ML18040A330
| ML18040A330 | |
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| Site: | Nine Mile Point  |
| Issue date: | 02/28/1998 |
| From: | SMITH R E, WILLIAMS D S ALTRAN CORP. |
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| ML17059B904 | List: |
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| 97181-TR-03, 97181-TR-03-R00, 97181-TR-3, 97181-TR-3-R, NUDOCS 9803090216 | |
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EPRTestingofBoatSamplesfromCoreShroudVerticalWeldsV-9andV-10atNMP-1TechnicalReportNo.971S1-TR-03Revision0Volume1of1preparedfor:NiagaraMohawkPowerCorporationNineMilePointUnit1February199898030902ib980227IIPDRADQCK05000220PPDRI I
DocumentNo.:NuclearSafetyRelatedYesReportRecordRev.No.:0SheetNo.:~No~TotalNo.ofSheets~4TITLE:andV-aetinofotamlefrom.orehroudVerticalWeld.V-P-1CLIENT:NiaarhawkFACILITY:NMP-nt1REV.DESCRIPTION:Revisin-riinalIeCOMPUTERRUNS(identifiedonComputerFileIndex):Errorreportsevaluatedby:Impactedbyerrorreports:Date:NoYes(ifyes,attachexplanation)Oriinatr(s}R.E.SmithDateChecker(s).a/~/jp2/20/9SDateDESIGNVERIFICATION:(EOP3.4)"JustificationNon"A"Performedby:Methodofdesignverification:RequiredDate:NotRequired"DesignReviewAlternateCalculations(Attached)QualificationTest(Data/ResultsAttd.iCommentsresolvedby:Designverifierconcurrence:Date:Date:APPROVEDFORRELEASEPROJECTMANAGER:Date:e~~~gR.E.SmithENGINEERINGMANAGER:~~Date:D.S.Williams I
I AltranCorporationTechnicalReportTR97181-TR-03Revision0EPRTestingofBoatSamplesfromCoreShroudVerticalWeldsV-9andV-10atNMP-11.IntrodnctiontoEPRTestingAmethodofmeasuringthesusceptibilityofamaterialtointergranularstresscorrosioncracking(IGSCC)wasproposedinthemid-1970sandisknownasElectrochemicalPotentiokineticReactivation(EPR)testing.Themethodusesthepotentiodynamicreactivationresponseofelectrochemicallypassivatedstainlesssteelandmeasurestheelectrochemicalactivityofgrainboundaries.Thesusceptibilityofausteniticstainlesssteels,andotherausteniticmaterials'ncludingnickel-basedmaterials,isproducedbytheprecipitationofchromiumcarbidesatthegrainboundariesofthesematerials.Theprecipitationofchromium-richcarbidesatthegrainboundariesdepletesthechromiumcontentofthematrixmaterialimmediatelyadjacenttotheprecipitates.Thisphenomenonisknownasgrainboundarysensitization.SensitizationrendersthematerialsusceptibletoIGSCCinasupportingenvironment.Theelectrochemicalresponseattheselocationswillincreaseasthedegreeofsensitizationincreases.Thereactivationtechniquewasdevelopedasa'quantitativemeasureofthedegreeofsensitizationintypes304and304Lstainlesspiping.Itwasinitiallydevelopedtoscreenstainlesssteelrecirculationpipingandweldingprocessesusedinboilingwaterreactor(BWR)powerplants.TheEPRtechniqueusesseveraltestingmethodsinordertominimizethescatterinresultsduetotestingvariablessuchassurfaceroughnessandgrainsize.Thesemethodsincludethesingle-scantechnique,thedouble-looptechnique,andafieldversionofthedouble-looptechnique.Thefirsttwotechniquesaremethodssuitedtolaboratorysettings,andthefielddouble-loopmethodwasdesignedfordirectcomponentapplications.AllmethodsconsistoffirstestablishingthecorrosionpotentialE~ofthespecimeninthetestsolution0.50molarH,SO4+0.01molarKSCN.Thespecimensurfaceispreparedbypolishingthesurfacetoa1micronfinishusingdiamondpaste.Thetestsurfaceispolarizedatapotentialof+200mv[saturatedcalomelelectrode(SCE)]foraperiodof2minutes.Afterpolarizationisestablished,thepotentialisdecreasedtoitsopencircuitvalue,E~ataconstantrateof6V/hr(1.67mV/sec).Thisreactivationleadstothepreferentialbreakdownofthepassivefilmonthesensitizedmaterialwherethereischromiumdepletion.Asaresultalargeloopisgeneratedinthecurveofthepotentialversuscurrent.Theareaunderthisloopisproportionaltotheelectriccharge,Q,whereQdependsonthesurfaceareaandthegrainsize.Onnonsensitizedmaterialthepassivefilmremainsessentiallyintact,andthesizeoftheloop,andtherefore,Q,aresmall.Thechargeoftenisnormalized(adjusted)tothetotalgrainboundaryarea.Thisproducesaquantitativemeasureofthedegreeofsensitization.Theadjustedchargeisthendividedbythetestsurfaceareaandisexpressedintermsofchargeperunitarea.Page3 IIIIIII AltranCorporationTechnicalReportTR97181-TR-03Revision0Thedouble-looptechniquesareconductedinasimilarfashion,excepttheanodicscanisfollowedbyacathodic(reverse)scan.Theratioofthemaximumcurrentattainedinthereversescandividedbythemaximumcurrentattainedintheanodicscanisusedasameasureofthedegreeofsensitization.Thismethodisreportedtoworkwithroughersurfacesproducedusing100gritsiliconcarbidepolishingpapers(140micron).Typicallyfinerpapersareusedsuchas600grit.TechnicalworkersatIshikawajimaHeavyIndustries(IHI)establishedthismethodasapreferredtestmethodinJapan.IthasbeensuggestedthattheratioIR/IAshouldberelativelyinsensitivetotestvariablesgrainsizeandsurfaceroughness(seeAppendix3).Thegrainsizeinfluencesthesurfaceareaofthematerialactivatedinthetest.Theelectrochemicalresponseshouldbesimilarforbothanodicandreversescans.Anincreaseddegreeofsurfaceroughnessincreasesthesurfaceareabeingtested.However,theincreasedareashouldproduceasimilarelectrochemicalresultregardlessofwhichdirectionisscanned.Sincethemethodratiosthetwomaximumcurrents,thereshouldbenoneteffectfromeithervariablegrainsizesordifferingdegreesofsurfaceroughnessassumingsimilarresponsesfrombothscanningdirections.MajidiandStreicherreportedthatthegrainsizeresponseisdependentuponscanningdirection,andthereforeagrainboundarycorrectionisrequiredtoachieveself-consistentresults(Reference1).2.BoatSampleDescriptionsThedegreeofsensitizationofamaterialinfluencesIGSCC,andisoneinputparameterusedtopredictcrackgrowthratesusingtheGeneralElectricPLEDGEcode(Reference9).AquantitativemeasurementofthedegreeofsensitizationassociatedwiththecoreshroudverticalweldswasneededtoconfirmthematerialconditionsthathadbeenassumedtoestimatecrackgrowthratesusingthePLEDGEmodel.ThesepredictedcrackgrowthrateswereusedtoestimatetheprogressionofidentifiedcracksintheV-9andV-10verticalcoreshroudweldsatNMP-1forthedurationbetweenrestartandthenextplannedoutage.CrackdispositionhasbeendetailedinthecrackevaluationandthesafetyanalysisreportssubmittedtotheNuclearRegulatoryCommission(References4and5).Thesereportsassumedamoderatelysensitizedmaterialcondition.AusteniticstainlesssteelmaterialthatismoderatelysensitizedshouldyieldEPRtestresultsbetween2and15coulombs/cminthesinglelooptest.EPRtestingwasundertakentoconfirmtheseassumptions.TwoboatsampleswereremovedfromtheNMP-1coreshroudtovalidatethecrackedconditionsidentifiedbyinspection,andtodeterminethenatureandpotentialcausesofcracking.Thesesamplesweretakenfromthematerialadjacenttotheverticalseamsformingthecoreshroudmid-cylinder.WeldV-10andweldV-9identifytheverticalweldsthatjointworoll-formedtype304austeniticstainlesssteelplates,li/~inchesthick.Thefirstsample,identifiedasV-10,wasremovedfromtheheat-affectedzoneofweldV-10ontheoutsideoftheshroud.SampleV-i0wasremovedfromtherightsideofweldV-i0ataverticalpositionapproximately57.5inchesbelowtheupperhorizontalweldjoiningthismid-cylindertotheuppercylinder.ThehorizontalweldwasidentifiedasH-4.SampleV-10containedaportionofthecrackidentifiedwithverticalweldV-10.Page4
AltranCorporationTechnicalReportTR97181-TR-03Revision0SampleV-9wasremovedfromtheheataffectedzoneofWeldV-9ontheinsidesurface.Thesamplinglocationwasapproximately25inchesbelowhorizontalweldH-4.Thissamplecontainednocrack.TheV-9samplematerialhadbeenexposedtoagreaterneutronfluencethantheV-10samplematerial.Fluenceisavariableknowntoinfluencethedegreeofsensitizationasthefluencelevelincreases.Noevidenceofirradiationassistedstresscorrosion(IASCC)wasidentifiedineitheroftheboatsamples(Reference3).However,itwasimportanttoexplorethepossibilitythatthedegreeofsensitizationmayhavebeenenhancedandtheresultingcrack'rowthrateincreased.Thefluenceofbothboatsampleswasmeasured(References2and10).Themid-wallfluenceofboatsampleV-10measured1.54x10'/cm,andthesurfacefluenceofboatsampleV-9(fluenceatinnersurfaceofcoreshroud)measured3.088x10"n/cm'.3.DOSEvalnationbasedonOpticalMetallographyTheopticalmicrostructureswerecarefullyexaminedforbothsamples.TheseevaluationsindicatedthatthedegreeofsensitizationinsampleV-10wasslightlygreaterthanthedegreeofsensitizationinsampleV-9.Theweldheataffectedzone(HAZ)microstructureinsampleV-10wasclearlydelineated;however,theHAZforweldV-9waslessdefined,althoughevidenceofgrainboundarycarbideprecipitationwasapparentinbothsamples.Bothmicrostructureswerejudgedmoderatelysensitized.ThesequalitativeestimatesareconsistentwiththemoderatesensitizationassumptionsusedinthePLEDGEmodeltoestimatecrackgrowthrates.Noevidenceofneutroninducedsensitizationcouldbedeterminedfromtheopticalmetallography.Thereforeaquantitativetestwasneededtoprovideanindicationofthedegreeofsensitization.EPRtestingwasperformedonarepresentativecross-sectionprepared&omeachboatsample.4.EPRTestResnltsandDiscussionThelaboratoryfacilitiesatMcDermottTechnologieswerenotequippedtoperformthelaboratoryEPRtestingtechniques,becausetheradiationlevelsofthesampleswerehigh.Therefore,thedouble-loopfieldprocedurewasselectedandequipmentobtainedtoperformthetest.Itwasrecognizedthatacorrelationofthedouble-loopfieldtestresultswithresultsfromsinglescantestswouldbeneededtoprovidedirectcomparisonswithDOSparametersassumedinthePLEDGEmodelingofthesecrackgrowthrates.TheIHIFieldDOSTesterequipmentwasselected(Appendix3)andsetupintheradiationcontrolledexaminationfacilityattheMcDermottTechnologies(MDT)laboratory.TheIHIequipmentwasfurnishedwithType304stainlesssteelstandardsthatrepresentedbothalowdegreeofsensitization(SampleS,engraved0.008)andahighdegreeofsensitization(SampleF,engraved0.434).Thetestequipmentwasappliedtothestandardstovalidatethecalibration.Valuesaveraging0.007Ii,/Iwereobtainedfor,SampleS,andvaluesaveraging0.373Ii,/IwereobtainedforSampleF(Reference7).Thesevalueswereconsideredacceptableandthemethodswerevalidated.Thedouble-looptestingmethoddoesnotprovidedirectoutputofchargeperunitsurfacearea.Therefore,thesamestandardspecimensweretransportedtoGECorporateR2Dforcomparativetestingwithlaboratorydevicescapableofboththesingleloopandthedouble-loopPage5 III AltranCorporationTechnicalReportTR97181-TR-03Revision0procedures.Theseresultsproducedamethodwithwhichtocalibratethedouble-loopfieldresultstothesingleloopresults.Thereforecharge/unitareacouldbeestablishedtointerpretthedouble-loopfieldresultsmeasuredontheradioactivesamples(Reference8).Double-looptestresultsatMTIusingtheIHITypeS-61DOStestingequipmentarereportedinAppendix1(Reference7)forfieldtestStandardsFandS,asamplehavingamediansensitizationlevel(Type316L),andboatsamplesV-9andV-10.MeasurementsforboatsampleV-9rangedfrom0.06to0.09I~/I,andmeasurementsforV-10rangedfrom0.042to0.169Ii,/I.References7and8areincludedintheirentiretyasAppendices1and2respectively.Appendix1(Reference7)reportsthedouble-loopfieldtestingresults.Itshouldbenotedthatseveralindividualtestresultswerediscountedforthefollowingreasons.TheresultofRun¹1forthestandardlabeled"S"hasbeeneliminatedfromtheaveragingstepforresultsonthisspecimen.Thereasonisthatthisvalueisoutoflinewiththeotherfourmeasurementsonthisspecimen.Thereasonforthehighnumberisnotknown.Runs¹4and¹5weremadetoverifythattheresultofRun¹1wasanomalousforanunknownreason.ThenexttestingwasperformedonboatsamplesV-9andV-10.TwotestresultsofSpecimenV-9havebeendiscountedasfollows.ThetestsurfaceareaofRun¹4includedbothwelddepositandheataffectedzonematerial.Theelectrochemicalresponseofwelddepositisdifferentfromwroughtbasematerialandthecombinedresponsewillnotrepresenteithermaterial.Thereforethisresultwasdiscounted.ThetestresultofRun¹1wasdiscountedbecausethetestareapreparationwasincorrect.Run¹1ofsampleV-10wasdiscountedbecausethevaluewastwiceashighastheother4tests.Thereasonwasunknown,butthetestresultwasclearlyanomaloustoallfouroftheothertestsonthissample.ItshouldbenotedthatmaterialusedtoobtainacalibrationtestresulthavingalevelofsensitizationmidwaybetweenthetwostandardswasType316Lmaterial.Theresultsproducedinthedouble-loopexperiments,bothwiththelaboratoryset-upandthefieldset-up,wereinconsistentwiththetestresultsonType304material.SincetheType316materialcontainsmolybdenum,thesurfaceoxideswouldhavecontainedmolybdenum.Theelectrochemicalresponsefromthissurfacehasbeenreported,butwasinappropriateforuseasacalibrationforType304.TheDOSTestermanual(Appendix3)cautionsregardingresultsobtainedfromdifferentmaterialssuchasType316becauseoftheincorporationofmolybdenuminthesurfaceoxidelayer.Allothervalueswereusedintheevaluation.ThecalibrationresultsareshowninFigure1,andtherangesofboatsampleresultsaresuperimposedonthisplot.ThisplothasbeentakendirectlyfromAppendix2(Reference8).ThedataindicatethatboatsampleV-9hasameasuredEPRrangefrom2to5coulombs/cm',andboatsampleV-10hasameasuredEPRrangeof6to15coulombs/cm.TheseresultsareconsistentwiththeopticalmetallographicevaluationthatsuggestedaslightlygreatersensitizationinsampleV-10thaninsampleV-9,althoughbothexhibitedamoderatedegreeofsensitization.Page6 III AllanCorporationTecfaticalReportTR97181-TR-03Revision0TheslightdifferencesinDOSbetweenthetwoplatesofmaterialprovidearationaleforthegreaterdegreeofcrackingseenwiththeV-10weld.TheslightlyhigherdegreeofsensitizationmeasuredintheV-10sample(comparedtoV-9)suggestsamaterialconditionslightlymorefavorabletocrackinitiationthanthematerialintheV-9sample.ItshouldbenotedthatthelevelofsensitizationineithersampleissufficienttosupportIGSCC.OncethecrackingformedontheV-10sideoftheverticalweld,thestressontheothersideoftheweldisgreatlyreduced.ThematerialontheothersideoftheweldisthesameplatematerialfromwhichtheV-9samplewasremoved.OpticalmetallographicevaluationsandtheEPRtestresultsbothconfirmthepotentialforcrackingineitherplateofmaterial.TheresultsalsoconfirmtheappropriatenessoftheEPRassumptionforthedegreeofsensitizationusedtopredictcrackgrowthrateswiththePLEDGEmodelingalgorithms.ThecrackgrowthratespredictedusingthesameDOSparametersrateswereappliedinthecrackgrowthanalysisusedtodispositioncrackingobservations(References4,5and9).t5.ConclnsionsResultsofEPRtestinghavebeensuccessfullycompletedonthecross-sectionalsurfacesofsamplespreparedfromNMP-1coreshroudboatsamplesV-9andV-10.Theseresultsindicatethatbothplatesofmaterialusedtoconstructthemid-cylinderofthecoreshroudareinamaterialconditionthatwillsupportIGSCC.ItisfurtherseenthatthematerialintheV-10sample(crackedsample)isslightlymoresensitizedthanisthematerialintheV-9sample(uncracked).ThismayindicatethatcrackinginitiatedfirstintheV-10materialproducingacrackthatrelievedthehoopstressesacrosstheweld.ThiswouldreduceoneoftheessentialparametersrequiredtoinitiatecrackingintheV-9material.ThisactionreducedtheprobabilityforcrackingtheV-9material.Finally,themeasuredvaluesofEPRareconsistentwithandsupporttheassumptionsusedtoestimatecrackgrowthratesforcrackdisposition.Page7 IIII AitranCorporationTechnicalReportTR971Sl-TR-03Revision0Figure1:SLEPRValuesBasedonDLEPRCalibrationatGECR&DandMcDermottLabs(CharttakendirectlyfromReferenceS)SLEPRvs.DLEPR0.1RangoofSLEPRforV10WoldRangoofSLEPRforVSWold0.01fL'LUJ0-DLEPR:GECRaD-DLEPR:IHl/BOW0.0010.00010.0010.010.11SLEPR(Clcm2)106.References1.AzarMajidiandMichaelStreicher,"TheDouble-loopReactivationMethodforDetectingSensitizationinAISI304StainlessSteels",Corrosion,Volume40,No.11,November1984.2.KevinHour,"NiagaraMohawk'sNineMilePointUnit1BoatSampleAnalyses-PartII:Dosimetery",McDermottTechnology,Inc.,RDD:98:55863-003-000:01,September1997.3.KevinHour,"NiagaraMohawk'sNineMilePointUnit1BoatSampleAnalyses-PartI:Metallography",McDermottTechnology,Inc.,RDD:98:55863-002-000:01,September1997.4.GeneralElectricNuclearEnergy(GENE),"AssessmentoftheVerticalWeldCrackingontheNMP1Shroud".GENE-523-B13-01869-043.5.NRCSafetyEvaluationReportdatedMay8,1997,regardingtheresultsofthereinspectionofthecoreshroudforNineMilePoint1.Page8 IIIII AllanCorporationTechnicalReportTR97ISI-TR-03Revision06.RichardE.Smith,"NineMilePointUnit1CoreShroudCrackingEvaluation",AltranCorporationletterreportRomRichardE.SmithtoGeorgeInchdatedApril3,1997.7.KevinHour,"DegreeofSensitizationEPRTestingResultsfortheNineMilePointUnit1BoatSamples.",letterreportfromKevinHourtoBrianHall(FramatomeTechnology,Inc.),January14,1998.8.R.M.Horn,"InterpretationofEPRMeasurementsonNMP1BoatSamples",letterreportfromR.M.Horn(GeneralElectricCompany)toG.B.Inch(NiagaraMohawkCompany),February6,1998.9.R.M.Horn,"AssessmentofCrackGrowthRatesApplicabletoNineMilePoint-1VerticalWeldIndications",GE-NE-B13-01869-113,Rev.0.10.FramatomeAnalysisReport:86-1266298-00,"FluenceAnalysisReportforBoatSamples-NineMilePt.1",January28,1998.7.Appendices1."DegreeofSensitizationEPRTestingResultsfortheNineMilePointUnit1BoatSamples",letterreportfromKevinHourtoBrianHall(FramatomeTechnology,Inc,January14,1998.2."InterpretationofEPRMeasurementsonNMP1BoatSamples",letterreportfromR.M.HorntoG.B.Inch,February6,1998.3."DOS(DegreeofSensitization)Tester,TypeS-61-OperationManual,IshikawajimaInspection&InstrumentationCo.,I.td.Page9 IIII AltranCorporationTecinncalReportTR97ISI-TR-03Revision0APPClldlX1-"DegreeofSensitizationEPRTestingResultsfortheNineMilePointUnit1BoatSamples",letterreportfromKevinHourtoBrianHall(FramatomeTechnology,Inc,January14,1998.Page10 I,IIIIII McoermottTechnology,Inc.ResearchandDevelopmentDivisionaMcDermottcompanyISO9001R0.Box11165Lynchburg,Virginia24506-1165(804)522-5165February9,1998BrianHallFramatomeTechnologyInc.3315OldForestRoadLynchburg,Va24501
Reference:
FTIPurchaseOrder¹60109MTIR8:DD¹55863
DearBrian:
ThisletterincorporatesDickSmith'scommentsandistoprovidethetestresultsfortheDegreeofSensitization(DOS)onNiagaraMohawkPowerCorporation(NMPC)V-9andV-10boatsamplesthatwereremovedfromthecoreshroudduringlastoutage.TheDOSTesterwasprovidedbyDickSmithofAltranCorporation.ThisisaTypeS-61modelmanufacturedbyIshikawajimaInspection8r,InstrumentationCo.Ltd.Anoperationmanualforthisinstrumentwasalsoprovidedwiththistesterandwasusedastheguidanceforsettingupthistester.TwosamplesidentifiedasFandSwerealsoprovidedbyDickSmithasstandardstoverifytheadequacyofthisinstrumentpriortoactualtests.Thefollowingtablesdocumentthetestresultsforthesetwostandards.StandardSReferenceValue=0.008(engravedontheSStandard)StandardSEC(V)IA(mA)IO(mA)IO/IAIR(mA)IR/IARun¹I*Run¹2Run¹3Run¹4Run¹5-0.427-0.434-0.437-0.435-0.4289.9010.9611.5811.3010.80-0.16-0.04-0.04-0.08-0.060.0000.0000.0000.0000.000-0.16-0.08-0.06-0.080.100.0160.0070.0050.0070.009~ThefirstrunhadahighIR/IAvalue.Thereasonwasunknown.StandardFReferenceValue=0.434(engravedontheFStandard)StandardFRun¹1Run¹2Run¹3Run¹4EC(V)-0.451-0.432-0.423-0.436IA(mA)10.8410.9812.5212.34IO(mA)-0.06-0.04-0.040.02IO/IA0.0000.0000.0000.001IR(mA)4.064.144.744.480.3740.3770.3780.363Note:1.Standardsurfacewaspolishedusing600gritpaper.2.Fieldset-upwasused.3.Freshchemical(0.5MH2SO4and0.01MKSCN)waspreparedpriortoeachtest.4.Testarea=0.049in(0.25inchindiameter).
IIII Observations:1.ConsistentresultscomparedtotheStandardReferenceValueengravedontheStandard(alittlelowontheFStandard,however,itwasbelievedthatbyadjustingthesizeofthetestarea,valuesclosetotheReferenceValuecouldbeobtained.However,thedifferencebetweenFandSStandardswasappropriatetodistinguishbetweensensitizedandnon-sensitizedmaterials).2.Thescatterwassmall.McDermottTechnologyInc.recommendedtoproceedwiththeactualtestsonV-9andV-10metmountsandthiswasapprovedbyGeorgeInchofNMFC.SameprocedureswereusedforspecimensV-9andV-10exceptthetestareawas3.25mmindiameter(testarea=0.0127inch)toallowmoreteststobeconducted.Thefollowingtablesdocumentthetestresults.SpecimenV-9SpecimenV-9EC(V)IA(mA)IO(mA)IO/IAIR(mA)Run¹1Run¹2Run¹3Run¹4-0.399-0.432-0.376-0.4131.983.522.503.08-0.20-0.04-0.08-0.060.0000.0000.0000.0001.200.340.164.220.6060.0960.0641.37Note:1.SeeAttachment1forthetestlocations.2.Run¹1wasnotvalidsincetheoperatoracknowledgedthatthepreparationofthetestareamightnotbeappropriate.3.Runs¹2and¹3wereintheHAZarea.4.Run¹4testareacontainsbothHAZandweldarea.SpecimenV-10SpecimenV-10EC(V)IA(mA)IO(mA)IO/IAIR(mA)IR/IARun¹IRun¹2Run¹3Run¹4Run¹5-0.472-0.449-0.386-0.375-0.3513.764.602.722.822.78-0.10-0.00-0.10-0.10-0.100.0000.0000.0000.0000.0001.220.780.440.12-0.340.3240.1690.1610.0420.122Note1.SeeAttachment2forthetestlocations.2.ItwasunclearwhyIRvalueforRun¹5wasnegative.Thisvaluewasquestionableuntilfurtherclarificationisobtained.3.Run¹1wasconductedinthebasemetalarea.TheIR/IAvaluewashighcomparedtothosefromtheHAZmetals.
I Finally,asample(specimenID~K34043-2)wasreceivedfromRonHornofGENuclearEnergy.Thissamplewastestedusingthesamesetupusedfortheactualtestsforcomparisonpurpose.GESpecimenK34043-2(DIEPR(IR/IA)=0.025)SpecimenK34043-2Run//IEC(V)-0.373IA(mA)15.20IO(mA)-0.14IO/IA0.000IR(mA)0.32IR/JA0.021Note:1.Testarea=0.25inch.2.Testresults(IR/IA=0.021)wereclosetotheexpectedvalue(IR/IA=0.025).PleaseforwarddatapresentedheretoGeorgeInchofNMPCandDickSmithofAltranCorporation.evinHourCt:L.J.FerrellFile I
METALLOGRAPHYSPECIMENV-9-M III'IIII METALLOGRAPHYSPECIMENV-IOMETI I
AllanCorporationTechnicalReportTR97181-TR-03Revision0APPendiX2-"InterpretationofEPRMeasurementsonNMP1BoatSamples",letterreportfromR.M.HorntoG.B.Inch,February6,1998Page11 IIIIIII February6,1998To:G.B.InchFrom:R.M.Horn
Subject:
InterpretationofEPRMeasurementsonNMP1BoatSamplescc:R.Smith,S.Ranganath,T.M.AngeliuEffortswereundertakenbyMcDermottLabs,underthedirectionofDickSmithandKevinHour,toquantitativelymeasurethesensitizationlevelinboththeo.d.V10andthei.d.V9samples.TheIHIDoubleLoop(DL)EPRFieldunitwasemployed.Thissystemusedaspecialcelltoholdtheelectrolyteandevaluatesasmallareaofthematerial.ThisalsoallowedmeasurementstobemadeinareasadjacenttothecrackintheV10metsample.ThevaluesaregiveninTable1astransmittedbyDickSmithofAltran.ThevaluesarenoteasilyconvertedtotheSingleLoop(SL)EPRvaluesthathavebeenusedinthePLEDGEcrackgrowthmodel.However,theIHIsystemincludestwodifferentreferencestandardsforuseincalibration.Thesestandardsareatextremesofsensitization:onenon-sensitizedandonehighlysensitized.InthattheIHIprocedurewasdevelopedforfielduse,thestandardsprovidedameansofcomparingtheIHImeasurementsontheboatsamplematerialtowellcontrolledlaboratoryteststherebyallowinganassessmentofthesingleloop(SL)EPRvaluesthatareusedinthePLEDGEcrackgrowthratemodel.ThelaboratoryevaluationwasperformedbyGECRUDLabunderthedirectionofDr.TomAngeliu.TheDLEPRwereperformedfollowingthestandardapproach;1.2.3.4Surfacewasgroundusing600gritpaperUsedDL-EPRprocedureofAkashiet.al.Freshsolutionvs.oldsolutionmadenodifferenceTestarea1cmTheSL-EPRconditionswereasfollows:1.1micronpolishsurfacefinish2.ProcedureofClark,et.al.30'C,1.67mU/s,+200mUsc~to-400mUsca3.DatawereadjustedtoaccountforthegrainsizeusingPa=Q/(specimenarea*[5.095x10-3exp(0.34696*ASTMgrainsizeat100X)],accordingtoClark,et.al.MeasurementsweremadeontheIHIstandardsatbothlabs.AsummaryofthemeasurementsaregiveninTable2.ThetabledisplaysthemeasurementsfrombothlabsforthetwostandardsaswellasthequotedvaluesprovidedbyIHIforthetwopiecesof IIIIIIIII stainlesssteel.ThetablealsodisplaystheSLEPRvaluesonthesamematerial,measuredbyGECR&D.ThesevaluesprovidedameansofcorrelatingtheDLEPRtoSLEPRandcouldbeusedtointerpolatetoSLEPRvaluesfortheboatsamples.Thisprocesscouldbeused(1)toverifythattheEPRvaluesusedinthecrackgrowthmodelingwereappropriateand(2)togiveanestimateofthesensitizationlevelusingtheconventionalSLEPRvaluesthathavebeencommonlyusedintheliterature.Thiswouldbackuptheeffortsmadetomakemetallographiccomparisons.Figure1displaystheconversionofDLEPRtoSLEPRvaluesbasedonthemeasurementsonthestandards.Thelog-log~g'~relationshipbetweenDLEPRandSLEPRhasbeendiscussedintheliteratureby~("l<<Streicher.ItisclearthattheIHIsystemtendstoproducehighervalues.Thiscouldbeexpectedduetothenatureofthefieldprocessandthesmallerareaexamined.TheendpointsaresetbytheGECRUDSLEPRmeasurements.TheplotalsoshowstherangeofmeasuredvaluesfortheU9andU10samples.Thesevaluesareshownasaregionbetweenthetwolines.ThisapproachshowsthattheV9predictedSLEPRvalueswouldrangefrom2-5C/cmandtheV10valueswouldrangefrom6-15C/cm.Thesevaluesareconsistentwiththemetallographicdeterminedvaluesandthevaluesusedinthecrackgrowthassessments.Insummary,effortsweremadetocorrelatetheDLEPRvaluesmeasuredontheNMPIboatsamples.ThiswasperformedbybenchmarkingtheIHIfieldcellmeasurementsatGECR&DLaboratory.TheassessmentestablishedthattheSLEPRvaluesthatwereassignedtotheV10crackedboatsamplewereconsistentwiththevaluesusedinthecrackgrowthanalysis.Preparedby:R.M.orn,EngineeringFellowMaterialsTechnologyReviewedby:S.Ranganath,ngineeringFellowStructuralMechanics gIlII
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Figure1:SLEPRValuesBasedonDLEPRCalibrationatGECREEDandMcDermottLabsSLEPRvs.DLEPR0.1RangeofSLEPRforV10WoldRangoofSLEPRforV9Wold0.01-DLEPA:GECR80DLEPR:IHI/Baw0.0010.00010.0010.010.1SLEPR(C/cm2)10
AitranCorporationTechnicalReportTR971Sl-TR-03Revision0APPendiX3-"DOS(DegreeofSensitization)Tester,TypeS-61-OperationManual,IshikawajimaInspection&InstrumentationCo.,LtdPage12 III DOS(DegreeofSerisitization)TesterTypeS-8>OPEARATIONMANUALishikawajimainspection8instrumentationCo.,Ltd.
IIIIIIII (1)DOSTESTERcanaccuratelymeasurethedegreeofsensitizationof300seriesstainlesssteelwithinashortoperationtime.(2)Theelectrochemicalpotantiokineticreactivationmethod(EPRmethod)isutilizedfortheevaluationofintergranularcorrosionandintergranularstresscorrosioncrackingsusceptibility.(3)ThecriteriausedinDOSTESTERtoevaluatethedegreeofsensitizationisthepeakcurrentratio(Ir/Ia)inbothanodicandreversepolarizationprocesses,whichimprovesreliabilityandaccuracycomparedwithconventionaltechnique..(4)DOSTESTERcontrolledbyamicrocomputerinterlinkewithapotentiostatisfullyautomaticallyoperatedandanalyticalresultsareprintedoutonatape.
IIII 2.SPECIFICATIONSDriftResponcespeed0.10mV/'610-2secInputresistanceSettingPotential-Minimumscaleofpotentiometer----ElectrolyticcurrentMinimumscaleofammeter----------Currentrecordsensitivily-------Potentialrecordsensitivity-----Powersupplyinput10--ohmmax(Ccapacity150PF)0-4V,ldig.lmV0.05V(class2.5)0-80mA1-100mA(class2.5)3ranges0.15mA0.25mVAC100V50/60Hz3.COMPOSITIONDOSTESTERconsistsofthefollowingmainpackageandaccessories.3-1MainpackagePowersupplyunitInputpowersupplyAC100V(50/60HZ),PotentiostatunitICpotentialDCamplifierElectrolyticcurrentoutputcircuitIndicatingpotentiometer(Electrodepotentialmeter)RegulatedpowersupplyRegulatedpowersupplyforelectrolyticcurrentElectrolyticcurrentmeasuringcircuitSettingpotentialadjustingcircuit*ComputerunitCPU(Z-80A)ROM(Arithmeticandsequencecontrol)RAM(lKwordsx2)datamemoryinterfacedatastorage*PrinterPrinter(Dottype,15-digitpneumericthermalprinter)
III 3-2Accessories1.Referenceelectrode2.Platinumconnteremectrode3.Electrolyticcellforfieldmeasurement4.Electrolyteinjector5.Bondingagent6.Sandpaper7.Thermometer(A)0-100'c,l50mm(encased)B..Powercord,3m9.Coderforcounterelectrodeandspecimen10.Referencespecimen(Type304)12.Electrolytevessel3-3Packagedimensions300mmwidex350mmdeepx140mmhigh IIIII 4.PROCEDURETurnonresetswitcTurnonstartswitc-------OperationstartMeasurementofopencircus.-----Measureactivationconditionontestingsurfacepotential(EC)Printout'.opencircuitpotential(EC)StopECERRORrintout-----Operationstopsandalarmsounds,iftheopencircuit,potentialexceeds-0.35Vevenjfterrepeatingthecathodicreductiontreatmenttwice.Cathodicreductiontreatment-----Performone-minutecathodicreductiontreatmentat-1.0Vwhentheopencircuitpotantialexceeds-0.35VAnodicpolarizationstart-0.45VAnodicpolarizationend-----Continuouslypolarizefrom-0.45tepassivepotentialISto-----Operationstopsandanalarmsounds,iftheanodecurrentflowsexcessively.Measurementandprintoutinanodicpolarizationprocesspeakcurrent(Ia)MeasurementandprintoutpassivestateholdincurrentIoCalculationandprintoutIo/XaSto'II-----Operationstopsandanalarmsounds,ifthepassivationisinsufficientorIaissmallandIo/Xa0.01Reversedpolarizationstart-----ContinuouslypolarizetocathodicdirectionReversedpolarizationend-0.4VXo/IaERRORrintoutMeasurementandprintoutinreversedpolarizationpeakcurrent(Ir)CalculationandprintoutofIr/IaTurnoffresetswitchOperationstop9$03oQQg(Q-QTurnoffstartswitchEnd(operationtimetakesabout15minutes) f PrintingexampleNOXXAddressnumberEC-0.420V----------OpencircuitpontentialVvsSCEIa1090MA---------AnodicpolarizationmaximumcurrentmAIoIo/Ia0.01002MA----------PassivestatecurrentmAIotoIaratioIr00.12MA----------ReversedpolarizationmaximumcurrentmAIr/Za0001----------IrtoIaratio(Reactivationratio)ErrordisplayexampleECERRORWhenopencircuitpotentialexceeds-0.35VevenafterrepeatingcathodicreductiontreatmenttwiceADOVERRANGE--------WhenanodicpolarizationcurrentoverflowsZo/IaERROR----------WhenpassivestateisinsufficientorZaissmallandIo/Ia)0.01; IIII OPERATIONPANELgPA-."DDS-TF.STER4qoa'35>QW~@gp;8[-.(1)Powerswitch(2)ACpowersocket(3)Workingandcounterelectrodeconnector(4)Referenceelectrodeconnector(5)ResetSwitch(6)S'tartswitch(Z)Ammeter(8)Voltmeter(9)Recorderterm-inal(current)(10)Recorderterm-inal(potential)(11)Modeindica-tionpanel(12)Printer(13)Tapederiver IIIII ACCESSORZESgfpa:g.~>>C~v.4,<<-<<Wr(4)(5)lectrolytevessel------.----------------------EfWElectrolyticcellforfieldmeasurement1061(6)Platinumcounterelectrode------------------7)Electrolyteinjector----------------.-----=--((8)Bonds.ngagent------------------------.-----(9)(10)(11)(12)Cordforcounterelectrodeandspecimen-------Thermometer(A)0'-100'C,150mm(encased)andpaper------------------------------"--SReferencespecimen(Type304)1)Referenceelectrode---.-----------------.-((2)Cordforcounterelectrodeandspecimen3)Powercor>3m----------------------------(1pc.1pc.1pc.2pcs~2pcs2pcs~1pc.1pc.1pc.1pc.1pc.5sheets2pcs~
IIII 5.ASSEMBLY IIIIII Connectingmethodofelectrodecordandrecorderterminal.(1)Electrodecordconnector(2P)(a)redclip......Connecttoplatinumcounterelectrode(b)blackclip....Connecttospecimen(2)Referenceelectrodeconnector.....ConnecttoRef.electrode.(3)ConnectionmethodofrecorderterminalsA-.REC........Connecttocurrentrecordingterminal.V-REC........Connecttovoltagerecordingterminal.6.OPERATION6.1FIELDMEASUREMENTSpecimenReference.electrodePlatinurrrcounterelectrodeElectrolyticcellFIELDMEASUREMENT(1).Removedirtandscalefromthespecimensurface.(2)Polishthetestingsurfacewithsandpaper.Afteruniformalizingthepolishingtracesofsandpaperinonedirection,polishthetestingsurfaceagaintotheparpendiculardirectionuntilthepolishingtracesarecompletelyeliminated.(3)Degreasethepolishedsurfacewithacetoneorthinner.
III (4)Filgtheelectrolyticcelltomeettheshapeofthespecimenbyapplyingasandpapertothetestingfaceuntiltheirbondingfacesmeeteachother.(5)Bondtheelectrolyticcelltothetestsurface.Ifthetestingfaceistiltedorvibrating,depressthetestingfacebyhandorfixitbyusingatapeuntilthebondingagentisfullydriedup.(6)Makesurethatthebondingagenthasbeendriedupandthecelldoesnotmoveanylonger.(7)Prepareelectrolyteasinformedinnextsection(8)Injectelectrolyteintotheelectrolyticcelltoan80@level.(9)Fixreferenceandcounterelectrodeintocellasshowninillustration.Keepaspaceofabout10mmbetweenthetipofreferenceelectrodeandthespecimensurface.Becarethattheplatinumcounterelectrodedoesnottouchthespecimen.(10)Connectelectrodecordstooperationpanelconnectors.(11)Connecttheworkingelectrodeturminaltothespecimenwithsolderorclip.(12)Turnonthepowerswitch.(14)Pushtheresetbutton.(Makesurethattheresetbuttoninlighting)(15)Pushthestartbutton.(Makesurethatthestartbuttoninlighting)Measurementiscompletedabout.15minutesafterthestartbuttonhasbeenlit,andmeasuringresultsarerecordedontheprinter.whenmeasurementends,analarmsoundstoinformyouofitfor1minute.(16)Pushtheresetbutton.(17)Incaseofabnormaloperationconditions,measurementisinterrupted,analarmsoundsandsomeerrormessagesareprintedout.,(18)Aftercompletionofallmeasurements,'urnoffthepowerswitch,andsucktheelectrolytebyusinganinjector.(19)Rincecell,electrodesandspecimenwithfreshwater.
IlI 6.2LABORATORYMEASUREMENTReferenceelectrodeCEPlatinumcounterelectrodeSpecimenLABORATORYMEASUREMENT(l)Cutthespecimentoasuitablesize.Thetestingsurfaceshouldbeabout50mm2(2)(3)(4)Solderaleadwireto,therearofthetestingface.EmbedthespecimenandinsulatedleadwireintoreSin.Polishthetestingsurfaceinthesamemanneras,in"fieldmeasurement".(5)(6)Degreasewithacetoneorthinner.Ifthetestingsurfaceislargerthan50mm,adjusttheareabycoveringwithenamelresin(manicureorthelike).Ifaclearanceisproducedbetweenthespecimenandresin,covertheclearancewithenamelresin.(7)Putelectrolyteintotheelectrolyticcellmorethan200ml.
Il+/IIl (8)Diptheplatinumcounterelectrode,referenceelectrodeandspecimenintotheelectrolyte.Keepaspacebetweenplatinumcounterelectrodeandthespecimensothattheyarenotshortedwitheachother.(9)Connecttheelectrodecordstooperationpanelconnectors.(10)Turnonthepowerswitch.(11)TurnthecurrentrangeknobfromOPPto100mA.(12)Pushtheresetbutton.(Makesurethattheresetbuttoninlighting)(13)Pushthestartbutton.(Makesurethatthestartbuttoninlighting)Measurementiscompletedabout15minutesafterthestartbuttonhasbeenlit,andmeasuringresultsarerecordedontheprinter.Whenmeasurementends,analarmsoundstoinformyouofitfor1minute.(14)Pushtheresetbutton.(15)Incaseofabnormaloperationconditions,measurementininterrupted,analarm,soundsandsomeerrormessagesareprintedout.(16)Rincethespecimenwithfreshwater.
IIIII 8.TROUBLESHOOTING(1)Thepowerindicatorlampdoesnotlightwhenturningonthepowerswitch.IspowercordconnectedincaseofACpowersupply?(2)Themeasuringvoltmeterandammeterpointersfluctuateduringstartbuttonislighting.Aretheelectrodecordsconnectedtotheterminalscorrectly?Isthereferenceelectrodesetcorrectlywithnormalcontinuity7IstheplatinumcounterelectrodeseparatedfromthespecimenwithoutanycontactAretheplatinumelectrode,thereferenceelectrodeandspecimendippedintotheelectrolyte'P(3)Ameasuringoperationisalwaysinterruptedwithsomeerrorinformation.Fullypolishandwashthemeasuringsurfaceagain.Adjustthemeasuringareaincaseoflowtemperaturecondition.UsethespecialelectrolyteforMocontainingstainlesssteel.Checkthereferenceelectrode.13
9CAUTIONSThoughthiselectrolyteisnotanoxioussubstance,becarefulwithhandlingsoasnottoscatterit.Wearrubbergloves.Ifyourhandsorskinwascontaminatedwithelectrolyte,washitoutwithrunningwater.Ifyoureyesshouldhavebeencontaminatedwithitorifyoushouldhavedrunkitbymistake,takeanemergencymeasurelikewashing,vomit,etc.,andconsultadoctoratonce.(2)Xfelectrolyteleaksandattachestotheinternalmecha-nismsofDOSTESTER,itmaycorrodethemtocauseatrouble.Particularlybecarefulwithitshandling,accordingly.(3)Treatthewasteelectrolytebyasuitablewastesolutiontreatmentvesselafterneutralizingit.(4)Becareforhandlingthereferenceelectrode.Keeptheceramictipwetcondition.ConfirmtheKClcristalinthesolution.Whenthebubbleisrecognizedatthepointof"A"inthefigure,shaketheelectrodesoftlyandremoveKC1cristalbubbletotheupperside.
III ElectrodecordSealAHoleforinjectionofKClStandardelectrodebodyCrystalofKClCeramic'Capf'rpreventionofdryingREFERENCEELECTRODE15 Il 10.TECHNICALINFORMATION10-1PREPARATIONOFELECTROLYTETwokindsofelectrolytearerecommendedforDOS,TESTERasshowninTablel.Thoughthestandardelectrolyte(0.5MH2S040.01MKSCN)canbeusedforvariouskindsofstainless,steels,theconcentratedelectrolyte(1.0MH2S04O.lMKSCN)ispreferforMocontainedstainlesssteelssuchastype316,whichanodiccurrent(Ia)issmallerthanthatofnon-Momaterialincaseoflowtemperaturecondition.TheexampleofpreparationisshowninTable2.Table1RecommendedelectrolyteElectrolyteStandardH25040.5MKSCN0.01MConcentrated1.0M0.1MTable2PreparationexampleElectrolyteWater*H2S04**KSCN~DeionizedWaterStandardConcentrated1000ml29ml1000ml60ml1.0g10.3g**9510-2SELECTIONOFTHETESTINGAREAIa(anodicpolarizationpeakcurrentvalue)andIr(reveresedpolarizationpeakcurrentvalue)dependuponthetestingtemperature.Fig.lindicatesthetemperaturedependencyofthecurrentdensity,Iaof304S.S.asanexample.
III Astemperaturebecomeslower,thecurrentdensitydecreases.Itisdesirabletousealargercelltoimprovethemeasuringaccuracy.Accordingly,itisrecommendedtoselectthesuitabletestingareaasshowninthetableincaseof304stainlesssteel.AsIaofMocontainedstainlesssteelsuchastype316islowerthanthatof304,largerdiameterelectrolyticcellmaybeused.TABLE3RECOMMENDEDTESTINGAREA(304S.S.)Testtemperature10'CTESTINGAREA0.5-2cm214$20~C30oC40C0.3-1.3cm0.2-0.8cm0.1-0.4cm210-14610$10$2000iso~4CoIOO50;lO203040TEMPERATURE(~C)Fig.1TemperaturedependencyofIa(Type304)17 IIlI 10-3TEMPERATURECORRECTIONThe'reactivationratio(Ir/Ia)indicatesthetemperaturedependency.Fig.2showstheEPRtestresultsatrespectivetemperature,regardingmanyspecimenshavingdifferentdegreesofsensitizationWhencomparingtestresultsatdifferenttemperaturewitheachother,itisrecommendedtocomparethemafterconvertingthemintotestresultsatthesametemperature(30C,forexample)accordingtoFig.2.Howtousethechart.Example1Ifyoumeasure7%o'fIr/Zaat15C,theequivalentIr/Zavalueat30Cisreadtobe17%asindicatedontheequi.Ir/Ialine.Example2Ifyoumeasure3%ofIr/Zaat15C,youmustdrawalinereasonableyseparatedinbetweenthetwoadjacentchartlinestoread8%of30Cequivalencevalue.
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I 10-6MEASUREMENTOFMoCONTAININGSTAINLESSSTEELSSinceMohastheeffectofdepressionofthedissolutioninac'tivestate,theanodicpeakcurrent(Ia)inMo'ontainedstainlesssteelsisdecreasedinporalizationprocessthoughthepassivestateholdingcurrent(Io)isnotchanged.TheratioofIatoIo,therefore,frequentlyexceeds1/100andDOSmeasurementisinterruptedwitherrormessage.Expansionoftestingarea,increasingofenvironmentaltemperatureandapplicationofspecialelectrolytearerequiredforimprovingthestabilityofmeasurement.Itisalsonecessarytokeepabout3minutesinelectrolytebeforestartingoperationinordertodissolve"theremainedoxidefilmontestingsurface.20