ML17251B094

Rev 2 to Steam Generator Hydraulic Snubber Replacement Program.

ML17251B094
Person / Time
Site:	Ginna
Issue date:	05/08/1988
From:	ROCHESTER GAS & ELECTRIC CORP.
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ML17251B091	List: ML17251B090 ML17251B092 ML17251B093 ML17251B094
References
PROC-880508, NUDOCS 8805200121
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ROCHESTER GASANDELECTRICCOMPANYGINNANUCLEARPOWERPLANTSTEAMGENERATOR HYDRAULIC SNUBBERREPLACEMENT PROGRAMMAY8,1988REVISION2'8805200121 880513PDR'ADOCK05000Z44'PDCD

SectionTABLEOFCONTENTSTitleLISTOFTABLESLISTOFFIGURESPage1v1.02.03.04.

05.0INTRODUCTION

1.1ExistingDesign1.2ProgramOverview1.3Anticipated Benefits1.4PrimarySystemQualification 1.5IntentofReportDESIGNLOADSANDCRITERIA2.1DesignBasisLoads2.1.1LoadingConditions 2.1.2Postulated PipeRuptures2.2GeneralCriteriaPRIMARYSYSTEMANALYSIS3.1PipingAnalysis3.1.1Mathematical Models3.1.2Methodology 3.1.3ComputerPrograms3.1.4SupportStiffnesses 3.1.5PipingEvaluation Criteria3.1.6PipingLoadCombinations 3.2PrimaryEquipment SupportsEvaluation 3.2.1Methodology 3.2.2SupportLoadingsandLoadCombinations 3.2.3Evaluation Criteria3.2.4ComputerProgramsEVALUATION ANDRESULTS4.1ReactorCoolantLoopPiping4.2Application ofLeak-Before-Break 4.3MainSteamLineBreakLocations 4.4PrimaryEquipment Supports4.5PrimaryComponent NozzleLoadConformance 4.6Evaluation ofAuxiliary Lines4.7BuildingStructural Evaluation 4.7.1Evaluation ofLocalAreas4.7.2Secondary ShieldWalls4.7.3Conclusions ADDITIONAL CONSIDERATIONS 5.1Overtemperature Event5.2ColdShutdown5.2.1RCSAnalysis5.2.2PrimaryEquipment Supportsii1-11-11-11-31-31-42-12-12-12-22-43-13-13-13-23-73-73-103-113-113-113-123-133-84-14-14-14-14-24-24-34-34-34-44-45-15-15-15-15-1 Section6.0TABLESOFCONTENTS(cont'd.)

TitleQUALITYASSURANCE 6.1Rochester GasandElectricCorporation 6.2Westinghouse 6.3AltranPage6-16-16-16-

17.0CONCLUSION

S 7-

18.0REFERENCES

8-1APPENDIXACombination ofSeismicModalResponses A-1 1

LISTOFTABLESTable1:RCSPipingLoadCombinations andStressLimitsPacaeT-lTable2:Table3:Definition ofLoadingConditions forPrimaryEquipment Evaluation LoadCombinations and.Allowable StressLimitsforPrimaryEquipment SupportsEvaluation T-2T-3Table4:MaximumReactorCoolantLoopPipingStressesTable5:CombinedLoadsforLoopPipingLeak-Before-Break Table6:RCSPrimaryEquipment SupportsStressMarginSummaryTable7:SteamGenerator UpperSupportsSeismicLoadMargin(BasedonKavg)T-4T-5T-6T-7Table8:Table9:SteamGenerator UpperSupportsSeismicLoadMargin(BasedonKavgandKmax/Kmin)

PrimaryEquipment SupportsColdShutdownSeismicLoadMarginSummaryT-8T-9 1

GINNASTATIONSTEAMGENERATOR SNUBBERREPLACEMENT PROGRAMLISTOFFIGURESFigure1:Equipment LayoutPacCeF-1Figure2:UpperSupportConfiguration

-ProposedModification F-2Figure3:SteamGenerator 1A/1B-DetailsFigure4:RigidStructural Member(Bumper)-DetailsFigure5:ReactorCoolantLoops1A&1BAnalytical Model(StaticandSeismicAnalysis)

Figure6:ReactorCoolantLoopPiping/Support Model(One-Loop ModelforTime-History PipeRuptureAnalysis)

Figure7:ReactorCoolantLoop-Hydraulic ForceLocations Figure8:ReactorCoolantLoopPiping/Support Model(One-Loop ModelShowingLocationofLumpedMassesforApplication ofTime-History Hydraulic Loads)F-3F-4F-5F-7F-8Figure9:BlowdownForcingFunctionTime-History Plot-RCSBranchPipingRuptureF-9Figure10:ReactorCoolantLoopsA&B-HotCondition Figure11:SeismicResponseSpectrum-SSEF-10F-11 1

1.0INTRODUCTION

Thisreportdescribes aproposedmodification totheexistingsteamgenerator upperlateralsupportconfiguration atGinnaStation,andtheanalyseswhichdemonstrate theacceptability ofresulting loadsfrompostulated seismicandotherdesignbasisevents.1.1ExistingDesignRestraining supportsexistforboththeupperandlowerportionofeachsteamgenerator (SG).ThelowerportionofeachSGisrestrained laterally andvertically byasetofsupportsindependent of,andnotaffectedby,theproposedmodification.

Theupperportionofeachofthetwosteamgenerators isrestrained againstlateralseismicandpipebreakloadsbyeight,large(532,000lb.capacity) hydraulic snubbersasshowninFigure1.Thesesnubbersareconnected betweenthebuildingstructure andaringgirderwhichisattachedtofourlugsweldedtotheSGshell.Thesnubbersareinstalled infourpairswithonepairapproximately paralleltothehotlegonthereactorsideofthesteamgenerator, andtheotherpairsplacedapproximately 90'part.1.2ProgramOverviewTheintentoftheproposedupperlateralsupportmodification istoreplacesix'oftheeighthydraulic snubbersperSGwithrigid1-1

structural members(bumpers),

therebyminimizing thenumberofhydraulic snubbersinserviceforthisapplication.

Theredesigned SGuppersupportconfiguration willretaintwohydraulic snubbersoneachsteamgenerator ringgirder.Thesesnubbers, alongwiththerearbumpers,willrestrainthesteamgenerator againstdynamicmotionsandloadingsalongtheaxisofthehotleg.Restraint ofmotionsandloadingsnormaltothehotlegwillbeprovidedbythereplacement bumpersinthatdirection.

Theredesigned SGuppersupportconfiguration isshowninFigure2.Thereplacement supporthardwareconsistsofindividual structural assemblies whichwillbeinstalled whereveranexistinghydraulic snubberisremoved.AtypicalassemblyisshowninFigure4.Eachassemblyisstructurally rigidundercompression butwillallowfreedomofmovementinthetensiledirection.

Eachassemblyisindividually adjustable inthefieldtoensurethatclearances ateachbumperpositionareadequateforReactorCoolantLoop(RCL)expansion yetdonotexceedthosepermitted bytheRCLanalysis.

Thebumperassembly, anditsindividual components, issizedtowithstand thenewdesignflloads.Detaileddesignoftherigidstructural membershasbeenperformed byRG&E.Fabrication has'beenperformed byaqualified supplierhavingaQualityAssurance Programmeetingtherequirements ofANSIN.45.2.1-2 II 1.3Anticipated BenefitsTherequiredmaintenance, in-service inspection andtestingoftheexistingsnubbersareperformed duringannualrefueling outages.Surveillance activities areperformed periodically throughout theyear..Byreplacing selectedsnubberswithbumpers,annualmaintenance activities and,consequently, annualradiation exposures tomaintenance personnel canbeminimized.

Thehydraulic snubbersreplacedwithbumperswillberefurbished, andstoredforuseasspares.Itisexpectedthatsparepartsprocurement, aswellasutilization ofshopfacilities andriggingequipment, canbeoptimized asaresultofthissnubberreplacement program.1.4PrimarySystemQualification Thesteamgenerator hydraulic snubberreplacement programhasresultedinchangesintheresponseoftheprimarysystem.TheeffectofthesechangesupontheRCLequipment, pipingandpipingsupportsystemhasbeenanalyzedbyWestinghouse.

Anindependent reviewbyaconsultant withbroadexperience inRCSIsupportdesignhasalsobeenperformed.

Theuseofrigidstructural members(bumpers) intheSGupperlateralsupportsystemwillchangethedegreeofstiffness withwhichtheSGsarerestrained.

againstdynamicloads.Thesenewstiffnesses havebeencalculated andareincludedinthereanalyses.

Loadingsfromadesignbasispipebreak(DBPB)postulated tooccurinan1-3 0

auxiliary line(RHR,SIaccumulator orpressurizer surgeline)branchconnection havealsobeendeveloped usingthenewupperlateralsupportstiffnesses, toassesstheeffectofthenewSGuppersupportconfiguration onthereactorcoolantsystem.PipebreaksintheMainSteamandFeedwater pipingatthecorresponding SGnozzleshavealsobeenconsidered.

TheanalysisresultsindicatethatRCLstressesanddeflections havenotchangedsignificantly frompreviousanalyses.

ThedetailsoftheRCLpipingsystemanalysis, fortherevisedSGupperlateralsupportconfiguration, areprovidedinSection3.1ofthisreport.Theprimaryequipment supportswerealsore-evaluated fornewsupportloadsgenerated fromtherevisedRCSpipingsystemanalysisbasedontheproposedSGupperlateralsupportconfiguration.

Theevaluation wasconservatively performed inaccordance withtherequirements oftheASMEBoilerandPressureVesselCode-1974Edition,subsection NFandAppendixF.Adetailed.

discussion oftheprimaryequipment supportevaluation isprovidedinSection3.2ofthisreport.Resultsoftheevaluation aresummarized inTable6.1.5IntentofReportThisreportisintendedtopresentthestructural qualifications fortheredesigned steamgenerator upperlateralsupport1-4

configuration.

ltcontainsthesupporting datatoconcludethatthemaximumstressesintheRCS,andtheprimaryequipment

supports, arelessthantheCodeallowable values.

2.0DESIGNZOADSANDCRITERIA2.1DesignBasisLoads2.1.1LoadingConditions TheSGhydraulic snubberreplacement programwillassurethatadequatesupportcapacityismaintained withrespecttothedesignbasisloads.TheRCZ,withthemodifiedsteamgenerator upperlateralsupportconfiguration, wasanalyzedforthefollowing loadingconditions:

a~b.c~d.e.Deadweight InternalPressureThermalexpansion Seismicevents(OBEandSSE)Postulated piperupturesatSGsecondary-side nozzles(MainSteam,Feedwater)

Postulated piperupturesatRCLauxiliary linenozzles(Pressurizer Surge,SIAccumulator, ResidualHeat.Removal)

ITheloadsarecombinedinaccordance withTables1,2,and3.Theloadingconditions wereevaluated withtheRCSatfull-power conditions.

Thisisconsistent withgenericanalysesofthis2-1 type,representing thehigherprobability event,andoccurswhenhigherpipingstressesfromdesignRCLpressures existandcodeallowable stressesarelower.Adiscussion ofanalysisatotherthanfullpoweroperation isalsoprovidedinthisreport.2.1.2Postulated PipeRupturesa~RCSPipeRupturesIjTheprobability ofrupturing primarysystempipingisextremely lowunderdesignbasisconditions.

Independent reviewofthedesignandconstruction practices usedinWestinghouse PWRPlantsbyLawrenceLivermore NationalLaboratory (reference 2)hasIprovidedassurance thattherearenodeficiencies intheWestinghouse RCLdesignorconstruction whichwillsignificantly affecttheprobability ofadouble-ended guillotine breakintheRCL.Westinghouse topicalreport,WCAP-9S58, Rev.1(reference 1),providedthetechnical basisthatpostulated designbasisflawswouldnotleadtocatastrophic failureoftheGinnastainless steelRCLpiping.ThisWCAPdocumented theplantspecificfracturemechanics studyindemonstrating theleak-before-break capability.

IthasbeenreviewedbytheNRCanditsconclusions wereapprovedforapplication toGinnabyletterdatedSeptember 9,1986(NRCapprovalofRG&EresponsetoGenericLetter84-04).2-2 IfIIl Intheanalysessupporting theproposedmodification, terminal-endpipebreaksarepostulated intheRCLatauxiliary linebranchconnection nozzlestotheResidualHeatRemoval(RHR)system,theSafetyInjection (SI)Accumulator pipingandthePressurizer Surgepiping.TheterminalendbreakattheSIaccumulator linenozzledefinesthelimitingpipebreakdesignbasisloadsfortheSGupperlateralsupportsystemunderemergency conditions.

b.Secondary SystemPipeRuptures'xistingpostulated pipebreaklocations inthesecondary systemswerereviewed.

Someintermediate'break locations havebeeneliminated.

fromconsideration asdescribed below.Existingpostulated terminal'-end breaksatMainSteamandFeedwater nozzlesoneachSGcontinuetobeassumed.i.MainSteamLineRupturesThepreviouscontrolling designloadfortheSGupperlateralsupportsystemwasanarbitrary intermediate pipebreakinthehorizontal MainSteamlinenearthetopoftheSG(SeeFigure3).NRCGenericLetter87-l1,"Relaxation inArbitrary Intermediate PipeRuptureRequirements",

providesguidanceforelimination ofarbitrary intermediate breaksandhasbeenappliedinthisprogram.

PreviousGinnaSeismicUpgradeProgramanalyses(recently

reviewed, inNRCInspection No.50-244/87-11),

usingANSIB31.1criteria, havebeenrevisedasnecessary toreflectchangesresulting fromthissnubberreplacement program.Consistent withGenericLetter87-11,theseanalyseshaveestablished thatnointermediate pipebreaksneedtobepostulated intheMainSteam(MS)piping.ii.Feedwater ZinePipeRuptures.Aterminal-end pipebreakispostulated.

atthesteamgenerator Feedwater inletnozzleandnowdefinesthelimitingpipebreakdesignbasisloadsfortheSGupperlateralsupportsystemunderfaultedconditions.

AllotherFeedwater breaklocations arelesslimitingand,inaddition, arenotpostulated becauseoftheapplication ofGenericLetter87-11guidance.

2.2GeneralCriteria-SeismicUpgradeProgramThedesigncodesandcriteriautilizedintheanalysisareconsistent withthoseusedforRGGE'sSeismicUpgradeProgram.Thatprogramwasinitiated inresponsetoIEBulletins 79-02,79-14,andtheSystematic Evaluation Program(SEP).ThisprogramwasreviewedduringSEPandwasapprovedbytheNRCasdocumented 2-4

intheSEPSERsforTopicIII-6,"SeismicDesignConsiderations" andtheSEPIntegrated Assessment.

NRCInspection No.50-244/83-18andInspection No.50-244/87-11 providedareviewofRG&Eworkperformed.

inresponsetoIEB's79-02and79-14.Since1979,RG&Ehasupgradedcriticalsafety-related pipingandsupports, resulting inthereevaluation andmodification ofvirtually allsupportsoriginally coveredbytheIEB's.2-5 0

3.03.1PRIMARYSYSTEMANALYSISPipingAnalysis3.1.1Mathematical ModelsTheRCLpipingmodelconsistsofmassandstiffness representa-tionsforthetwoRCLsandthereactorvessel.EachRCLincludestheprimarylooppiping,asteamgenerator andareactorcoolantpump.Theprimaryequipment supportsarerepresented.

bystiff-.nessmatrices.

Thestatic,thermalandseismicanalysesoftheRCSwereper-formedusingatwo-loopmodel(SeeFigure5)toobtaincomponent andsupportloadsanddisplacements.

Thismodelisidentical totheoneusedpreviously intheGinnaPipingSeismicUpgradeProgramexceptforthefollowing:

a~ThenewSGupperlateralsupportdesignisrepresented bystiffness matricesintwodirections.

Onematrixprovidesstiffness alongadirection corresponding tothehotlegdirection andsnubberaxes.Thesecondprovidesstiffness perpendicular tothedirection corresponding tothehotlegdirection andsnubberaxes.Thispermitscomponent supportloadsinthesnubbersandbumperstobecalculated directly.

3-1 l

b.Eachexistingpinned-end, tubularsupportcolumnundertheSG'sandtheRCP'sisrepresented byastiffness matrixbasedonstiffness valueswhichaccountfortheembedment ofthesupporting structural frameinthereinforced concreteslab.Thisisarepresentation oftheexistingconfiguration andeliminates theneedfortranslation ofloadsfromglobaltolocalcoordinates.

3.1.2Methodology Theseismicanalysisisperformed usingtheenveloperesponsespectramethod.Peak-broadened floorresponsespectrafortwo-percentand.four-percent criticaldamping(OBEandSSE,respec-tively)wereusedinconformance withRegulatory Guides1.60and1.61.Theuseoffour-percent criticaldampingforSSEwasdeveloped andjustified bytesting.Thetestingprogramsaredescribed.

inWCAP-7921, whichhasbeenacceptedbytheNRC(reference 9).Themodification intheSGupperlateralsupportswillnotaffecttheconclusion ofthedampingtestingprogram.Responses tothethreedirections ofearthquake loadingwereevaluated inaccordance withtheGinnaPipingSeismicUpgradeProgrambycombining allthreedirectional earthquakes bythesquare-root-sum-of-the-squares (SRSS)method.TheWestinghouse epsilon-method ofclosely-spaced.

modescombination wasused.intheanalysis.

Thecombination equations arepresented inAppendixA.Thismethodofcombination ofmodalresponses andspatialcomponents isconsistent withtheNRCguidelines in3-2 Regulatory Guide1.92.Thismethodhasbeenusedonnumerous~~~jotherWestinghouse PWR's(suchasVogtleand.SouthTexas)asdiscussed intheirrespective FSAR's.TheNRChasapprovedtheuseofthismethodviatheSER'sassociated withmodalresponsecombination onthoseWestinghouse plants.3.1.2.1BranchLinePostulated RupturesThedynamictime-history piperuptureanalysesoftheRCLwereperformed usingaone-loopmodel(Figure6).Thesteamgenerator upperlateralsupportsaremodeledwithsnubber-in-compression supportstiffness inonedirection andthecombinedeffectofsnubber-in-tension plusbumper-in-compression supportstiffnesses intheoppositedirection.

Thesteamgenerator columnsupportsandreactorcoolantpumpcolumnsupportsaremodeledwithtensionandcompression stiffness intheoppositedirections.

Thereactorcoolantpumptie-rodsaremodeledtobeactiveintensiononly.Thesteamgenerator lowerlateralsupportstiffness matricesusedwerechosentobeconsistent withthecalculated dynamicmotions.Pipebreaksarepostulated intheprimarysystemattheloopbranchconnections ofthepressurizer surge,RHRandSIacc-umulatorpipingsystems.Thecalculated time-history forcingfunctions wereappliedtotheRCLanalytical modelatthelumped-masspointsandwhereeachauxiliary linejoinstheRCLtoobtainthecorresponding transient loads.Theappliedforcesassociated 3-3

withthesepipebreaksincludethefollowing threecomponents:

a~b.c~blowdownforcingfunctions atvariouslocations intheprimarypipingAthrustforceatthebreaklocation.

Ajetimpingement forceatthebreaklocation.

Theblowdownforcingfunctions, whichrepresent thetraveling compression blowdownwavesduetointernalfluidsystemloads,arecalculated (inthex,y,andzcoordinate directions) ateachchangeindirection orchangeinflowareas.Thirteensuchlocations occurineachone-loopmodelandareshownschema-ticallyinFigure7.Thesetime-varying forcesareappliedateightmasslocations showninFigure8.Arepresentative blowdownforcingfunctiontime-history plot(forasinglecoordinate direction atonelocation) isshowninFigure9.Thisisthestandardmethodology used.forWestinghouse RCLpipebreaksandisdescribed inWCAP-8172-A (Reference 13),whichhasbeenacceptedbytheNRC.Thethrustforceisatime-varying blowdownforceatappliedthebreaklocation.

Xtiscalculated usingthesamemethodology usedfortheaboveinternalfluidsystemblowdownloadsandisorientedalongthecenterline axisoftheauxiliary linenozzle.Thejetimpingement loadiscalculated usingthesimplified methodsofAppendixes BandDofReference 12.Thejetimpinge-mentloadistakenasKCPA(Equations D-1andD-3ofRef.12)3-4 E0 where:K=1.0(maximumvaluefromFigureB-1)C=1.3(FigureB-6,forpressureand.enthalpy)

P=initialpressureA=pipecross-sectional flowareaThisstepfunctionjetimpingement forceisaddedtothethrustforcetoobtainthetotalappliedforceatthebreaklocation.

3.1.2.2MainSteamandFeedwater Postulated RupturesAppliedforcesduetopipebreakspostulated tooccuronthesecondary sideofthesteamgenerator attheMainSteamoutletnozzleandFeedwater inletnozzlearerepresented bystep-functionforces.Theseforcesarecalculated astheabsolutesumofthrustforceandjetimpingement forceforeachbreakloc-ation.Forthepostulated pipebreakattheMainSteamoutletnozzle,thepipeisnotconstrained andthereisnojetimpingement loadonthesteamgenerator fromtheseveredpipe.Thethrustforceforthispipebreakiscalculated usingthesimplified methodsofAppendixBinReference 12.Thesteady-state forceistakenasCPA(Equation B-2ofRef.12)where:C=1.26(thrustcoefficient forsaturated-superheated.

steamfromEquationB-4)P=InitialpressureA=pipecross-sectional flowarea3-5 0

Astepforcingfunctionwhichisequaltothissteady-state forceisappliedtothesteamgenerator inadynamicmodelofoneprimarypipingloop(Figure6).Forthepostulated pipebreakattheFeedwater inletnozzle,ajetimpingement loadiscalculated bythesimplified methodsofAppendixDinReference 12.Thejetimpingement loadistakenasKCPA(Equations D-1andD-3ofRef.12)where:K=1.0(maximumvaluefromFigureD-1)C=1.0(maximumvaluefromFigureB-7,forfL/D>1)P=initialpressureA=pipecross-sectional flowareaThepipehydraulic frictionterm(fL/D)islargerthan1.0sincethereareseveralelbowsupstreamofthepostulated.

breaklocationintheFeedwater piping.Thethrustforceforthispipebreakiscalculated bythesamesimplified methodsusedforthepostulated MainSteamoutletnozzlebreak.lnthiscase,C=1.0basedonFigureB-7ofRef.12.Thepipehydraulic frictionterm(fL/D)islargerthan1.0sincethereareJ-tubesandacircularfeedwater ringheaderonthesteamgenerator sideofthebreak.Astep-function forcewhichisequaltothesumofthejetimpingement loadandthethrustforcewhichresultsinatotalcoefficient of2.0,is3-6 0IE appliedtothesteamgenerator inadynamicmodelofoneprimarypipingloop.3.1.3ComputerProgramsPipinganalysesareperformed onthe"WESTDYN" Westinghouse computerprogram(reference 5).WESTDYNperforms3-dimensional, linear,elasticanalysesofpipingsystemssubjected.

tointernalpressureandotherloadings(staticanddynamic).

Theprogramiscapableofcombining loadsinaccordance withtheapplicable codeclassofeitherASMESectionIIIorANSIB31.1.Separatecomputerrunsanalyze,eachloadingcondition (deadweight, thermal,sustained loads,occasional loads,pipebreakandseismic).~~TheprimaryoutputfromWESTDYNdisplaysinformation abouteachanalysisperformed, including forces,moments,anddisplacements ateachpoint.TheWESTDYNcomputercodehasbeenutilizedonnumerousWestinghouse plantsandwasreviewedandapprovedbytheNRCin1981(reference 8).Thecodeisverifiedforthisapplication andacontrolled versionismaintained byWestinghouse.

3.1.4SupportStiffnesses Toaccurately represent theequipment supportsinthepipinganalyses, themodifiedsupportsystemstiffness characteristics weredeveloped forinputtothepipinganalysiscomputermodel.Individual springconstants inthelocaldirections of3-7

restraint weredeveloped forthemodifiedSGupperlateralsupportconfiguration andtheotherRCLprimaryequipment supports.

Thestiffness calculations considered thestiffness characteristics ofallstructural elementsintheloadpathincluding thesupporting

concrete, structural members,aswellasthetensionandcompression stiffnesses oftheremaining hydrau-licsnubbers.

In,thehot(i.e.fullpower)condition, thebackupperbumpersandbacklowerlateralrestraints arealternatively activeandinactivea'safunctionofthebuildingmotionrelativetotheSG's.TheRCShotlegsincompression restrainthemotionofeachsteamgenerator astheytrytomovetowardthereactorvessel.TherearenoSGupperbumpersorlowerlateralre-straintsavailable inthis"towardthevessel"direction.

Thehotlegrestrains theSGinbothdirections ofmotionalongthedirection ofthehotleg.TheupperSGsnubberswillbeactiveintensionandcompression.

Whenthebuildingmovesintheseismicevent,itpushesontheSG'sandthevesselinthesamedirection and,hence,thewholesystemmovestogether.

OneSGmovestowardsthevesselwhiletheotherismovingawayatthesametime.Therefore, backlowerlateralrestraints areactiveforthesteamgenerator inoneloopandsimultaneously inactiveforthesteamgenerator intheotherloop.Figure10illustrates thishotcondition supportcon-figuration.

3-8 Twoanalysesareperformed.

forthehot(i.e.fullpower)con-dition.Inoneanalysis, oneSGisassumedtobemovingtowardthevesselwhiletheotherSGmovesawayfromthevessel.Intheotheranalysis, theoppositemotionisassumed.TheSGwhichisassumedtobemovingtowardthevesselhasnoactivebumpers,and,sincetheresponsespectrumtechnique isusedwhereallforcesarereversible, thisanalysisprovidesbothtensionandcompression forcesinthehotlegasiftherewere'obackbumpersactiveononeSG.Thehotlegsineachloopare,therefore, capableofrestraining thesteamgenerator motionformotionsinthedirection ofthehotlegtowardand.awayfromthevessel.Duringaseismiceventloadsmayshiftbetweenthesnubberandthebumperalongtheaxisofthehotleg.Thisshiftingisboundedintheanalysisbyutilizing threevaluesoftheuppersupportstiffnesses (K~,K,and.K)inthreeseparateanalyses.

Thebumperisstifferthanthesnubber.Thus,thelowerboundvalueis,Case1,K=K(compression).

TheupperboundvalueisCase2,K=K(compression)

+K(tension).

Kistheactualstiffness whenthesteamgenerator movestowardthereactorvessel.Kistheactualstiffness whenthesteamgenerator movesawayfromthereactorvessel.Finally,athirdvalueofK=1/2(K+K)wasused.toprovidedataonanintermediate stiffness.

Thethreevaluesareasfollows:K=19.15x10lb/in3-9 0

K=7.8x10lb/in.K=13.46x10~lb/in.Severalevaluations wereperformed usingCase1and.Case2stiffnesses, andtheworstloadsoneachindividual bumperweredetermined.

Theresultsaresummarized inTable8alongwithcorresponding loadsbasedontheaveragestiffness value,KUseofboundingstiffness valuesproducesadecreaseintheseismicstressmarginateachlocationascomparedwithKAdequateseismicstressmarginstillexistssincethelowestmargin,usingtheboundingstiffness, is1.73(SG1Bsnubbers).

Basedonthesechangesinseismicmargin,and,thecalculated marginsforlooppiping(showninTable4)andtheprimaryequipment supports(showninTable6),itisconcluded thatadequateseismicmarginsexistfortheredesigned.

SGupperlateralsupports.

ThedatainTables4,5,6,and7arebasedontheKvalueofSGuppersupportstiffness.

3.1.5PipingEvaluation CriteriaThepipingevaluation criteriaarebasedonANSIB31.1-1973 Edition.TheoriginaldesignbasisoftheseismicCategoryIpipingatGinnawasinaccordance withthe1955and1967EditionsofUSASB31.1.WhenUSASB31.1wasupdatedtotheANSIB31.1,thestressanalysisformulaandstressintensification factorswererevised.Theprimarystressequations intheinitialB31.13-10

-1973EditionweresimilartothosegivenintheASMESectionIIICodeofthattime.Thestressintensification factorsgiveninthisversionofB31.1wereexpandedtoincludemorefittings.

InusingANSIB31.1,thePipingSeismicUpgradeProgramupdatedtheanalysistoreflectASMESectionIIIconceptswhilestillretaining thephilosophy ofB31.1.However,thestressinten-sification factorsforbuttandsocketweldsoftheoriginalEditionofB31.1havebeenusedbecauseoflackoforiginalweldconfiguration information.

3.1.6PipingLoadCombinations Thepipingwasevaluated fortheloadcombinations definedinTable1.3.2PrimaryEquipment SupportsEvaluation 3.2.1Methodology Thesteamgenerator upperlateralsupportsystemhasbeenredesigned byreplacing sixoftheeightsteamgenerator snubbersineachloop.Therevisedconfiguration isshowninFigure2.TheRCLanalysismodelwasrevisedtoreflectthenewsupportconfigurations.

Computeranalyseswereperformed, asdescribed inSection3.1,togeneratenewRCLloadsontheprimaryequip-mentsupportsystemandtheprimaryequipment supportswere3-11 evaluated forthesenewloads.Theevaluation wasperformed forsupportsassociated withthereactorvessel,steamgenerators andreactorcoolantpumps.Inappropriate cases,finiteelementmodelsofsupports, usingtheSTRUDLprogram,wereutilizedtoassistintheevaluation.

Thesupportswererequalified fortherequiredcombinations ofpressure, thermal,deadweight, seismicandpiperuptureloads.3.2.2SupportLoadingsandLoadCombinations Theloadsusedintherequalification oftheequipment supportstructures aredefinedinTable2.Theseloadswerecombinedfortheplantasidentified inTable3.Thecorresponding loadcombinations andtheallowable servicestresslimitsarealsoprovidedinTable3.3.2.3Evaluation CriteriaTherigidstructural members(bumpers) intheSGupperlateralsupportsystemaredesignedtotherequirements ofthecurrenteditionoftheoriginaldesigncode(American Institute ofSteelConstruction, AISCManual,8thEdition).

However,toevaluatetheequipment supportsfornormal,upset,emergency andfaultedconditions, theprovisions ofASMEBoilerandPressureVesselCodeSectionIII,Subsection NFandAppendixFwereused-1974edition.TheASMEB&PVCodeSectionIII,Subsection NFwasusedtoestablish allowable stresscriteriafortheequipment support3-12 evaluation inlieuoftheAISCCodebecauseSubsection NFandAppendixFcoupled.withUSNRCRegulation Guide1.124establish amoreconsistent andconservative setofcriteria.

Forexample,Subsection NFwasdeveloped specifically toaddresscomponent supportswhereastheAISCgenerally addressbuildingstructures.

Additionally, theuseofSubsection NF,AppendixF,andRG.1.124requiretheuseofmaterialproperties atservicetemperature, limitbucklingto0.67criticalbuckling, andestablish upperboundallowables ontensionandshearstress.Theevaluation wasperformed.

usingmanualcalculations andcomputeranalysiswhereappropriate.

3.2.4~~ComputerProgramsTheprimaryequipment supportswereevaluated byhandcalcula-tionsand,whereappropriate, byfiniteelementcomputeranalysisusing"STRUDL."

STRUDL,partoftheICEScivilengineering computersystem,iswidelyusedfortheanalysisanddesignofstructures.

Itisapplicable tolinearelastictwo-andthree-dimensional frameortrussstructures, employsthestiffness formulation, andisvalidonlyforsmalldisplacements.

Struc-turegeometry,

topology, andelementorientation andcross-sectionproperties aredescribed infreeformat.Printedoutputcontent,specified byinputcommands, includesmemberforcesanddistortions, jointdisplacement, supportjointreactions, andmemberstresses.

TheSTRUDLcomputercodehasbeenutilizedon3-13

numerousWestinghouse plantsandwasreviewedandapprovedbytheNRCin1981(reference 8).Thecodeisverifiedforthisapplication andacontrolled versionismaintained byWestin-ghouse.3-14 4.04.1EVALUATlON ANDRESULTSReactorCoolantLoopPipingTable4providesthelevelofstressintheRCLpipingandtheallowable stressesfromtheDesignCode(reference 4).Theresultsshowthatthestressesinthepipingarewithinallowable limits.Acomparison betweenthemaximumstressintheRCLpipingforthecurrentandredesigned supportconfiguration showsthatthereareonlyverysmallchangesinthecalculated stresses.

4.2Application ofLeak-Before-Break Withtheredesigned steamgenerator upperlateralsupportconfiguration, revisedloads(forcesandmoments)intheRCLpipinghavebeengenerated.

TherevisedloadsarecomparedwiththoseloadsinGenericLetter84-04(reference 7)inTable5.Thecalculated axialstress(19.42ksi)is60%oftheallowable axialstress(32.4ksi).Basedonthecomparison, itisverifiedthattheleak-before-break conclusions ofWCAP-9558, Rev.1remainvalid.fortheredesigned supportconfiguration.

4.3MainSteamLineBreakLocations Theterminal-end breakinthemainsteamlinepipingatthesteamgenerator nozzleisadesignbasispipebreak.Themaximum4-1 calculated stressintensity atintermediate locations for~~~combinedpressure, deadweight, thermalandOBEloadingsis27.1ksi.Thisislessthanthethreshold stressintensity of0.8(1.2S+S)or29.6ksi.Therefore, therearenohigh-stress

'intermediate breaklocations inthemainsteamlinesinsidecontainment.

4.4PrimaryEquipment SupportsThestressmarginsforRCLequipment supportsresulting fromtheRCLanalysisconsidering theredesigned steamgenerator upperlateralsupportconfigurations aresummarized inTable6forallloadingcombinations.

Thestressmarginisdefined.astheratiooftheallowable supportstresstotheactualsupportstress.Loadingevaluations performed withtheredesigned supportconfiguration demonstrate thatallRCLequipment supportstressessatisfystresslimitswithanadequatemarginofsafety.Seismicmarginisassessedbythestressmarginfortheload.combination, (DW+TN+SSE).Thesestressmarginsaresummarized inTable7fortheexistingandredesigned steamgenerator upperlateralsupportconfiguration.

Theresultsdemonstrate thatasig-nificantmarginofsafetyexistsfortheredesigned steamgenerator upperlateralsupport.4.5PrimaryComponent NozzleLoadConformance TheRCLpipingloadsontheprimarynozzlesofthereactor4-2 0

vessel,thesteamgenerators, andthereactorcoolantpumpswereevaluated..

Theconformance evaluation consisted ofloadcom-ponentcomparisons, andloadcombination comparisons, inaccor-dancewitheachoftherespective Equipment Specifications orwithapplicable nozzleallowable limits.Itwasconcluded thatallRCLpipingloadsactingontheprimarycomponent nozzleswereacceptable.

4.6Evaluation ofAuxiliary LinesTheRCLpipingandprimaryequipment displacements werecomparedtothecorresponding displacements usedinthepreviousanalyses.

Theyarefoundtobelessthanthepreviousanalysisresultsorwithin+1/16inch.Duetotheflexibility oftheattachedpipingsystems(designed tobeflexibletoaccommodate thermalgrowthoftheRCL)andthegapswhichnormallyexistbetweenthepipeandthesupporting structure, anincreaseinanchormotionsattheloopconnection pointofupto1/16inchwillnotcausesignificant changesinpipingstress.Therefore, auxiliary'piping systemsattached.

totheRCLarenotaffectedbytheredesigned steamgenerator uppersupportcon-figuration.

4.7BuildingStructural Evaluation 4.7.1Evaluation ofLocalAreas4-3 Corbelsandembedments wereevaluated, fortensionloadsandtheircapacitywasfoundtoexceedthatofthehydraulic snubbers.

Corbelswerealsoevaluated fortherigidstrutural member(bumper)bearingloads,andwerefoundtobeloadedtonomorethan60'-oofallowable.

Allevaluations wereperformed withrespecttoACI-349,andAppendixBofACI-349.4.7.2Secondary ShieldWallsTheelevation oftheSGupperlateralsupportsisthesameastheReactorBuildingOperating Floor.Thereisnolocalized bending,sincethefloorslabactsasastiffening ring.Resulting tensilestressesarelow,withamaximumofabout40%ofallowable.

Allevaluations weredonewithrespecttoACI-349.4.7.3Conclusion Inconclusion, theexistingcontainment buildingstructures areadequateforthenewdesignbasisloadsassociated withthenewsnubber/bumper SGupperlateralsupport.configuration.

4-4 1l

5.0 ADDITIONAL

CONSIDERATIONS 5.1Overtemperature EventsThedesignbasisovertemperature eventistheloss-of-load transient.

RCLequipment supportstressmarginsforthistransient areadequateasshowninTable6.Anevaluation hasalsobeenperformed for'theovertemperature conditions following afeedwater linepipebreak.Themaximumloadonanyindividual bumperwasfoundtobe23.4kips.Thisissignificantly lessthanthe820kipsmaximumcapacityofeachbumper.Thecor-responding RCLpipingstresseswerealsofoundtobemuchlessthanthecode-allowable thermalstress.5.2ColdShutdown5.2.1RCSAnalysisInadditiontotheplantdesignbasisfullpower(i.e.hotcondition) evaluation described inparagraph 3.1,selectedanalyseswereperformed forthecoldshutdowncondition.

Themathematical modeldescribed inparagraph 3.1.1wasreconfigured torepresent theRCSinacoldshutdowncondition.

AlthoughtheRCLpipingwillhavecontracted thermally (creating gapsatsomesupportlocations),

itrespondstotheseismiceventinamannersimilartothatforhotconditions.

Seismicloadswillbedistributed differently throughout theRCS,withthehotlegpipingcarryinggreaterloadsinrestraining motionbetweenthe5-1 reactorvesselandthesteamgenerators.

ThemaximumRCSpipingstressinthecoldshutdowncondition (duetothecombination ofpressure, deadweight andSSEearthquake) wasfound.tobe20.7ksi(64%ofallowable)

.Asdescribed inTable1,thisisanemer-gencycondition andtheallowable stressis1.8S,corresponding toavalueof32.4ksiinaccordance withtheANSIB31.1codeatcoldshutdowntemperatures.

Code-allowable stressesarehigheratcoldshutdowntemperatures thanatthehotconditions.

Theincreased gapsatsomesupportlocations willreducetheoverallstiffness ofthesystem.TheSGfrequency willhavebeenreducedfromapproximately 8.2Hzinthehotcondition toapproximately 7.0Hzinthecoldcondition.

ThereactorbuildingseismicresponsespectrumforanSSE(asshowninFigure11)isessentially flatinthisfrequency regionand,consequently, nosubstantial increaseinseismicloadsoccurs.5.2.2PrimaryEquipment SupportsTheRCLpipingmodel(described inparagraphs 3.1.1and.3.1.3)wasanalyzedfordisplacements resulting fromthermalchangesbetweentemperatures corresponding tofullpoweroperation andcoldshutdown.

Acombination ofcomputeranalyses(usingtheRCLpipingmodel),manualcalculations (i.e.fortheSGshell)andfieldmeasurements, areusedtopredictthegapswhichwillexistatRCLsupportlocations inthecoldshutdowncondition.

5-2 I

TheSGupperlateralsupports(bumpers) areadjustedduringplantstartupsuchthat,atpoweroperation, thegapbetweenthesebumpersandthesteamgenerators willbeverysmall(lessthan1/16ofaninch).Nhencoolingtocoldshutdownconditions itiscalculated thatthetotaldiametrical gapbetweeneachsteamgenerator and.theassociated SGupperlateralsupports(bumpers) isapproximately 0.4inchesinthedirections perpendicular totheRCLhotleg(i.e.acrosssteamgenerator 1Aatbumperreference locations 2and3,andacrosssteamgenerator 1Batbumperreference locations 4and5asshowninFigure2).Also,asshowninFigure2,therevisedsteamgenerator uppersupportconfiguration willretainexistingsnubbersatlocations app-roximately paralleltothehotlegdirection andtheywill~~~provideseismicrestraint inthatdirection duringcoldshutdown.

Thesesnubberswillpreventseismically-induced motionsfromclosingthe2-inchcoldshutdowngapsatsteamgenerator 1Abumperreference location1andatsteamgenerator 1Bbumperreference locations 6and7shownonFigure2.Otherprimaryequipment supportshavebeenevaluated forseismicloadsinthecoldshutdowncondition.

Theseloadshavebeencalculated andarewellwithinthecapacityforthecorresponding supportcomponent.

Theloads,supportcapacities andtheir'omparison (expressed asloadmargins)arepresented inTable9.5-3

6.0 QUALITYASSURANCE

Rochester GasandElectricCorporation Theoverallprojectisbeingconducted undertheRG&EQualityAssurance Program.Thereplacement rigidstructural members(bumpers) hasbeenfabricated by'a'supplier havingaQualityAssurance Programmeetingtherequirements ofANSIN45.2.RG&Ehasspecified materialtraceability, welderqualification, non-destructive examination andotherrequirements applicable tothenewbumpers.6.2Westinghouse ElectricCorporation Thestructural qualification workperformed byWestinghouse hasbeenindependently reviewedatWestinghouse asasafety-related calculation andmeets10CFR50,AppendixB,QualityAssurance requirements.

Thedetailedresultsoftheanalysesaremain-tainedinWestinghouse CentralFilesinaccordance withWestin-ghouseQualityAssurance procedures (ref.10and11).6.3AltranCorporation Anindependent, thirdpartyreviewisbeingperformed byAltranCorporation andDr.ThomasC.Esselman.

Dr.Esselmanandhisassociates haveconducted athoroughreviewoftheassumptions, designbases,analysesand.otherdesigndocuments producedbyWestinghouse.

I

7.0CONCLUSION

S Basedontheresultsoftheevaluation ofthereactorcoolantsystemwiththeredesigned SGupperlateralsupportconfiguration thefollowing conclusions aremade:Thecombination ofhydraulic snubbersandrigid,structural members(bumpers) whichcomprisetherevisedsteamgenerator upperlateralsupportsystemmaintainadequaterestraint ofeachsteamgenerator underthedesignbasisloads.b.ThemaximumstressesintheRCSpipingandprimaryequipment supportsarewithinCodeallowables.

cThemaximumdisplacements intheRCSpipinghavebeenaccounted forinanalysesofauxiliary pipingsystemsattachedtotheRCS,anddonotsig-nificantly affectthoseanalyses.

Thereactorcoolantlooppipingandequipment supportscontinuetohaveacceptable marginsofsafetyforalldesignbasisevents.e.TheContainment Buildingstructures areadequatetocarrytheloadsimposedbythenewsnubber/bum-perSGupperlateralsupportconfiguration.

I1 Therefore, theproposed.

modifiedconfiguration meetsallcon-ditionsnecessary toassuresafeoperation oftheplantinaccordance withthelicenseddesignbases.7-2

8.0REFERENCES

1.WCAP-9558, Rev.1,Mechanistic FractureEvaluation ofReactorCoolantPipeContaining APostulated Circumferential Through-Wall Crack,June1980.2.NUREG/CR-3660, UCID-1988, Volume3,February, 1985,"Probability ofPipeFailureinReactorCoolantLoopsofWestinghouse PWRPlants,"Volume3,"Guillotine BreakIndirectly InducedbyEarthquakes,",

LawrenceLivermore NationalLaboratory.

3.ASMEBoilerandPressureVesselCode,SectionIII,Subsection NFandAppendixF,AmericanSocietyofMechanical Engineers, 1974Edition(forSupportsEvaluation).

4.ANSIB31.1PowerPipingCode1967Edition,including Summer1973Addenda.5."PipingAnalysisComputerCodesManualII"Westinghouse Proprietary Class3,Westinghouse ElectricCorporation, Pittsburgh, PA.6.NRCBranchTechnical PositionMEB3-1,Rev.2,1987,Postulated RuptureLocations inFluidSystem8-1 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.Westinghouse PowerSystemBusinessUnitQualityAssurance ProgramforBasicComponents Manual,WCAP-9550, Rev.16,June30,1987.11.Westinghouse NTSD/GTSD QualityAssurance ProgramManualforNuclearBasicComponents, WCAP-9565, Rev.11,Aug.31,1987.12.ANSI/ANS-58.2-1980, "ANSStandard-Design BasisforProtection ofLightWaterNuclearPowerPlantsAgainstEffectsofPostulated PipeRupture".

13.WCAP-8172-A, January,1975,"PipeBreaksfortheLOCAAnalysisoftheWestinghouse PrimaryCoolantLoop".8-2 Table1RCSPIPINGLOADCOMBINATIONS ANDSTRESSLIMITSCondition NormalUpsetEmergency FaultedMax.ThermalNormal6Max.ThermalLoadinCombination DesignPressure+Deadweight DesignPressure+Deadweight

+OBEDesignPressure+Deadweight

+SSEDesignPressure+Deadweight

+(SSE+DBA)**Max.ThermalStressRange***+OBEDisplacement DesignPressure+Deadweight

+Max.ThermalStressRange+OBEDisplacements ANSIB31.1Euations111212121314**SRSScombination ofSSEandDBAloads***Loss-of-load overtemperature transient condition Thepipingstressequations are: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=Resultant momentduetodeadloadandothersustained loads.M=Resultant momentduetooccasional loads.M=Resultant momentduetorangeofthermalexpansion loadings.

P=InternalDesignPressure.

D=Outsidediameterofpipe.Nominalwallthickness ofpipe.Z=SectionmodulusS~=Materialallowable stressatmaximumtemperature.

S=Allowable stressrangeforexpansion stress.i=StressIntensification Factor.T-1 I\i TABLE2DEFINITION OFLOADINGCONDITIONS FORPRIMARYEQUIPMENT SUPPORTSEVALUATION LoadinCondition 1.Sustained Loads2.Transients a.Over-temperature Transient 3.Operating BasisEarthquake 4.SafeShutdownEarthquake 5.DesignBasisPipeBreaka.ResidualHeatRemovalLineb.Accumulator Zinec.Pressurizer SurgeZine6.MainSteamLineBreak7.FeedWaterPipeBreakAbbreviations DW,Deadweight

+P,Operating Pressure+TN,NormalOperating ThermalSOT,SystemOperating Transient TAOBESSEDBPBRHRACCSURGMS TABLE3LOADCOMBINATIONS ANDALLOWABLE STRESSLIMITSFORPRIMARYEQUIPMENT SUPPORTSEVALUATION PlantEvent1.NormalOperation SystemOperating Conditions NormalServiceLoadingCombinations Sustained.

LoadsServiceLevelStressLimits2.Plant/System UpsetOperating Transients (SOT)+OBESustained.

Loads+SOT+OBEB3.DBPB4.SSE5.DBPB(orMS/FWPB)+SSENote:Emergency FaultedFaultedSustained Loads+DBPBSustained Loads+SSEDSustained Loads+.(DBPBorDMS/FWPB)+SSE1.ThepipebreakloadsandSSEloadsarecombinedbythesquare-root-sum-of-the-squares method.2.StresslevelsasdefinedbyASMEB&PVCodeSectionIII,Subsection NF,1974Edition.

TABLE4MAXIMUMREACTORCOOZANTLOOPPIPINGSTRESSES(BasedonK)AVGCurrentANSI(1)Configuration B31.1CodeRCLStressRedesigned Configuration Stres's(ksi)ANSIB31.1CodeAllow-Percentage ableStressof(ksi)Allowable HLXLCL(12)DesignHZandUpsetXLCZ(12)HLEmergency XLCL(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-Crossover leg,CL-Coldleg*Piperuptureloadswerenotconsidered.

Nofaultedstresseswerecalculated forcurrentdesign.(2)Loadcombinations areshowninTable1.(3)Loss-of-load overtemperature transient effectsareincluded.

TABLE5COMBINEDLOADSFORLOOPPIPINGLEAK-BEFORE-BREAK (BasedonK)AVGLoadCombination AzialForce(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)Allowable basedonWCAP-9558, Rev.l.(2)UmbrellabendingmomentinNRCGenericLetter84-04is42,000in-kips.

TABLE6RCSPRIMARYEQUIPMENT SUPPORTSSTRESSMARGINSUMMARY'Stress Margin=Allowable/Actual)

(BasedonK)AVGServiceLevelNormalUpsetEmergency SSEFaultedLoadCombination DW+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)Undernormalconditions nosignificant loadsareimposed.ontheselateralsupportelements.

I TABLE7STEAMGENERATOR UPPERSUPPORTSSEISMICLOADMARGINS(BasedonK)AVGSEISMICLOADSDW+TN+SSE (kips)SGUSCAPACITY(kips)SEISMiCLOADMARGIN(Allowable/Actual)

LOOPNO~BUMPERIDEXISTING~SGUS1REDESIGNEDSGUS8CHANGEEXISTINGREDESIGNED EXISTINGREDESIGNED 1ASN-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.

NOTETOTABLE7Theoriginalseismicsupportloadcalculations includedanadditional contribution whichisnotrequiredintherevisedsupportloadcalculations.

Intheoriginalcase,thetotalseismicsupportplaneloadattheuppersupportwasfirstcalcu-latedbydynamicanalysisinglobalcoordinates andthenrotatedtothelocalcoordinates ofthesupportmembers.Intherevisedcase,theindividual supportmembersweremodeleddirectlyinthedynamicmodelsothatarotationfromsupportplaneloadstomemberloadswerenotrequired.

Therotationofcoordinates mustbedoneconservatively, sincetherearenosignsassociated withthetotalseismicforcecomponents inglobalcoordinates.

Therefore, theoriginaldesignloadsaremoreconservatively calculated thanthereviseddesignloads.T-7A II TABLE8STEAMGENERATOR UPPERSUPPORTSSEISMICLOADMARGINS(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

Table9RCSPRIMARYEQUIPMENT SUPPORTSLOADMARGINSUMMARYCOLDSHUTDOWNSEISMICANALYSIS(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)indirection ofRCLhotleg.Loadandcapacitycorresponds tothepairofsnubbers(532kipscapacity, each)Coldshutdownseismicloadsarecalculated fornewbumpersorientedapproximately perpendicular toRCLhotleg.Loadandcapacitycorresponds toapairofbumpers(820kipscapacity, each).EachSG(AandB)hasfoursupportcolumnswith1349.0kipscapacity, each,incompression.

Loadgivenisworstcasesinglecolumncompression load.EachSG(AandB)hasalowerlateralsupportframeatthebottomoftheSGshell.DuringColdShutdown, lateralsupportfromtheframeisdisengaged.

duetocontraction oftheRCS.T-9 II0 5.EachRCP(AandB)hasthreesupportcolumnswith397.0kipscapacity, each,intension.Loadgivenisworstcasesinglecolumntensionload.6.EachRCP(AandB)hastwotie-rods.

DuringcoldshutdownallRCPtie-rodsaredisengaged asaresultofcontraction ofRCS.7.TherearesixRPVsupports(oneateachoffourmajornozzles)andtwoatseparatevesselsupportbrackets.

Loadsandcapacities arefortheworstcasesingleRPVsupportin'achdirection.

8.Loadsincludedeadweight andSSE.T-9A

APPENDIXACOMBINATION OFSEISMICMODAlRESPONSES ForSeismic.CategoryIcomponents withintheNSSSscope,themethodusedtocombinemodalresponses isdescribed below.Thetotalunidirec-tionalseismicresponseforNSSSequipment isobtainedbycombining theindividual modalresponses usingtheSRSSmethod.Forsystemshavingmodeswithcloselyspacedfrequencies, thismethodismodifiedtoincludethepossibleeffectofthesemodes.Thegroupsofcloselyspacedmodesarechosensuchthatthedifference betweenthefrequencies ofthefirstmodeandthelastmodeinthegroupdoesnotexceed10percentofthelowerfrequency.

Combinedtotalresponseforsystemswhichhavesuchcloselyspacedmodalfrequencies isobtainedbyaddingtotheSRSSofallmodestheproductoftheresponses ofthemodesineachgroupofcloselyspacedmodesandacouplingfactor,c.Thiscanberepresented

-mathematically as:N2SXR+2Ei=1j=lNj<<lNjEZRkRc~(Equation A-1)k=MjX=k+1where:R=Totalunidirectional responseR=AbsolutevalueofresponseofmodeiLN=Totalnumberofmodesconsidered S=Numberofgroupsofc3.oselyspacedmodesMj=l,owestmodalnumberassociated withgroupjofcloselyspacedmodesN=Highestmodalnumberassociated withgroupjofcloselyspacedmodeschal=Couplingfactordefinedasfollows:k~kkand,kk~~k2b5kdA-l Iwhere:e=Frequency ofcloselyspacedmodeKkp=FractionofcriticaldampingincloselyspacedmodeKktd=Durationoftheearthquake Forexample,assumethatthepredominant contributing modeshavefrequencies asgivenbelow:Node12345678Frequency 5.08.08.38.611.015.516.020Therearetwogroupsofcloselyspacedmodes,namelymodes2,3,4and6,7.Therefore:

S=2,NumberofgroupsofcloselyspacedmodesM1N1M2N2N2,Lowestmodalnumberassociated withgroup14,Highestmodalnumberassociated withgroup16,Lowestmodalnumberassociated withgroup27,Highestmodalnumberassociated withgroup28,Totalnumberofmodesconsidered Thetotalresponseforthissystemis,asderivedfromtheexpansion ofEquationA-1:R=fR+R+R+....+Rl+2R2R3<23+2R2R422222123+2R3R4c34+2R6R7Thefirstterminbracketsrepresents theSRSSsummation ofeachoftheeightexamplemodes.Thenext,threetermsaccountfortheadditional effectsduetointeraction betweenexamplemodes2,3and4.Thefinaltermsimilarly accountsforinteraction effectsbetweenexamplemodes6and7.A-2

ENCLOSURE 2RESPONSETONRCLETTER4/13/88Thepurposeofthisenclosure istoprovideresponses tothesixNRCauestions regarding RG&E'sproposaltoreplacecertainsteamgenerator snubberswithrigidsupports(bumpers),

transmitted byletterof4/13/88.RG&Ehasintegrated theseresponses, asapplicable, intothesummaryreport"SteamGenerator Hydraulic SnubberReplacement Program",

May1988,Rev.2,includedasEnclosure 1toAttachment BofRG&E'sApplication forAmendment toreplacecertainsteamgenerator snubberswithbumpers.NRCREQUEST:1.Providethesizeandbasisofthebumpergapsinthecoldcondition.

RG&ERESPONSE:

1.Thisinformation isdetailed, inSection5.2.2ofEnclosure 1.NRCREQUEST=2.Thedetailedcalculations ofthecoldshutdowncondition loadsinallsteamgenerator

supports, reactorvesselsupportsand.reactorcoolantpumpsupports, whensubjected toSSEseismicloading.RG&ERESPONSE:

2.Detailedcalculations wereperformed.

undercold.shutdownconditions.

Thedescription ofthemethodology usedtoperformthecoldshutdownanalysisisprovidedin-Section5.2ofEnclosure 1.TheresultsoftheseanalysesareprovidedinTable9ofEnclosure 1.ItcanbeseenthatstressesinthesupportsarewellwithintheCodeallowable values.Thedetailedcalculations performed forcoldshutdownconditions, aswellasthoseperformed.

forhotconditions, areavailable forrevieworauditintheWestinghouse offices.'INRCREQUEST:3.Thecalculation oftheminimum,maximumandaveragesteamgenerator upperstiffnesses andtheirinclusion intheRCLmodel.

~I RG&ERESPONSE:

3.Theminimum,maximum,andaveragesteamgenerator upperstiffnesses areprovidedinSection3.1.4ofEnclosure 1.Theaveragestiffness wasusedtoprovideanassessment ofstressesusinganintermediate stiffness, andtosimplifycalculations.

Analysesperformed.

usingKandKxratherthanK(Table8ofEnclosure 1)canbeusedtocorrelate theresultsofstressesusingthetwomethods.NRCREQUEST:4.Thejustification ofthethrustcoefficients usedforthetime-history analysisofthesteamgenerator outletnozzleand,thefeedwater nozzles.RG&ERESPONSE:

4.Thejustification ofthethrustcoefficients usedintheanalysisofthepostulated steamandfeedwater nozzlerupturesareprovid'ed inSection3.1.2.2.Forthesepostulated

ruptures, the-appliedforcesarecalculated usingthesimplified methodsofAppendixBtoANSI/ANS58.2-1980.

5.Description ofthenon-linear time-history analysesoftheRCLwhensubjected toloadingduetopostulated breaksatthepressurizer surge,RHRandSIaccumulator nozzles,andtheSGsteamoutletnozzleandthefeedwater nozzles.Thisshouldincludethespecified time-history loadingforcingfunction.

RG&ERESPONSE:

5.Thisdescription andjustification oftheloadingfunctions isprovidedinSection3.1.2.1ofEnclosure 1.NRCREQUEST6.Provideclarification ofthemodelingandcalculational resultsofthetwoanalyseswhichareperformed, inthehotcondition.

RG&ERESPONSE:

6.Additional clarification ofthetwoanalysesperformed forfullpowerconditions isprovidedin3.1.4ofEnclosure 1,andthecalculational resultsareprovidedinTables4-8ofEnclosure

1.

(0(I*]

STEAllOENERATOR COOLANTPUMP-fA00IIExistingnubbers0S/GLowerLateralSupporS/GSupportColumnsRCpsupportColumnsREACTORCOOLANTPtNPREACTORREACTORBUILDINGPLANREACTORBUILDINGELEVATION GINNASTATIONSTEA51GENERATOR SNUBBERREPLACEMENT PROGRAMRGGE5-1-88FIGURE1EQUIPMENT LAYOUT 1

ExistingSnubbers(2perS/Gremaininplace)ExistingStructural RingGirderSG)AOiReactorCavitY0'xisting Structural RingGirder0s04SG1BReactorVesselNewStructural Members(Bumpers) 0O~NewStructural Members(Bumpers) 45670ExistingSnubbers(2perS/Gremaininplace)lNewStructural Members(Bumpers)

ZocationReference Number.RG&E5-1-88GINNASTATIONSTEAMGENERATOR SNUBBERREPLACEMENT PROGRAMFIGURE2UPPERSUPPORTCONFIGURATION-PROPOSED MODIFICATION MainSteamOutletNozzle~MainSteamManway(2)NormalWaterLevelFeedwater InletNozzleFeedwater

~~Feedwater RingLiftingTrunnions (2)RingGirderRCLNozzle(2)LowerSupportBrackets(4)Manwap(2)GINNASTATIONSTEAMGENERATOR SNUBBERREPLACEMENT PROGRAMRG&E5-1-88FIGURE3STEAMGENERATOR lA/lB-DETAILS F-3

~~~oQoS~~040~$~~~~~b~b.'.PinCenterline 3I9II-10.5"PLANVIEW-TYPICAL BodyPinCenterline 1'gQ~4.C~d.'a..~~.~~0'~Lb".-b-rbd.ilJIllI'uideShaftIIIII..IIII-StopNutIJII'I~II'ounting Bracket(Existing)

Reinforced ConcreteShieldWall(Existing)

MountingBracket(Existing)

S/GRingGirder(Existing)

GXNNASTATIONSTEAMGENERATOR SNUBBERREPLACEMENT PROGRAMRG&E5-1-88FIGURE4RIGIDSTRUCTURAL MEMBER(BUMPER)-DETAILS l

QsG233223SGUpperSupportORCP277273269263RCPSupportRG&E5-1-882590219SGUpperSupport~~~RCP1772418921340024922209SGLoweSupport253~LooP1B1203194123173101LooplA109RV1294169119103283500143129SGLowerSupport289163VesselSupports149159North153GINNASTATIONSTEAMGENERATOR SNUBBERREPLACEMENT PROGRAM.REACTORCOOLANTLOOPS1A&1BANALYTICAL MODEL(STATICANDSEISMICANALYSES)

FIGURE5RCPSupport 189133SiWGHRSUPPORTSICI1831195lLOCI5gftHT523143li9159177173159163ICt%PONDGINNASTATIONSTEAMGENERATOR SNUBBERREPLACEMENT PROGRAMFIGURE6:REACTORCOOLANTPIPING/SUPPORT SYSTEM-ONELOOPMODELFORTIME-HISTORY PIPERUPTUREANALYSISRGGE5-1-88F-6

~t.Itl STT'AI<GENERATOR TUBESREACTORVESSELCOLDLEGPIIMP1I13INOTLEGI123'2IK2IeIIIl~IreIOSTEAMGENERATOR 9CROSSOVER LEGGINNASTATIONSTEAMGENERATOR SNUBBERREPLACEMENT PROGRAMRGRE5-1-88~iciure7REACTORCOOLANTLOOPMODEL-HydraullcFarceLocatfons F-7 qr<g 289223SGUpperSupports219269ReactorVessel213SGLowerSupports243RCP263Supports253GINNASTATIONSTEAMGENERATOR SNUBBERREPLACEMENT PROGRAMFiciure8REACTORCOOLANTPIPING/SUPPORT MODEL(Locatfon ofLumpedMassesForthe.App'lfcatfon ofT)meHistoryKqdraulic Loads)RG&E5-1"88F-8 X,4I TlTLERGESURGESK'LPHYDFOPROGRAMHYDFOt15FYRGEHYD09/15/47g%L$a~5~l%e)2$.N,Sel.4C.STfl<<Q54S09/15/87GINNASTATIONSTEAMGENERATOR SNUBBERREPLACEMENT PROGRAMFiciure9REPRESENTATION BLOWDOWNFORCINGFUNCTIONPLOT(onecoordinate direction atonelocation)

RG&E5-1-88F-9 4

BuildingMotionIIAllSGLowerlateral.restraints in-linewithRCLhotlegareengaged,forbuildingmotiontowardSG"A".0tg0~4MotionofSG"A"isrestrained bytheRCLhotlegandthelowerbacklateralrestraint.

AttRCPogQ'~MotionofBuildingandRPVRPVSupportsarealwaysactiveReactorVessel"B"RCPod>0Cy0IIBIISGMotionofSG"B"isrestrained onlybythehotleg.,rI.ItLowerlateralrestraints in-linewithRCLhotlegprovidenegligible restraint forbuildingmotionawayfromSG"B".GINNASTATIONSTEAMGENERATOR SNUBBERREPLACEMENT PROGRAMRGGE5-1-88F-10 C~~

IlllllllllHlllllllllllllll IIIIIIIIHllllllll GINNASTATIONBROADRESPONSESPECTRUMFORSSEREACTORBUILDINGINTERIORSTRUCTURE ELEVATION 278'-4"X-RESPONSE FIGURE23B-XOCTOBER15,19790H2oEQUIPMENTDAMPING3%EQUIPMENT DAMPING4'tEQUIPMENT DAMPING7%EQUIPMENT DAMPINGZPA=0.29g20FREQUENCY (cPs)nz~asae3osa34~4~e~0GINNASTATIONSTEAMGENERATOR SNUBBER-REPLACEMENT PROGRAMRG&E5-1-88

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