfur causing

the corrosion in the Model 753 transmitters.



A test was devised to expose copper and copper alloy items to components

removed from the transmitters actually subject to the corrosion concerns

in an accelerated corrosion environment.  This test demonstrated that the

corrosion could be recreated.  This testing 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 the

gaskets of concern, substitution of a gasket made from a more stable

material, assembly procedure upgrades, operator training, and cleaning of

all existing fink adjust assemblies.



                               Page 1 of 3





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 at least days for 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.



ITT Barton recommends that the transducer housing gasket be replaced in

all Model 7533 transmitters at the first convergent opportunity with the

new gasket (ITT Barton P/N 0590-1244C).  ITT Barton also recommends that

lead wire attachment to the top of the strain gage beam, the link clip

and the grip ring at the bourdon tube bearing be inspected for evidence

of sulfur induced corrosion when the gasket is replaced.  All instruments

showing any visual evidence of the sulfur induced corrosion should be

returned to the factory for repair (strain gage assembly replacement

required which invalidates the existing temperature compensation).  The

sulfur induced corrosion of copper and copper alloy components appears as

a heavy/fuzzy black substance on exposed surfaces (not under the wire

insulation and not a thin coating/darkening of the material which is

normal).  The strain gage lead wires corrode at the short portion of the

exposed copper conductors where they leave the solder pool on the strain

gage beam just before the wire insulation resumes.  This location is

embedded in a clear silicone material which can be inspected using

magnification (8X minimum recommended along with good lighting).



It is the opinion of ITT Barton that only instruments manufactured or

subjected to repair activities involving replacement of the housing

gasket since 1992 are highly suspect of this sulfur induced corrosion

concern.  Furthermore, it is the opinion of ITT Barton that the

instrument can be considered free of the concern following replacement of

the gasket and performance of the visual inspection without finding

evidence of the corrosion.  ITT Barton formed these opinions based on the

following facts:



     o    There has been no reported sulfur induced corrosion concerns

          since 19833 until units built in 1992 have shown evidence of

          the problem.



     o    Significant instrument performance degradation generally occurs

          within a short period of time (less than one year).



     o    Corrosion of the strain gage lead wires is not limited to a

          single wire.  All four conductors showed evidence of the

          corrosion product buildup in all the failures inspected.



If you have any questions please contact Theodore Holdredge, Quality

Assurance Manager, at (818) 961-2547 Ext. 363.



                               Page 2 of 3





Figure "Model 753 Transducer Assembly" omitted.





GENERAL INFORMATION or OTHER            EVENT NUMBER: 31570



LICENSEE: ITT INDUSTRIES                NOTIFICATION DATE:  01/10/97

    CITY: CITY OF INDUSTR     REGION: 4 NOTIFICATION TIME:  16:07 [ET]

  COUNTY:                     STATE: CA EVENT DATE:         01/10/97

LICENSE#: AGREEMENT:      AGREEMENT: Y  EVENT TIME:         16:07[PST]

  DOCKET:                               LAST UPDATE DATE:   01/10/97



                                             NOTIFICATIONS



                                        VERN HODGE          RDO



NRC NOTIFIED BY: TED HOLDREDGE

HQ OPS OFFICER: JOHN MacKINNON



EMERGENCY CLASS: NOT APPLICABLE

10 CFR SECTION:

CDEG 21.21(c)(3)(i)      DEFECTS/NONCOMPLIANCE



                               EVENT TEXT



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

BOS 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



                        (Continued on next page)





LICENSEE: ITT INDUSTRIES                  PAGE 3 2 OF EVENT NUMBER; 31570



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 AT LEAST DAYS FOR STEADY STATE CONDITIONS).  TH 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 IN 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).





*** END OF DOCUMENT ***



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