ML18026A218

Susquehanna Units 1 and 2 - SSES Design Assessment Report, Revision 1

ML18026A218
Person / Time
Site:	Susquehanna
Issue date:	04/14/1978
From:	Pennsylvania Power & Light Co
To:	Office of Nuclear Reactor Regulation
References
Download: ML18026A218 (21)

Text

SUSQUEHANNA STEAMELECTRICSTATIONDESIGNASSESSMENT REPORT(DAR)""-'";",:So-+6'tio'goI ggV-lq.pS.=.Revision1

,~>'h)~h PREPACEThisReportcontainsdata,descriptions andanaylsisrelativetotheadequacyoftheSusquehanna SteamElectricStationdesigntoaccommodate loadsresultinq fromsafetyreliefvalve(SRV)discharqe and/orloss-of-coolant accident(LOCA)conditions.

Rev.2,5/8p

DARTABLEOFCONTENTSChapter1GENERAL.INFORMATION 1.1PurposeofReport1.2HistoryofProblem1.3SSESContainment Program1.4PlantDescription 1.5Figures16TablesChapter2SUMMARY2.1LoadDefinition Summary2.2DesignAssessment SummaryIChapter3SRVDISCHARGE ANDLOCATRANSIENT DESCRIPTION 3.1Description ofSafetyReliefValve(SRV)Discharge 3.2Description ofLoss-of-Coolant Accident(LOCA)Chapter4LOADDEFINITION 4.1LoadsfromSafetyReliefValveDischarge 4.2LoadsfromLoss-of-Coolant Accident4.3AnnulusPressurization 4.4Figures4.5TablesChapter5LOADCOMBINATIONS FORSTRUCTURES~

PIPING~A'NDEQUIPMENT 5.1ConcreteContainment andReactorBuildingLoadCombinations 5.2Structural SteelLoadCombinations 5.3LinerPlateLoadCombinations 5.4Downcomer LoadCombinations 5.5Piping,Quencher, andQuencherSupportLoadCombinations 5.6NSSSLoadCombinations 5.7Equipment LoadCombinations 5.8Electrical RacewaySystemLoadCombinations 5.9HVACDuctSystemLoadCombinations 5.10Figures5.11TablesChapter6DESIGNCAPABILITY ASSESSMENT 6.1ConcreteContainment andReactorBuildingCapability Assessment Criteria6.2Structural SteelCapability Assessment Criteria6.3LinerPlateCapability Assessment Criteria'ev.

2,5/80

TABLEOFCONTENTSfContinued)-

6.4Downcomer Capability Assessment Criteria6.5Piping,Quencher, andQuencherSupportCapability Assessment Criteria6.6NSSSCapability Assessment Criteria67Equipment Capability Assessment CriteriaChapter7DESIGNASSESSMENT 7.1Assessment Methodology 7.2DesignCapability Margins7.3FiquresChapter8SSE~S-U~ECHERVERIFICATION TEST8.1Introduction 82TestFacilityandInstrumentation 8.3TestParameters andMatrix8.4TestResults8.5DataAnalysis'andVerification ofLoadSpecification 8.6Figures8.7TablesChapter9GKMIIMSTEAMBLOWDOWNTESTS9.1Introduction 9.2TestFacilityandMatrix9.3TestParameters andMatrix9.4TestResults9.5DataAnalysis9.6Verification oftheDesignSpecification 9.7FiguresChapter10RESPONSES TONRC~UESTIONS 10110210.310.4Identification ofQuestions UniquetoSSESQuestions UniquetoSSESandResponses TheretoQuestions Pertaining totheNRC~sRevievoftheDARandResponseTheretoFiguresChapte'r11REFERENCES AppendixACONTAINMENT DESIGNASSESSMENT A.1Containment Structural DesignAssessment A.2Submerged Structures DesignAssessment AppendixBCONTAINMENT RESPONSESPECTRADUETOSRVANDLOCALOADS'.1Containment ModeShapesB.2Containment ResponseSpectraAppendixCREACTORBUILDINGRESPONSESPECTRADUETOSRVANDXOCALOADSRev.2,5/80

AppendixDpRgGRggVgRIFICQTIQN D.1Poolsvell ModelVerification D.2VelpotProqramVerification D.3FiquresD.4TablesAppendixF.REACTOQBUILDINGSTRUCTURAL DESIGNASSL'SSMEPTAppendixFBOP-ANDNSSSGRIPINGDESIGNASSESSMFNT AppendixGVASSSQESIGNASSESSMENT QDELETFOQ AppendixHEQUIPMENT DESIGNASSESSMENT

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AppendixISUPPRESSION POOLTFMPERATJJRE RFSPONSETOSRVDISCHARGE-AppendixJVFRIFICATION OFSRVSUBMERGED STRUCTURE DRAGLOAD(PRO'PRIETARY)

AppendixKDBYMELLFLOORVACCUMBREAKERJVB}CYCLINGDURINGCHUGGINGAppendixL.SUppLEMEQTAL DESIGN.ASSFSSMENT L.1Assessment Methodoloqy L.2Assessment ResultsJ..3FiquresL.4TablesRev.8,2/83 ICHAPTER"'1GENERALINFORMATTION TABLEOPCONTENTS1.11.2PURPOSEOFREPORTHISTORYOFPROBLEM1-3SSESCONTAINMENTPROGRAM'4PLANTDESCRIPTION 1.41Primary'ontainment'.

1.41.1Penetrations 1.4.1.2InternalStructures",'~

',,'"lI'5"FZGURES1.6TABLESI,wIIIIII>>Rev.2,.5/801-1 CHAPTER1FIGURESNumberTitle1-11-3CrossSectionofContainment Suppression Chamber,PartialPlanSuppression Chamber,SectionVie@1-0QuencherDistribution Rev.2,5/801-2

~O'XTACHAPTER1TABLES~umber1-3TitleSSESLicensing BasisSSESContainment Dimensions SSESContainment DesignParameters Comparison oftheSSESProgramforSRVandLOCA,loadingswiththeNUREG0487Acceptance

Criteria, LeadPlantProgramandGenericLongTermProgramRev.2,5/801-3 10GNRRALINFORMATION 1.1PU'RPOSEANDORGANIZATION OFREPORTThepurposeofthisreportistopresentevidencethattheSusquehanna SteamElectricStation(SSES)designmarginsareadequateshouldtheplantbesubjected totherecentlydefinedthermohydrodynamic loadswhichresultfromsafetyreliefvalve(SRV)operations and/ordischarges duringaloss-of-coolant accident(LOCA)inaGEhoilinqwaterreactor(BWR).Rev;2,5/801-4 12HISTORy'F PROBLEMInApril1972attheGermanAEG-Kraftwerk UnionMurgassen NuclearPlant,aboilingwater,reactor(BMR)safetyreliefvalve(SRV)wasopenedduringstartuptestingandfailedtoclose.Thereactorremainedatfullpressure,'and thevalvedischarged reactorsteamintothecontainment suppression chamberuntilthesuppression poolwaterheatedfromgustaboveambienttoalmost170~C{inapproximately 30minutes).

Pulsating condensation developed andlargeimpulsive forceswithsubstantial underpressure amplitudes acteduponthecontainment, eventually causinqleakaqefromthebottomlinerplate.Therefore, concern'as expressed thatthestructural integrity ofotherBMRpressurecontainment systemscouldbesensitive toSRVinduceddynamicloads.TheNuclearRegulatory Commission (NRC)issuedBulletin74-14toallBWRownersonNovember14,1974toalertthemtothepotential problemsofcondensation instability (Murgassen effect)'ue toSRVoperation TheNRCrequested verification thatBMRsuppression poolshadbeendesignedtowithstand loadssimilartothosewhichwerebeingexperienced.

InJanuary1975theGeneralElectric-NuclearEnergyProgramDivision(GE-NEPD) identified thefollcwing dynamicloadingconditions whichhadnotbeenfullyconsidered inthedesigncriteriaofMarkIIBMRcontainments:

a.HainsteamSRVdischarge thermo-hydrodynamic phenomena.

b.Desiqnbasisaccident(DBA):loss-of-coolant accident(LOCA)hydrodynamic phenomena Following theGEannouncement, thecontainment construction sequencefortheSSESwasalteredtoenablethePennsylvania PowerandLightCompany(PPSL)anditsarchitect-engineer, BechtelPowerCorporation, toascertain theeffectofthesephenomena ontheexistingSSESdesign.AtaskforcewasformedinNarch1975withrepresentatives fromBechtel-San Francisco, GE-NEPD,PPGL,andPhiladelphia ElectricCompanytoevaluateexistinqdesigncriteriawithrespecttothenewlydefinedSRVandDBA-LOCAloadinqs.

InNay1975Bechtelcompleted apreliminary studyincorporatinq theeffectsofthenewphenomena inthedesigncriteriafortheSSESsuppression chamberstructures andsafetyrelatedequipment Asaresultofthisinvestigation, itwasdecidedthatthefollowing civil-structural modifications weretobeincorporated immediately inthecontainment designtoaidinloadtransferandaddadditional conservatism totheexistingdesign:a.Thenumberofreinforcing barsinthesuppression chamberverticalwallswasincreased.

b.Thenumberofembedments inthesuppression chamberwallsfordowncomer/piping restraints wasincreased toaccommodate futurerequirements.

1-5 cAnchor.boltswereplacedontheunderside ofthediaphragm slabtoaccommodate additional supportsfoz'heSRVdischarge pipingforhorizontal runsshouldtheybeneeded.d.e.Additional anchorboltswereplacedwithinthedrywellwalltoallowinstallation ofadditional snubbersandpiperestraints, ifrequiredThediaphragm slabshearreinforcement waschangedfroma45~toa90~orientation

{withrespecttothehorizontal plane)toaccommodate themostconservative poolswellupliftloadingsyetpredicted.

Itbecameevidentthatacomplex,technical issueexistedforallNarkIIplants,andPPGl.soughttocreateaunifiedutilitygrouptoaddressthematter.AMarkIIBMRcontainment ownersgroupwasformedinJune1975todefineprecisely thesuppression pooldynamicloadsandexplorewaystoassesstheirimpact,.AsthedirectresultofactiontakenbytheMarkIIcontainment ownersorganization, agenericDynamicForcinqFunctionInformation Report,NEDE-21061P Rev.1,whichwasalsoknownastheDFFIR,wasissuedjointlybyGE-NEPDandSargentandLundyfortheMarkIIownersinSeptember 1975Basedontheanalytical techniques includedintheDFFIR,apreliminary SSESuniquecontainment designassessment wassubmitted byPPGI.totheNuclearRegulatory Commission

{NRC)onNarch15,1976Asthebodyoftheusefulsupportive dataincreased, Revision2oftheDFFZHwasissuedjointlybyGE-NEPDandSargentandt.undyfortheMarkIIcontainment ownersgrouponSeptember 1,1976,asNEDO/NEDE 21061,Rev.2.Itwasatthistimerenamed.theDFFR.Thelicensing documentation considered fortheSSESissummarized inTable1-1.1-6 1'SSES-CONTAINMENT PROGRAM.PPGLisamemberoftheHarkIIowners-group thatvasformedinJune,1975todefineandinvestigate thedynamicloadsduetoSRVdischarge andLOCA.TheMarkIIovnersgroupcontainment programconcentrated initially onthetasksrequiredfo'rthelicensing oftheleadplants(Zimmer,LaSalle,andShoreham)

.Thisphaseofvork,calledtheshort'erm proqram,iscompleteandalongertermprogramisunderway.

ThefinalgoaloftheHarkIIprogramistoevolveacompleteDFFRwhichvillsupporttheplant-unique DARssubmitted bye'achplantforitslicensetooperate.Aftergainingsomeunderstanding ofthecontainment

.loadsthroughtheinitialMarkIXwork,PPGLdecidedtofindaqualified, consultant tosupplement in-housetechnical resources andassistinthedetermination ofarealistic courseofactionforSusquehanna InNovember, 1976,StanfordResearchInstitute, nowcalledSRIInternational (SRI),wasselected, andaninformation exchangebetweenSRZ.andPPGLensuedtodetermine whatcausedthegreatestloadsonthecontainment structure.

Afterconducting acompletereviewofknowndatafromtheMarkIIprogramandotherknowledgeable personsandorganizations, PPGLandSRIdecidedthattheloadsfrommainsteamsafetyreliefvalve(SRV)d'ischarge verethekeyloadstobecontrolled.

Astudyofpossiblemethodsofcontrolling theloadandareviewofvhatactivities vereoccurrinq inEuropeledPPGLandSRItotheconclusion thatanSRVdischarge mitigating device(quencher) shouldbeemployedtoreduce.thisloadinqontheSusquehanna containment.

AlthoughtheHarkIIownersgrouphadquencher-relatedtasksintheirprogram,thesetasksverenotsufficiently timelytosatisfySSES-construction scheduleneeds.Promreviewing thevorkdoneinEuropebysuchfirmsasASEATOMMARVIKEN, andKraftverk Union,PPGLdiscovered thatallknownquencher'designs werebasedondatafromKraftverk Union(KWU).Thus,inMarch,1977,SRI,Bechtel(theSSESArchitect/Engineer) andPPGLvisitedKWUfordiscussion andtourofquencher-related facilities.

XnlateJuly,1977,PPGLemployedtheservicesofKWUtodesignaSSES-unique quencherdevice.Kraftwork UnionprovidedPPGLapackageofsignificant designandtestreportspertaining tothequencherdevelopment todemonstrate designadequacyandqualityoftheirdevice(refertoTablel-l).Thesedocuments weresubmitted totheNRCinJanuary,1978.Thequencherloadspecification vassubmitted totheNRCinApril,1978.ToverifyKWU~sdesignapproach, afull-scaleSSESuniqueunitcelltest,asdescribed inChapter8,wasperformed byKWUforPPGL.Thedocumentation ofthistestseriesandverification ofthedesignspecification vassubmitted inMarch,1979.Subsequently thequencherdesignbyKWUforuseonSSEShasbeenadoptedastheSRVdischarge usedbysixofthesevenotherHarkIIownersandtheSSESprogramhasbecomethegenericMarkIIprogram.Rev.2,5/801-7 Thedefinition ofLOCAloads(Section4.2)isinbasicaccordance withtheMarkIIprogram.Inadditionthough,'PSL hasdecidedtoconductaseriesoftransient steamblowdowntestsinamodifiedGKMIItesttankinNannheim, Germany(refertoChapter9).ThesetestswillprovidedatatoresolveNRCconcernsonthedifferences inventconfiguration betweentheoriginalGE4Tfacilityandaprototypical MarkIIcontainment and,toverifythecondensation oscillation loadspecification usedontheSSESdesign.Tablel-lprovidesasummaryofthedocumentation supporting theSSESlicensing.

Inaddition, Table1-4providesacomparison oftheSSESprogramforSRV.andLOCAloadingwiththeNUREG0487acceptance

criteria, LeadPlantProgramandGenericLongTermProgram.I'naccordance withthedirections oftheNRCstaffattheOctober19,1978meetingwiththeMarkIIOwnersGroupthesepositions assumethattheuseoftheSRSSmethodofloadcombination willbeacceptedforuseontheMarkIIcontainments.

Rev.2,5/800-8 1.4-Pl.M1TDESCRIPTION TheSSES,Units1and2,isbeingbuiltinSalemTownship, LuzerneCountyabout5milesnortheast oftheBoroughofBerwick.Twogenerating unitsofapproximately 1,100megawatts eacharescheduled foroperation:

Unit1forNovember1,1980,andUnit2forMay1,1982.GeneralElectricissupplying thenuclearsteamsupplysystems;BechtelPowerCorporation isthearchitect-engineer andconstructor.

Thereactorbuildingcontainsthemajornuclearsystemsandequipment ThenuclearreactorsforUnits1and2areboilingwater,directcycletypeswitharatedheatoutputof11.2x10~Btu/hr.Eachreactorsupplies13.4x10~lb/hrofsteamtothetandemcompound, doubleflowturbines.

1.4.1PrimarvContainment Thecontainment isareinforced concretestructure consisting ofacylindrical suppression chamberbeneathatruncated conicaldrywell.Figure1-1showsthegeometryofthecontainment andinternalstructures.

Theconicalportionoftheprimarycontainment (drywell) enclosesthereactorvessel,reactorcoolantrecirculation loops,andassociated components ofthereactorcoolantsystem.Thedrywelli.sseparated fromthewetwell,ie,thepressuresuppression chamberandpool,bythedrywellfloor,alsonamedthediaphragm slab.Majorsystemsandcomponents inthecontainment includetheventpipesystem(downcomers) connecting thedrywellandwetwell,isolation valves,vacuumreliefsystem,containment coolingsystems,andotherserviceequipment.

Theconeandcylinderformastructurally integrated reinforced concretevessel,linedwithsteelplateandclosedatthetopofthedrywellwithasteeldomedhead.Thecarbonsteellinerplateisanchoredtotheconcretebystructural steelmembersembeddedintheconcreteandweldedtotheplate.Theentirecontainment isstructurally separated fromthesurrounding reactorbuildingexceptatthebasefoundation slab(areinforced concretemat,toplinedwithacarbonsteellinerplate)whereacoldjointbetweenthetwoadjoining foundation slabsisprovided.

Thecontainment structure dimensions andparameters arelistedinTables1-2and1-3.Adetailedplantdescription canbefoundintheSSESFSAR,Section3.8.1.4.11'Penetrations Servicesandcommunication betweentheinsideandoutsideofthe.containment aremadepossiblebypenetrations throughthecontainment wall.Thebasictypesofpenetrations arethedrywellhead,accesshatches(eguipment hatches,personnel lock,suppression chamberaccesshatches,CRDremovalhatch),electrical penetrations, andpipepenetrations.

ThepipingRev.2,5/801-9 penetrations consistbasically ofapipewithplateflangeweldedtoit.Theplateflangeisembeddedintheconcretewallandprovidesananchorage forthepenetration toresistnormaloperatinq andaccidentpipereactionloads.1.4.1.2InternalStructures Theinternalstructures consistofreinforced concreteandstructural steelandhavethemajorfunctions ofsupporting andshielding thereactorvessel,supporting thepipingandequipment, andformingthepressuresuppression boundary.

Thesestructures includethedrywellfloor(diaphragm slab),thereactorpedestal(aconcentric cylindrical reinforced concreteshellrestingonthecontainment basefoundation slabandsupporting thereactorvessel),thereactorshieldwall,thesuppression chambercolumns(hollowsteelpipecolumnssupporting thediaphragm slab),thedrywellplatforms, theseismictrusses,thequenchersupports, andthereactorsteamsupplysystemsupports.

SeeFigures1-1thr'ough1-4andTables1-2and1-3.Rev.2,5/801-10 ILOFPRIMARYCONTAINMENT ISYM.ABT.(LMORYWELLHEAD48'OV"0D.CONC.I36'PSI"(OUTSIDEFACEIWP.W.PEL.791'.9"J.'Lr5'"9/:,'/.../;/SHIELDIANNULUS/::-/r2/4DOWNCOMER

/'JETDEFLECTOR SHIELDi29'.I"O.D.18'JI"I.O.'IX~~EL.723'4(X"I2(P-3"I.D.CONC.:86'3"I.D.CONCT.O.C.rEL,703'l"

,'I'~~~C.~rT.O.S.EL.778'.9"JIlr7REACTORSHIELDII25"7"I.D.hIII4~)"Jh~~'Ij',~4htTOC~'EL.729'.95/8"DIAPHRAGM SLABW.P87'.O.C.L.704'-0"lhEI'DRYWELLEL.701'-11"OOWNCOMER (87TOTALIQUENCHERDEVICE(16TOTALICONTAINMENT WALLWATEASTOPS BASEMATWATEASTOP I~Ij~tII'.~~rhCI1S0sSIII.D.CONCI12FT.'1'.6"

'.,O'QII"'r~IQDECKANDSUPPORTBEAMIRP.V.PEDESTALIR.P.V.PEDESTALSTEELFOAMI19'.7"'Ar12,3'6"DIAM.STEELCOLUMNST,rhhig'~'~'1:~,III~I~I'".~I24FT.HIGHWATERLEVEL3'.6"~IhSUPPRESSION CHAMBER7'41"COLDJOINT629'9".30'41"RO.O.CONC.I.D.CONC.MUDMATANDWATERPROOFING 44'JY'.BOTTOMOFBASEMATEL.640'G"REACTORBUILDINGBASEMATCOLDJOINTSUSQUEHANNA STEAMELECTRICSTATIONtJNITS1AND2DESIGNASSESSMENT REPORTCROSSSECTIONOFCONTAINMENT FIGURE1-1 1064IgOi~4~Q'ICONTAINMENT VV~EgrOdy~r~e~013soSRVDIAPHRAGM SLABPENETRATION FROMDIAPHRAGM SLABPENETRATION OeC/03COLUMNOg30o>~~f0oo150oo>~o~'Ply+er~w~orOs..O~'EDESTAL TOQUENCHERSSRVDIAPHRAGM SLABPENETRATION NOTE:BRACINGISNOTSHOWNRev.2,5/80SUSQUEHANNA STEAMELECTRICSTATIONUNITS1AND2DESIGNASSESSMENT REPORTSUPPRESSION CHAMBER"PARTIALPLANFIGURE1-2