ML17262A482

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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 Constellation icon.png
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

ACCELERATED DILUTIONDEMONS~TION SYSTEMiPREGULATORY INFORMATION DISTRIBUTION SYSTEM(RIDS)ACCESSION NBR:9105210249 DOC.DATE:

91/05/13NOTARIZED:

NOFACIL:50-244 RobertEmmetGinnaNuclearPlant,Unit1,Rochester GAUTH.NAME.AUTHORAFFILIATION GORSKI,P.

Rochester Gas&ElectricCorp.MECREDY,R.C.

Rochester Gas&ElectricCorp.RECIP.NAME

'ECIPIENT AFFILIATION DOCKETg05000244R

SUBJECT:

LER91-005-00:on 910414,steam generator tubedegradation.

Causedby"A"&"B"S/GStubedegradation inexcessofGinnaQAMreportability limits.TubesrepairedusingCombustion Engineering weldedsleeve.W/910513 ltr.DISTRIBUTION CODE:IE22TCOPIESRECEIVED:LTR ENCLSIZE:TITLE:50.73/50.9 LicenseeEvent,Report(LER),IncidentRpt,etc..SNOTES:License Expdateinaccordance with10CFR2,2.109(9/19/72).

05000244RECIPIENT IDCODE/NAME PD1-3LAJOHNSON,A INTERNAL:

ACNWAEOD/DSP/TPABNRR/DET/ECMB 9HNRR/DLPQ/LHFB11 NRR/DOEA/OEAB NRR/DST/SELB SDNj%/BS~LBSD1 RE~IL~02FILE01EXTERNAL:

EG&GBRYCE,J.HNRCPDRNSICPOORE,W.COPIESLTTRENCL1111221111111111111111331111RECIPIENT IDCODE/NAME PD1-3PDAEOD/DOAAEOD/ROAB/DSP NRR/DET/EMEB 7ENRR/DLPQ/LPEB10 NRR/DREP/PRPB11 NRR/DST/SICB 7ENRR/DST/SRXB SERES/DSIR/EIB LSTLOBBYWARDNSICMURPHY,G.A NUDOCSFULLTXTCOPIESLTTRENCL1111221'1122111111111111DNOTETOALL"RIDS"RECIPIENTS:

PLEASEHELPUSTOREDUCEiVASTE!CONTACTTHEDOCUMENTCONTROLDESK,ROOMPl-37(EXT.20079)TOELIMINATE YOURNAMEFROMDISTRIBUTION LISTSFORDOCUMENTS YOUDON'TNEED!DDFULLTEXTCONVERSION REQUIREDTOTALNUMBEROFCOPIESREQUIRED'TTR 31ENCL31

ROCHESTER GASANDELECTRICCORPORATION o89EASTAVENUE,ROCHESTER N.Y.14649-0001+,

ROBERTC.MECREDYVicePresident CinnaNuclearProduction TELEPHONE AREACODE7165462700May13,1991U.S.NuclearRegulatory Commission DocumentControlDeskWashington, DC20555

Subject:

LER91-005,SteamGenerator TubeDegradation DuetoIGA/SCCCausesQ.A.ManualReportable LimitstobeReachedR.E.GinnaNuclearPowerPlantDocketNo.50-244Inaccordance with10CFR50.73,LicenseeEventReportSystem,item(Other),andtheGinnaStationQualityAssurance ManualAppendixB,whichrequiresthat,"Ifthenumberoftubesinagenerator fallingintocategories aorbbelowexceedsthecriteria, thenresultsoftheinspection shallbeconsidered aReportable Eventpursuantto10CFR50.73,"theattachedLicenseeEventReportLER91-005isherebysubmitted.

Thiseventhasinnowayaffectedthepublic'shealthandsafety.Vertrulyyours,XC:RobertC.MeredyU.S.NuclearRegulatory Commission RegionI475Allendale RoadKingofPrussia,PA19406GinnaUSNRCSeniorResidentInspector 9105210249 9i05i3PDFlADQCK0000244sFDRWG&a~II I

rACSeeaIIOIOAIIUCENSEEEVENTREPORTLER)U*IACLIAIAIOULATON>

COANI~Ase1ovtoOUIINLIIIIOlovCISINCIIIII/IIOOCltTNUIIOCNQlo6oo0244>ot SACILITYNAIICI'lR.E.GinnaNuclearPowerPlantTLIlelSteamGenerator TubeDegradation DuetoIGA/SCCCausesQ.A.ManualReportable LimitstobeReachedCVINTOATIItlLC1NVIIOCAIN1CSOA'1OATIIhOTNI1SACILITIC

~INVOLVtoNleeoeeTNOAYYCANeyIIOVINTIAL I.Nvee~11AIVeeeee~evWIANOeeTNOAYYCA1SACILITYNAeeleoocCITNUIIIIAQI 0600004149110050005139106000OSCAATINO

~eOOIOll~OIVIACIVILPPP'101TNII1tSONTQWINITTCOSVIQVANTT~OOI4lQlIIelN.T041QIIelII.T$4IQIIeel~IOI41QIINIIW

~O.TIlelQIIVNIQl~O.TSNIQIIII Io.cotl~IIO.IOllel IOOIlellll IOMWItlIO.AOI4111110I0%4411IIIIICO.III4)l1IINI~O.T04IQIll~O.TI41QIIIICOAS4IIIIOel!O.IIIIIIIIllelIOJIIIIQIINILICtNtllCONTACTSONTIIQLI1Iltl0Teel1lovlAILIINTI os10cs1j;IceeeeeeeeyeeaeelSNeeeeeeel1111%71OITXTIWoTIIC1lteeexyleAeeeeet~eeeteeeeeTeeLNICSowJIIAINAVCPaulGorskiMechanical Maintenance ManaerTILCSeeONC NVNII1ANIACOOC3155COUSLCT8ONILINtSONCACIICOIISONCNTSAILUICOCICIIItoNITNII1CSOITIltlCAUtlIYITIIIXCONSONINT TBNANUSAOTUNIIIH34TONSIOIAIjl+M(lh w7CAUIIIYCTCIIcoeesoNINT

~IANUIAOTUNCN~P0IITUg~(A~t:@%FATS!M%~V:IVSSLCNINTAL IICSOATCLSCCTCOIIIIYltOyy<<.~CXSCCTCOCVINIC>>ON OAT>>NOAICTAACTILJevc0IAxleeeee.IA,eeeyeeeeeMy NINeeeeeseeeeeee Iyftsrlllee

<<eeeIIWIIONTIICAYYCA1CISCCTCOWIINCCIONOATI11~IDuringthe1991AnnualRefueling andMaintenance Outagesubsequent totheeddycurrentexamination performed onboththe"A"and"B"Westinghouse series44SteamGenerator (S/G),116tubesinthe"A"S/Gand117tubesinthe"B"S/Grequiredcorrective actionduetotubedegradation.

Theimmediate causeoftheeventwasthatthe"A"and"B"S/Gstubedegradation wasinexcessoftheGinnaQualityAssurance Manualreportability limits.Theunderlying causeofthetubedegradation isacommonS/Gproblemofapartially rolledtubesheetcrevicewithrecurring Intergranular Attack/Stress Corrosion Cracking(ZGA/SCC) andPrimaryWaterStressCorrosion Cracking(PWSCC)attackonS/Gtubing.Corrective actiontakenwastoei.thersleeveorplugtheaffectedtubeswithacceptedindustryrepairmethods.NACSeeeIOII&All

1114terU~10451LICENSEEEVENTREPORTILERITEXTCONTINUATION II.5.IIIICLtA1 154MLATOAY COQMINIISI rAftAOvtOOUOHO5ltOWIOtt)CPIII55 t/TIESFACILITYIIAAIt111OOCKtTIIIIlttt1 IllL51IluatttaIa~54VtleTIAL UVISIONUA~AOtItlR.E.GinnaNuclearPowerPlantTtXTIIT~~1~.~~I@AC/4PIII~tlIITIosooo24491-005-0002OFPRE-%TENT PLANT'ONDITIONS TheunitwasintheCold/Refueling Shutdowncondition for~theAnnualRefueling andMaintenance Outage.ReactorCoolantSystem(RCS)pressurewaszero(0)psigandRCStemperature wasapproximately 68F.SteamGenerator eddycurrentinspection wasinprogress.

DESCRIPTION OP~9FZA.DATESANDAPPROXIMATE TIMESOPMAZOROCCtJREUBTCES:

oApril14,1991,1600EDST:Eventdateandtime.oApril14,1991,1600EDST:Discovery dateandtime.oApril16,1991,1430EDST:Oralnotification madetotheNRCofficeofNuclearReactorRegulation (NRR).oApril22,1991,0400EDST:SteamGenerator repairscompleted.

oApril26,1991,Follow-up writtenreportsenttoNRCOfficeofNRR.rB.&TENT:Duringthe1991AnnualRefueling andMaintenance Outage,aneddycurrentexamination

.wasperformed inboththe"A"and"B"Westinghouse miseries44iDesignrecirculating steamgenerators.

Thepurposeoftheeddycurrentexamination wastoassessanycorrosion ormechanical damagethatmayhaveoccurredduringthecyclesincethe1990examin-ation.vAC14111tttAr~

I NACtermESSAI~ILICENSEEEVENTREPORTILERITEXTCONTINUATION U.S.NUCEtANAtoULATOAV COMMISOON

/Aee1OVEOOMSNOSISO&IOeEXPIIIES.

SIS14SDOCKETNUMStllItlEEIINUMOSNItlstoUENnAI.

"etv4ONNM1MA~AOEISIR.E.GinnaNuclear~PlantTExT/1I'veeNMeee~.eeeeeeaonMITIIC~JKI'elIITIosooo24491-005-00030F08Theexamination wasperformed bypersonnel fromRochester GasandElectric(RG&E)andAllenNuclear.Associates, Inc.(ANA)..Allp'ersonnel weretrainedandqualified intheeddycurrentexamination methodandhadbeencertified toaminimumafLevelIfordataacquisition andLevelIIfordataanalysis.

Theeddycurrentexamination ofthe"A"and"B"steamgenerators wasperformed utilizing theZetecMiz-18DigitalDataAcquisition system.Thefrequencies selectedwere400,200,100and25KHZ.Theinletorhotlegexamination programplanincludedtheexamination of100%ofeachopenunsleeved steamgenerator tubefromthetubeendtothefirsttubesupport.20%ofthehotlegtubeswereselectedforexamination fortheirfulllength(20%randomsampleasrecommended intheElectricPowerResearchInstitute (EPRI)guidelines.)

Inaddition, 20%ofeachtypeofsleevewasexaminedandtheremaining tubeexaminedfulllength.Allprevioustubeswithindications greaterthan20%throughwall(TW)depthwereexamined, asaminimum,tothelocationoftheirdegradation.

AllRow1andRow2U-Bendregionsselectedaspartofthe20%randomsamplewereexaminedwiththeMotorized RotatingPancakeCoil(MRPC)betweentheg6TubeSupportPlateHot(TSPH)andtheg6TubeSupportPlateCold(TSPC)fromthecoldlegside.Resultsoftheaboveinspections indicated that116tubesinthe"A"steamgenerator (i.e.91newrepairs--plus1pulledtubeplus24previously pluggedtubes)and117tubesinthe"B"steamgenerator (i.e.98new-mepairsplus1obstructed sleevedtubeplus16previously pluggedtubesplus2plugsexhibiting PWSCC)requiredcorrective action.NACeOAMSNA(eg]I

IIACtens~(t43ILICENSEEEVENTAEPOATILEA)TEXTCONTINUATION U~IIUCl,fAll1SOUlATOAT COMMt%IOSI AttAOVEOOUSSIO31SO&IOSIIItkAl5SI3lkTStACILITTISASISIIIOOCIISTIIUMISIIQlLlllIIIASCIRISISSQVSATkAL

~kU1gkSkQkk1tAOEISIR.E.GinnaNuclearPowerPlantTEXTlS'tktt~etWVsrC~~tIIICIktttk~'SlIITI2449l-005-0004Oi08OnApril14,1991atapproximately 1600EDST,thereactorwasintheCold/Refueling Shutdowncondition withRCSTemperature andpressureatapproximately 68Fandzero(0)psigrespectively.

Atthistimeafinalreviewoftheeddycurrentdatawascompleted andresultsindicated thatmorethan1percentofthetotaltubesinspected weredegraded(i.e.imperfections greaterthantherepairlimit).Becauseoftheabove,theresultsoftheinspection areconsidered areportable eventpursuantto10CFR50.73perAppendixBoftheGinnaStationQualityAssurance Manual.OnApril16,1991atapproximately 1430EDSTOralNotification wasmadetotheNRC'officeofNRRpursuanttoAppendixBoftheGinnaStationQualityAssurance Manual.OnApril26,1991,afollow-up writtenreportofthesteamgenerators inspection andrepairswassenttotheNRCOfficeofNRRpursuanttoAppendixBoftheGinnaStationQualityAssurance Manual:CINOPERABLE STRUCTURESt COMPONENTSt ORSYSTEMSTHATCONTRIBUTED TOTHEEVENT:None.D.OTHERSYSTEMSORSECONDARY FUNCTIONS AFFECTED-kNone.E.METHODOFDISCOVERY:

Theeventwasapparentafterthereviewofthe"A"and"B"SteamGenerators eddycurrentexamination results.F.OPERATORACTION:None.VACtOAISSQSAkt4$I

11CSons5$5AI$45ILICENSEEEVENTREPORT(LERITEXTCONTINUATION VS.IIVCL5AA150VLATOAT COI<<It&IOII ASSAOV50O<<5HO5I$4&IOI5)ISI1555ITI4$SACILITTIIA<<5IIIOOCKSTIIV<<llllITILl114<<ll1IN$$4yonnsLM1ylglosvSA4lI5IR.E.GinnaNuclearPowerPlantTTXTIIS~<<eee1<<O<<OO,y<<OOSS<<nOS ITACSOno~$IIITIosooo244910050005OFG.SAFETYSYSTEMRESPONSES:

None.III.CAUSEOPEVE2FZA.IMMEDIATE CAUSE:TheImmediate Causeoftheeventwasthatthe"A"and~"B"steamgenerator tubedegradation wasinexcessoftheGinnaStationQualityAssurance ManualReportable limits.B.ROOTCAUSE:Theresultsoftheexamination indicatethatIGAandIGSCCcontinuetobeactivewithinthetubesheet creviceregionontheinletsideofeachsteamgenerator.

Asinthepast,IGA/SCCismuchmoreprevalent inthe"B"steamgenerator with42newIGAindication and37newIGSCCindications reported.

Inthe"A"steamgenerator, 14newIGAindications and16newIGSCCindications werereported.

Themajorityoftheinlettubesheet crevicecorrosion

.indications areIGA/SCCoftheMil-annealed Inconel600TubeMaterial.

Thisformofcorrosion isbelievedtobetheresultofthetubesheet crevicesforminganalkalineenvironment.

Thisenvironment hasdeveloped overtheyearsasdepositsandactivespecieslikesodiumandphosphates, havereacted,changinganeutralorinhibited creviceintotheaggressive environment thatpresently exists.AlongwithIGA/SCCinthecrevice,PWSCCattherolltransition appearstohaveaslightincreaseingrowthduringthelastoperating cycle.Thismechanism wasfirstaddressed in1989andthisyeartherewere19PWSCCindications in"B"SteamGenerator and59PWSCCindications in"A"SteamGenerator.

ssCs41<<$4AA

IIACtvvMI~lLICENSEEEVENTREPORTILERITEXTCONTINUATION II%NVCLfAAAfOIJLATOAT CCNQN&IOII' AttAOVfOOllfrOfISO&10if)Irlllf5~ITIS'ACILITTHAIrfIIIOOCCfTIILAWfAlflLfllIIUMMR(flyfAAWOMLNTIAL

'4IOHr1~AofIflR.E.GinnaNuclearPowerPlantTEXTIll'VrvrteWeer.yvereecveVr'IIC~~'alIITIosooo24491-00500060FO8ANALYSISOFEVENTTheeventisreportable inaccordance with10CFR50.73,LicenseeEventReportitem(Other)andtheGinnaStationQualityAssurance ManualAppendixBwhichrequiresthat,"Ifthenumberoftubesinagenerator fallingintocategories aorbexceedsthecriteria, thenresultsoftheinspection shallbeconsidered aReportable Eventpursuantto10CFR50.73."The,tubedegradation inthe"A"and"B"steamgenerators exceededthecriterion of(b)whichstates,"morethan1%oftotaltubesinspected aredegraded, (imperfections greaterthantherepairlimit)."Thisrepairlimitisdefinedas,"steamgenerator tubesthathaveimperfections greaterthan404throughwall,asindicated byeddycurrent,shallberepairedbypluggingorsleeving."

Anassessment wasperformed considering thesafetycon-sequences andimplications ofthiseventwiththefollowing resultsandconclusions:

Therewerenooperational orsafetyconsequences orsafetyimplications resulting fromthesteamgenerator tubedegradation inexcessoftheQualityAssurance Manualreportable'imits because:oThedegradedtubeswereidentified andrepairedpriortoanysignificant leakageorsteamgenerator tuberuptureoccurring.

oEvenassumingacompleteseverance ofasteamgenerator tubeatfullpower,asstatedintheR.E.GinnaNuclearPowerPlantupdatedFinal,SafetyAnalysisReport(Ginna/UFSAR) section15.6.3,(SteamGenerator TubeRupture)thesequenceofrecoveryactionsensuresearly'ermination ofprimarytosecondary leakagewithorwithoutoffsitepoweravailable thuslimitingoffsiteradiation dosestowithintheguidelines of10CFR100.Basedontheabove,itcanbeconcluded thatthepublic'shealthandsafetywereassuredatalltimes.rACNOAH~

IIAC>vssstttAI944ILICENSEEEVENTREPORT(LER)TEXTCONTINUATION V.t.ISVCEEAAAEOVLATOIIY COAIMIttIOII IAlrAOYEOOastssO)Ito&IOaEXPIAE$IttIstSlACILITYIIA1ltIIIOOCXETISVIMtllIllEEIIIIIAAtltI~Itt4SStSSTSA4ssYstsOss~stA~AOEItlR.E.GinnaNuclearPowerPlantTExfillsssvYAsAcs0~.ssvAtsssawss sYAcssssssss~TOIITIosooo2449-1-05-0007ov08V.CORRECTIVE ACTIONA.ACTIONTAKENTORETURNAPPECTEDSYSTEMSTOPRE-E%9lT

'ORMALSTATUS:00Ofthe116degradedtubesinthe"A"steamgenerator, 61tubeswererepairedusingaCombustion Engineering'27" weldedsleeveinthehotlegplus41tubeswererepairedusingaCombustion Engineering 30"weldedsleeveinthehotlegandalloftheabovetubeswillremaininservice.Theremaining 14tubeswereremovedfromservicebypluggingboththehotandcoldlegtubeends.Atotalof190tubesin"A"@Gare.currently pluggedand324tubesaresleeved.Ofthe117degradedtubesinthe"B"steamgenerator, 80tubeswererepairedusingaCombustion Engineering 27"weldedsleeveinthehotlegplus28tubeswererepairedusingaCombustion Engineering 30"weldedsleeveinthehotlegandalloftheabovetubeswillremain.inservice.Theremaining 9tubeswereremovedfromservicebypluggingboththehotandcoldlegtubeends.Atotalof326tubesinthe"B"S/Garecurrently pluggedand938tubesaresleeved.B.ACTIONTAKENORPLANNEDTOPE~TENTRECURMQTCE Theoccurrence/presence ofIGA,SCCandPWSCCisacommonPWRSteamGenerator problem.Utilities with~usceptible tubingandpartially rolledcrevicesmustdealwiththisrecurring attackonsteamgenerator

--<ubing.R.E.GinnaStationwillcontinuecarefulmonitoring ofbothprimaryRCSandsecondary sidewaterchemistry parameters.

Thesewaterchemistry parameters willbeevaluated againstacceptedindustryguidelines inordertominimizeharmfuland/orsecondary sideenvironments.

asAClOAsAtttAhaI~as

NIICSeamSNAI04SI1LICENSEEEVENTREPORTILER)TEXTCONTINUATION U.S.NUCLSANAS4ULATOIIY COAIAIISSION ASSAOYSOOMSNOSlSOWI04rs>>sIAsssnInsSACILITYNAIICIllDOC>>STNU~SIIITILSIINI>>AOSIIIIIssQUANT>AL YNIOHSAOSISIR.E.GinnaNuclearPowerPlantTGCTIIIee>>eNNee~teeeecceoeeeeeeeIJV>>CSee>>~'elIITIo5ooo24491-005-0008OFO8DegradedSteamGenerator tubesshallbesleevedorpluggedinaccordance withtheinservice inspection programandacceptedindustryrepairmethods.ADDITIONAL INFORMATION FAILEDCOMPONENTS.

Thedegradedcomponents are:InconelGrade600tubeshavinganoutsidediameterof0.875inchesandanominalwallthickness of0.050inches.B.PREVIOUSLERsONSIMILAREVENTS:AsimilarLEReventhistorical searchwasconducted withthefollowing results:Thecreviceindications aresimilartothosereportedinA0-74-02, A0-75-07, R0-75-013, andLERs76-008,77-008,78-003,79-006,79022s80003s81009s82003s82022s83013s89001,and90-004.C.SPECIALCOMMIBFXS:

Foramoreindepthreport,refertothe,"1991SteamGenerator EddyCurrentExamination SummaryReport"senttotheNRCApril26,1991.~vACSOAKSAAAIeeSTI

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