ML17251B094

From kanterella
Revision as of 14:06, 18 May 2018 by StriderTol (talk | contribs) (Created page by program invented by StriderTol)
Jump to navigation Jump to search
Rev 2 to Steam Generator Hydraulic Snubber Replacement Program.
ML17251B094
Person / Time
Site: Ginna 
Issue date: 05/08/1988
From:
ROCHESTER GAS & ELECTRIC CORP.
To:
Shared Package
ML17251B091 List:
References
PROC-880508, NUDOCS 8805200121
Download: ML17251B094 (112)
v • d • e


Text

ROCHESTERGASANDELECTRICCOMPANYGINNANUCLEARPOWERPLANTSTEAMGENERATORHYDRAULICSNUBBERREPLACEMENTPROGRAMMAY8,1988REVISION2'8805200121880513PDR'ADOCK05000Z44'PDCD

SectionTABLEOFCONTENTSTitleLISTOFTABLESLISTOFFIGURESPage1v1.02.03.04.

05.0INTRODUCTION

1.1ExistingDesign1.2ProgramOverview1.3AnticipatedBenefits1.4PrimarySystemQualification1.5IntentofReportDESIGNLOADSANDCRITERIA2.1DesignBasisLoads2.1.1LoadingConditions2.1.2PostulatedPipeRuptures2.2GeneralCriteriaPRIMARYSYSTEMANALYSIS3.1PipingAnalysis3.1.1MathematicalModels3.1.2Methodology3.1.3ComputerPrograms3.1.4SupportStiffnesses3.1.5PipingEvaluationCriteria3.1.6PipingLoadCombinations3.2PrimaryEquipmentSupportsEvaluation3.2.1Methodology3.2.2SupportLoadingsandLoadCombinations3.2.3EvaluationCriteria3.2.4ComputerProgramsEVALUATIONANDRESULTS4.1ReactorCoolantLoopPiping4.2ApplicationofLeak-Before-Break4.3MainSteamLineBreakLocations4.4PrimaryEquipmentSupports4.5PrimaryComponentNozzleLoadConformance4.6EvaluationofAuxiliaryLines4.7BuildingStructuralEvaluation4.7.1EvaluationofLocalAreas4.7.2SecondaryShieldWalls4.7.3ConclusionsADDITIONALCONSIDERATIONS5.1OvertemperatureEvent5.2ColdShutdown5.2.1RCSAnalysis5.2.2PrimaryEquipmentSupportsii1-11-11-11-31-31-42-12-12-12-22-43-13-13-13-23-73-73-103-113-113-113-123-133-84-14-14-14-14-24-24-34-34-34-44-45-15-15-15-15-1 Section6.0TABLESOFCONTENTS(cont'd.)TitleQUALITYASSURANCE6.1RochesterGasandElectricCorporation6.2Westinghouse6.3AltranPage6-16-16-16-

17.0CONCLUSION

S7-

18.0REFERENCES

8-1APPENDIXACombinationofSeismicModalResponsesA-1 1

LISTOFTABLESTable1:RCSPipingLoadCombinationsandStressLimitsPacaeT-lTable2:Table3:DefinitionofLoadingConditionsforPrimaryEquipmentEvaluationLoadCombinationsand.AllowableStressLimitsforPrimaryEquipmentSupportsEvaluationT-2T-3Table4:MaximumReactorCoolantLoopPipingStressesTable5:CombinedLoadsforLoopPipingLeak-Before-BreakTable6:RCSPrimaryEquipmentSupportsStressMarginSummaryTable7:SteamGeneratorUpperSupportsSeismicLoadMargin(BasedonKavg)T-4T-5T-6T-7Table8:Table9:SteamGeneratorUpperSupportsSeismicLoadMargin(BasedonKavgandKmax/Kmin)PrimaryEquipmentSupportsColdShutdownSeismicLoadMarginSummaryT-8T-9 1

GINNASTATIONSTEAMGENERATORSNUBBERREPLACEMENTPROGRAMLISTOFFIGURESFigure1:EquipmentLayoutPacCeF-1Figure2:UpperSupportConfiguration-ProposedModificationF-2Figure3:SteamGenerator1A/1B-DetailsFigure4:RigidStructuralMember(Bumper)-DetailsFigure5:ReactorCoolantLoops1A&1BAnalyticalModel(StaticandSeismicAnalysis)Figure6:ReactorCoolantLoopPiping/SupportModel(One-LoopModelforTime-HistoryPipeRuptureAnalysis)Figure7:ReactorCoolantLoop-HydraulicForceLocationsFigure8:ReactorCoolantLoopPiping/SupportModel(One-LoopModelShowingLocationofLumpedMassesforApplicationofTime-HistoryHydraulicLoads)F-3F-4F-5F-7F-8Figure9:BlowdownForcingFunctionTime-HistoryPlot-RCSBranchPipingRuptureF-9Figure10:ReactorCoolantLoopsA&B-HotConditionFigure11:SeismicResponseSpectrum-SSEF-10F-11 1

1.0INTRODUCTION

ThisreportdescribesaproposedmodificationtotheexistingsteamgeneratorupperlateralsupportconfigurationatGinnaStation,andtheanalyseswhichdemonstratetheacceptabilityofresultingloadsfrompostulatedseismicandotherdesignbasisevents.1.1ExistingDesignRestrainingsupportsexistforboththeupperandlowerportionofeachsteamgenerator(SG).ThelowerportionofeachSGisrestrainedlaterallyandverticallybyasetofsupportsindependentof,andnotaffectedby,theproposedmodification.Theupperportionofeachofthetwosteamgeneratorsisrestrainedagainstlateralseismicandpipebreakloadsbyeight,large(532,000lb.capacity)hydraulicsnubbersasshowninFigure1.ThesesnubbersareconnectedbetweenthebuildingstructureandaringgirderwhichisattachedtofourlugsweldedtotheSGshell.Thesnubbersareinstalledinfourpairswithonepairapproximatelyparalleltothehotlegonthereactorsideofthesteamgenerator,andtheotherpairsplacedapproximately90'part.1.2ProgramOverviewTheintentoftheproposedupperlateralsupportmodificationistoreplacesix'oftheeighthydraulicsnubbersperSGwithrigid1-1

structuralmembers(bumpers),therebyminimizingthenumberofhydraulicsnubbersinserviceforthisapplication.TheredesignedSGuppersupportconfigurationwillretaintwohydraulicsnubbersoneachsteamgeneratorringgirder.Thesesnubbers,alongwiththerearbumpers,willrestrainthesteamgeneratoragainstdynamicmotionsandloadingsalongtheaxisofthehotleg.Restraintofmotionsandloadingsnormaltothehotlegwillbeprovidedbythereplacementbumpersinthatdirection.TheredesignedSGuppersupportconfigurationisshowninFigure2.Thereplacementsupporthardwareconsistsofindividualstructuralassemblieswhichwillbeinstalledwhereveranexistinghydraulicsnubberisremoved.AtypicalassemblyisshowninFigure4.Eachassemblyisstructurallyrigidundercompressionbutwillallowfreedomofmovementinthetensiledirection.EachassemblyisindividuallyadjustableinthefieldtoensurethatclearancesateachbumperpositionareadequateforReactorCoolantLoop(RCL)expansionyetdonotexceedthosepermittedbytheRCLanalysis.Thebumperassembly,anditsindividualcomponents,issizedtowithstandthenewdesignflloads.DetaileddesignoftherigidstructuralmembershasbeenperformedbyRG&E.Fabricationhas'beenperformedbyaqualifiedsupplierhavingaQualityAssuranceProgrammeetingtherequirementsofANSIN.45.2.1-2 II 1.3AnticipatedBenefitsTherequiredmaintenance,in-serviceinspectionandtestingoftheexistingsnubbersareperformedduringannualrefuelingoutages.Surveillanceactivitiesareperformedperiodicallythroughouttheyear..Byreplacingselectedsnubberswithbumpers,annualmaintenanceactivitiesand,consequently,annualradiationexposurestomaintenancepersonnelcanbeminimized.Thehydraulicsnubbersreplacedwithbumperswillberefurbished,andstoredforuseasspares.Itisexpectedthatsparepartsprocurement,aswellasutilizationofshopfacilitiesandriggingequipment,canbeoptimizedasaresultofthissnubberreplacementprogram.1.4PrimarySystemQualificationThesteamgeneratorhydraulicsnubberreplacementprogramhasresultedinchangesintheresponseoftheprimarysystem.TheeffectofthesechangesupontheRCLequipment,pipingandpipingsupportsystemhasbeenanalyzedbyWestinghouse.AnindependentreviewbyaconsultantwithbroadexperienceinRCSIsupportdesignhasalsobeenperformed.Theuseofrigidstructuralmembers(bumpers)intheSGupperlateralsupportsystemwillchangethedegreeofstiffnesswithwhichtheSGsarerestrained.againstdynamicloads.Thesenewstiffnesseshavebeencalculatedandareincludedinthereanalyses.Loadingsfromadesignbasispipebreak(DBPB)postulatedtooccurinan1-3 0

auxiliaryline(RHR,SIaccumulatororpressurizersurgeline)branchconnectionhavealsobeendevelopedusingthenewupperlateralsupportstiffnesses,toassesstheeffectofthenewSGuppersupportconfigurationonthereactorcoolantsystem.PipebreaksintheMainSteamandFeedwaterpipingatthecorrespondingSGnozzleshavealsobeenconsidered.TheanalysisresultsindicatethatRCLstressesanddeflectionshavenotchangedsignificantlyfrompreviousanalyses.ThedetailsoftheRCLpipingsystemanalysis,fortherevisedSGupperlateralsupportconfiguration,areprovidedinSection3.1ofthisreport.Theprimaryequipmentsupportswerealsore-evaluatedfornewsupportloadsgeneratedfromtherevisedRCSpipingsystemanalysisbasedontheproposedSGupperlateralsupportconfiguration.TheevaluationwasconservativelyperformedinaccordancewiththerequirementsoftheASMEBoilerandPressureVesselCode-1974Edition,subsectionNFandAppendixF.Adetailed.discussionoftheprimaryequipmentsupportevaluationisprovidedinSection3.2ofthisreport.ResultsoftheevaluationaresummarizedinTable6.1.5IntentofReportThisreportisintendedtopresentthestructuralqualificationsfortheredesignedsteamgeneratorupperlateralsupport1-4

configuration.ltcontainsthesupportingdatatoconcludethatthemaximumstressesintheRCS,andtheprimaryequipmentsupports,arelessthantheCodeallowablevalues.

2.0DESIGNZOADSANDCRITERIA2.1DesignBasisLoads2.1.1LoadingConditionsTheSGhydraulicsnubberreplacementprogramwillassurethatadequatesupportcapacityismaintainedwithrespecttothedesignbasisloads.TheRCZ,withthemodifiedsteamgeneratorupperlateralsupportconfiguration,wasanalyzedforthefollowingloadingconditions:a~b.c~d.e.DeadweightInternalPressureThermalexpansionSeismicevents(OBEandSSE)PostulatedpiperupturesatSGsecondary-sidenozzles(MainSteam,Feedwater)PostulatedpiperupturesatRCLauxiliarylinenozzles(PressurizerSurge,SIAccumulator,ResidualHeat.Removal)ITheloadsarecombinedinaccordancewithTables1,2,and3.TheloadingconditionswereevaluatedwiththeRCSatfull-powerconditions.Thisisconsistentwithgenericanalysesofthis2-1 type,representingthehigherprobabilityevent,andoccurswhenhigherpipingstressesfromdesignRCLpressuresexistandcodeallowablestressesarelower.Adiscussionofanalysisatotherthanfullpoweroperationisalsoprovidedinthisreport.2.1.2PostulatedPipeRupturesa~RCSPipeRupturesIjTheprobabilityofrupturingprimarysystempipingisextremelylowunderdesignbasisconditions.IndependentreviewofthedesignandconstructionpracticesusedinWestinghousePWRPlantsbyLawrenceLivermoreNationalLaboratory(reference2)hasIprovidedassurancethattherearenodeficienciesintheWestinghouseRCLdesignorconstructionwhichwillsignificantlyaffecttheprobabilityofadouble-endedguillotinebreakintheRCL.Westinghousetopicalreport,WCAP-9S58,Rev.1(reference1),providedthetechnicalbasisthatpostulateddesignbasisflawswouldnotleadtocatastrophicfailureoftheGinnastainlesssteelRCLpiping.ThisWCAPdocumentedtheplantspecificfracturemechanicsstudyindemonstratingtheleak-before-breakcapability.IthasbeenreviewedbytheNRCanditsconclusionswereapprovedforapplicationtoGinnabyletterdatedSeptember9,1986(NRCapprovalofRG&EresponsetoGenericLetter84-04).2-2 IfIIl Intheanalysessupportingtheproposedmodification,terminal-endpipebreaksarepostulatedintheRCLatauxiliarylinebranchconnectionnozzlestotheResidualHeatRemoval(RHR)system,theSafetyInjection(SI)AccumulatorpipingandthePressurizerSurgepiping.TheterminalendbreakattheSIaccumulatorlinenozzledefinesthelimitingpipebreakdesignbasisloadsfortheSGupperlateralsupportsystemunderemergencyconditions.b.SecondarySystemPipeRuptures'xistingpostulatedpipebreaklocationsinthesecondarysystemswerereviewed.Someintermediate'breaklocationshavebeeneliminated.fromconsiderationasdescribedbelow.Existingpostulatedterminal'-endbreaksatMainSteamandFeedwaternozzlesoneachSGcontinuetobeassumed.i.MainSteamLineRupturesThepreviouscontrollingdesignloadfortheSGupperlateralsupportsystemwasanarbitraryintermediatepipebreakinthehorizontalMainSteamlinenearthetopoftheSG(SeeFigure3).NRCGenericLetter87-l1,"RelaxationinArbitraryIntermediatePipeRuptureRequirements",providesguidanceforeliminationofarbitraryintermediatebreaksandhasbeenappliedinthisprogram.

PreviousGinnaSeismicUpgradeProgramanalyses(recentlyreviewed,inNRCInspectionNo.50-244/87-11),usingANSIB31.1criteria,havebeenrevisedasnecessarytoreflectchangesresultingfromthissnubberreplacementprogram.ConsistentwithGenericLetter87-11,theseanalyseshaveestablishedthatnointermediatepipebreaksneedtobepostulatedintheMainSteam(MS)piping.ii.FeedwaterZinePipeRuptures.Aterminal-endpipebreakispostulated.atthesteamgeneratorFeedwaterinletnozzleandnowdefinesthelimitingpipebreakdesignbasisloadsfortheSGupperlateralsupportsystemunderfaultedconditions.AllotherFeedwaterbreaklocationsarelesslimitingand,inaddition,arenotpostulatedbecauseoftheapplicationofGenericLetter87-11guidance.2.2GeneralCriteria-SeismicUpgradeProgramThedesigncodesandcriteriautilizedintheanalysisareconsistentwiththoseusedforRGGE'sSeismicUpgradeProgram.ThatprogramwasinitiatedinresponsetoIEBulletins79-02,79-14,andtheSystematicEvaluationProgram(SEP).ThisprogramwasreviewedduringSEPandwasapprovedbytheNRCasdocumented2-4

intheSEPSERsforTopicIII-6,"SeismicDesignConsiderations"andtheSEPIntegratedAssessment.NRCInspectionNo.50-244/83-18andInspectionNo.50-244/87-11providedareviewofRG&Eworkperformed.inresponsetoIEB's79-02and79-14.Since1979,RG&Ehasupgradedcriticalsafety-relatedpipingandsupports,resultinginthereevaluationandmodificationofvirtuallyallsupportsoriginallycoveredbytheIEB's.2-5 0

3.03.1PRIMARYSYSTEMANALYSISPipingAnalysis3.1.1MathematicalModelsTheRCLpipingmodelconsistsofmassandstiffnessrepresenta-tionsforthetwoRCLsandthereactorvessel.EachRCLincludestheprimarylooppiping,asteamgeneratorandareactorcoolantpump.Theprimaryequipmentsupportsarerepresented.bystiff-.nessmatrices.Thestatic,thermalandseismicanalysesoftheRCSwereper-formedusingatwo-loopmodel(SeeFigure5)toobtaincomponentandsupportloadsanddisplacements.ThismodelisidenticaltotheoneusedpreviouslyintheGinnaPipingSeismicUpgradeProgramexceptforthefollowing:a~ThenewSGupperlateralsupportdesignisrepresentedbystiffnessmatricesintwodirections.Onematrixprovidesstiffnessalongadirectioncorrespondingtothehotlegdirectionandsnubberaxes.Thesecondprovidesstiffnessperpendiculartothedirectioncorrespondingtothehotlegdirectionandsnubberaxes.Thispermitscomponentsupportloadsinthesnubbersandbumperstobecalculateddirectly.3-1 l

b.Eachexistingpinned-end,tubularsupportcolumnundertheSG'sandtheRCP'sisrepresentedbyastiffnessmatrixbasedonstiffnessvalueswhichaccountfortheembedmentofthesupportingstructuralframeinthereinforcedconcreteslab.Thisisarepresentationoftheexistingconfigurationandeliminatestheneedfortranslationofloadsfromglobaltolocalcoordinates.3.1.2MethodologyTheseismicanalysisisperformedusingtheenveloperesponsespectramethod.Peak-broadenedfloorresponsespectrafortwo-percentand.four-percentcriticaldamping(OBEandSSE,respec-tively)wereusedinconformancewithRegulatoryGuides1.60and1.61.Theuseoffour-percentcriticaldampingforSSEwasdevelopedandjustifiedbytesting.Thetestingprogramsaredescribed.inWCAP-7921,whichhasbeenacceptedbytheNRC(reference9).ThemodificationintheSGupperlateralsupportswillnotaffecttheconclusionofthedampingtestingprogram.ResponsestothethreedirectionsofearthquakeloadingwereevaluatedinaccordancewiththeGinnaPipingSeismicUpgradeProgrambycombiningallthreedirectionalearthquakesbythesquare-root-sum-of-the-squares(SRSS)method.TheWestinghouseepsilon-methodofclosely-spaced.modescombinationwasused.intheanalysis.ThecombinationequationsarepresentedinAppendixA.ThismethodofcombinationofmodalresponsesandspatialcomponentsisconsistentwiththeNRCguidelinesin3-2 RegulatoryGuide1.92.Thismethodhasbeenusedonnumerous~~~jotherWestinghousePWR's(suchasVogtleand.SouthTexas)asdiscussedintheirrespectiveFSAR's.TheNRChasapprovedtheuseofthismethodviatheSER'sassociatedwithmodalresponsecombinationonthoseWestinghouseplants.3.1.2.1BranchLinePostulatedRupturesThedynamictime-historypiperuptureanalysesoftheRCLwereperformedusingaone-loopmodel(Figure6).Thesteamgeneratorupperlateralsupportsaremodeledwithsnubber-in-compressionsupportstiffnessinonedirectionandthecombinedeffectofsnubber-in-tensionplusbumper-in-compressionsupportstiffnessesintheoppositedirection.Thesteamgeneratorcolumnsupportsandreactorcoolantpumpcolumnsupportsaremodeledwithtensionandcompressionstiffnessintheoppositedirections.Thereactorcoolantpumptie-rodsaremodeledtobeactiveintensiononly.Thesteamgeneratorlowerlateralsupportstiffnessmatricesusedwerechosentobeconsistentwiththecalculateddynamicmotions.Pipebreaksarepostulatedintheprimarysystemattheloopbranchconnectionsofthepressurizersurge,RHRandSIacc-umulatorpipingsystems.Thecalculatedtime-historyforcingfunctionswereappliedtotheRCLanalyticalmodelatthelumped-masspointsandwhereeachauxiliarylinejoinstheRCLtoobtainthecorrespondingtransientloads.Theappliedforcesassociated3-3

withthesepipebreaksincludethefollowingthreecomponents:a~b.c~blowdownforcingfunctionsatvariouslocationsintheprimarypipingAthrustforceatthebreaklocation.Ajetimpingementforceatthebreaklocation.Theblowdownforcingfunctions,whichrepresentthetravelingcompressionblowdownwavesduetointernalfluidsystemloads,arecalculated(inthex,y,andzcoordinatedirections)ateachchangeindirectionorchangeinflowareas.Thirteensuchlocationsoccurineachone-loopmodelandareshownschema-ticallyinFigure7.Thesetime-varyingforcesareappliedateightmasslocationsshowninFigure8.Arepresentativeblowdownforcingfunctiontime-historyplot(forasinglecoordinatedirectionatonelocation)isshowninFigure9.Thisisthestandardmethodologyused.forWestinghouseRCLpipebreaksandisdescribedinWCAP-8172-A(Reference13),whichhasbeenacceptedbytheNRC.Thethrustforceisatime-varyingblowdownforceatappliedthebreaklocation.Xtiscalculatedusingthesamemethodologyusedfortheaboveinternalfluidsystemblowdownloadsandisorientedalongthecenterlineaxisoftheauxiliarylinenozzle.ThejetimpingementloadiscalculatedusingthesimplifiedmethodsofAppendixesBandDofReference12.Thejetimpinge-mentloadistakenasKCPA(EquationsD-1andD-3ofRef.12)3-4 E0 where:K=1.0(maximumvaluefromFigureB-1)C=1.3(FigureB-6,forpressureand.enthalpy)P=initialpressureA=pipecross-sectionalflowareaThisstepfunctionjetimpingementforceisaddedtothethrustforcetoobtainthetotalappliedforceatthebreaklocation.3.1.2.2MainSteamandFeedwaterPostulatedRupturesAppliedforcesduetopipebreakspostulatedtooccuronthesecondarysideofthesteamgeneratorattheMainSteamoutletnozzleandFeedwaterinletnozzlearerepresentedbystep-functionforces.Theseforcesarecalculatedastheabsolutesumofthrustforceandjetimpingementforceforeachbreakloc-ation.ForthepostulatedpipebreakattheMainSteamoutletnozzle,thepipeisnotconstrainedandthereisnojetimpingementloadonthesteamgeneratorfromtheseveredpipe.ThethrustforceforthispipebreakiscalculatedusingthesimplifiedmethodsofAppendixBinReference12.Thesteady-stateforceistakenasCPA(EquationB-2ofRef.12)where:C=1.26(thrustcoefficientforsaturated-superheated.steamfromEquationB-4)P=InitialpressureA=pipecross-sectionalflowarea3-5 0

Astepforcingfunctionwhichisequaltothissteady-stateforceisappliedtothesteamgeneratorinadynamicmodelofoneprimarypipingloop(Figure6).ForthepostulatedpipebreakattheFeedwaterinletnozzle,ajetimpingementloadiscalculatedbythesimplifiedmethodsofAppendixDinReference12.ThejetimpingementloadistakenasKCPA(EquationsD-1andD-3ofRef.12)where:K=1.0(maximumvaluefromFigureD-1)C=1.0(maximumvaluefromFigureB-7,forfL/D>1)P=initialpressureA=pipecross-sectionalflowareaThepipehydraulicfrictionterm(fL/D)islargerthan1.0sincethereareseveralelbowsupstreamofthepostulated.breaklocationintheFeedwaterpiping.ThethrustforceforthispipebreakiscalculatedbythesamesimplifiedmethodsusedforthepostulatedMainSteamoutletnozzlebreak.lnthiscase,C=1.0basedonFigureB-7ofRef.12.Thepipehydraulicfrictionterm(fL/D)islargerthan1.0sincethereareJ-tubesandacircularfeedwaterringheaderonthesteamgeneratorsideofthebreak.Astep-functionforcewhichisequaltothesumofthejetimpingementloadandthethrustforcewhichresultsinatotalcoefficientof2.0,is3-6 0IE appliedtothesteamgeneratorinadynamicmodelofoneprimarypipingloop.3.1.3ComputerProgramsPipinganalysesareperformedonthe"WESTDYN"Westinghousecomputerprogram(reference5).WESTDYNperforms3-dimensional,linear,elasticanalysesofpipingsystemssubjected.tointernalpressureandotherloadings(staticanddynamic).TheprogramiscapableofcombiningloadsinaccordancewiththeapplicablecodeclassofeitherASMESectionIIIorANSIB31.1.Separatecomputerrunsanalyze,eachloadingcondition(deadweight,thermal,sustainedloads,occasionalloads,pipebreakandseismic).~~TheprimaryoutputfromWESTDYNdisplaysinformationabouteachanalysisperformed,includingforces,moments,anddisplacementsateachpoint.TheWESTDYNcomputercodehasbeenutilizedonnumerousWestinghouseplantsandwasreviewedandapprovedbytheNRCin1981(reference8).ThecodeisverifiedforthisapplicationandacontrolledversionismaintainedbyWestinghouse.3.1.4SupportStiffnessesToaccuratelyrepresenttheequipmentsupportsinthepipinganalyses,themodifiedsupportsystemstiffnesscharacteristicsweredevelopedforinputtothepipinganalysiscomputermodel.Individualspringconstantsinthelocaldirectionsof3-7

restraintweredevelopedforthemodifiedSGupperlateralsupportconfigurationandtheotherRCLprimaryequipmentsupports.Thestiffnesscalculationsconsideredthestiffnesscharacteristicsofallstructuralelementsintheloadpathincludingthesupportingconcrete,structuralmembers,aswellasthetensionandcompressionstiffnessesoftheremaininghydrau-licsnubbers.In,thehot(i.e.fullpower)condition,thebackupperbumpersandbacklowerlateralrestraintsarealternativelyactiveandinactivea'safunctionofthebuildingmotionrelativetotheSG's.TheRCShotlegsincompressionrestrainthemotionofeachsteamgeneratorastheytrytomovetowardthereactorvessel.TherearenoSGupperbumpersorlowerlateralre-straintsavailableinthis"towardthevessel"direction.ThehotlegrestrainstheSGinbothdirectionsofmotionalongthedirectionofthehotleg.TheupperSGsnubberswillbeactiveintensionandcompression.Whenthebuildingmovesintheseismicevent,itpushesontheSG'sandthevesselinthesamedirectionand,hence,thewholesystemmovestogether.OneSGmovestowardsthevesselwhiletheotherismovingawayatthesametime.Therefore,backlowerlateralrestraintsareactiveforthesteamgeneratorinoneloopandsimultaneouslyinactiveforthesteamgeneratorintheotherloop.Figure10illustratesthishotconditionsupportcon-figuration.3-8 Twoanalysesareperformed.forthehot(i.e.fullpower)con-dition.Inoneanalysis,oneSGisassumedtobemovingtowardthevesselwhiletheotherSGmovesawayfromthevessel.Intheotheranalysis,theoppositemotionisassumed.TheSGwhichisassumedtobemovingtowardthevesselhasnoactivebumpers,and,sincetheresponsespectrumtechniqueisusedwhereallforcesarereversible,thisanalysisprovidesbothtensionandcompressionforcesinthehotlegasiftherewere'obackbumpersactiveononeSG.Thehotlegsineachloopare,therefore,capableofrestrainingthesteamgeneratormotionformotionsinthedirectionofthehotlegtowardand.awayfromthevessel.Duringaseismiceventloadsmayshiftbetweenthesnubberandthebumperalongtheaxisofthehotleg.Thisshiftingisboundedintheanalysisbyutilizingthreevaluesoftheuppersupportstiffnesses(K~,K,and.K)inthreeseparateanalyses.Thebumperisstifferthanthesnubber.Thus,thelowerboundvalueis,Case1,K=K(compression).TheupperboundvalueisCase2,K=K(compression)+K(tension).Kistheactualstiffnesswhenthesteamgeneratormovestowardthereactorvessel.Kistheactualstiffnesswhenthesteamgeneratormovesawayfromthereactorvessel.Finally,athirdvalueofK=1/2(K+K)wasused.toprovidedataonanintermediatestiffness.Thethreevaluesareasfollows:K=19.15x10lb/in3-9 0

K=7.8x10lb/in.K=13.46x10~lb/in.SeveralevaluationswereperformedusingCase1and.Case2stiffnesses,andtheworstloadsoneachindividualbumperweredetermined.TheresultsaresummarizedinTable8alongwithcorrespondingloadsbasedontheaveragestiffnessvalue,KUseofboundingstiffnessvaluesproducesadecreaseintheseismicstressmarginateachlocationascomparedwithKAdequateseismicstressmarginstillexistssincethelowestmargin,usingtheboundingstiffness,is1.73(SG1Bsnubbers).Basedonthesechangesinseismicmargin,and,thecalculatedmarginsforlooppiping(showninTable4)andtheprimaryequipmentsupports(showninTable6),itisconcludedthatadequateseismicmarginsexistfortheredesigned.SGupperlateralsupports.ThedatainTables4,5,6,and7arebasedontheKvalueofSGuppersupportstiffness.3.1.5PipingEvaluationCriteriaThepipingevaluationcriteriaarebasedonANSIB31.1-1973Edition.TheoriginaldesignbasisoftheseismicCategoryIpipingatGinnawasinaccordancewiththe1955and1967EditionsofUSASB31.1.WhenUSASB31.1wasupdatedtotheANSIB31.1,thestressanalysisformulaandstressintensificationfactorswererevised.TheprimarystressequationsintheinitialB31.13-10

-1973EditionweresimilartothosegivenintheASMESectionIIICodeofthattime.ThestressintensificationfactorsgiveninthisversionofB31.1wereexpandedtoincludemorefittings.InusingANSIB31.1,thePipingSeismicUpgradeProgramupdatedtheanalysistoreflectASMESectionIIIconceptswhilestillretainingthephilosophyofB31.1.However,thestressinten-sificationfactorsforbuttandsocketweldsoftheoriginalEditionofB31.1havebeenusedbecauseoflackoforiginalweldconfigurationinformation.3.1.6PipingLoadCombinationsThepipingwasevaluatedfortheloadcombinationsdefinedinTable1.3.2PrimaryEquipmentSupportsEvaluation3.2.1MethodologyThesteamgeneratorupperlateralsupportsystemhasbeenredesignedbyreplacingsixoftheeightsteamgeneratorsnubbersineachloop.TherevisedconfigurationisshowninFigure2.TheRCLanalysismodelwasrevisedtoreflectthenewsupportconfigurations.Computeranalyseswereperformed,asdescribedinSection3.1,togeneratenewRCLloadsontheprimaryequip-mentsupportsystemandtheprimaryequipmentsupportswere3-11 evaluatedforthesenewloads.Theevaluationwasperformedforsupportsassociatedwiththereactorvessel,steamgeneratorsandreactorcoolantpumps.Inappropriatecases,finiteelementmodelsofsupports,usingtheSTRUDLprogram,wereutilizedtoassistintheevaluation.Thesupportswererequalifiedfortherequiredcombinationsofpressure,thermal,deadweight,seismicandpiperuptureloads.3.2.2SupportLoadingsandLoadCombinationsTheloadsusedintherequalificationoftheequipmentsupportstructuresaredefinedinTable2.TheseloadswerecombinedfortheplantasidentifiedinTable3.ThecorrespondingloadcombinationsandtheallowableservicestresslimitsarealsoprovidedinTable3.3.2.3EvaluationCriteriaTherigidstructuralmembers(bumpers)intheSGupperlateralsupportsystemaredesignedtotherequirementsofthecurrenteditionoftheoriginaldesigncode(AmericanInstituteofSteelConstruction,AISCManual,8thEdition).However,toevaluatetheequipmentsupportsfornormal,upset,emergencyandfaultedconditions,theprovisionsofASMEBoilerandPressureVesselCodeSectionIII,SubsectionNFandAppendixFwereused-1974edition.TheASMEB&PVCodeSectionIII,SubsectionNFwasusedtoestablishallowablestresscriteriafortheequipmentsupport3-12 evaluationinlieuoftheAISCCodebecauseSubsectionNFandAppendixFcoupled.withUSNRCRegulationGuide1.124establishamoreconsistentandconservativesetofcriteria.Forexample,SubsectionNFwasdevelopedspecificallytoaddresscomponentsupportswhereastheAISCgenerallyaddressbuildingstructures.Additionally,theuseofSubsectionNF,AppendixF,andRG.1.124requiretheuseofmaterialpropertiesatservicetemperature,limitbucklingto0.67criticalbuckling,andestablishupperboundallowablesontensionandshearstress.Theevaluationwasperformed.usingmanualcalculationsandcomputeranalysiswhereappropriate.3.2.4~~ComputerProgramsTheprimaryequipmentsupportswereevaluatedbyhandcalcula-tionsand,whereappropriate,byfiniteelementcomputeranalysisusing"STRUDL."STRUDL,partoftheICEScivilengineeringcomputersystem,iswidelyusedfortheanalysisanddesignofstructures.Itisapplicabletolinearelastictwo-andthree-dimensionalframeortrussstructures,employsthestiffnessformulation,andisvalidonlyforsmalldisplacements.Struc-turegeometry,topology,andelementorientationandcross-sectionpropertiesaredescribedinfreeformat.Printedoutputcontent,specifiedbyinputcommands,includesmemberforcesanddistortions,jointdisplacement,supportjointreactions,andmemberstresses.TheSTRUDLcomputercodehasbeenutilizedon3-13

numerousWestinghouseplantsandwasreviewedandapprovedbytheNRCin1981(reference8).ThecodeisverifiedforthisapplicationandacontrolledversionismaintainedbyWestin-ghouse.3-14 4.04.1EVALUATlONANDRESULTSReactorCoolantLoopPipingTable4providesthelevelofstressintheRCLpipingandtheallowablestressesfromtheDesignCode(reference4).Theresultsshowthatthestressesinthepipingarewithinallowablelimits.AcomparisonbetweenthemaximumstressintheRCLpipingforthecurrentandredesignedsupportconfigurationshowsthatthereareonlyverysmallchangesinthecalculatedstresses.4.2ApplicationofLeak-Before-BreakWiththeredesignedsteamgeneratorupperlateralsupportconfiguration,revisedloads(forcesandmoments)intheRCLpipinghavebeengenerated.TherevisedloadsarecomparedwiththoseloadsinGenericLetter84-04(reference7)inTable5.Thecalculatedaxialstress(19.42ksi)is60%oftheallowableaxialstress(32.4ksi).Basedonthecomparison,itisverifiedthattheleak-before-breakconclusionsofWCAP-9558,Rev.1remainvalid.fortheredesignedsupportconfiguration.4.3MainSteamLineBreakLocationsTheterminal-endbreakinthemainsteamlinepipingatthesteamgeneratornozzleisadesignbasispipebreak.Themaximum4-1 calculatedstressintensityatintermediatelocationsfor~~~combinedpressure,deadweight,thermalandOBEloadingsis27.1ksi.Thisislessthanthethresholdstressintensityof0.8(1.2S+S)or29.6ksi.Therefore,therearenohigh-stress'intermediatebreaklocationsinthemainsteamlinesinsidecontainment.4.4PrimaryEquipmentSupportsThestressmarginsforRCLequipmentsupportsresultingfromtheRCLanalysisconsideringtheredesignedsteamgeneratorupperlateralsupportconfigurationsaresummarizedinTable6forallloadingcombinations.Thestressmarginisdefined.astheratiooftheallowablesupportstresstotheactualsupportstress.LoadingevaluationsperformedwiththeredesignedsupportconfigurationdemonstratethatallRCLequipmentsupportstressessatisfystresslimitswithanadequatemarginofsafety.Seismicmarginisassessedbythestressmarginfortheload.combination,(DW+TN+SSE).ThesestressmarginsaresummarizedinTable7fortheexistingandredesignedsteamgeneratorupperlateralsupportconfiguration.Theresultsdemonstratethatasig-nificantmarginofsafetyexistsfortheredesignedsteamgeneratorupperlateralsupport.4.5PrimaryComponentNozzleLoadConformanceTheRCLpipingloadsontheprimarynozzlesofthereactor4-2 0

vessel,thesteamgenerators,andthereactorcoolantpumpswereevaluated..Theconformanceevaluationconsistedofloadcom-ponentcomparisons,andloadcombinationcomparisons,inaccor-dancewitheachoftherespectiveEquipmentSpecificationsorwithapplicablenozzleallowablelimits.ItwasconcludedthatallRCLpipingloadsactingontheprimarycomponentnozzleswereacceptable.4.6EvaluationofAuxiliaryLinesTheRCLpipingandprimaryequipmentdisplacementswerecomparedtothecorrespondingdisplacementsusedinthepreviousanalyses.Theyarefoundtobelessthanthepreviousanalysisresultsorwithin+1/16inch.Duetotheflexibilityoftheattachedpipingsystems(designedtobeflexibletoaccommodatethermalgrowthoftheRCL)andthegapswhichnormallyexistbetweenthepipeandthesupportingstructure,anincreaseinanchormotionsattheloopconnectionpointofupto1/16inchwillnotcausesignificantchangesinpipingstress.Therefore,auxiliary'pipingsystemsattached.totheRCLarenotaffectedbytheredesignedsteamgeneratoruppersupportcon-figuration.4.7BuildingStructuralEvaluation4.7.1EvaluationofLocalAreas4-3 Corbelsandembedmentswereevaluated,fortensionloadsandtheircapacitywasfoundtoexceedthatofthehydraulicsnubbers.Corbelswerealsoevaluatedfortherigidstruturalmember(bumper)bearingloads,andwerefoundtobeloadedtonomorethan60'-oofallowable.AllevaluationswereperformedwithrespecttoACI-349,andAppendixBofACI-349.4.7.2SecondaryShieldWallsTheelevationoftheSGupperlateralsupportsisthesameastheReactorBuildingOperatingFloor.Thereisnolocalizedbending,sincethefloorslabactsasastiffeningring.Resultingtensilestressesarelow,withamaximumofabout40%ofallowable.AllevaluationsweredonewithrespecttoACI-349.4.7.3ConclusionInconclusion,theexistingcontainmentbuildingstructuresareadequateforthenewdesignbasisloadsassociatedwiththenewsnubber/bumperSGupperlateralsupport.configuration.4-4 1l 5.0ADDITIONALCONSIDERATIONS5.1OvertemperatureEventsThedesignbasisovertemperatureeventistheloss-of-loadtransient.RCLequipmentsupportstressmarginsforthistransientareadequateasshowninTable6.Anevaluationhasalsobeenperformedfor'theovertemperatureconditionsfollowingafeedwaterlinepipebreak.Themaximumloadonanyindividualbumperwasfoundtobe23.4kips.Thisissignificantlylessthanthe820kipsmaximumcapacityofeachbumper.Thecor-respondingRCLpipingstresseswerealsofoundtobemuchlessthanthecode-allowablethermalstress.5.2ColdShutdown5.2.1RCSAnalysisInadditiontotheplantdesignbasisfullpower(i.e.hotcondition)evaluationdescribedinparagraph3.1,selectedanalyseswereperformedforthecoldshutdowncondition.Themathematicalmodeldescribedinparagraph3.1.1wasreconfiguredtorepresenttheRCSinacoldshutdowncondition.AlthoughtheRCLpipingwillhavecontractedthermally(creatinggapsatsomesupportlocations),itrespondstotheseismiceventinamannersimilartothatforhotconditions.SeismicloadswillbedistributeddifferentlythroughouttheRCS,withthehotlegpipingcarryinggreaterloadsinrestrainingmotionbetweenthe5-1 reactorvesselandthesteamgenerators.ThemaximumRCSpipingstressinthecoldshutdowncondition(duetothecombinationofpressure,deadweightandSSEearthquake)wasfound.tobe20.7ksi(64%ofallowable).AsdescribedinTable1,thisisanemer-gencyconditionandtheallowablestressis1.8S,correspondingtoavalueof32.4ksiinaccordancewiththeANSIB31.1codeatcoldshutdowntemperatures.Code-allowablestressesarehigheratcoldshutdowntemperaturesthanatthehotconditions.Theincreasedgapsatsomesupportlocationswillreducetheoverallstiffnessofthesystem.TheSGfrequencywillhavebeenreducedfromapproximately8.2Hzinthehotconditiontoapproximately7.0Hzinthecoldcondition.ThereactorbuildingseismicresponsespectrumforanSSE(asshowninFigure11)isessentiallyflatinthisfrequencyregionand,consequently,nosubstantialincreaseinseismicloadsoccurs.5.2.2PrimaryEquipmentSupportsTheRCLpipingmodel(describedinparagraphs3.1.1and.3.1.3)wasanalyzedfordisplacementsresultingfromthermalchangesbetweentemperaturescorrespondingtofullpoweroperationandcoldshutdown.Acombinationofcomputeranalyses(usingtheRCLpipingmodel),manualcalculations(i.e.fortheSGshell)andfieldmeasurements,areusedtopredictthegapswhichwillexistatRCLsupportlocationsinthecoldshutdowncondition.5-2 I

TheSGupperlateralsupports(bumpers)areadjustedduringplantstartupsuchthat,atpoweroperation,thegapbetweenthesebumpersandthesteamgeneratorswillbeverysmall(lessthan1/16ofaninch).Nhencoolingtocoldshutdownconditionsitiscalculatedthatthetotaldiametricalgapbetweeneachsteamgeneratorand.theassociatedSGupperlateralsupports(bumpers)isapproximately0.4inchesinthedirectionsperpendiculartotheRCLhotleg(i.e.acrosssteamgenerator1Aatbumperreferencelocations2and3,andacrosssteamgenerator1Batbumperreferencelocations4and5asshowninFigure2).Also,asshowninFigure2,therevisedsteamgeneratoruppersupportconfigurationwillretainexistingsnubbersatlocationsapp-roximatelyparalleltothehotlegdirectionandtheywill~~~provideseismicrestraintinthatdirectionduringcoldshutdown.Thesesnubberswillpreventseismically-inducedmotionsfromclosingthe2-inchcoldshutdowngapsatsteamgenerator1Abumperreferencelocation1andatsteamgenerator1Bbumperreferencelocations6and7shownonFigure2.Otherprimaryequipmentsupportshavebeenevaluatedforseismicloadsinthecoldshutdowncondition.Theseloadshavebeencalculatedandarewellwithinthecapacityforthecorrespondingsupportcomponent.Theloads,supportcapacitiesandtheir'omparison(expressedasloadmargins)arepresentedinTable9.5-3 6.0QUALITYASSURANCERochesterGasandElectricCorporationTheoverallprojectisbeingconductedundertheRG&EQualityAssuranceProgram.Thereplacementrigidstructuralmembers(bumpers)hasbeenfabricatedby'a'supplierhavingaQualityAssuranceProgrammeetingtherequirementsofANSIN45.2.RG&Ehasspecifiedmaterialtraceability,welderqualification,non-destructiveexaminationandotherrequirementsapplicabletothenewbumpers.6.2WestinghouseElectricCorporationThestructuralqualificationworkperformedbyWestinghousehasbeenindependentlyreviewedatWestinghouseasasafety-relatedcalculationandmeets10CFR50,AppendixB,QualityAssurancerequirements.Thedetailedresultsoftheanalysesaremain-tainedinWestinghouseCentralFilesinaccordancewithWestin-ghouseQualityAssuranceprocedures(ref.10and11).6.3AltranCorporationAnindependent,thirdpartyreviewisbeingperformedbyAltranCorporationandDr.ThomasC.Esselman.Dr.Esselmanandhisassociateshaveconductedathoroughreviewoftheassumptions,designbases,analysesand.otherdesigndocumentsproducedbyWestinghouse.

I

7.0CONCLUSION

SBasedontheresultsoftheevaluationofthereactorcoolantsystemwiththeredesignedSGupperlateralsupportconfigurationthefollowingconclusionsaremade:Thecombinationofhydraulicsnubbersandrigid,structuralmembers(bumpers)whichcomprisetherevisedsteamgeneratorupperlateralsupportsystemmaintainadequaterestraintofeachsteamgeneratorunderthedesignbasisloads.b.ThemaximumstressesintheRCSpipingandprimaryequipmentsupportsarewithinCodeallowables.cThemaximumdisplacementsintheRCSpipinghavebeenaccountedforinanalysesofauxiliarypipingsystemsattachedtotheRCS,anddonotsig-nificantlyaffectthoseanalyses.Thereactorcoolantlooppipingandequipmentsupportscontinuetohaveacceptablemarginsofsafetyforalldesignbasisevents.e.TheContainmentBuildingstructuresareadequatetocarrytheloadsimposedbythenewsnubber/bum-perSGupperlateralsupportconfiguration.

I1 Therefore,theproposed.modifiedconfigurationmeetsallcon-ditionsnecessarytoassuresafeoperationoftheplantinaccordancewiththelicenseddesignbases.7-2

8.0REFERENCES

1.WCAP-9558,Rev.1,MechanisticFractureEvaluationofReactorCoolantPipeContainingAPostulatedCircumferentialThrough-WallCrack,June1980.2.NUREG/CR-3660,UCID-1988,Volume3,February,1985,"ProbabilityofPipeFailureinReactorCoolantLoopsofWestinghousePWRPlants,"Volume3,"GuillotineBreakIndirectlyInducedbyEarthquakes,",LawrenceLivermoreNationalLaboratory.3.ASMEBoilerandPressureVesselCode,SectionIII,SubsectionNFandAppendixF,AmericanSocietyofMechanicalEngineers,1974Edition(forSupportsEvaluation).4.ANSIB31.1PowerPipingCode1967Edition,includingSummer1973Addenda.5."PipingAnalysisComputerCodesManualII"WestinghouseProprietaryClass3,WestinghouseElectricCorporation,Pittsburgh,PA.6.NRCBranchTechnicalPositionMEB3-1,Rev.2,1987,PostulatedRuptureLocationsinFluidSystem8-1 lI PipingInsideandOutsideContainment(GenericLetter87-11)7.'RCGenericLetter84-04,2/1/84.8.NRCapprovalletterforWCAP-8252(WESTDYN),LetterfromR.L.Tedesco,NRC,toT.M.Anderson,Westinghouse,dated4/7/81.9.WCAP7921-AR,May1974,"DampingValuesofNuclearPlantComponents."10.WestinghousePowerSystemBusinessUnitQualityAssuranceProgramforBasicComponentsManual,WCAP-9550,Rev.16,June30,1987.11.WestinghouseNTSD/GTSDQualityAssuranceProgramManualforNuclearBasicComponents,WCAP-9565,Rev.11,Aug.31,1987.12.ANSI/ANS-58.2-1980,"ANSStandard-DesignBasisforProtectionofLightWaterNuclearPowerPlantsAgainstEffectsofPostulatedPipeRupture".13.WCAP-8172-A,January,1975,"PipeBreaksfortheLOCAAnalysisoftheWestinghousePrimaryCoolantLoop".8-2 Table1RCSPIPINGLOADCOMBINATIONSANDSTRESSLIMITSConditionNormalUpsetEmergencyFaultedMax.ThermalNormal6Max.ThermalLoadinCombinationDesignPressure+DeadweightDesignPressure+Deadweight+OBEDesignPressure+Deadweight+SSEDesignPressure+Deadweight+(SSE+DBA)**Max.ThermalStressRange***+OBEDisplacementDesignPressure+Deadweight+Max.ThermalStressRange+OBEDisplacementsANSIB31.1Euations111212121314**SRSScombinationofSSEandDBAloads***Loss-of-loadovertemperaturetransientconditionThepipingstressequationsare:PD+.75i~M4tZ<1.OSP,Equation(11)PD+.75i(M+M.)4tZ1.2SP,(Upset)Equation(12)<1.8S(Emergency)2.4S(Faulted)iMZ<SEquation(13)PD+.75i~M+iM~4tZZ<S~+SEquation(14)Where:M=Resultantmomentduetodeadloadandothersustainedloads.M=Resultantmomentduetooccasionalloads.M=Resultantmomentduetorangeofthermalexpansionloadings.P=InternalDesignPressure.D=Outsidediameterofpipe.Nominalwallthicknessofpipe.Z=SectionmodulusS~=Materialallowablestressatmaximumtemperature.S=Allowablestressrangeforexpansionstress.i=StressIntensificationFactor.T-1 I\i TABLE2DEFINITIONOFLOADINGCONDITIONSFORPRIMARYEQUIPMENTSUPPORTSEVALUATIONLoadinCondition1.SustainedLoads2.Transientsa.Over-temperatureTransient3.OperatingBasisEarthquake4.SafeShutdownEarthquake5.DesignBasisPipeBreaka.ResidualHeatRemovalLineb.AccumulatorZinec.PressurizerSurgeZine6.MainSteamLineBreak7.FeedWaterPipeBreakAbbreviationsDW,Deadweight+P,OperatingPressure+TN,NormalOperatingThermalSOT,SystemOperatingTransientTAOBESSEDBPBRHRACCSURGMS TABLE3LOADCOMBINATIONSANDALLOWABLESTRESSLIMITSFORPRIMARYEQUIPMENTSUPPORTSEVALUATIONPlantEvent1.NormalOperationSystemOperatingConditionsNormalServiceLoadingCombinationsSustained.LoadsServiceLevelStressLimits2.Plant/SystemUpsetOperatingTransients(SOT)+OBESustained.Loads+SOT+OBEB3.DBPB4.SSE5.DBPB(orMS/FWPB)+SSENote:EmergencyFaultedFaultedSustainedLoads+DBPBSustainedLoads+SSEDSustainedLoads+.(DBPBorDMS/FWPB)+SSE1.ThepipebreakloadsandSSEloadsarecombinedbythesquare-root-sum-of-the-squaresmethod.2.StresslevelsasdefinedbyASMEB&PVCodeSectionIII,SubsectionNF,1974Edition.

TABLE4MAXIMUMREACTORCOOZANTLOOPPIPINGSTRESSES(BasedonK)AVGCurrentANSI(1)ConfigurationB31.1CodeRCLStressRedesignedConfigurationStres's(ksi)ANSIB31.1CodeAllow-PercentageableStressof(ksi)AllowableHLXLCL(12)DesignHZandUpsetXLCZ(12)HLEmergencyXLCL(12)HL(Faulted)XZCL7.26.96.99.89.810.011.712.112.57.16.96.98.08.99.48.610.611.519.711.517.816.816.816.820.120.120.130.230.230.240.340.340.343'o41'o40o41%29'o38'o49%29'5%(13)SeeNote3(14)HLXZCLHLXLCZ9.75.37.416.811.113.19.75.37.416.811.113.127.527.527.544'44.444436%20'o27038%25'5%NOTES:(1)HL-HotLeg,XL-Crossoverleg,CL-Coldleg*Piperuptureloadswerenotconsidered.Nofaultedstresseswerecalculatedforcurrentdesign.(2)LoadcombinationsareshowninTable1.(3)Loss-of-loadovertemperaturetransienteffectsareincluded.

TABLE5COMBINEDLOADSFORLOOPPIPINGLEAK-BEFORE-BREAK(BasedonK)AVGLoadCombinationAzialForce(kis)BendingMoment(in-kis)CombinedAxialStress(ksi)SSE251Normal+SSE2190Normal19391676028201958016.88(calculated)2.54(calculated)19.42(calculated)Normal+SSE180045600(2)32.4(allowable)(SeeNote2)Notes:(1)AllowablebasedonWCAP-9558,Rev.l.(2)UmbrellabendingmomentinNRCGenericLetter84-04is42,000in-kips.

TABLE6RCSPRIMARYEQUIPMENTSUPPORTSSTRESSMARGINSUMMARY'StressMargin=Allowable/Actual)(BasedonK)AVGServiceLevelNormalUpsetEmergencySSEFaultedLoadCombinationDW+TNDW+TA+DW+TN+OBEDBPBDW+TN+DW+TN+SSE[(SSE+PIBK)]SGUpperSupportsBumpersSnubbersSeeNote3SeeNote32.533.173.24(ACC)2.416.26(ACC)2.251.79(FW)1.11(FW)SGLowerSupportsLateralColumnsSeeNote31.673.511.651.57(SURG)1.773.11(ACC)3.291.21(SURG,2.19(MS)ReactorCoolantPumpsLateralSeeNote34.5518.12(ACC)8.10Columns5.151.872.76(ACC)1.877.46(ACC)1.87(ACC)ReactorVesselLateralSeeNote3Vertical3.054.331.291.31(ACC)5.942.09(ACC)4.531.41(ACC)3.45(ACC)Notes:1)TheloadsymbolsaredefinedinTable2.2)PIBKincludesDBPBandMS/FWbreaks3)Undernormalconditionsnosignificantloadsareimposed.ontheselateralsupportelements.

I TABLE7STEAMGENERATORUPPERSUPPORTSSEISMICLOADMARGINS(BasedonK)AVGSEISMICLOADSDW+TN+SSE(kips)SGUSCAPACITY(kips)SEISMiCLOADMARGIN(Allowable/Actual)LOOPNO~BUMPERIDEXISTING~SGUS1REDESIGNEDSGUS8CHANGEEXISTINGREDESIGNEDEXISTINGREDESIGNED1ASN-1123582.0582.0582'582F6410.4335'410.5410.5-30-42-30-30106410641064106410641640164016401.831.831.831.832.594.893.993.99SN-24567514'470.0448.0312.2287.2472.3453.3386.5309.9340.0-8-4-14-1+18.41064106410645325321064164016408208202.072'62.371.701.852'53.614.242.642~41(1)SeeNoteAttached.

NOTETOTABLE7Theoriginalseismicsupportloadcalculationsincludedanadditionalcontributionwhichisnotrequiredintherevisedsupportloadcalculations.Intheoriginalcase,thetotalseismicsupportplaneloadattheuppersupportwasfirstcalcu-latedbydynamicanalysisinglobalcoordinatesandthenrotatedtothelocalcoordinatesofthesupportmembers.Intherevisedcase,theindividualsupportmembersweremodeleddirectlyinthedynamicmodelsothatarotationfromsupportplaneloadstomemberloadswerenotrequired.Therotationofcoordinatesmustbedoneconservatively,sincetherearenosignsassociatedwiththetotalseismicforcecomponentsinglobalcoordinates.Therefore,theoriginaldesignloadsaremoreconservativelycalculatedthanthereviseddesignloads.T-7A II TABLE8STEAMGENERATORUPPERSUPPORTSSEISMICLOADMARGINS(UsingK~andK/K~)SEISMICLOADSDW+TN+SSE(kips)SGUSCAPACITY(kips)SEISMICLOADMARGIN(Allowable/Actual)LOOPNO.BUMPERIDKav<aKmaxKmin+oCHANGEREDESIGNED~KavKmazKmin1ASN-1123410.4335.4410.5410.5533.5436.0533.7533.7+30+30+30+3010641640164016402.594'93.993.991'93.763.073'71BSN"24567472'453.3386.5309.9340.0614.0589.3502.5402.9442.0+30+30+30+30+301064164016408208202.253.614.242.642.411.732.783.262.031.86

Table9RCSPRIMARYEQUIPMENTSUPPORTSLOADMARGINSUMMARYCOLDSHUTDOWNSEISMICANALYSIS(LoadMargin=Capacity/Load)SuortComonentSGSnubbers(SeeNote1)SGUpperLateralSupports(Bumpers)(SeeNote2)SGColumns(SeeNote3)SGLowerLateralSupports(SeeNote4)RCPColumns(SeeNote5)RCPTieRods(SeeNote6)RPVSupport(Vertical)(SeeNote7)RPVSupport(Horizontal)(SeeNote7)NOTES:Load(kips)(SeeNote8)385.1912.0495.6256.6623.1364.3Capacity~(kis)1064.01640.01349.0397.03000.01300.0LoadMarin2.761.802.721.554.813.572.3.4OnepairofexistingsnubbersremaininplaceateachSG(AandB)indirectionofRCLhotleg.Loadandcapacitycorrespondstothepairofsnubbers(532kipscapacity,each)ColdshutdownseismicloadsarecalculatedfornewbumpersorientedapproximatelyperpendiculartoRCLhotleg.Loadandcapacitycorrespondstoapairofbumpers(820kipscapacity,each).EachSG(AandB)hasfoursupportcolumnswith1349.0kipscapacity,each,incompression.Loadgivenisworstcasesinglecolumncompressionload.EachSG(AandB)hasalowerlateralsupportframeatthebottomoftheSGshell.DuringColdShutdown,lateralsupportfromtheframeisdisengaged.duetocontractionoftheRCS.T-9 II0 5.EachRCP(AandB)hasthreesupportcolumnswith397.0kipscapacity,each,intension.Loadgivenisworstcasesinglecolumntensionload.6.EachRCP(AandB)hastwotie-rods.DuringcoldshutdownallRCPtie-rodsaredisengagedasaresultofcontractionofRCS.7.TherearesixRPVsupports(oneateachoffourmajornozzles)andtwoatseparatevesselsupportbrackets.LoadsandcapacitiesarefortheworstcasesingleRPVsupportin'achdirection.8.LoadsincludedeadweightandSSE.T-9A

APPENDIXACOMBINATIONOFSEISMICMODAlRESPONSESForSeismic.CategoryIcomponentswithintheNSSSscope,themethodusedtocombinemodalresponsesisdescribedbelow.Thetotalunidirec-tionalseismicresponseforNSSSequipmentisobtainedbycombiningtheindividualmodalresponsesusingtheSRSSmethod.Forsystemshavingmodeswithcloselyspacedfrequencies,thismethodismodifiedtoincludethepossibleeffectofthesemodes.Thegroupsofcloselyspacedmodesarechosensuchthatthedifferencebetweenthefrequenciesofthefirstmodeandthelastmodeinthegroupdoesnotexceed10percentofthelowerfrequency.CombinedtotalresponseforsystemswhichhavesuchcloselyspacedmodalfrequenciesisobtainedbyaddingtotheSRSSofallmodestheproductoftheresponsesofthemodesineachgroupofcloselyspacedmodesandacouplingfactor,c.Thiscanberepresented-mathematicallyas:N2SXR+2Ei=1j=lNj<<lNjEZRkRc~(EquationA-1)k=MjX=k+1where:R=TotalunidirectionalresponseR=AbsolutevalueofresponseofmodeiLN=TotalnumberofmodesconsideredS=Numberofgroupsofc3.oselyspacedmodesMj=l,owestmodalnumberassociatedwithgroupjofcloselyspacedmodesN=Highestmodalnumberassociatedwithgroupjofcloselyspacedmodeschal=Couplingfactordefinedasfollows:k~kkand,kk~~k2b5kdA-l Iwhere:e=FrequencyofcloselyspacedmodeKkp=FractionofcriticaldampingincloselyspacedmodeKktd=DurationoftheearthquakeForexample,assumethatthepredominantcontributingmodeshavefrequenciesasgivenbelow:Node12345678Frequency5.08.08.38.611.015.516.020Therearetwogroupsofcloselyspacedmodes,namelymodes2,3,4and6,7.Therefore:S=2,NumberofgroupsofcloselyspacedmodesM1N1M2N2N2,Lowestmodalnumberassociatedwithgroup14,Highestmodalnumberassociatedwithgroup16,Lowestmodalnumberassociatedwithgroup27,Highestmodalnumberassociatedwithgroup28,TotalnumberofmodesconsideredThetotalresponseforthissystemis,asderivedfromtheexpansionofEquationA-1:R=fR+R+R+....+Rl+2R2R3<23+2R2R422222123+2R3R4c34+2R6R7ThefirstterminbracketsrepresentstheSRSSsummationofeachoftheeightexamplemodes.Thenext,threetermsaccountfortheadditionaleffectsduetointeractionbetweenexamplemodes2,3and4.Thefinaltermsimilarlyaccountsforinteractioneffectsbetweenexamplemodes6and7.A-2

ENCLOSURE2RESPONSETONRCLETTER4/13/88ThepurposeofthisenclosureistoprovideresponsestothesixNRCauestionsregardingRG&E'sproposaltoreplacecertainsteamgeneratorsnubberswithrigidsupports(bumpers),transmittedbyletterof4/13/88.RG&Ehasintegratedtheseresponses,asapplicable,intothesummaryreport"SteamGeneratorHydraulicSnubberReplacementProgram",May1988,Rev.2,includedasEnclosure1toAttachmentBofRG&E'sApplicationforAmendmenttoreplacecertainsteamgeneratorsnubberswithbumpers.NRCREQUEST:1.Providethesizeandbasisofthebumpergapsinthecoldcondition.RG&ERESPONSE:1.Thisinformationisdetailed,inSection5.2.2ofEnclosure1.NRCREQUEST=2.Thedetailedcalculationsofthecoldshutdownconditionloadsinallsteamgeneratorsupports,reactorvesselsupportsand.reactorcoolantpumpsupports,whensubjectedtoSSEseismicloading.RG&ERESPONSE:2.Detailedcalculationswereperformed.undercold.shutdownconditions.Thedescriptionofthemethodologyusedtoperformthecoldshutdownanalysisisprovidedin-Section5.2ofEnclosure1.TheresultsoftheseanalysesareprovidedinTable9ofEnclosure1.ItcanbeseenthatstressesinthesupportsarewellwithintheCodeallowablevalues.Thedetailedcalculationsperformedforcoldshutdownconditions,aswellasthoseperformed.forhotconditions,areavailableforrevieworauditintheWestinghouseoffices.'INRCREQUEST:3.Thecalculationoftheminimum,maximumandaveragesteamgeneratorupperstiffnessesandtheirinclusionintheRCLmodel.

~I RG&ERESPONSE:3.Theminimum,maximum,andaveragesteamgeneratorupperstiffnessesareprovidedinSection3.1.4ofEnclosure1.Theaveragestiffnesswasusedtoprovideanassessmentofstressesusinganintermediatestiffness,andtosimplifycalculations.Analysesperformed.usingKandKxratherthanK(Table8ofEnclosure1)canbeusedtocorrelatetheresultsofstressesusingthetwomethods.NRCREQUEST:4.Thejustificationofthethrustcoefficientsusedforthetime-historyanalysisofthesteamgeneratoroutletnozzleand,thefeedwaternozzles.RG&ERESPONSE:4.Thejustificationofthethrustcoefficientsusedintheanalysisofthepostulatedsteamandfeedwaternozzlerupturesareprovid'edinSection3.1.2.2.Forthesepostulatedruptures,the-appliedforcesarecalculatedusingthesimplifiedmethodsofAppendixBtoANSI/ANS58.2-1980.5.Descriptionofthenon-lineartime-historyanalysesoftheRCLwhensubjectedtoloadingduetopostulatedbreaksatthepressurizersurge,RHRandSIaccumulatornozzles,andtheSGsteamoutletnozzleandthefeedwaternozzles.Thisshouldincludethespecifiedtime-historyloadingforcingfunction.RG&ERESPONSE:5.ThisdescriptionandjustificationoftheloadingfunctionsisprovidedinSection3.1.2.1ofEnclosure1.NRCREQUEST6.Provideclarificationofthemodelingandcalculationalresultsofthetwoanalyseswhichareperformed,inthehotcondition.RG&ERESPONSE:6.Additionalclarificationofthetwoanalysesperformedforfullpowerconditionsisprovidedin3.1.4ofEnclosure1,andthecalculationalresultsareprovidedinTables4-8ofEnclosure1.

(0(I*]

STEAllOENERATORCOOLANTPUMP-fA00IIExistingnubbers0S/GLowerLateralSupporS/GSupportColumnsRCpsupportColumnsREACTORCOOLANTPtNPREACTORREACTORBUILDINGPLANREACTORBUILDINGELEVATIONGINNASTATIONSTEA51GENERATORSNUBBERREPLACEMENTPROGRAMRGGE5-1-88FIGURE1EQUIPMENTLAYOUT 1

ExistingSnubbers(2perS/Gremaininplace)ExistingStructuralRingGirderSG)AOiReactorCavitY0'xistingStructuralRingGirder0s04SG1BReactorVesselNewStructuralMembers(Bumpers)0O~NewStructuralMembers(Bumpers)45670ExistingSnubbers(2perS/Gremaininplace)lNewStructuralMembers(Bumpers)ZocationReferenceNumber.RG&E5-1-88GINNASTATIONSTEAMGENERATORSNUBBERREPLACEMENTPROGRAMFIGURE2UPPERSUPPORTCONFIGURATION-PROPOSEDMODIFICATION MainSteamOutletNozzle~MainSteamManway(2)NormalWaterLevelFeedwaterInletNozzleFeedwater~~FeedwaterRingLiftingTrunnions(2)RingGirderRCLNozzle(2)LowerSupportBrackets(4)Manwap(2)GINNASTATIONSTEAMGENERATORSNUBBERREPLACEMENTPROGRAMRG&E5-1-88FIGURE3STEAMGENERATORlA/lB-DETAILSF-3

~~~oQoS~~040~$~~~~~b~b.'.PinCenterline3I9II-10.5"PLANVIEW-TYPICALBodyPinCenterline1'gQ~4.C~d.'a..~~.~~0'~Lb".-b-rbd.ilJIllI'uideShaftIIIII..IIII-StopNutIJII'I~II'ountingBracket(Existing)ReinforcedConcreteShieldWall(Existing)MountingBracket(Existing)S/GRingGirder(Existing)GXNNASTATIONSTEAMGENERATORSNUBBERREPLACEMENTPROGRAMRG&E5-1-88FIGURE4RIGIDSTRUCTURALMEMBER(BUMPER)-DETAILS l

QsG233223SGUpperSupportORCP277273269263RCPSupportRG&E5-1-882590219SGUpperSupport~~~RCP1772418921340024922209SGLoweSupport253~LooP1B1203194123173101LooplA109RV1294169119103283500143129SGLowerSupport289163VesselSupports149159North153GINNASTATIONSTEAMGENERATORSNUBBERREPLACEMENTPROGRAM.REACTORCOOLANTLOOPS1A&1BANALYTICALMODEL(STATICANDSEISMICANALYSES)FIGURE5RCPSupport 189133SiWGHRSUPPORTSICI1831195lLOCI5gftHT523143li9159177173159163ICt%PONDGINNASTATIONSTEAMGENERATORSNUBBERREPLACEMENTPROGRAMFIGURE6:REACTORCOOLANTPIPING/SUPPORTSYSTEM-ONELOOPMODELFORTIME-HISTORYPIPERUPTUREANALYSISRGGE5-1-88F-6

~t.Itl STT'AI<GENERATORTUBESREACTORVESSELCOLDLEGPIIMP1I13INOTLEGI123'2IK2IeIIIl~IreIOSTEAMGENERATOR9CROSSOVERLEGGINNASTATIONSTEAMGENERATORSNUBBERREPLACEMENTPROGRAMRGRE5-1-88~iciure7REACTORCOOLANTLOOPMODEL-HydraullcFarceLocatfonsF-7 qr<g 289223SGUpperSupports219269ReactorVessel213SGLowerSupports243RCP263Supports253GINNASTATIONSTEAMGENERATORSNUBBERREPLACEMENTPROGRAMFiciure8REACTORCOOLANTPIPING/SUPPORTMODEL(LocatfonofLumpedMassesForthe.App'lfcatfonofT)meHistoryKqdraulicLoads)RG&E5-1"88F-8 X,4I TlTLERGESURGESK'LPHYDFOPROGRAMHYDFOt15FYRGEHYD09/15/47g%L$a~5~l%e)2$.N,Sel.4C.STfl<<Q54S09/15/87GINNASTATIONSTEAMGENERATORSNUBBERREPLACEMENTPROGRAMFiciure9REPRESENTATIONBLOWDOWNFORCINGFUNCTIONPLOT(onecoordinatedirectionatonelocation)RG&E5-1-88F-9 4

BuildingMotionIIAllSGLowerlateral.restraintsin-linewithRCLhotlegareengaged,forbuildingmotiontowardSG"A".0tg0~4MotionofSG"A"isrestrainedbytheRCLhotlegandthelowerbacklateralrestraint.AttRCPogQ'~MotionofBuildingandRPVRPVSupportsarealwaysactiveReactorVessel"B"RCPod>0Cy0IIBIISGMotionofSG"B"isrestrainedonlybythehotleg.,rI.ItLowerlateralrestraintsin-linewithRCLhotlegprovidenegligiblerestraintforbuildingmotionawayfromSG"B".GINNASTATIONSTEAMGENERATORSNUBBERREPLACEMENTPROGRAMRGGE5-1-88F-10 C~~

IlllllllllHlllllllllllllllIIIIIIIIHllllllllGINNASTATIONBROADRESPONSESPECTRUMFORSSEREACTORBUILDINGINTERIORSTRUCTUREELEVATION278'-4"X-RESPONSEFIGURE23B-XOCTOBER15,19790H2oEQUIPMENTDAMPING3%EQUIPMENTDAMPING4'tEQUIPMENTDAMPING7%EQUIPMENTDAMPINGZPA=0.29g20FREQUENCY(cPs)nz~asae3osa34~4~e~0GINNASTATIONSTEAMGENERATORSNUBBER-REPLACEMENTPROGRAMRG&E5-1-88

,lI'g

Retrieved from "https://kanterella.com/w/index.php?title=ML17251B094&oldid=653846"