ML17326A471
| ML17326A471 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 12/31/1979 |
| From: | JANIK C R, NOREIKA J F, PADMANALHAN M ALDEN RESEARCH LABORATORY |
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| ML17326A472 | List: |
| References | |
| 1-80-M178PF, NUDOCS 8002010499 | |
| Download: ML17326A471 (52) | |
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EXPERIMENTALINVESTIGATIONOFAIRENTRAINMENTATAREACTORCONTAINMENTSUMPDUETOBREAKANDDRAINFLOWSDONALDC.COOKNUCLEARPOWERSTATIONbyMahadevanPadmanabhanJohnF.NoreikaCarlR.JanikResearchSponsoredbyAmericanElectricPowerServiceCorporationDocket885,,+igo~>0>~mui~O<yy0fOoeumme-~~."8.">>+-YWa(vrag~n(~ccarRye~GeorgeE.Hecker,DirectorALDENRESEARCHLABORATORYWORCESTERPOLYTECHNICINSTITUTEHOLDEN,MASSACHUSETTSDecember1979 ABSTRACTAmericanElectricPowerServiceCorporation(AEPSC)authorizedtheAldenResearchLaboratory(ARL)ofWorcesterPolytechnicInstitute(WPI)tocon-ductextensivehydraulicmodeltestingoftheReactorContainmentSumpoftheDonaldC.CookNuclearPowerPlant,Units1and2.Themodelstudieswereconductedintwophases.Aseparatereportofthefirstphaseofthemodelstudiestoinvestigatevortexing,swirl,andinletlosseswassubmittedearlier(ARLReportNo.108-78/M178PF,September1978).Themainpurposeofthesecondphaseofthemodelstudiesreportedhereinwastoverifythatthereactorcontain-mentsumpwouldperformsatisfactorilywithoutthedevelopmentofobjec-tionableair-entrainmentduetobreakflowanddrainflowimpingementthroughthewatersurfacenearthesump.Suchpossibleair-entrainmentcouldaffecttheoperationofthepumpsintheEmergencyCoreCoolingSystem(ECCS)duringtherecirculationmode.AmodelbasedonFroudesimilaritywasdesignedandconstructedtoascaleof1:2.5toincludethesumpandthesurroundingareaofthecontainmentbuildingwithallthestruc'turesthatcouldinfluencetheapproachflow.Revisionstothesumpconfigurationbasedon'thevortexingandswirlstu-diesconductedearlierwereincorporatedinthemodel.Possiblescaleef-fectsofmodelingairentrainmentduetojetimpingementwereconsideredandasuitabletestprocedurewasdevelopedinvolvingtestingathigherthanFroudescaledjet.velocitiesandsuctionpipevelocities.Testswereconductedincorporatingvariouspossibleflowandpumpcombinations,alongwithpossiblebreakanddrainflowsnearthesumparea,includingdiffer-entpossiblescreenblockage.Itwasdeterminedthatredirectingoficecondenserdrainpipesawayfromthesumpareawasdesirabletoreduceexcessiveairentrainmentwithinthesumpandtoeliminateairbubblesbeingcarriedtothesuctionpipesundercertainscreenblockageconditions.Breakflowimpingementtestsdidnotindicateanysignificantair-entrainmentand,hence,nomodificationsinthesumpgeometryitselfwasfeltnecessary.
TABLEOFCONTENTSPacaeNo.ABSTRACTTABLEOFCONTENTSINTRODUCTIONPROTOTYPEDESCRIPTIONReactorBuildingTheContainmentRecirculationSumpBreakFlowLocationsOperatingCasesforTests2234AIRENTRAINMENTDUETOJETIMPINGEMENTSIMILITUDEFroudeScalingSimilarityofAir-EntrainmentDuetoJetImpingement910MODELDESCRIPTIONANDINSTRUMENTATION14GeneralLayoutSupplyLoopforBreakandDrainFlowsModelingofBreakFlowsModelingofDrainFlows14141516TESTPROCEDURE16ModelingofAir-VentingSystematTopCovers18~RESULTS18Air-EntrainmentduetoDrainFlowAir-EntrainmentduetoBreakFlowsSumpModificationsandRetestingAirVentingatDownstreamTopCover18192121CONCLUSIONSREFERENCESTABLESFIGURESPHOTOGRAPHS2225 INTRODUCTIONThereactorcontainmentbuildingsoftheDonaldC.CookNuclearPowerStation,Unitsland2,areprovidedwithemergencycorecoolingsys-tems(ECCS)designedtocooltheshutdownreactorcoresandthecon-tainmentsintheeventofalossofcoolantaccident(LOCA).TheECCSinjectswatertomaintaincorecoolingand,initially,thewaterforthisisdrawnfromtherefuelingwaterstorage"tank(RWST).Whenthewaterlevelinthistankisdepletedtoapredeterminedlevel,theECCSisswitchedfrominjectiontorecirculationmode.Atthispoint,waterisdrawnfromthe,containmentrecirculationsumpcontainingwa-terdrainedfromthebreak,waterfromtheicecondensermeltdown,andwaterfromthecontainmentspraysystem.Theapproachflowtothesumpisaffectedbytheequipmentsandappurtenantstructuresintheflowpath.Thewaterlevel,thepumpdischarges,andthewatertemperaturecouldvaryoverawiderangeduringtherecirculationmode,whichlastsforanextendedperiodoftimetoprovidesufficientheatremoval.The,breakflowanddrainflowvarywithtimeandtheyimpingeonthewatersurfaceasahighvelocityjet.Itisveryimportantthatnoadverseflowconditionscausedbybreakandicedrainflowjetsexistwithinthesumporthesuctionpipesthatcouldaffectperformanceofthepumps~TheAldenResearchLaboratory(ARL)wasauthorizedbyAmericanElectric'owerServiceCorporation(AEPSC)toconstructandtestamodeloftheDonaldC.CookNuclearPowerStationcontainmentrecirculationsumpwiththeobjectofinvestigatingfreesurfacevortexformation,swirl,inletlosses,airentrainmentduetoimpingement,oranyotherundesirableflowconditionsthatcouldadverselyaffecttheperformanceoftheRe-sidualHeatRemoval(RHR)andContainmentSprayPumps(CTS),andSafetyInjection(SI)PumpsoftheEmergencyCoreCoolingWaterSystem(ECCS)intherecirculationmode.Operatingconditionsinvolvingawiderangeofvariouspossibleapproachflowdistributions,waterdepths,watertemperatures,screenblockageeffects,andpumpoperatingcombinationsweretobetestedinthemodel.Ifpotentiallyundesirableflowcondi-
,-2tionsoccurred,modificationsinthesumpconfigurationweretobede-veloped.Thefirstphaseofthemodelstudywastheinvestigationofairentrainmentduetovortexing,suctionofentrappedair,swirlinthesuc-tionpipes,andtheinletlossesatthesumpandthedetailsofthisphasewereincludedinaseparateARLreport(1).Thisreportpresentsthefindingsofthesecondphaseofthestudyin-volvingbreakanddrainflowimpingementandinclu'desadescriptionoftheprototypeandmodel,andsummarizesconditionsinvestigated,simi-litudeconsiderations,testprocedures,instrumentation,interpretationofresults,andconclusions.PROTOTYPEDESCRIPTIONReactorBuildinThereactorbuildingiscircularinplanwithtwoconcentricouterwalls;Jnamely,thecranewallandthecontainmentwall,withinnerradiiof41.5ftand57.5ft,respectively.Thesteamgenerators,reactorcoolantpumps,containmentcleanupfilterunits,andtheconnectedaccessoriesarealllo-catedintheportionbetweenthereactorchamberandthecranewall,asseeninFigure1.Theannularportionbetweenthecraneandcontai:nmentwallsaccommodatedthevariouspipes,valves,airducts,andcablesforvariousoperatingsystems,suchasblowdown,coolingwater,ventilation,andliquidwasterecycling.TheContainmentRecirculationSumTheContainmentRecirculationsumpislocatedclosetothecranewallbe-tweenthesteamgeneratornumber2andreactorcoolantpumpnumber2(ex-tendingfrombearing120to150degreesapproximately),asmarkedinFi-gure1.Thesumpismoreorlessrectangularinplan,about18ftlongand10.5ftwide,withthecranewalldividingitintotwoportions.
Recirculationflowenterstheupstreamportionthroughstainlesssteelgratingsandscreensprovidedattheentrance,continuesdownandunderthecranewall,andfinallyentersthesuctionpipes.Figure2showsthesumpdetailsandillustratesthattheupstreamportionwouldhaveafreesurfacewhilethedownstreamportionwouldbeunderpressure.Thetopslabofthedownstreamportionofthesumpisprovidedwithasingleairventpiperunningupwardthroughthecranewall.ThesumpfloorisatEL591ft1inch,whereasthebuildingfloorisatEL598ft9-3/8inches.Theaverageapproachvelocityupstreamofthegratingwouldbeabout0.34fpsattheminimumsubmergence(EL602ft10inches).Thetwooutletpipesare18inchesindiameter(Sch.40),andarepro-videdwithbellmouthentrancesand24inchdiameterguardpipes.Thesuctionpipesrundownwardataninclinationof13'34'ohorizontal,asshowninFigure2.ThecenterofthepipeentranceisatEL595ft6inches,andeachpipeisconnectedtoavalveatEL589ft9inches.AsindicatedinFigure1,alowersump,rectangularinplan(about2ft4inchesby4ft,10inches),and7ft8-3/8inchesdeep,isprovidedadjacenttothemaincontainmentsumptoallowforproperdrainageinnormalconditions.Thissumpisconnectedtothemaincontainment.sumpbyan8inchdiameterpipe.BreakFlowLocationsThepossiblebreakflowlocationsinthesumpvicinity(providedbyAEPSC)arelocatedinthecross-over,highpressurepipeconnectingthereactorcoolantpumpandsteamgeneratorasindicatedinFigure3.Therearesixbreaklocationsinthisloopwithtwoadditionalbreaklocations,oneeachinthe3inchand2inchpipesattachedtotheloopatthebottomstraightportion.Thehotlegjoiningthesteamgeneratortothereactorhasonebreaklocation.Thesixbreaksinthecross-overloopandtheonebreakinthehotlegareallcircumferentialtypebreaks.The3inchand2inch pipebreakswillcausecircularjetsissuingverticallyupordown.Thebreakarearesultingfromtheaxialdisplacementforthebreaksinthecross-overloopandhotlegisapproximately25.0squareinches.Table1indicatestherateofbreakflowfollowingaLOCA.Thefouricecondenserdrainflowlocationsclosetothesump(fourloca-tions)areindicatedinFigure4.Thedrainsarel2inchesindiameterandterminatehorizontallyatabout36ftfromthebuildingfloor.Thedrainsmaynotbeflowingfullformostofthetime.ThedrainflowratefollowingLOCAisgivenbythecurveshowninFigure5.ThebreakflowanddrainflowlocationswillbeidentifiedhereafterinthisreportbythenumbersgiveninFigures3and4.0eratinCasesforTestsThedischargeandsubmergenceconditionsatthesumpwouldchangewiththedifferentoperatingsequencesfromtheinstantofaLOCA.Thefol-lowingsystemoperationswereconsideredimportantininvestigatingthehydraulicperformanceofthesump:l.9500gpmithroughonesuctionpipe-Thissimu-latestherunoutconditionofoneECCStrainuponcompletefailureoftheothertrain.2.7700gpmpersuctionpipe,bothpipesoperating-ThissimulatestherunoutconditionofECCSpumpswithbothtrainsoperating.3.9500gpmthroughonepipeand3600gpmthroughtheother-,Sameascase1exceptthatthecon-tainmentspraypumpfromtheothertrainisatrunoutflowrate.
ShouldaLOCAoccurinanyofthebreaklocationsdescribedearlier,theECCSpumps,whicharealignedtotherefuelingwaterstoragetank(RWST),wouldinject350,000gallonsofboratedwaterintotheprimaryloopbe-foretherecirculationsumpiscompletelyused.OnetrainofECCSpumpswouldbeswitchedtotherecirculationsumpwhenthewaterlevelintheRWSTreachesapredeterminedlowlevel,thetimeforthisbeingabout10minutesafterthestartofECCS.ItisnotuntiltheRWSTreachesthelowestlevelthatthesecondtrainofECCSpumpswouldbeswitchedtotherecirculationsump.Atthistime,theentire350,000gallonswouldhavebeenpumpedintothesumpviatheprimaryloop.Awaterlevelof602ft,10inchesistheelevationatwhichthefirstECCStrainsuctionsupplywouldbeswitchedfromtheRefuelingWaterStorageTank(RWST)tothecontainmentrecirculationsump.AwaterlevelofEL606ftwillbethepointatwhichthesuctionsourceofthesecondstringofECCSwouldbeswitchedfromtheRWSTtothecon-tainmentrecirculationsump.TheabovelevelsarecalculatedbyAPESCassumingthatthebreaksin'heprimarysystemoccurinsidethebiologicalboundary.Thisassumptionre-sultsinthelowestpossiblecontainmentlevelssinceitpostulatesthatapproximately128,000gallonsoffluidmustspillwithinthebiologicalbarrierbeforeanyfluidspillsintotherecirculationsumpcavity.This,ofcourse,isconservativeandtheabovewaterlevelsareusedformodeltestswithdrainflowsbutnobreakflowsnearthesumpportion.=Jetimpingementmodelingwithbreakflownearthesumpisbasedonabreakintheprimarysystemoccurringoutsidethebiologicalboundary(ifitwereinside,itcouldhavenoeffectonthesump).Therefore,the128,000gal-lonswhichwasconsideredunavailablewithinthebiologicalboundaryisnowavailabletosupplyadditionalfluidinventoryoutsidetheboundary.Sincethecontainmentwaterleveloutsidetheboundarywillriseapproximately1ftperadditional28,000gallonsoffluid(asperAPESC),thetotalrisewillbeapproximately4.5ft.Thenewwaterlevelswouldthenbe607ft4inchesforfirstECCSswitchoverand610ftforsecondECCSswitchover.
Table2summarizesthesystemoperations,eachofwhich,forconvenience,willbeidentifiedbythecasenumberhereafterinthisreport.Thewatertemperatureofthebreakflow,whichwouldbecollectedinthesump,couldbeashighasl90'F.Acontainmentpressureofupto3.0psigwouldbepossible.AIRENTRAINMENTDUETOJETIMPINGEMENTHighvelocityjetsimpingingonawatersurfaceareknowntoproducecon-siderableairentrainment.Ifsuchaconditionexistsveryclosetothesump,theapproachflowwilldrawwithitalargenumberofairbubblesintothesump.FortheparticularsumpconfigurationoftheD.C.Cookplant,allbubbleswhichhaverisevelocitieslessthanthedownwardvelocityoftheflowintheupstreamportionofthesumparelikelytobecarriedunderneaththecrane'wall.Thebubblesmaygetentrainedinthemainflowtowardsthesuctionpipes,andwouldbe'rawnintothepipes.Ifsufficientretentiontimeisavailable,thebubblescouldreachthetopcoverandgetcollectedorescapethroughtheventingsystem,dependingonitseffectiveness.Bubblescollectedonthetopcovermaycoalescetoformairpockets,andtheseairpocketscouldbedrawnintermittentlyintothesuctionpipesasslugs,orcouldhelpformair-corevortices.Itisevidentthatevenalowairconcentrationinthesuctionpipes,suchas5%,couldlowertheefficiencyofthepumpconsiderably(2).Further,air-watermixtureflowcouldgeneratepressurefluctuationsontheimpeller.Hence,airentrainmentisrecognizedasapotentialadverseconditiontobeexamined.
SIMILITUDEThestudyofdynamicallysimilarfluidmotionsformsthebasisforthede-signofmodelsandtheinterpretationofexperimentaldata.Thebasicconceptofdynamic,similaritymaybestatedastherequirementthattwosystemswithgeometricallysimilarboundarieshavegeometricallysimilarflowpatternsatcorrespondinginstantsoftime(3).Thus',allindivi-dualforcesactingoncorrespondingfluidelementsofmassmusthavethesameratiosinthetwosystems.TheconditionrequiredforcompletesimilitudemaybedevelopedfromNewton'ssecondlawofmotion:F.=F+F'+F+FipgvtwhereF.=inertiaforce,definedasmass,M,timestheiacceleration,aF=pressureforceconnectedwithorresultingfromthemotionF=gravitationalforcegF=viscousforcevF=force'uetosurfacetensiontAdditionalforcesmayberelevantunderspecialcircumstances,suchasfluidcompression,magneticorCoriolisforces,butthesehadnoinfluenceonthisstudyandwere,therefore,notconsideredinthefollowingdevelop-ment.Equation(1)canbemadedimensionlessbydividingallthetermsbyF..1Twosystemswhicharegeometricallysimilararedynamicallysimilarifbothsatisfythedimensionlessformoftheequationofmotion,Equation(1).WemaywriteeachoftheforcesontherightsideofEquation(1)as:
F.PFg2netpressurexarea=adpL13specificweightxvolume=ayL2F=shear,stressxarea=aphu/hyxarea=cpuLv3~3FtF.isurface.tensionxlength=aaL43222densityxvolumexacceleration=apLu/L=apuL55wherea,a,etc.=proportionalityfactorsL=representativelineardimensionhp=netpressure=specificweight=dynamicviscositya=surfacetensionp=densityu=representativevelocitySubstitutingtheabovetermsinEquation(1)andmakingitdimensionlessbydividin'gtheinertialforce,weobtain1-22-23-14-2-E+-F+-R+-W=1a5a505a5(2)whereE=InertiaForce=Eulernumber~PressureForceuF=-/gz,InertiaForce=Froudenumber~PressureForce uLR=-u/vInertiaForce=ReynoldsneerViscousForceW=~alps,InertiaForce=Webernumber~SurfaceTensionForceSincetheproportionalityfactors,n,arethesameinmodelandproto-type,completedynamicsimilarityisachievedifallthedimensionlessgroups,E,F,R,andW,havethesamevaluesinmodelandprototype.Inpractice,thisisdifficulttoachieve.Forexample,tohavethevaluesofFandRthesamerequires.eithera1:1"model"orafluidofverylowkinematicviscosityinthereducedscalemodel.Hence,theacceptedapproachistoselectthepredominantforceanddesignthemodelaccordingtotheappropriatedimensionlessgroup:Thein-fluenceofotherforceswouldbesecondaryandare.calledscaleef-fects(3).Specialtestingproceduresmaybeestablishedtodetermineortoaccountforscaleeffectsapproximatelybutusuallyconservatively.FroudeScalinModelsinvolvingafreesurfaceareconstructedandoperatedusingFroudesimilaritysincetheflowprocessiscontrolledbygravityandinertiaforces.TheFroudenumber,representingtheratioofinertiatogravi-tationalforce,F=u//gs(3)whereu=averagevelocityinthepipeg=gravitationalaccelerations=submergencewas,therefore,madeequalinmodeland.prototype(4) 10wherem,p,andrdenotemodel,prototype,andratiobetweenmodelandprototype,respectively.Inmodelingofanintakesumptostudytheformationofvortices,itisimportanttoselectareasonablylargegeometricscaletoachievelargeReynoldsnumbersandtoreproducethecurvedflowpatterninthevici-nityoftheintake(4).AgeometricscaleofL=L/L.=1/2.5wasrmp'hosenforthemodel,whereLreferstolength.AthigherReynoldsnum-ber,anasymptoticbehaviorofenergylosscoefficientswithReynoldsnumberisusuallyobservedinsimilarflows.Hence,withF=1,therbasicFroudianscalingcriterion,theEulernumbers,E,willbeequalinmodelandprototype.Thisimpliesthatflowpatternsandlossco-efficientsareequalinmodelandprototype.FromEquation(4),usings=L,thevelocity,discharge,andtimescaleswere:0.5rr(5)Q=Lu=L22.5rr-rr(6)0.5rrSimilaritofAir-EntrainmentDuetoJetIminementDimensionalAnalysisThemajorparametersinfluencingtherateofaerationofarectangularjetimpingingonapoolofwaterare(5):a.Thedepthoffall(H)b.Thejetvelocityatimpact(u.)c.Jetwidthbandthicknessdd.Minimumimpactvelocitytocauseairentrainment,u'.e.Thejetperimeter,pf.FroudenumberF.,ReynoldsnumberR.,andWebernumberW.ofthejetj' Forlargescaleair-entrainmentcausedbyhighvelocityjetsofrelativelylargethickness,theeffectofR.andW.arenegligible(5).Hence,there-jjlativeairconcentration(volumetricquality)g,isgivenby:HB=f(F.,-,~,~)3du'.dj(8)Theminimumimpactvelocityforair-entrainment,u.isabout3.6fps(5),jandisconsideredaconstantindependentofotherjetparameters.Basedonexperimentaldata,reference(6)gives0.446u.B=K(-)(-)(1-~)pduwhereKisafunctionofF.,butmoreorlessindependentofF.ifF.isjjgreaterthan10.Hence,b0.4468=-=(-)(d)mrgpprdru.(1-~)3(10)assumingF.isgreaterthan10formodelandprototype.jIfthebreakareaismodeledtochosengeometricscalewithanassumedbreakwidthandthicknessandthebreaklocationsarealsocorrectlymo-deledtothegeometricscale,thenb/pandH/d"valuesareconceivablythesameinmodelandprototype.However,inthisstudy,onlythebreakareaandheight,H,areknownbeforehandwhereasthevalues'ofb,p,anddareassumedmakingsurethattheirinfluenceontheproblemofconcernisnotoverlooked.FromEquation(10),if(b/p)and(H/d)areequaltounity,()willberrrequaltounityonlyifthejetimpactvelocityismadeequalinthemodelandprototype,u'.beingaconstant.However,thisispossibleonlyifthejchosenmodelislargeenough.Also,ifthevaluesofH,p,anddaretoosmall,scaleeffects>suchasduetotheinfluenceofsurfacetension,mayresult.Inthepresent.study,thescaleof1:2.5isconsideredsufficientbylarge.
12B.BubbleRiseVelocitiesHighvelocityjetsofwaterimpingingonastagnantwatersurfaceproduceaswarmofbubbles,theinteractionbetweenthebubblescausingareducedrisevelocitycomparedtothatforsinglebubbles(7).Theentrainedaircouldbeintheformofbubblesofvaryingsizes.Within,awiderangeofdownfalljetvelocities,thecorrespondingbubblesizerangeshavebeenobservedtodifferverylittle(8).Thismeansthatthemodelandproto-typearelikelytohavemoreorlessthesamerangeofbubblesizes,evenwhenthejetvelocitiesandheightsoffallaremodeledusingtheFroudelawofsimilarity.Therisevelocityofbubblesaredependentontheirsizesandtheairconcentration,B(7),andhencetherisevelocitiesarenotsimulatedtoFroudevelocityscalewhenamodelisoperatedonFroudelaw.Air-entrainmentmeasurementsinamodeloperatedonFroudelawdonotpredicttheairconcentrationsintherealsituation,asevidentfromEquation(10).Infact,theprototypeislikelytohavehigheraircon-centrationsduetohigherjetvelocities.Asthebubblerisevelocitiesarehigherwithlowerairconcentrationsforsamebubblesizeranges,themodelmayhavehigherrisevelocitiesthantheprototype,whereasscaledflowvelocitiesarelowerinthemodel.ThissuggeststhatthemodelcannotbeoperatedonFroudelawalonetoobtainanymeaningfulresultsonairentrainmentandonairbeingdrawnintothesuctionpipes.C.EntrainmentofBubblesintoSuctionPipesAsdiscussedintheabovesections,thesamebubblerisevelocitiesandrelativeairconcentrationscouldbeexpectedinthemodelduetojetimpingement,providedthejetimpingementvelocityinthemodelisthesameasthatintheprototypeandallthelinearjetdimensionsaremo-deledtothegeometricscale.Thequestionofhowtoscalethemodelflowsthroughthesuctionpipes(whichalsogovernsapproachvelocities)mustalsobeaddressed.
13ReferringtoFigure6,letusconsiderabubbleatalocationxftfromPthesumpentranceandyftbelowwatersurfaceintheprototype.LetP(u.)bethebubblerisevelocityandlet(u)betheapproachvelocitypaptothesump.Thedownwardvelocityofwaterinthesumpformaximumflowoperatingconditionscouldbeashighas0.75fps,whichismuchhigherthantherisevelocitiesofmostofthesmallsizebubbles(lessthan1cm).Hence,itisreasonabletoassumethatanysmallbubblethatcouldreachthesumpwillbecarrieddownthesumptothedownstreamsideofthewall,withareasonablygoodchanceofbeingdrawntothesuctionpipes.Therequirementforabubbletoreachthesumpis(u)-,(u)PPSimilarlyforthemodel,ymxm(u)-(u)mm(12)Ifthemodelproducesthesamebubblesizerangeasintheprototypeandthesameairconcentrationsduetojetimpingement,then(u.)willbeamthesameas(u.).Ifthemodeljetimpingementlocationsandwater>PdepthsarefixedtothegeometricscaleL,wegetr'myxm-=LxrP(13)BasedonEquations(ll)to(13)forsimilarityofbubblemotion,itisessentialtohave(u)=(u)pm(14) 14Thismeanstheapproachvelocitiesinthemodelandprototypeshouldbethesame.This,bycoincidence,isthesameasthe"equalvelocityrule"usedinthemodeltestsforinvestigatingvortexseverities.Theflowpatternsinthesumpportiondownstreamofthecranewalltothesuctionpipescanbeconsideredsimilarbetweenthemodelandprototype,beingclosedconduitflowatsufficientlyhighReynoldsnumbers.MODELDESCRIPTIONANDINSTRUMENTATIONGeneralLaoutAphysicalmodelof,thecontainmentsumpandaportionofthereactorbuild-ingformingtheapproachtothesumpwereconstructedtoageometricscaleofapproximately1:2.5onanelevatedplatform,asshowninPhotographl.Detailsofthemodelconstruction,dimensions,andgeneralpipingarrange-mentareincludedinanearlierARLreport(1).Su1LooforBreakandDrainFlowsFigure7andPhotograph2showthearrangementofsupplypipesforbreakanddrainflows.A75HPhighheadpump(300ft)wasusedtorecirculatethewaterfromthemodel(takingsuctionfromalocationbehindtheflowdistributors)throughthebreakanddrainflowpipes.Theseparatesupplypipesconnectedtobreakanddrainlocations,eachcontainedacalibratedorificemeterandabypasslineforflowmeasurementandadjustment.Thesupplypipeforbreakflowendedinaflexiblehosewhich,inturn,wasattachedtoanozzleoracircumferentialpipering(dependinguponthetypeofbreaktobemodeled)atthedesiredlocation.Thepiperingwasessentiallyacircumferentialringof2inchdiameterpipefastenedaroundthebreakpipeattheappropriatelocationandwasprovidedwith 15slots1/8inchwideand1'inchlongandatabout1inchspacingforhalfthecircumferenceatadesiredangle,asshowninPhotograph3.Theopenareaoftheslotswaskeptasthescaledareafromtheassumedprototypebreakarea.Onlyhalfthecircumferencewasprovidedwithslotstomaketheflowdirectedtowardsthesump,asaconservativeassumption.Theringwassetsoastomaketheslotsfacingthesump-andtheslotswerecutatabout60'othehorizontalsoastodirecttheflowrightatthesumpentranceontothewatersurface.Thissimulatedrectangularjetsfromcircumferentialbreaks.Anozzleofsuitablediameter(givingthesameflowareaatthebreak)wasusedwhenacircularjetwassimulated.Thesupplypipefordrainflowendedatthemodeleddrainlocations,withaflexiblehoseincorporatedsuchthatthepipeendcouldbedirectedatadesiredlocation.Thepipesizesscaledtheprototypedraindiameters.ModelingofBreakFlowsBreakflowlocations1and2(Figure3)weremodeledasasinglelocation,aswere4and5,asthesetwolocationsareveryclosetoeachother.Cross-overbreaklocations3and8,location9inthehotleg,andloca-tions,6and7inthe3inchand2inchpipes,respectively,weremodeledseparately.Theareaofthecircumferentialbreaksinthemodelwasscaledfromthegiven(assumed)prototypeareaof25squareinches.Arectangu-larjetformedbyslotsdescribedearlieralonghalfthecircumferenceofthepipefacingthesumpwasmodeledandtestedatall,locationsinthecross-overloopandhotleg.The3inchand2inchpipebreaksweremo-deledonlyascircularjetssimilartothosepossibleintheprototype.Photograph4showstheslottedcircumferentialpipeatlocation2andthebreakflowissuingoutofitdirectedatthesump.Thejetvelocityofimpactatthewatersurfacewascalculatedfortheprototypebreaksusingthebreakflowandareaandheightoffallas,(15) 16whereu.istheexitvelocitygivenbyQ/A,theratioofbreakflowtojeareaandHistheheightoffall.Themodelbreakflowrequiredtogivethesamevalueofu.wasthencalculatedasthebreakareaandheightoffallinthemodelareknown.Thisvaluewassetinthemodel.ModelinofDrainFlowsIcecondenserdrainflowlocations1and2(Figure4)weremodeledbeingveryclosetothesump.Locations3and4wereconsideredunimportantasthedrainflowjetatlocation3wouldmostlybeinterceptedbythesteamgeneratoranditssupportsandthejetatlocation4wasconsideredtoofartherawayfromthesump.Inmodelingthedrainflows,itwasconsider-edimportanttosimulatethedrainpipediameterandheightofthedraintothegeometricscale.ThepointofimpingementofthedrainflowjetonwatersurfacewaslocatedfortheFroudescaledflowthroughthedrain,asthepathofdrainflowessentiallywasgravitycontrolled.Oncethisimpactpointwaslocated,theflowwasincreasedtogiveprototypeimpinge-mentvelocity,atthesametimeadjustingtheflexiblehoseendofthemodeldrainsuitablytokeeptheimpingementregionthesame.Theproto-typevelocityofimpingementwascalculatedusingEquation(15).TESTPROCEDURETeststoinvestigateair-entrainmentinthesumpareaduetotheimpinge-mentofhighvelocitybreakanddrainflowsonthewatersurfacewereconsiderednecessaryforbreaklocationsordrainlocationsclosetothesumpsothatimpingementcouldtakeplaceintheimmediatevicinityofthesump.Itwasrealizedthataircouldbedrawnintothesuctionpipeseitherdirectlyfromtheimpingingjetorafterasufficientquantityofsmallbubblescollectedonthetopcoverofthesump.Theobjectionablelimitofairentrainmentwasconsideredtodependonthepump,andthislimitwasnot,known.Ingeneral,anyairentrainmentoflargebubblesin-tothesuctionpipeswasdeemedobjectionable.
Asdiscussedinearliersectionsofthereport,sincebubblesizesandbubblerisevelocities"donotscaleinaFroudemodel,specialtestpro-cedureswereusedtoapproximatetheprototypeconditions.Thetest'rocedurefollowedisdescribedbelow.a.Thebreakflowordrainflowareasandtheirlocationsweremo-deledbasedonthegeometricscaleofthemodel.Breakflowtypes,whethercircumferentialorcircular,wereusedinde-cidingthejetdimensionstogivetheproperscaledarea.b.Onlyonebreakwasconsideredpossibleatatime.Aworstpos-sibledirectionofthejettowardsthesumpentrancewasassum-ed.Fordrainflowjets,animpactpointwasdeterminedbyscalingthecorrectwaterlevelandFroudescaledflowforeachlocationofdrainflow.c.Thejetflowwasincreasedtogiveprototypeimpactvelocitiesofthejet,andthejetdirectionwasadjustedtokeepthesameimpactlocationdecidedfromstepb.Toaccomplishthereorientation,adjustableconnectionstothebreaknozzles(orslottedring)ordrainpipeendswereprovided.d.Themodelwasrunsothatprototypevelocitieswereobtainedinthepumpsuctionpipescorrespondingtopossibleprototypeflowcombination.Thesubmergences(ordepthofwaterinthemodel)correspondedtogeometricallyscaledvalues.e.Air-entrainmentinthesumpareaandinthepumpsuctionpipeswasascertainedbyobservinganyaircollectedonthetopcoversofthesumporbeingdrawnintopipes.Photographicdocumentationasrequiredwasobtained.f.Ifobjectionableconditionswerenoted,modificationssuchasaddingbaffleplates,deflectors,airvents,etc.,wereimple-mented.Majorsumplocationorconfigurationchangeswereconsideredonlyifabsolutelyessential.
18g.Theabovestepswererepeatedforeachwaterlevelandflow.conditionandforeachbreakordrainflowlocations.Also,theeffectsofscreenblockages(upto50%),usingthesameworstblockageschemesderivedfromvortexingtests,wereinvestigated.~h.Whileperformingthetests,anyincreasedvortexactivityduetomodificationswereobserved.Ifobjectionableair-pullingvorticeswerepresent,alternativemodificationsweretried.ModelinofAir-VentinSstematToCoversTheearlierARLstudy(1)onthevortexingbehaviorofthesumphadindi-catedthenecessityofimprovingtheair-ventingatthetopcoversbothupstreamanddownstreamofthecranewall.Fortheupstreamtopcover,itwasrecommendedthatonerowof1/2inchdiameterholesbeprovidedatabout18inchesc/c,andtheseholesweremodeledtoscale.Forthedownstreamtopcover,slopingroofplatesangleduptowardsasingleventpipewasproposedbyAEPSC,asshowninFigure8.Thisvent-ingsystemwasbuilttoscaleinthemodel.Thehorizontalslababovetheslopingplateswas'notmodeled,beingunnecessary.RESULTSAir-EntrainmentduetoDrainFlowDrainflowatthemodeledlocationscouldexistforacasewhenthere-circulationmodeisinitiatedatEL602ft10inches(operatingcaselaorlbonly)whereasthebreakflowatthelocationsinthecross-overleginthevicinityofthesumpmodelhavetobeconsideredonlyforacasewhentherecirculationmodeisinitiatedatEL607ft4inches.Hence,drainflowjetimpacttestswereconductedfirstforonepipeoperationcases(laandlbofTable2).Inthiscase,thesumpentrancewasnot 19submerged,thetopcoverbeingatEL604ft11-3/8inches.Considerableair-entrainmentwasgeneratedattheimpactlocationasseeninPhoto-graph5.Mostofthebubbles,beinglarge(ofsizesgreaterthan5mm),werenotdrawn,downintothesumpunderthecranewall.However,smallquantitiesofrelativelysmallerbubbleswerepulleddowntheupstreamsumpportionintothedownstreamarea,andmostofthesecollectedatthetopcoverinthedownstreamportion.Theair-ventsystemofsingleventpipeandslopingplates(Figure8)wasnotefficientenoughtoventallthebubblescollected.Thiscausedaccumulationofbubblesandoc-casionalpullingofslugsofairintothesuctionpipe(moresowitha50%blockageofsumpscreens).Itwasdecidedtoextendthedrainflowpipesfartherfromthesumparea,"alongthecranewall,toallowthemtodischargeatasubmergedlocationawayfromthesumpentrancearea,therebytotallyeliminatingthedrainflowjetimpactinfrontofthesump.Withthischange,furthertestingwascarriedoutwithoutdrainflowmodeling.Air-EntrainmentduetoBreakFlowsA.UnsubmergedBreakLocationsAhighvelocityjetimpactatthewatersurfaceoccurredformodeledbreaklocations1(or2)and4(or5)(Figure3),whichwerenotsubmergedforthelowestwaterelevationofEL607ft4inches,atwhichoperatingcase"laorbwaspossible.Thesebreaklocationsweretestedoneatatime.Eventhoughtheyproducedconsiderableairentrainment,noairbubblesofreadilyvisiblesizeswereseentobedrawnintothesumpdownthecranewall.Thisisbecausethesumpentrancewascompletelysubmergedwithitstopcoverbelowthewatersurface(about1ftinmodelor2.5ftinproto-type)andmostoftheair-entrainmentwasinthetopfewinches.Photo-graphs6and7showtheairentrainmentatthesurfaceinthesumpareaforbreaklocations1and4.Thesurfaceairentrainment,althoughcon-siderably,wasrestrictedtoasmalldepthandnoairbubblesofany 20significantsizeweredrawndeepintothesump.Novisiblequantityofbubblesweredrawnintothepipes,asindicatedbyobservationsthroughwindowsinthepipe.Hence,thesumpperformancewasconsideredsatis-factorywithregardtoairentrainmentduetounsubmergedbreakjets.B.SubmergedBreakLocationsEventhoughsubmergedbreaklocationsarenotlikelytoproduceair-en-trainment,particularbreakfloworientationcouldaugmentanyborder-linevortexactivitybyaddingmoretoanyexistingcirculation.Withthisinmind,allthesubmergedbreaklocations;namely3,6;7',and8,iweretested(Figure3)foralloperatingcases.Breaklocations6and7werecorrespondingtobreaksinthe3inchand2inchlinesjoiningthecross-overpipeandwereconsideredasverticalupwardordownwardcircularjets.Thesesubmergedverticaljetsdidnotproduceanysigni-ficantvortexactivitynordidtheycauseanyairentrainmentproblem's.Averticalupwardjetwasobservedtoemergeoutofthewatersurface;butwasbrokenintoaspraybyhittingobjectsandwasofnoconcern.Breakflowlocation8wasseentohavelittleinfluenceonvortexingandnoproblemsofconcernwerenoticed.Breaklocation3inthebendportionofthepipewhenproperlyoriented,togetherwitha50%blockage[blockageschemes3and5ofARLreportonvortexing(1)]didaddconsiderablecirculationtoanotherwiseweaksur-facedimple,frequentlyproducingastrongvortexwithanaircoreex-tendingafewinchesbelowwater(Photograph8).Thisvortex'wasveryunstableandunsteady,andmovedfromapositioninthecenterofthesumpentrancetoapositionclosetothebreakflowjet,whichcausedadispersionoftheaircoretoastreamofbubblesdirectedtowardsthesump.Thesebubbleswerelargeenoughandhadenoughbuoyancynottobedrawnunderthecranewallintothedownstreamportionofthesump.Thistypeofvortexoccurredforbothoperatingcases1and2(waterlevels607ft4inchesto610ft0inches).
21SumModificationsandRetestinThevortexingdescribedintheearlierparagraphwasoutsidethesump,andthesumpscreensandgratingspresumablyactedasvortexsuppressoisasnovortexcorewasseenextendingintothesump.Ifitisdesiredtoreducethisvortexing,apossiblemethodwouldbetoinstallaverticalstandardfloorgrating,infrontofthehorizontalcrossoverpipe,extendingoveralengthandheighttoobstructthebreakflowjetsfromlocations3or8,asshowninFigure9.Itwasobservedinthemodelthatagratingof1inchdeepbearingbarsservedtodispersethejetsoastoreduceitscontribu-Ctiontorotationalflowfield.Theadditionofthegratingshowedadecreaseinvortexstrengthandfre-fluencyatthelowerwaterlevelfortheonepipeoperation(Photograph9a).Infrequently,aweaksurfacedimplevortexmovedtowardsthebreakflowjetwhichdispersedfewlargebubblestowardsthesump,however,noneofthesebubblesenteredthedownstreamsumpregion.Forbothpipesoperat-ingatawaterlevelofEL610ft,thevortexintensitywasreducedbytheextragratingtoasurfaceswirlandnosignificantactivitywaspresent(Photograph9b).AirVentinat,DownstreamToCoverIngeneral,therightsideofthesumproofdownstreamofthecranewallwasfoundlessefficientinair-ventingcomparedtotheleftside,wherethesingleair-ventpipeislocated.Sincenoobjectionablerateofairaccumulationandwithdrawalthroughthesuctionpipeswerenotedforanyofthetestconditions,thereappearslittleneedforanymodificationorredesignofthetopcover.However,someadditionaleffortsweremadetoevolveadesigntoimprovetheair-venting,incaseitisdesired.Theslopingplatesattachedtotheoriginalhorizontalslabbottomweremodeledalongwiththeventpipe(Figure8).However,thehorizontalslabitselfwasnotincludedinthemodel,beingunnecessaryforsimu-latingtheairventingsystem,whichessentiallyconsistedoftheslop-ingplatesandventpipe.Toimprovetheperformanceofthisventsys-22tern,itwasdecidedtoprovideafew1/2inchdiameterholesat5inchesc/cinthemodelalongtheportionsofslopingcoverplateontherightsideofthesumpawayfromthemainventpipe.Asthehorizontalslabwasnotmodeled,theholeswereallconnectedtoacommonmanifoldlocatedap-proximatelyatthesameelevationcorrespondingtothebottomofthehori-zontalslababovetheplate.Thecommonmanifold,inturn,wasconnectedtoanadditionalverticalventpipe.Suchanarrangementwasseentoim-provetheventingsystem,reducingtheaccumulationofbubblesundertheslopingplate.Thebubbles.continuouslyescapedthroughtheholesandwereeventuallyflushedthroughtheadditionalventpipe.CONCLUSIONSDrainflowjetsimpinginginfrontofthesumpproducedconsider-ableair-entrainment.Forlowerwaterlevels(atoraboutEL602ft10inches),thesumpentrancewasnot,submerged(freesurfacepresentinsidesump)andsmallquantitiesofsmallersizeairbubblesweredrawnwiththeflowtotheportionofthesumpdown-streamofthecranewall.Inspiteoftheair-ventingsystem,someof-thebubbleswerecollectedunderthetopcoverandwereoccasionallydrawnintothesuctionpipe.Toavoidthis,itisrecommendedtoredirectthedrainflowatlocations1and2(Fi-gure4)awayfromthesumpareabyextendingthedrainpipesalongthecranewallandpreferablydischargingthedrainflowclosetoorbeneaththewatersurfaceinthesump.2.Breaklocations1,2,4,5,and9(Figure3)couldcauseunsub-mergedhighvelocityjetsimpingingonthewatersurfacenearthesumpentranceforarangeofwaterlevelsbelowthecorres-pondingbreaklocations.Thesumproofandentrancewouldbesub-mergedforallthepossibleoperatingconditions,thesumptopcoverbeingbelowtheminimumwaterlevelofEL607ft4inches.Themodeltestresultsindicatedthattheunsubmergedjetscaus-edconsiderableair-entrainmentatandneartheimpactregion.However,nonoticeablemovementofbubblestothesumpportion downstreamofthecranewallwasobservedfortheabovebreaklocations.Thiscouldbeduetosufficientlyhighwaterdepthsandlowapproachvelocities,whichallowbubblereleasetosur-face,andalsoduetothefactthatthesumpentrancewaswellsubmerged(morethan2ft)belowthewatersurface.Hence,noadverseair-entrainmentproblemswereencounteredforunsubmergedbreakflowjets.3.Nosubmergedbreakflowtestedcausedanyair-entrainment.How-ever,itwasimportanttoassesstheprobablecontributionsofsubmergedbreakflowsinaugmentingvortexingtoanyobjection-ableextent,asnotedbelow.a.Breaklocations6and7generatedverticalcirculaijetsinthecorresponding2inchor3inchpipe.Thesejetsweresubmergedforalloperatingconditions,andwereseentocausenovortexingproblemsevenwith'0%screen'lockages.b.Breaklocations4and5(circumferentialbreaks)weresubmergedforwaterlevelshigherthantheirlocations.Atthesewaterlevels,modeltestsindicatednosignifi-cantvortexingproblems,evenwith50%screenblockages.c.Breaklocations3and8weresubmergedforalloperatingconditions.nBreakflowatlocation8didnotcauseanyobjectionablevortexingproblems.However,breakflowatlocation3wasobservedtostrengthenaweakdye-coretypevortexwhichexistedevenwithoutbreakflows(seeref.1)outsidethesumpscreenbetweentheverticallegsofthecross-overline.Thisvortexwasunstableandintermittentandwasseentohaveanaircoreex-tendingtoafewinchesbelowthewatersurfacewhentestedwith50%screenblockage.Whensuchanaircoreformed,andthevortexmovedtowardsthebreak,the 24breakflowjetwasseentobreakthecoreintobubbles.Someofthesebubblesenteredthesumparea,butwerelargeenoughtoescapetothesurfaceandwerenotdrawntotheportionofthesumpdownstreamofthecranewall(andhencenotdrawnintosuctionpipes).Asanoption,thisvortexseveritycouldbereducedconsiderablybyplacingastandardfloorgrating(2-1/2inchdeepbars)asindicatedinFigure9.4.Thereappearslittleneedforanyredesignormodificationsof,thesumptopcovers,asnoobjectionablerateofbubbleaccumu-latioqunderneaththesecoverswerenotedforthetestconditionswiththedrainflowsredirected.Therateofairventinginthedownstreamslopingtopcoverplatecouldbefurtherimprovedifanadditionalventpipeweretobeprovidedintherightportionofthesumpcover(lookingdownstream)andafewrowsofl-l/4inchdiameterholesatabout.12inchesc/caredrilledonthisportionoftheplate.
25REFERENCES1.Padmanabhan,M.,"HydraulicModelInvestigationof'ortexingandSwirlWithinaReactorContainmentRecirculationSump-DonaldC.CookNuclearPowerStaton,"ARLReportNo.108-78/M178PF,September1978.2.Murakami,M.,etal.,"FlowofEntrainedAirinCentrifugalPumps,"13thIAHRCongress,Japan,August31toSeptember5,1969,Vol.2,p.71-0.'.Rouse,H.,HandbookofHdraulics,JohnWiley6Sons,1950.4.Anwar,H.O.,"PreventionofVorticesatIntakes,"WaterPower,October1968,p.393.5.Ervine,D.A.,andElsawy,E.M.,"TheEffectofaFallingNappeonRiverAeration,"IAHR16thCongress,SanPaulo,Brazil,1975,Vol.3,p.390-397.6.Elsawy,E.M.,andMcKeogh,E.J.,"StudyofSelf-AeratedFlowwithRegardtoModelingCriteria,"IAHR17thCongress,1977,Vol.1,p.475-482.7.Govier,G.W.,andAziz,K.,FlowofComlexMixturesinPies,VanNostrandReinhold,1972.8.Chanishvilli,A.G.,"AirEntrainmentandVerticalDownwardMotionofAeratedFlows,"IAHR8thCongress,Montreal,Canada,1959.
TABLES
TABLE1BreakFlows*1.Breaklocationsinthecross-overandhotlegs(circumferentialbreaks)BreakArea=25sq.inches.Maximumflowof540lb/secoccurringat15minutesafterLOCA.2.Breaklocationin3inchSch.160line.TimefromLOCA,secsMassFlowrate(lb/sec)7501000125015001750200025003000116.3114~0ill.3109.0108.5106.0105.0100.03.Breaklocationin2inchSch.160line.TimefromLOCA,secsMassFlowrate(lb/sec)20003000400050006000700080009000444236.533.7532.25313028.75*DetailssuppliedbyAEPSC.
TABLE2OperatingCasesTestedOperatingCaseNo.Flow/Pipecg>mRangeofWaterSurfaceElevationRemarksla9500602'10"-606'0"607'4"-610'0"*RunoutconditionofoneECCStrainuponcompletefailureofother.Leftpipeoperational.lb9500602'10"-606'0"607'4"-610'0"*RunoutconditionofoneECCStrainuponcompletefailureofother.Rightpipeoperational.3a77001x95001x3600606'0"-612'0"610'0"-612'0"*606'0"-612'0"610'0"-612'0"*RunoutconditionofECCSpumpswithbothtrainsoperating.RunoutconditionofoneECCStrain(left);con-tainmentspraypumpfromother,.trainatrunoutflow(right).3b1x36001x'9500606sOi612i0'10s0n612s0nRunoutconditionofoneECCStrain(right);con-tainmentspraypumpfromothertrainatrunoutflow(left).*Applicableforbreakflowtests.
PHOTOGRAPHS
~p5i~t7~1'77'7~(.'.im7A(~A.77)I~jg'y,.'L7151Photograph1OverallViewofSumpModel(1:2.5Scale) fPJI~DRAINFLOWiS/r~>>i)p'yIgp,',II.",-*'5t:+Ij."rBREAKFLOWPhotograph2ModelSimulationofBreakandDrainFlows4~I,1$'p/Photograph3SimulationofCircumferentialBreakArea Photograph4TypicalCircumferentialBreakFlowO;ff.!Photograph5DrainNowImpingement;WaterLevelEL602'10" lP;tI'llPhotograph6BreakFlowImpingement;BreakLocation1;WaterLevelEL607'4";OperatingCase1~~I'Ill555III*I5IItI,l-5.-'},151'*Photograph7BreakFlowImpingement;BreakLocation4;WaterLevelEL607'4";OperatingCase1 Photograph8aSubmergedBreakFlow;BreakLocation3;WaterLevelEL607'4";OperatingCase1l~~I1(tltPhotograph8bSubmergedBreakFlow;BreakLocation3;WaterLevelEL610'0";OperatingCase2 Photograph9aSubmergedBreakFlow;BreakLocation3;WaterLevelEL607'4";OperatingCase1;WithVerticalGratingforJetInterception(c;Q=mtry%i)1IJPhotograph9bSubmergedBreakFlow;BreakLocation3;WaterLevelEL610'0";OperatingCase2;WithVerticalGratingforJetInterception FIGURES 103o27MODELBOUNDARYHOTLEGR.C.PUMPNO.2~'5xSTEAMGENERATORNO.20+~+4'12o42'ODELBOUNDARY125o-44'3024140.30'3151-04"23"0CONTAINMENTVESSEL2f15052215321'.57"0FIGURE1LOCATIONOFSUMPWITHINCONTAINMENTBUILDING GRATINGSCREENEL599'A3/8"OEL591'-1".O.:4.0':i.:i"W'44-Vi~-'4."."Ot.':;..OOj~0~o..%~EL593'-9.3/4";r49oo'.~4C40:"~'.u:..CRANEWALL'o.u'~'O,'4~oot44EL598'-9-3/8"EL596'-9.1/4"'r4.~t10'412'-7"9t+tt5t+t~9tt2t9ttSECTIONB-BMINIMUMW.S.E..EL607'4"EL604'-11-3/8"6oVENT:d.d~~)Odq'~4.'d~O'lt.od~,.'RANEWALL3t+t3t+ttcI-SUMPQ3t+tt3t6ttEL598'-93/8"GRATINGC.44...EL598'-9-3/8"EL596'-9-1/4".o.'td'.Orqd0)Od0d.,t..d.q.d<4O~0d.0"ot.0/8tr~C7/pP/a/~88~13o34EL591'-1"'g~"eV'fr~""~!d"':!.t."d:4'~.~4/I+I+Jr'4"DIA.SECTIONA-AEL596'9-1/4"EL595'4"EL591'-1"SECTIONG-CFIGURE2DETAILSOFORIGINALSUMP EL614'-0"STEAMGENERATOR1EL615'-8.3/4"NOTE:BREAKELEVATION615'-11"615'.8.3/4"604'-11-1/2"608'-2-1/4"608'.5"HOTLEG5I7II3'5~R.C.PUMP-EL608'-2-1/4"I86-7-M6EL603'-8-1/4"CROSSOVERPIPEEVENTSWITCHOVEROFFIRSTECCSTRAIN(BREAKOUTSIDEBIOLOGICALBOUNDARY)SWITCHOVEROFSECONDECCSTRAINWATERLEVEL(CONSIDERINGPARTIALICECONDENSERMELTDOWN)ATSWITCHOVEROFSECONDECCSTRAINSWITCHOVEROFFIRSTECCSTRAIN(BREAKINSIDEBIOLOGICALBOUNDARY)WATERLEVELINSUMP607'-4"'10'0"612'0"602'-10"'BASEDONNOICECONDENSERMELTFROMICECONDENSERFIGURE3POSTULATEDBREAKLOCATIONS 90180z"IIICECONDENSERDRAINS)(/X/'y;1..'j4F"j5pP'ONTAINMENTSUMP.".i':,'.;.";:)j//'tlag..23NOTE:a)ICECONDENSERFLOOREL642'.0"b)DRAINCENTERLINEELEVATIONATEXITEL634'-6"c)ALLDRAINSAREOF12"DIA.PIPEFIGURE4DRAINLOCATIONS 250200150CJCl0100~ONERHRPUMPONRECIRC.II)~TWORHRPUMPSONRECIR.I001020TIME(MIN)406070FIGURE5POSTLOCAFLOWRATEOFEACHICECONDENSERFLOORDRAIN SUCTIONPIPE=::4::'RANEWALLSUMP~~\v~~~o~~~~~~~i~.i~I~'oooo"~o:ouboYu'~~0~~~~BREAKFLOWJETAIRBUBBLE(ARBITRARY)HWATERLEVEL,'I+%Pi,'I~Jr'".i:,:p$$ub'BUBBLERISEVELOCITYu:SUMPAPPROACHVELOCITYuI'JETIMPINGEMENTVELOCITYFIGURE6DEFINITIONSKETCHFORBUBBLEMOTIONTOWARDSSUMP ICEDRAINS(2PIPES)rrrrrrNOZZLEENDFLEXIBLETUBEORIFICEMETER4"PIPEDRAINFLOWSUMPENTRANCEMODELTANKFLEXIBLEHOSEBREAKLOCATIONORIFICEMETER6"PIPEBYPASSLINEBREAKFLOWOUTLETPIPESPUMPSUCTIONCENTRIFUGALPUMP(75HP)FIGURE7SCHEMATICDIAGRAMOFBREAKANDDRAINFLOWSUPPLYPIPINGIN'MODEL 0I-oI-3~O.4.OO"OO~i.3.OaO3o.33~.':.o,t/'fj~ta'.j:tt.o:Pjo.3I.'o'3oto0,o.c'O3o".By2'tt2tt2'~gt~3lt."'"0o6IQtt'4.B1/4"CLITYP.)7tQtt3t6tt2'-7-1/2"7tPtt1/4"THICKSTAINLESSSTEELPLATE15/16"DIA.HOLEFOR3/4"DIA.SELF-DRILLINGANCHORAT1'0"O.C.14'-0"PLAN-SUMPPITROOFIL6"DIA.VENTPIPESTAINLESSSTEELBAR1"1"1/4"THICKSTAINLESSSTEELPLATESECTIONC-CEL596'-7"~033otEL596'-9-1/4"'P~1/4"THICKSTAINLESSSTEELPLATESECTIONA-AEL596'-9-1/4"1CALE5/8IN.>3FT.EL596'-7"BOTTOMOFSTAINLESS~""."ILATLOWPOINT3'3"~7'4"~3'4"I%24"DIAIL24"DIASECTIONB-Bi..'.no'.ts.,~EL596'-9-1/4"';.~...44~1/4"THICKSTAINLESSSTEELPLATESTAINLESSBARFIGURE8IMPROVEDAIRVENTINGATTOPCOVER STEAMGENERATOREL615'-8.3/4"6I2IIPROPOSEDVERTICALGRATINGR.C.5PUMP4EL608'-2-1/4"MIN.WATERLEVELEL607'4"FLOOREL598'-9.3/8"86EL601'-2-3/8"glpllglPll18'-0"NOTE:2-1/2"STANDARDFLOORGRATINGTOBEPLACEDCLOSETOTHEPIPE.FIGURE9POSITIONOFSUGGESTEDVERTICALGRATING(OPTIONALMODIFICATION)