ML17265A743

LER 99-004-01:on 990412,discovered That Containment Recirculation Fan Chevron Separator Vanes Were Installed Backwards.Caused by Improper Assembly by Mfg.Moisture Separator Vanes Were Dismantled & Correctly re-installed

ML17265A743
Person / Time
Site:	Ginna
Issue date:	08/24/1999
From:	VITALI C ROCHESTER GAS & ELECTRIC CORP.
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ML17265A742	List: ML17265A741 ML17265A743
References
LER-99-004, NUDOCS 9909010030
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I)NRCFORM366{61688)U.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAMEi1)R.E.GinnaNuclearPowerPlantLICENSEEEVENTREPORT(LER){Seereverseforrequirednumberofdigits/charactersforeachblock)PAGEI3)1OF7DOCKETNUMBERl2)050002448"ICPYPP"BthPILew(P"informationcollectionrequest:50hrs.Reportedlessonslearnedareincorporatedintothelicensingprocessandfedbacktoindustry.ForwardcommentsregardingburdenestimatetotheRecordsManagementBranch(TRF33),U.S.NuclearRegulatoryCommission,Washington.DC205554001~andtothePapenvorkReductionProject{3150%104),OfficeofManagementandBudget,Washington,DC20503.IfaninformationcollectiondoesnotdisplayacurrentlyvalidOMBcontrolnumber,theNRCmaynotconductorsponsor.andaTITlE(4)ContainmentRecirculationFanMoistureSeparatorVanesIncorrectlyInstalledResultsinPlantBeingOutsideItsDesignBasisEVENTDATE(5ILERNUMBER{6)REPORTDATE(7)OTHERFACILITIESINVOLVED{6)MONTHDAYYEARYEARSEOUENTIALNUMBERREYLSIONNUMBERMONTHOAYYEARFACILITYNAMEDOCKETNUMBER05000041219991999-004-0108241999FACILITYNAMEDOCKETNUMBER05000OPERATINGMODE(9)POWERLEVEL(10)000THISREPORTISSUBMITTEDP20.2201(b)20.2203(a)(T)20.2203(a)(2)(i)20.2203(a)(2)(ii)URSUANTTOTHEREQUIREMENTSOF10CFRE:(Check50.73(a)(2){i)(B)20.2203(a)(2)(v)20.2203(a){3)(i)20.2203(a)(3)(ii)20.2203(a)(4)X50.73{a)(2)(ii)50.73(a)(2){iii)50.73(a)(2)(iv)oneormore)(11)50.73(a)(2)(viii)50.73(a)(2)(x)73.71OTHER20.2203(a)(2)(iii)20.2203(a)(2)(iv)50.36(c)(1)50.36(c)(2)LICENSEECONTACTFORTHISLER{12)50.73(a){2)(v)50.73(a)(2){vii)SpecifylnAbstractbeloworinNRCForm366ANAMETELEPHONENUMBER(IiciudeAreaCode)CarmenVitali-SeniorEngineer(716)771-3606CAUSESYSTEMCOMPONENTMANUFACTURERREPORTABLETOEPIXIln>.CAUSESYSTEMCOMPONENTMANUFACTURERREPORTABIETOEPIXSUPPLEMENTALREPORTEXPECTED(14)YES(Ifyes,completeEXPECTEDSUBMISSIONDATE).XNoEXPECTEDSUBMISSIONDATE(15)MONTHOAYYEARABSTRACT{Limitto1400spaces,i.e.,approximately15single-spacedtypewrittenlines)(16)OnApril12,1999,atapproximately1600EDST,theplantwasshutdowninMode5.Itwasdiscoveredthatthecontainmentrecirculationfanchevronmoistureseparatorvaneswereinstalledbackwards,sothatthepathforairflowwaslesstortuous,decreasingmoistureseparationeffectiveness.Correctiveactionwastoremovethevanesandinstallthemintheproperorientation.Theincorrectinstallationwasaresultofimproperassemblybythemanufacturerinthe1960's.Theoriginalmoistureremovalequipmentconsistedofanassemblymadeupofthechevrontypevanesandfiberglassmoistureremovalpads.Thisequipmentwasshop-assembledandshippedtoGinnaStation.Vendorphotographstakenduringoriginalshopassemblyshowthevanesinstalledinamannernowknowntobeincorrect.CorrectiveactiontopreventrecurrenceisoutlinedinSectionV.99090i0030990E)24PDRADOCK050002448PDR NRCFORM366A(6.1998)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAME(1)R.E.GinnaNuclearPowerPlantDOCKET(2)05000244LERNUMBER(6)yEARSEIIUENTIAENUMBERNUMBER1999-004-01PAGE(3)2OF7TEXTiifmorespaceisrequired,useadditionalcopiesofhfRCForm366AI(17)PRE-EVENTPLANTCONDITIONS:OnApril12,1999,theplantwasshutdowninMode5forthe1999refuelingoutage.Amongthemanyactivitiesinprogressduringthe1999refuelingoutage,maintenancewasbeingperformedontheContainmentRecirculationFanCoolers(CRFC)~Atapproximately1600EDST,anengineerfromNuclearEngineeringServices(NES)discoveredthatthechevronmoistureseparatorvanesfortheCRFCswereinstalledcontrarytothatshowninavendormanualdiagram,butcorrectlyasshownonavendoroutlinedrawing.DESCRIPTIONOFEVENT:A.DATESANDAPPROXIMATETIMESOFMAJOROCCURRENCES:oOriginalconstructioncirca1969:Eventdateandtime.oApril12,1999,1600EDST:Discoverydateandtime.oApril17,1999,1000EDST:Chevronmoistureseparatorvanesarecorrectlyinstalled.B..EVENT:OnApril12,1999,theplantwasshutdowninMode5forthe1999refuelingoutage.Amongthemanyactivitiesinprogressduringthe1999refuelingoutage,maintenancewasbeingperformedontheContainmentRecirculationFanCoolers(CRFC).Atapproximately1600EDST,anengineerfromNuclearEngineeringServices(NES)discoveredthatthechevronmoistureseparatorvanesfortheCRFCswereinstalledcontrarytothatshownonavendormanualdiagram,butcorrectlyasshownonavendoroutlinedrawing.Afterfurtherevaluationanddiscussionswiththevendor,itwasconcludedthatthevaneswereinstalledbackwards,sothatthepathforairflowislesstortuousthanifthevaneswerecorrectlyinstalled.ThesevanesareTypeTMistExtractors,manufacturedbyAmericanAirFilterCo.,Inc.TheCRFCSystemconsistsoffourfanunits(A,B,C,andD),ofwhichtheAandCunitssupplycharcoalfilters.Eachcoolingunitconsistsofamotor,fan,coolingcoils,dampers,moistureseparators(vanesandpads),highefficiencyparticulateair(HEPA)filters,ductdistributorsandnecessaryinstrumentationandcontrols.Airisdrawnintothecoolersthroughthefananddischargedintothecontainmentatmosphere.ThemoistureseparatorsfunctiontoreducethemoisturecontentoftheairstreamtosupporttheeffectivenessoftheHEPAandpost-accidentcharcoalfilters.

NRCFORM366A(61998)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMIVIISSIONFACILITYNAME(1)R.E.GinnaNuclearPowerPlantDOCKET(2)05000244LERNUMBER(6)rEANSEGUENTNLNUMUENNUMSEA1999-004-01PAGE(3)3OF7TEXT(Ifmorespaceisrequired,useadditionalcopiesofNRCForm366AI(17)Followingthecoolingcoilsisthemoistureseparatorsection,designedtoremoveentrainedmoistureexitingthecoolingcoils.Twoseparatemoistureremovalprocessesareemployed;thefirstbydirectimpingementonverticalhookedvanes,andthesecondbytrappingonseparatorpads.Runofffrombothstagesflowsintocollectionpansfromwhichitispipedtothecontainmentsump.Themoistureseparatorcasings,hookedvanes,andcollectionpansarefabricatedofgalvanizedsteel.Withthevanesinstalledbackwards,themoistureseparationcapabilityisdecreased.CRFCperformancewasnotcompletelyanalyzedforthiscondition.Thesupplierofthemoistureremovalequipment(AmericanAirFilter)wascontacted.Itwasconcludedthatthisconditionwasaresultofimproperassemblybythemanufacturerinthe1960's.Theoriginalmoistureremovalequipmentconsistedofanassemblymadeupofthechevrontypevanesandfiberglassmoistureremovalpads.Thisequipmentwasshop-assembledandshippedtoGinnaStation.Vendorphotographstakenduringoriginalshopassemblyshowthevanesinstalledinamannernowknowntobeincorrect.Asdirectedbythesupplier,thevaneshadtobedismantledandthencorrectlyinstalled.C.INOPERABLESTRUCTURES,COMPONENTS,ORSYSTEMSTHATCONTRIBUTEDTOTHEEVENT:NoneD.OTHERSYSTEMSORSECONDARYFUNCTIONSAFFECTED:NoneE.METHODOFDISCOVERY:ThiseventwasdiscoveredbyanengineerfromNES,whowassupportingCRFCmaintenance.F.OPERATORACTION:TheplantwasinMode5atthetimeofdiscovery,andtheCRFCsarenotrequiredtobeoperableinthismode.AftertheNESengineernotifiedtheShiftSupervisorofthiscondition,noimmediateactionswereneededbytheControlRoomoperators.Subsequently,theShiftSupervisornotifiedhighersupervisionandtheNRCGinnaSeniorResidentInspector.TheShiftSupervisornotifiedtheNRCper10CFR50.72(b)(2)(i),non-emergencyfourhournotification,atapproximately1948EDSTonApril12,1999.G.SAFETYSYSTEMRESPONSES:None NRCFORM366AISIB98)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAMEI1)R.E.GinnaNuclearPowerPlantDOCKETI2)05000244LERNUMBERIB)TEARSEQUENTIALREVISIQNNUMBERNUMBER1999-OP4..O1PAGEI3)4OF7TEXTllfmorespaceisrequired,useadditionalcopiesofNRCForm366'17)III.CAUSEOFEVENT:A.IMMEDIATECAUSE:Theimmediatecauseoftheplantpossiblyoperatingoutsideitsdesignbasiswasthattheinstalledconfigurationresultedindecreasedmoistureseparationcapabilityafteradesignbasisaccident,resultinginlesscoolingcapability.B.INTERMEDIATECAUSE'heintermediatecausewasinstallationofimproperlyassembledmoistureseparatorunits.Theoriginalmoistureremovalunitsconsistedofassembliesmadeupofthechevrontypevanesandfiberglassmoistureremovalpads.Thisequipmentwasshop-assembledandshippedtoGinnaStation.Vendorphotographstakenduringoriginalshopassemblyshowthevanesinstalledinamannernowknowntobeincorrect.C.ROOTCAUSE:Theunderlyingcauseofthevanesbeinginstalledbackwardswasamanufacturingerror.IV.ANALYSISOFEVENT:Thiseventisreportableinaccordancewith10CFR50.73,LicenseeEventReportSystem,item(a)(2)(ii)(B),whichrequiresareportof,"Anyeventorconditionthatresultedintheconditionofthenuclearpowerplant,includingitsprincipalsafetybarriers,beingseriouslydegraded;orthatresultedinthenuclearpowerplantbeing:(B)Inaconditionthatisoutsidethedesignbasisoftheplant.Anassessmentwasperformedconsideringboththesafetyconsequencesandimplicationsofthiseventwiththefollowingresultsandconclusions:Therewerenooperationalorsafetyconsequencesorimplicationsattributedtothemoistureseparatorvanesinstalledbackwardsbecause:Themaximumairvelocitythroughthecontainmentrecirculationfancoolingcoilsafteraloss-of-coolantaccident(LOCA)airvelocitythroughthecoilisbelowtheAmerican'SocietyofHeating,RefrigeratingandAir-ConditioningEngineers(ASHRAE)thresholdof600feetperminute(FPM)formoistureentrainmentbothforthenewandoldconfiguration.Thecoilswillactasmoistureseparatorsduetothedepthofthecoilandspacingbetweenfins,eveniftheyarenotoperating.AheatingcoilsimilartothecoolingcoilsinstalledatGinna,wastestedwithaspraystreamequivalenttotheGinnaStationLOCAenvironmentdirectedatthecoilentrance,butwithaslightlylowerairstreamvelocity(400FPM)thanGinna.Nomoisturecarry-overwasobservedontheoutletofthecoiloronthemoistureseparatordownstreamofthecoil.Approximately5%ofthespraywasevaporatedbythecoilheating.

NRCFORM366A(91998)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAME(1)R.E.GinnaNuclearPowerPlantDOCKET(2)05000244LERNUMBER(6)"TEARSEOUENTIALREUISIONNUMBERNUMBER1999-004-01PAGE(3)6OF7TEXTIifmorespaceisrequired,useadditionalcopiesofNRCForm366AI(17)Additionallouversarelocatedontheinlettothecoilswhichwillremovesomeentrainedmoisturepriortoenteringthecoolingcoils,whicharenottakencreditforintheCRFCunitoperation.Theairvelocitysignificantlyreducesafterexitfromthecoolingcoils,andwouldallowentraineddropletstofalltothefanunitfloorpriortoreachingtheHEPAfilterswhicharelocatedapproximately6feetfromthecoolingcoils.0ThemoistureseparatormediapadslocatedupstreamoftheHEPAfiltershavebeentestedandfoundtoremovemoistureupto1.5Ibs/100cu.ft.ThemaximumexpectedentrainedmoisturecontentinthecontainmentenvironmentduetocontainmentsprayandcondensationisonlyOAIbs/1000cu.ft.TheoriginalmediapadsinstalledatGinna(AmericanAirFilterModelM-105)werereplacedwithnewmodelM-81padsthathavenotbeentestedtoGinnaLOCAconditions.However,duetosimilaritiesindesign,theyareexpectedtoremainfunctionaleventhoughtheyhavenotbeencreditedtofunctionduetolackofqualification.Themoistureseparatorvanesontheoutletofthecoilwouldstillremoveentrainedwatereventhoughtheyareinstalledbackwards,duetotheirtortuouspath.Thenumberofhookswhichprotrudeintotheflowstreamisreducedfrom3to1.However,themoistureremovalisdominatedbythespacingbetweenadjacentvanes,lengthofeachvaneandnumberofvaneturnsinpath,allofwhichareunaffectedwiththevanesinstalledbackwards.Thewaterdropsfollowasine-wavepaththroughthevanes.Theoverallefficiencyforthebackwardsinstallationisestimatedtobe25%.ThemoistureremovalcapacityrequirementasspecifiedintheoriginalBillofMaterialsforthemoistureremovalsectionoftheCRFCunitis0.4Ibs/1000cu.ft.This25%reductioninthevaneefficiencycanbeeasilycompensatedforbythemoistureremovalpadssincetheyweretestedatmoisturelevelsofgreaterthan1.0Ibs/1000cu.ft.Inaddition,theHEPAfilterswerealsotestedandtheirpressuredropincreasedby0.5incheswithanequivalentmoistureloadingofOAIbs/1000cu.ft.Itisbelievedthattheadditional0.5inchesofpressurelossiswithintheexistingmarginoftheas-installedequipmentandwouldresultinreductionintotalsystemCRFCflowoflessthan10%0ThemainimpactofaslightlyreducedCRFCcoolingcapabilityonthedesignbasisaccidents(DBAs)suchasLOCAsandMainSteamLineBreaks(MSLBs)wouldbeareductioninthelongtermcoolinganddepressurizationcapabilityofcontainment.ImpactonpeakcontainmentpressuresforDBAsisexpectedtobenegligible.SincepeakcontainmentpressurestypicallyoccurwithinthefirstcoupleofminutesfollowingDBAs,theincreaseinHEPAfilterhydraulicresistancewouldnotbefullydevelopedoverthistimeduetothelimitedwaterloadingontheHEPAfiltersimmediatelyfollowingaDBA.Additionally,theearlyoccurrenceofcontainmentpeakpressureslimitstheintegratedamountofenergythatisremovedbytheCRFCsuptothetimeofpeakcontainmentpressure.Therefore,anydegradationinCRFCheatremovalcapabilityduetoreducedairsideflowimmediatelyfollowingaDBAwouldhaveanegligibleimpactontheoverallcontainmentenergybalanceatthetimeofpeakcontainmentpressure.Baseduponthesefactors,anyincreaseinpeakcontainmentpressurethatcouldhaveoccurredasaresultoftheimproperlyinstalledlouversisjudgedtobewithintheoverallstructuralcapabilityofthecontainmentfollowingaDBA,althoughcontainmentdesignpressuremayhavebeenslightlyexceeded.

r NRCFORM366A(61968)LlCENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAME(1)R.E.GinnaNuclearPowerPlantDOCKET(2)05000244LERNUMBER(6)yEARBEOUENTNLNUMBERNUN'IBER1999-004-01PAGE(3)6OF7TEXTIlfmorespaceisrequired,useadditionalcopiesofNRCForm366AI(17)Aspreviouslystated,themajorimpactofreducedheatremovalcapabilityduetowaterloadingoftheHEPAfilterswouldbeonlongtermcontainmentcooling,sinceContainmentSprayflowisterminatedaftertheplanthastransitionedtotheRecirculationModeofcooling.AnyreductioninCRFCcoolingcapabilityduetoreducedairflowwouldcauseaslowercontainmentcoodownanddepressurization.AlthoughthisslowercontainmentcooldowncouldpotentiallyaffecttheEquipmentQualification(EQ)profilesofsafety-relatedequipmentincontainment,areviewoftheexistingGinnaEQprofilesforcontainmentindicatesthatsufficientmarginexistsduringthefirsttwenty-fourhoursfollowingaDBAtoaccommodateaslowercooldown.Consequently,noadverseimpactonpastoperabilityofqualifiedequipmentincontainmentisexpectedtohaveexisted.oTheGinnaControlRoomandoff-sitedosecalculationswerere-evaluatedassumingactualcontainmentintegratedleakagefromtestingperformedin1996andactualpredictedcontainmentdepressurizationratesforGinna.BasedontheseassumptionsandcontinuousoperationoftheCRFCsinapost-LOCAenvironment,itisestimatedthataminimumcharcoalfilteriodineremovalefficiencyof10%wouldberequiredtomaintainoff-sitedosesbelow300RemandControlRoomthyroiddosesbelow30RemandtherebysatisfytheGinnalicensingbasisrequirementasrequiredby10CFR100andGeneralDesignCriterion(GDC)19.BasedonadditionalanalysisthatwasperformedbyRG(ltEin1999,charcoalfilterswerefoundtohave40%oftheirvolumestillavailableforiodineremovalevenwhen100%saturated.Sincetheminimumrequiredcharcoaliodineremovalefficiencyisappreciablysmallerthantheminimumexpectedcharcoalefficiencyof40%forawettedcondition,thedesignfunctionofthefiltersasitrelatestothyroidsdosetoon-siteandoff-sitepersonnelwouldstillhavebeensatisfiedevenwiththelouversinstalledbackwards.Basedontheaboveandthereviewofpastplanttransients,itcanbeconcludedthatthepublic'shealthandsafetywasassuredatalltimes.V.CORRECTIVEACTION:A.ACTIONTAKENTORETURNAFFECTEDSYSTEMSTOPRE-EVENTNORMALSTATUS:Themoistureseparatorvanesweredismantledandcorrectlyre-installed.B.ACTIONTAKENORPLANNEDTOPREVENTRECURRENCE:Theas-leftconfigurationofthemoistureseparatorunitsdoesnotallowthevanestobeinstalledincorrectly.VI.ADDITIONALINFORMATION:A.FAILEDCOMPONENTS:None

NRCFORM366A(6.1898)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAME(1)R.E.GinnaNuclearPowerPlantDOCKET(2)05000244LERNUMBER(6)yEARSEOUENTIAEREVISIONNUMBERNUMBER1999-004-01PAGE(3)7OF7TEXT(Ifmorespaceisrequired,useadditionalcopiesofNRCForm366AJ(17)B.PREVIOUSLERsONSIMILAREVENTS:AsimilarLEReventhistoricalsearchwasconductedwiththefollowingresults:NodocumentationofsimilarLEReventswiththesamerootcauseatGinnaStationcouldbeidentified.C.SPECIALCOMMENTS:None