ML17262A482

LER 91-005-00:on 910414,steam Generator Tube Degradation Occurred Due to Iga/Scc & Primary Water Stress Corrosion Cracking Attack on Steam Generator Tubing.Affected Tubes Sleeved or plugged.W/910513 Ltr

ML17262A482
Person / Time
Site:	Ginna
Issue date:	05/13/1991
From:	GORSKI P, MECREDY R C ROCHESTER GAS & ELECTRIC CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-91-005, LER-91-5, NUDOCS 9105210249
Download: ML17262A482 (20)

Text

ACCELERATEDDILUTIONDEMONS~TIONSYSTEMiPREGULATORYINFORMATIONDISTRIBUTIONSYSTEM(RIDS)ACCESSIONNBR:9105210249DOC.DATE:91/05/13NOTARIZED:NOFACIL:50-244RobertEmmetGinnaNuclearPlant,Unit1,RochesterGAUTH.NAME.AUTHORAFFILIATIONGORSKI,P.RochesterGas&ElectricCorp.MECREDY,R.C.RochesterGas&ElectricCorp.RECIP.NAME'ECIPIENTAFFILIATIONDOCKETg05000244R

SUBJECT:

LER91-005-00:on910414,steamgeneratortubedegradation.Causedby"A"&"B"S/GStubedegradationinexcessofGinnaQAMreportabilitylimits.TubesrepairedusingCombustionEngineeringweldedsleeve.W/910513ltr.DISTRIBUTIONCODE:IE22TCOPIESRECEIVED:LTRENCLSIZE:TITLE:50.73/50.9LicenseeEvent,Report(LER),IncidentRpt,etc..SNOTES:LicenseExpdateinaccordancewith10CFR2,2.109(9/19/72).05000244RECIPIENTIDCODE/NAMEPD1-3LAJOHNSON,AINTERNAL:ACNWAEOD/DSP/TPABNRR/DET/ECMB9HNRR/DLPQ/LHFB11NRR/DOEA/OEABNRR/DST/SELBSDNj%/BS~LBSD1RE~IL~02FILE01EXTERNAL:EG&GBRYCE,J.HNRCPDRNSICPOORE,W.COPIESLTTRENCL1111221111111111111111331111RECIPIENTIDCODE/NAMEPD1-3PDAEOD/DOAAEOD/ROAB/DSPNRR/DET/EMEB7ENRR/DLPQ/LPEB10NRR/DREP/PRPB11NRR/DST/SICB7ENRR/DST/SRXBSERES/DSIR/EIBLSTLOBBYWARDNSICMURPHY,G.ANUDOCSFULLTXTCOPIESLTTRENCL1111221'1122111111111111DNOTETOALL"RIDS"RECIPIENTS:PLEASEHELPUSTOREDUCEiVASTE!CONTACTTHEDOCUMENTCONTROLDESK,ROOMPl-37(EXT.20079)TOELIMINATEYOURNAMEFROMDISTRIBUTIONLISTSFORDOCUMENTSYOUDON'TNEED!DDFULLTEXTCONVERSIONREQUIREDTOTALNUMBEROFCOPIESREQUIRED'TTR31ENCL31

ROCHESTERGASANDELECTRICCORPORATIONo89EASTAVENUE,ROCHESTERN.Y.14649-0001+,ROBERTC.MECREDYVicePresidentCinnaNuclearProductionTELEPHONEAREACODE7165462700May13,1991U.S.NuclearRegulatoryCommissionDocumentControlDeskWashington,DC20555

Subject:

LER91-005,SteamGeneratorTubeDegradationDuetoIGA/SCCCausesQ.A.ManualReportableLimitstobeReachedR.E.GinnaNuclearPowerPlantDocketNo.50-244Inaccordancewith10CFR50.73,LicenseeEventReportSystem,item(Other),andtheGinnaStationQualityAssuranceManualAppendixB,whichrequiresthat,"Ifthenumberoftubesinageneratorfallingintocategoriesaorbbelowexceedsthecriteria,thenresultsoftheinspectionshallbeconsideredaReportableEventpursuantto10CFR50.73,"theattachedLicenseeEventReportLER91-005isherebysubmitted.Thiseventhasinnowayaffectedthepublic'shealthandsafety.Vertrulyyours,XC:RobertC.MeredyU.S.NuclearRegulatoryCommissionRegionI475AllendaleRoadKingofPrussia,PA19406GinnaUSNRCSeniorResidentInspector91052102499i05i3PDFlADQCK0000244sFDRWG&a~II I

rACSeeaIIOIOAIIUCENSEEEVENTREPORTLER)U*IACLIAIAIOULATON>COANI~Ase1ovtoOUIINLIIIIOlovCISINCIIIII/IIOOCltTNUIIOCNQlo6oo0244>otSACILITYNAIICI'lR.E.GinnaNuclearPowerPlantTLIlelSteamGeneratorTubeDegradationDuetoIGA/SCCCausesQ.A.ManualReportableLimitstobeReachedCVINTOATIItlLC1NVIIOCAIN1CSOA'1OATIIhOTNI1SACILITIC~INVOLVtoNleeoeeTNOAYYCANeyIIOVINTIALI.Nvee~11AIVeeeee~evWIANOeeTNOAYYCA1SACILITYNAeeleoocCITNUIIIIAQI0600004149110050005139106000OSCAATINO~eOOIOll~OIVIACIVILPPP'101TNII1tSONTQWINITTCOSVIQVANTT~OOI4lQlIIelN.T041QIIelII.T$4IQIIeel~IOI41QIINIIW~O.TIlelQIIVNIQl~O.TSNIQIIIIIo.cotl~IIO.IOllelIOOIlellllIOMWItlIO.AOI4111110I0%4411IIIIICO.III4)l1IINI~O.T04IQIll~O.TI41QIIIICOAS4IIIIOel!O.IIIIIIIIllelIOJIIIIQIINILICtNtllCONTACTSONTIIQLI1Iltl0Teel1lovlAILIINTIos10cs1j;IceeeeeeeeyeeaeelSNeeeeeeel1111%71OITXTIWoTIIC1lteeexyleAeeeeet~eeeteeeeeTeeLNICSowJIIAINAVCPaulGorskiMechanicalMaintenanceManaerTILCSeeONCNVNII1ANIACOOC3155COUSLCT8ONILINtSONCACIICOIISONCNTSAILUICOCICIIItoNITNII1CSOITIltlCAUtlIYITIIIXCONSONINTTBNANUSAOTUNIIIH34TONSIOIAIjl+M(lhw7CAUIIIYCTCIIcoeesoNINT~IANUIAOTUNCN~P0IITUg~(A~t:@%FATS!M%~V:IVSSLCNINTALIICSOATCLSCCTCOIIIIYltOyy<<.~CXSCCTCOCVINIC>>ONOAT>>NOAICTAACTILJevc0IAxleeeee.IA,eeeyeeeeeMyNINeeeeeseeeeeeeIyftsrlllee<<eeeIIWIIONTIICAYYCA1CISCCTCOWIINCCIONOATI11~IDuringthe1991AnnualRefuelingandMaintenanceOutagesubsequenttotheeddycurrentexaminationperformedonboththe"A"and"B"Westinghouseseries44SteamGenerator(S/G),116tubesinthe"A"S/Gand117tubesinthe"B"S/Grequiredcorrectiveactionduetotubedegradation.Theimmediatecauseoftheeventwasthatthe"A"and"B"S/GstubedegradationwasinexcessoftheGinnaQualityAssuranceManualreportabilitylimits.TheunderlyingcauseofthetubedegradationisacommonS/GproblemofapartiallyrolledtubesheetcrevicewithrecurringIntergranularAttack/StressCorrosionCracking(ZGA/SCC)andPrimaryWaterStressCorrosionCracking(PWSCC)attackonS/Gtubing.Correctiveactiontakenwastoei.thersleeveorplugtheaffectedtubeswithacceptedindustryrepairmethods.NACSeeeIOII&All

1114terU~10451LICENSEEEVENTREPORTILERITEXTCONTINUATIONII.5.IIIICLtA1154MLATOAYCOQMINIISIrAftAOvtOOUOHO5ltOWIOtt)CPIII55t/TIESFACILITYIIAAIt111OOCKtTIIIIlttt1IllL51IluatttaIa~54VtleTIALUVISIONUA~AOtItlR.E.GinnaNuclearPowerPlantTtXTIIT~~1~.~~I@AC/4PIII~tlIITIosooo24491-005-0002OFPRE-%TENTPLANT'ONDITIONSTheunitwasintheCold/RefuelingShutdownconditionfor~theAnnualRefuelingandMaintenanceOutage.ReactorCoolantSystem(RCS)pressurewaszero(0)psigandRCStemperaturewasapproximately68F.SteamGeneratoreddycurrentinspectionwasinprogress.DESCRIPTIONOP~9FZA.DATESANDAPPROXIMATETIMESOPMAZOROCCtJREUBTCES:oApril14,1991,1600EDST:Eventdateandtime.oApril14,1991,1600EDST:Discoverydateandtime.oApril16,1991,1430EDST:OralnotificationmadetotheNRCofficeofNuclearReactorRegulation(NRR).oApril22,1991,0400EDST:SteamGeneratorrepairscompleted.oApril26,1991,Follow-upwrittenreportsenttoNRCOfficeofNRR.rB.&TENT:Duringthe1991AnnualRefuelingandMaintenanceOutage,aneddycurrentexamination.wasperformedinboththe"A"and"B"Westinghousemiseries44iDesignrecirculatingsteamgenerators.Thepurposeoftheeddycurrentexaminationwastoassessanycorrosionormechanicaldamagethatmayhaveoccurredduringthecyclesincethe1990examin-ation.vAC14111tttAr~

I NACtermESSAI~ILICENSEEEVENTREPORTILERITEXTCONTINUATIONU.S.NUCEtANAtoULATOAVCOMMISOON/Aee1OVEOOMSNOSISO&IOeEXPIIIES.SIS14SDOCKETNUMStllItlEEIINUMOSNItlstoUENnAI."etv4ONNM1MA~AOEISIR.E.GinnaNuclear~PlantTExT/1I'veeNMeee~.eeeeeeaonMITIIC~JKI'elIITIosooo24491-005-00030F08TheexaminationwasperformedbypersonnelfromRochesterGasandElectric(RG&E)andAllenNuclear.Associates,Inc.(ANA)..Allp'ersonnelweretrainedandqualifiedintheeddycurrentexaminationmethodandhadbeencertifiedtoaminimumafLevelIfordataacquisitionandLevelIIfordataanalysis.Theeddycurrentexaminationofthe"A"and"B"steamgeneratorswasperformedutilizingtheZetecMiz-18DigitalDataAcquisitionsystem.Thefrequenciesselectedwere400,200,100and25KHZ.Theinletorhotlegexaminationprogramplanincludedtheexaminationof100%ofeachopenunsleevedsteamgeneratortubefromthetubeendtothefirsttubesupport.20%ofthehotlegtubeswereselectedforexaminationfortheirfulllength(20%randomsampleasrecommendedintheElectricPowerResearchInstitute(EPRI)guidelines.)Inaddition,20%ofeachtypeofsleevewasexaminedandtheremainingtubeexaminedfulllength.Allprevioustubeswithindicationsgreaterthan20%throughwall(TW)depthwereexamined,asaminimum,tothelocationoftheirdegradation.AllRow1andRow2U-Bendregionsselectedaspartofthe20%randomsamplewereexaminedwiththeMotorizedRotatingPancakeCoil(MRPC)betweentheg6TubeSupportPlateHot(TSPH)andtheg6TubeSupportPlateCold(TSPC)fromthecoldlegside.Resultsoftheaboveinspectionsindicatedthat116tubesinthe"A"steamgenerator(i.e.91newrepairs--plus1pulledtubeplus24previouslypluggedtubes)and117tubesinthe"B"steamgenerator(i.e.98new-mepairsplus1obstructedsleevedtubeplus16previouslypluggedtubesplus2plugsexhibitingPWSCC)requiredcorrectiveaction.NACeOAMSNA(eg]I

IIACtens~(t43ILICENSEEEVENTAEPOATILEA)TEXTCONTINUATIONU~IIUCl,fAll1SOUlATOATCOMMt%IOSIAttAOVEOOUSSIO31SO&IOSIIItkAl5SI3lkTStACILITTISASISIIIOOCIISTIIUMISIIQlLlllIIIASCIRISISSQVSATkAL~kU1gkSkQkk1tAOEISIR.E.GinnaNuclearPowerPlantTEXTlS'tktt~etWVsrC~~tIIICIktttk~'SlIITI2449l-005-0004Oi08OnApril14,1991atapproximately1600EDST,thereactorwasintheCold/RefuelingShutdownconditionwithRCSTemperatureandpressureatapproximately68Fandzero(0)psigrespectively.Atthistimeafinalreviewoftheeddycurrentdatawascompletedandresultsindicatedthatmorethan1percentofthetotaltubesinspectedweredegraded(i.e.imperfectionsgreaterthantherepairlimit).Becauseoftheabove,theresultsoftheinspectionareconsideredareportableeventpursuantto10CFR50.73perAppendixBoftheGinnaStationQualityAssuranceManual.OnApril16,1991atapproximately1430EDSTOralNotificationwasmadetotheNRC'officeofNRRpursuanttoAppendixBoftheGinnaStationQualityAssuranceManual.OnApril26,1991,afollow-upwrittenreportofthesteamgeneratorsinspectionandrepairswassenttotheNRCOfficeofNRRpursuanttoAppendixBoftheGinnaStationQualityAssuranceManual:CINOPERABLESTRUCTUREStCOMPONENTStORSYSTEMSTHATCONTRIBUTEDTOTHEEVENT:None.D.OTHERSYSTEMSORSECONDARYFUNCTIONSAFFECTED-kNone.E.METHODOFDISCOVERY:Theeventwasapparentafterthereviewofthe"A"and"B"SteamGeneratorseddycurrentexaminationresults.F.OPERATORACTION:None.VACtOAISSQSAkt4$I

11CSons5$5AI$45ILICENSEEEVENTREPORT(LERITEXTCONTINUATIONVS.IIVCL5AA150VLATOATCOI<<It&IOIIASSAOV50O<<5HO5I$4&IOI5)ISI1555ITI4$SACILITTIIA<<5IIIOOCKSTIIV<<llllITILl114<<ll1IN$$4yonnsLM1ylglosvSA4lI5IR.E.GinnaNuclearPowerPlantTTXTIIS~<<eee1<<O<<OO,y<<OOSS<<nOSITACSOno~$IIITIosooo244910050005OFG.SAFETYSYSTEMRESPONSES:None.III.CAUSEOPEVE2FZA.IMMEDIATECAUSE:TheImmediateCauseoftheeventwasthatthe"A"and~"B"steamgeneratortubedegradationwasinexcessoftheGinnaStationQualityAssuranceManualReportablelimits.B.ROOTCAUSE:TheresultsoftheexaminationindicatethatIGAandIGSCCcontinuetobeactivewithinthetubesheetcreviceregionontheinletsideofeachsteamgenerator.Asinthepast,IGA/SCCismuchmoreprevalentinthe"B"steamgeneratorwith42newIGAindicationand37newIGSCCindicationsreported.Inthe"A"steamgenerator,14newIGAindicationsand16newIGSCCindicationswerereported.Themajorityoftheinlettubesheetcrevicecorrosion.indicationsareIGA/SCCoftheMil-annealedInconel600TubeMaterial.Thisformofcorrosionisbelievedtobetheresultofthetubesheetcrevicesforminganalkalineenvironment.Thisenvironmenthasdevelopedovertheyearsasdepositsandactivespecieslikesodiumandphosphates,havereacted,changinganeutralorinhibitedcreviceintotheaggressiveenvironmentthatpresentlyexists.AlongwithIGA/SCCinthecrevice,PWSCCattherolltransitionappearstohaveaslightincreaseingrowthduringthelastoperatingcycle.Thismechanismwasfirstaddressedin1989andthisyeartherewere19PWSCCindicationsin"B"SteamGeneratorand59PWSCCindicationsin"A"SteamGenerator.ssCs41<<$4AA

IIACtvvMI~lLICENSEEEVENTREPORTILERITEXTCONTINUATIONII%NVCLfAAAfOIJLATOATCCNQN&IOII'AttAOVfOOllfrOfISO&10if)Irlllf5~ITIS'ACILITTHAIrfIIIOOCCfTIILAWfAlflLfllIIUMMR(flyfAAWOMLNTIAL'4IOHr1~AofIflR.E.GinnaNuclearPowerPlantTEXTIll'VrvrteWeer.yvereecveVr'IIC~~'alIITIosooo24491-00500060FO8ANALYSISOFEVENTTheeventisreportableinaccordancewith10CFR50.73,LicenseeEventReportitem(Other)andtheGinnaStationQualityAssuranceManualAppendixBwhichrequiresthat,"Ifthenumberoftubesinageneratorfallingintocategoriesaorbexceedsthecriteria,thenresultsoftheinspectionshallbeconsideredaReportableEventpursuantto10CFR50.73."The,tubedegradationinthe"A"and"B"steamgeneratorsexceededthecriterionof(b)whichstates,"morethan1%oftotaltubesinspectedaredegraded,(imperfectionsgreaterthantherepairlimit)."Thisrepairlimitisdefinedas,"steamgeneratortubesthathaveimperfectionsgreaterthan404throughwall,asindicatedbyeddycurrent,shallberepairedbypluggingorsleeving."Anassessmentwasperformedconsideringthesafetycon-sequencesandimplicationsofthiseventwiththefollowingresultsandconclusions:TherewerenooperationalorsafetyconsequencesorsafetyimplicationsresultingfromthesteamgeneratortubedegradationinexcessoftheQualityAssuranceManualreportable'imitsbecause:oThedegradedtubeswereidentifiedandrepairedpriortoanysignificantleakageorsteamgeneratortuberuptureoccurring.oEvenassumingacompleteseveranceofasteamgeneratortubeatfullpower,asstatedintheR.E.GinnaNuclearPowerPlantupdatedFinal,SafetyAnalysisReport(Ginna/UFSAR)section15.6.3,(SteamGeneratorTubeRupture)thesequenceofrecoveryactionsensuresearly'erminationofprimarytosecondaryleakagewithorwithoutoffsitepoweravailablethuslimitingoffsiteradiationdosestowithintheguidelinesof10CFR100.Basedontheabove,itcanbeconcludedthatthepublic'shealthandsafetywereassuredatalltimes.rACNOAH~

IIAC>vssstttAI944ILICENSEEEVENTREPORT(LER)TEXTCONTINUATIONV.t.ISVCEEAAAEOVLATOIIYCOAIMIttIOIIIAlrAOYEOOastssO)Ito&IOaEXPIAE$IttIstSlACILITYIIA1ltIIIOOCXETISVIMtllIllEEIIIIIAAtltI~Itt4SStSSTSA4ssYstsOss~stA~AOEItlR.E.GinnaNuclearPowerPlantTExfillsssvYAsAcs0~.ssvAtsssawsssYAcssssssss~TOIITIosooo2449-1-05-0007ov08V.CORRECTIVEACTIONA.ACTIONTAKENTORETURNAPPECTEDSYSTEMSTOPRE-E%9lT'ORMALSTATUS:00Ofthe116degradedtubesinthe"A"steamgenerator,61tubeswererepairedusingaCombustionEngineering'27"weldedsleeveinthehotlegplus41tubeswererepairedusingaCombustionEngineering30"weldedsleeveinthehotlegandalloftheabovetubeswillremaininservice.Theremaining14tubeswereremovedfromservicebypluggingboththehotandcoldlegtubeends.Atotalof190tubesin"A"@Gare.currentlypluggedand324tubesaresleeved.Ofthe117degradedtubesinthe"B"steamgenerator,80tubeswererepairedusingaCombustionEngineering27"weldedsleeveinthehotlegplus28tubeswererepairedusingaCombustionEngineering30"weldedsleeveinthehotlegandalloftheabovetubeswillremain.inservice.Theremaining9tubeswereremovedfromservicebypluggingboththehotandcoldlegtubeends.Atotalof326tubesinthe"B"S/Garecurrentlypluggedand938tubesaresleeved.B.ACTIONTAKENORPLANNEDTOPE~TENTRECURMQTCETheoccurrence/presenceofIGA,SCCandPWSCCisacommonPWRSteamGeneratorproblem.Utilitieswith~usceptibletubingandpartiallyrolledcrevicesmustdealwiththisrecurringattackonsteamgenerator--<ubing.R.E.GinnaStationwillcontinuecarefulmonitoringofbothprimaryRCSandsecondarysidewaterchemistryparameters.Thesewaterchemistryparameterswillbeevaluatedagainstacceptedindustryguidelinesinordertominimizeharmfuland/orsecondarysideenvironments.asAClOAsAtttAhaI~as

NIICSeamSNAI04SI1LICENSEEEVENTREPORTILER)TEXTCONTINUATIONU.S.NUCLSANAS4ULATOIIYCOAIAIISSIONASSAOYSOOMSNOSlSOWI04rs>>sIAsssnInsSACILITYNAIICIllDOC>>STNU~SIIITILSIINI>>AOSIIIIIssQUANT>ALYNIOHSAOSISIR.E.GinnaNuclearPowerPlantTGCTIIIee>>eNNee~teeeecceoeeeeeeeIJV>>CSee>>~'elIITIo5ooo24491-005-0008OFO8DegradedSteamGeneratortubesshallbesleevedorpluggedinaccordancewiththeinserviceinspectionprogramandacceptedindustryrepairmethods.ADDITIONALINFORMATIONFAILEDCOMPONENTS.Thedegradedcomponentsare:InconelGrade600tubeshavinganoutsidediameterof0.875inchesandanominalwallthicknessof0.050inches.B.PREVIOUSLERsONSIMILAREVENTS:AsimilarLEReventhistoricalsearchwasconductedwiththefollowingresults:ThecreviceindicationsaresimilartothosereportedinA0-74-02,A0-75-07,R0-75-013,andLERs76-008,77-008,78-003,79-006,79022s80003s81009s82003s82022s83013s89001,and90-004.C.SPECIALCOMMIBFXS:Foramoreindepthreport,refertothe,"1991SteamGeneratorEddyCurrentExaminationSummaryReport"senttotheNRCApril26,1991.~vACSOAKSAAAIeeSTI

~ss~