ML17326A883

Evaluation of Facility Containment to Determine Limiting Internal Uniform Pressure Capacity. Prepared for American Electric Power Co

ML17326A883
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Site:	Cook
Issue date:	03/16/1981
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SMA-80C129-1, NUDOCS 8104290520
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{{#Wiki_filter:SMA.8OC129-1SECTION1EVALUATION OFD.C.COOKCONTAINMEiNT TOOETERMINE LIMITINGINT""RNiAL UNIFORMPRESSURECAPACITYPreparedfor:americanElectricPowerCo.2BroadwayNewYork,N.Y.1000416March1981Preparedby:Structural Mechanics Associates 3645'i(arrensville CenterRd.Cleveland, Ohio44122(216)991-8841 TABLEOFCOilTEl<TS

1.0 Introduction

1.1PurposeandScopeofReport1.2Evaluation Criteria1.3Containment Description andDesignBasis1.4MaterialProperties

2.0 Identification

ofLimitingFailurei~iodesAssociated withUniformStaticInternalPressure3.0Potential FailureModeAnalysis3.1ShearFailureinBaseHat3.2blembrane HoopTensionFailureofConcreteCylinder3.3PressureCapacityofEquipment HatchClosure3.3.1SplicePlateHomentCapacity3.3.1.1HandCalculation 3.3.1.2FiniteElementAnalysis3.3.2Equipment HatchCoverPlatePressureCapacity3.4PressureCapacityofPersonnel Hatch3.4.1EndPlateClosure3.4.2Door4.0SummaryandConclusions

1.0INTRODUCTION

PURPOSEANDSCOPEOFREPORT-Theobjectofthisreportistodetermine abestestimateofthelimitinguniformequivalent staticinternalpressurecapacityofthecontainment structures fortheO.C.CookNuclearGenerating UnitsNo.1and2.Theevaluation reportedislimitedtothereinforced concretebasemat,thereinforced concreterightcircularcylinderandhemispherical domeaswellasmajorcontainment penetrations including theequipment andpersonnel hatches.Thisreportcompletes PhaseIofathreephaseeffortwhichwillincludeasPhaseIIanupperandlowerboundestimateoftheinternaluniformequivalent staticpressurecapacityofthe"asbuilt"containment structures andPhaseIIIwhichwillconsiderpotential timedependent localized non-uniform pressureloadeffects.1.2EVALUATION CRITERIATheevaluation todetermining thelimitingbestestimateuniformstaticpressurecapacityofthecontainment structures isbasedonalinearelasticanalysisofcriticalportionsofthestructure uptostresslevelslimitedby"asbuilt"meanvaluesamplesoftheyieldinsteelandultimatestrengthoftheconcrete. Itshouldbeunderstood thatthestructural andleaktightintegrity ofasteellinedconcretecontainment shellandslabstructure shouldbemaintained wellbeyondactualyieldofthesteelreinforcement. Thisisdueprimarily totherelativehighductility ofthesteelliner,(ie.20-23percentuniformultimatestrainatrupture)comparedto.the40ksisteelreinforcement (ie.8-11percentuniformultimatestrainatrupture)andstrainhardening inthereinforcement. Hencethelineringeneral~ouldbeabletoaccomodate relatively largenonlinear deformation oftheconcretestructure beforesignificant leakagewouldoccur.However,sincedeformations beyondtheyieldrangearedifficult topredictandlocalizddeformations inthestructure cansignificantly exceedthosecalculated

globally, thelimitinginternalpressurehasbeendetermined conservatively considering onlyassumedelasticresponseuptotheinitialyieldofthematerials used.Itistheauthor'sopinionbasedontheobservedresultsofmodelteststhatsignificant leakage(>1.0prcentofcontainment volume)ofthecontainment wouldnotoccuruntiloressures exceededthelimitingoressures calculated inthisstudybyatleast20percent.Assumingacomposite coefficient ofvariation of10percentandalognormaldistribution ofmaterialproperties theprobability ofsignificant leakageatthepressureleveldefinedinthisstudywouldbeapproximately 0.01.Theprobability ofsignificant leakageandupperandlowerboundsonpressurewillbeevaluated inmoredetailinPhaseII.

CONTAIililENT OESCRIPTIOH Atl0DESIGNBASISThereactorcontainment structure isareinforced concreteverticalcylinderwithaflatbaseandahemispherical domeasshowninFicure1:Aductileweldedsteellinerwithathickness of1/4-inchonthecontainment baseand.3/8-inch'on theCylinderisstudattachedtotheinsidefaceoftheconcreteshelltoinsureahighdegreeofleak-tightness. Thedesignobjective ofthecontainment structure istocontainallradioactive materialwhichmightbereleasedfromthereactorcoolantsystemfollowing apostulated lossofcoolantaccident. Thestructure servesasbothabiological shieldandapressurecontainer. Thestructure consistsofsidewallsmeasuring 113-feetfromthelineronthebasetothespringline ofthedome,andhasaninsidediameterof115-feet. Thesidewallthickness ofthecylinderattnebaseis4.5ft.taperingto3.5ft.,sevenfeetabovethebasematandcontinuing at3.5ft.tothespringline. Thereinforced concretethickness ofthedomevariesuniformly from3.5ft.atthespringline to2.5ftattheapexofthedome.Theinsideradiusofthedomeisequaltotheinsideradiusofthecylinder. Theflatconcretebasematis10-ft.thickwithanoutsidediameter, of140'-0"andwiththebottomlinerplate1/4"thicklocatedontopofthismat.Thebotto~linerplateiscoveredwitha2-ft.structural slabofconcretewhichservestocarryinternalequipment loadsandformsthefloorofthecontainment. Thebasematissupported directlybyrelatively stiffsoil.Thebasicstructural elementsconsidered inthedesignofthecontainment structure isthebaseslab,sidewallsanddomeactingasonestructure underallloadingconditions. Thelinerisanchoredtotheconcreteshellwallsbymeansofstudanchorssothatitformsanintegralpartoftheentirecomposite structure underallmembraneloadings. Thereinforcing inthestructure hasanelasticresponsetoallprimarydesignloads.Thebasematis10'-0"thickand140'-0"indiameter. Thereinforcement inthetopofthebaseslabconsistsprimarily ofonelayerof818Sbarsat12"c/cinthehoopand2layersof58Sbarsat9"c/cin'theradialdirections. Thebottomreinforcement consistsof2layersof818Sbarsat12"c/cinthehoopand3layersofalternate 818Sand811barsat9"c/cintheradialdirections. Thebaseslabwaspouredintwofivefootliftswhicharetiedtogetherinordertotransmithorizontal shearinducedbybendingmomentsbyshearkeysandverticalAllbarsat6'-0"c/cspacing.

Themembranehoop(horizontal) reinforcement inthecyclinder wallsisgenerally intworows,oneoneachfaceconsisting ofN18Sat18"c/ccircumferentially extending to20'bovethebasematreducedto9"c/cspacingbetween20'nd57'bovethebaseandthenincreased to12"c/cspacingbetween57'nd113'springline) abovethebasemat.Themembranemeridional, (vertical) reinforcement inthecontainment shellconsistsprimarily oftwolayersoneoneachfaceof818Sbarson18"c/c.Intheregionofdiscontinuity at'hebasemattheamountofverticalreinforcement isdoubledto4layersof~18barsat1S"c/candatthecylinderdomeintersection oneverticalstaggerdrowof411barsat18"c/cisaddedtotheexistingmembraneverticalreinforcement toprovidediscontinuity bendingmomentresistance. Inadditiontotheverticalandhorizontal membraneandbendingreinforcing steel,inplanediagonalreinforcement hasbeenprovidedtocarryseismically inducedmembraneshear.The45degreediagonalbarsconsistof811barsspaced3'-0"onthehorizontal c/cplacedintworowsineachfaceandineachdirection. Thediagonalreinforcement isembeddedinandextendsfromthebasematto4-3"abovethespringline intothedomeforalternate barsand7'-0"fortherestofthediagonals. Thedomereinforcement consistsof818barsat18"c/cineachfaceineachdirection. Thecontainment structure enclosesanicecondenser containment systemwhichisdesignedtolimitpressurization othecontainment underdesignbasisaccidentconditions to12.0psi.Othersignificant designloadparameters aretheequivalent safeshutdownearthquake loadingof0.2gzeroperiodgroundacceleration andadesignbasistornadoof360mph.windandand3.0psidifferential pressure. Hotprocesspipepenetrating thecontainment areanchoredinthecontainment shellwiththeanchorsdesignedtoresistthepostulated ruptureoftheprocesslinewithoutlossofcontainment leaktightintegrity. Aloadfactorof1.5(additional safetyfactor)isusedwiththeinternalpressurecomponent ofdesignloadwhilealoadfactorof1.0isusedwithboththeSSEandTornadoloading.!)ATERIAL PROPERTIES Theparticular specified minimummaterials properties usedintheconstruction ofthecontainments aresummarized asfollows:(a)concrete-fc=3,500psiat28day(ACI-308-63,301,66,and214-65)(b)reinforcing rod-fy=40,000psi(ASTNA15) (c)linerplate=-fy=32,000psi;fu=60,000psi(ASTtlSA442-Gr.60) (d)equipment hatch-fy=38,000psi;fu.=70,000psi(ASTHSA516-Gr.70) (e)personnel hatch-fy=38,000psi;fu=70,000psi(ASTt<SA516-Gr.60) (f)hatchbolts-fy=105,000psi;fu=125,000psi(ASTHSA193-6r.87) InTable1canbefoundasummaryofthe"asbuilt"strengths aswellasameasureofthedispersior. associated withthematerials usedinthecontainment construction, basedonalimitedsampleofexistingtestrecorddata.AspartofPhaseIIofthisevaluation amoredetailedevaluation of"asbuilt"materialpropertydatawillbedeveloped.

2.0 IDENTIFICATION

OFLItiITING FAILURENODESASSOCIATED MITHUNIFORi~l TATICNRNALPEUInselecting thepotential limitingfailuremodesassociated withequivalent staticuniforminternaloverpressurization ofaPPRreinforced concreteicecontainment anumberofexistinganalyseshavebeenreviewed'. Theseincludethefollowing references:

Harstead, G.A."D.C.CookNuclearPowerPlant,AmericanElectricPower,EstimateofUltimatePressureCapacityofContainment Structure",

HarsteadEngineering Associates, ReportpreparedfortheNRCStaff,September, 1980.(SeeAttachment A)(2)VonRiesemann, M.A.et.al."Structural ResponseofIndianPoint2and3Containment Ouildings"SummaryofDraftReport.resultspresented to!IRCStaff,Technology-Exchange t~eeting5,17June1980.(3)(4)(5)(6)UnitedEngineers andConstructors "Evaluation ofCapability ofIndianPointContainment VesselsUnits2and3"presented toNRCStaff,Technology Exchangeileeting5,17June1980.AmericanElectricPowerServiceCorp.,"D.C.Containment DesignCalculations, AEP,1969.S.3arneset.al.IndianPoint!!uclearGeneratin UnitNo.2Containment DesinRepor~,'!estinghouse NucearEnergyystems,UnitedEngineers andConstructors, !larch,1969.Shulman,J."Analysis ofTVASequoyahContainment ShelltoDetermine ResponseofaCriticalPaneltoUniformInternalPressure", OffshorePowerSystems,September, 1980. Basedonthisreviewthefollowing areashavebeenidentified aspotentially limitingthecontainment capacitytocarryuniforminternalpressureload.(1)Bendingshearinthereinforced concretecontainment basematadjacenttoreinforced concretecylinderwalls.(2)flembrane tensioninhoopdirection inthereinforced concretecylinderadjacenttothebasemat(assuming norotational orshearrestraint bythecylinder). (3)Bendingmomentinequipment hatchendplate.(4)Bendingmomentinpersonnel hatchendplate.3.0POTENTIAL FAILUREblODEANALYSIS3.1SHEARFAILUREINBASEYATTheprogramusedtodetermine netshearandtensileforcesinthebaseslabis"GENSHL"whichwasdeveloped bytheFranklinInstitute ResearchLaboratoryof Philadelphia. Theprogramconsistsofamulti-layered staticshellformulation whereeachshelllayermayhavedifferent stiffness oroperties andcanconsiderelasticfoundation supportconditions. Thisisthesameprogramthatwasusedintheoriginaldesignandanalysisofthebaseslabfordesignbasisloadings. Auniformsoilreactiondistribution isusedfordeadloadplusinternaluniformpressurecase.Resultsoftheanalysisaresummarized asfollows:1.Specified minimumdesignstrengthofconcreteat28days=3,500psi2.t<eanSampleValueat28days3.flinimumSampleValueat28daysFoundation Slab:=4,950psi=4,156psiT=120inchesd=114inchesFromcomputeroutputasshowninTables2and3atsectionsindicated in.Figure2:

Evaluation forlowestmeasuredconcretestrengthvalue:NxzQxsk/ink/inComp+RunCase12.0psi,internalpressureAssume49.5psi,internalpressureOeadLoadOL+49.5psipressure1.8987.8291.3009.129-2.948-12.160-0.193-12.353SoilPar.1SoilPar.1SoilPar.5v=i~=12.353x1000=108.36psiwhere:Nxi=membranetensioninbaseslabQia=maximumverticalshearinbaseslabv=maximumshearstressinbaseslabFromAStlESectionIII-Oivision2andACI-359-80 CodeforConcreteReactorYesselsandContainments CC3421.4.1rIUsinglowestmeasuredmeanvalueofconcretestrength: vc-2r0pfc(1+IOr002Nu/Agjjr-,rc=20~4166!1+[00021-9.129x1000xtfltvc=2(64.46)[1 -0.152]=103.59psiNote:InternalPressureCapacitywherevernotedas"Psi"means"Psig"-~gggQgllXCLXt% ~RX2~M Evaluateformeanofmeasuredconcretestrengthvaluesk/inQx.ak/inComp.RunAssume53.8psi,internalpressureOeadLoadOL+53.8psipressure8.5091.3009.809-13.217-0.193-13.410SoilPar.1SoilPar.5v=13.410(10)1x114v"-117.63psivc=274950)1+I0.002(-9.809x1000~,1balllvc=2(70~356)C1-0.1635jvc=117.71psiInlikemanneritcanbeshoNnforaspecified minimumconcretestrengthfc=3500psithattheinternalpressurecapacityis46.4psi.Inthisevaluation nocreditistakenforthevertical/Illbarat6'/cinthebasematnorisanycredittakenforshearcapacityofthefillslababovethebasemat.Intable4canbefoundthelimitingpressurecapacityadjustedfortheassumption ofminimumspecified andminimumsampledmaterialproperties asdefinedinTable1.InReference 1theHarseadreportPg.5-1-1identified afailuremodebasedontheassumedpulloutoftheverticalmembranesteelinthecylinderwallfromthebasematashavingacontainment internalpressurecapacityof46psi.Tnepulloutfailuremodecapacityof46psiinternalpressurecapacityofthecontainment wasdetermined ivithoutconsideration oftheradialshear(diagonal tension)capacityoftheconcretevihichispermitted bytheACI-359codeeveninpresenceofmembrantension.Toignoretheshearcapacityoftheconcreteisnotinaccordance riithnormaldesignnoranalysisprocedures. Hencethefailurepressureintheconcretecontainment of53.8psiasdefinedbythecalculations performed inthissectionislimiting. 3.2MEHBRA</E HOOPTHSIO'lFAILUREOFCOtlCRETE CYLII>OER i~lembrane loadduetocontainment pressurization inthehorizontal (hoop)direction P=pRwhere:P=membraneloadinlbs/inofwallp=uniforminternalpressureR=meanradiusofwall(57.5x12=690inches)Hembraneloadcapacityofreinforced concretecylinderatitsbaseneglecting discontinuity momenttransfer: Available Reinforcement 1)2Layers818barhoopreinforcement at18"c/c=8in=5.33in2/ftofwallft2)3/8"Linerplate=3/8"x12=4.50in2/ftofwall3)2Layers811bardiagonalreinforcement at36"c/cconsidering onlythosebarsactingintension2x1.56x~2=1.47in2/ftofwall333ftFromTable1ofthisreportthemeanvalueofthereinforcement yield=49.8ksiandlinerplate=48.3ksiP=(5.33in2x49.8ksi)+(4.50in2x48.3ksi)+(1.47in2x49.8ksi)=265.4k+217.4k+73.2k=556.0kips/ft=46.33kips/inFromEq.1p=46,330lbs/in=67.1psi690>nInTable4canbefoundthlimitingpressurecapacityadjustedfortheassumption ofminimumspecified andminimumsampledmaterialproperties asdefinedinTable=l. 3.3PRESSURECAPACITYOFTHEEQUIPMENT HATCHCLOSURETheequipment hatchclosuresusedontheD.CCookContainments havebeenidentified (Ref.l)aspotentially limitingthecapacityofthecontainment tocarryinternalpressureloads.Thereasonsforthislimitation areidentified asfollows:1.Theendclosureisintheformofaflatplatehencepressureinducedloadingmustbecarriedbybendingratherthanmembraneshellaction.2.Aboltedspliceisusedinaregionofhighbendingmomentwhichmaylimitthecapacityofthehatchcovertocarrypressureload.3.Thefarspacedboltpatternandtherelatively lowrotational .stiffness oftheequipment hatchbarrelresultinlittlerotational stiffness orfixedendmomentcapacityoftheequipment hatchcover-barrel attachment. Thisrequiresthatthehatchbeanalyzedessentially aspinconnected (allowedtorotate)ratherthanfixed(momentresistant) atitssupportstherebysignificantly increasing centerspanmomentsinthehatchcover.Becauseofthepresenceoftheunsymmetric spliceandtheunsymmetric insertion ofthepersonnel hatchintotheequipment hatchcoverasshowninFigure3theevaluation oftheequipment hatchuniformpressurecapacitycannotbeperformed withahighdegreeofaccuracywithoutrecoursetoafiniteelementformulation. Twosuchanalyseswereperformed, oneofthecoverplatespliceandtheotheroftheequipment hatchcoverplateincluding theeffectofthespliceandtheinsertedpersonnelhatch todetermine. theirmaximuminternalpressurecarryingcapacities. ~r3.3.1SplicePlatet1omentCaacity3.3.1.1HandCalculation -considering 1"fullpenetration welddetailasshowninFigure4(1~Beforeproceeding toareviewofthefiniteelementanalysisofthespliceplateshowninFigure4,ahandcalculation wasperformed inordertohaveabasisofcomparison withthemoredetailedfiniteelementcalculation (1)flotetheHarsteadreportneglected theweldgeometryinitscalculation ofstresses. Given:SpliceasshowninFigure4-checksectionattopofweld(a)95-1"A-193Gr87boltsona224"lengthofsplice=2.38"spacingbetweenboltsontensionsideofspliceLimitingcapacityofspliceattopofweldisassumedatmeanyieldinoutermost fiberof2inchspliceplateontensionbolt,sideofspliceM2PL=sZ=(53.2ksi)1(2.38)(4) =84.41k-in/2.38 in.ofspliceLimitedtensilecapacityofspliceplateTx=t'I~x=1o5in+T='M/1.5=S4.41/1.5 =56.27kips/bolt MgointT'jd=(56.27)x(2.5+4.0+1.875)=471.26k-in/2.38 in.ofspliceMomentcapacity/inofsplice471.26/2.38 =198.01k-in/inMomentcapacityof4"platewithoutspliceM4<<PL=sZ=53.2ksi(1)(1) 16=141.87k-in/in<198.01~s.".4"plategovernsdesignCapacityofSplice=198.01]39,6of4"plate~87Checksectionatbaseofweld Limitingcapacityofspliceatbaseofweldisassumedatmeanyieldinoutermost. fiberof2inchspliceplateplus1"weld.(MinimumSpecified FoftheHeldmaterial=60.0Ksi)M2<<PL+1<~weld=sZ=(53.2Ksi)1(2.38)9=189.92K-in/2.38in.ofspliceLimitedtensilecapacityofsectionTx=M;x=2.5in.T=M/2.5=189.92/2.5 =75.97Kips/bolt Since75.97>56.27KipstopofweldlimitsdesignCheckcapacityofboltFromTable1MeanYieldof1"bolt=121.3KsiTensilearea1"bolt=0.605sq.in.Pyie]d=121.3x0.606=73.51Kips/bolt >56.27:.OK~

3.3.1.2FiniteElementAnalysisInFigure5isthefiniteelementmodeloftheequipment hatchsplicejointshowingplateelements. UsingthecomputerprogramAtlSYSforanappliedmomenttothe4inchhatchcoverplateequaltoareference containment internalpressureof40psi,.the.maximumoutermostfiberstressinthe2inchspliceplateis27.82ksiinelement76.Themaximumoutermostfiberstressinthefourinchplateisdetermined as46.27ksiinelement145.Itappearstherefore thatthe4inchratherthan2inchplateatthejointcontrolsdesign.Thisisdueprimarily totheweldwhichsignificantly increases theeffective thickness ofthespliceplateatitsconnection tothefourinchplate.3.3.2EuimentHatchCoverPlatePressureCapacityInreference 1Harsteaddetermined theequipment hatchcapacityof53.0psiuniformpressureloadingbasedonsimplesupportboundaryconditions ofthecoverasauniform4"thickcircularplatehavingadiameterof19'-10".8ecauseoftheeffectoftheunsymmetric spliceandpersonnel hatchinsertafiniteelementanalysisoftheplateisperformed. AfinitelmentmodelingoftheplatewhichincludedthespliceisshowninFigure6.Thepersonnel hatchbecauseofitsrigidequiva'lent 12"thicksupportringconnection totheequipment hatchisassumedtotransmitonlyreactionloadsduetopressuretotheequipment hatch.Thespliceismodeledasanequivalent 12"x4"beamparallel, tothespliceandequaltothestiffness ofthefourinchplateacrossthesplice.UsingthecomputerprogramA"(SYSthemaximumstressintensity inthecoverplateisdterminedinelement95asshowninFigure7adjacenttothesplice.Theresultant limitinginternalpressureloadatelement95is45.1psiforan"asbuilt"meanyieldstressof53.2ksiintheplate.FromSections3.3.1.1and3.3.1.2ofthisreportitisdetermined thatthespliceplatehasagreatermomentcapacitythanthefourinchplate.ThelimitinginternalpressurecapacityoftheEquipment HatchCoverPlateistherefore limitedbythecapacityofthefourinchplateat45.1psi.InTable4canbefoundthelimitingpressurecapacityadjustedfortheassumption ofminimumspecifidandminimumsampledmaterialproperties. 3'.4'RESSURE CAPACITYOFPERSOiklEL HATCH3.4.1EndPlateClosure Hecauseoftheunsymmetric stiffening ofthepersonnel hatchcoverplateassnowninFigure8,afiniteelementanalysisoftheplateisperformed todetermine itsinternalpressureretaining capacity. Asinthecaseoftheequipment hatchtheloadingfromthepersonnel hatchdooristransmitted tothepersonnel hatchclosureplateasareactionlineloadattheoointofsupport.Alsotheplateisconservatively assumedsimplysupported ratherthanfixedendsupported atitsconnection tothepersonnel hatchbarrelbecauseoftherelativelowrotational stiffness ofthebarrel.InFigure9isfoundthefiniteelementmodelofthehatchshowingallelements. TheplatandstiffnersystemisanalyzedusingthecomputerprogramAISYS.Themaximumoutermost fiberstressisdetermined inthedoorstiffneratelement87as79.3ksiforarefrence70psiinternalpressureload.Thepressurecapacitypofthepersonnel hatchclosureisdetermined: p=70x53;2=47.0psi79.33.4.2DoorThepersonnel hatchdoorisshowninFigure8.Itactsessentially asaonewayspaningsimolysupported stiffened plate.Thetotalspanofthe1/2"tliickplateis42".Theplateisstiffened by3"x1-1/4"solidplatestiffners onapproximately 15inchcenters.Assumingacomposite Tsectionwiththeeffective outstanding flangelegofteeequalto8timestheflangethickness, themomentofinertiaoftheTsectionis6.93in4anddistances totheoutermost fibersofthesectionare1.03and2.47inchesrespectively. tlaximumappliedbendingmoment:)~i=1bp121(15)(p)(422)3307.5FHomentCapacityofStiffenOoorSection:H=sZ=(5,200)I=(53,200)6.93=149,261c22iTLimitinginternalpressurep=149,261=45.1psi3307.5 InTable4canbefoundthelimitingpressurecapacityadjustedfortheassumption ofminimumspecified andminimumsampledmaterialproperties. ,4.0SUt"'u~'IARY Af'lDCONCLUSIOHFromthesummaryresultsoftheanalysispresented inTable4itcanbeseenthatthecurrentlimitinginternalpressurecapacityoftheD.C.CookContainments aretheequipnent hatchclosureplateandtheequipment hatchdoorat45.1psibasedontheuseofmean"asbuilt"materialproperties. Itshouldalsobepointedoutthatevenifspecified minimummaterialproperties hadbeenusedaswasthecasereportedinRef.1byHarsteadtheminimumcapacityoftheD.C.Cook'Containment is32.3psibasedonthemoredetailedanalysesreportedhereinratherthanthe23.5psireportedinRef.1whichwerebasedonmoreapproximate handcalculations. Itshouldalsobeemphasized thattheanalytical assumption usedinthemorerigorousanalysesreportedinthisstudyoftheequipment andpersonnel hatcheswhoselimitingfailuremodeswereinbendingstillconsidered onlyelasticbehaviorandsectionproperties. Ithaslongbeenestablished inthebehaviorofplateelementsduringtestandasthe'asisforthe1.5increaseinallowable bendingversusmenbranestresslimitsoftheASt<EBoilerandPressureVesselCodethatpl.ateandshellbendingelementsbehaveessentially elastic(smalldeformations) untiltheplasticsectionmodulusisreached.Sincetheplasticsectionmodulusforrectangular shapesassociated withthehatchplatesis1.5timestheelasticsectionmodulusthereissignificant additional safetymargininthehatchanalysiswhichisnotapplicable tothemembraneorsheartypefailuremodesidentified inthecontainment concreteshellandbasemat.Toquantifytheeffectoftheplasticsectionmodulusoftheequipment hatchontheinternalpressurecapacityofthecontainment anon-linear elastic-plastic finiteelementanalysisofthehatchcoverplateusingthecomputerProgramAf"SYSwasperformed fortheassumedfy=50.3Ksimaterialproperty. Evaluation at70psiinternalpressureor1.64timestheelasticcapacityofthecoverplateindicated .thatthemaximumdeflection oftheplateisstilllinearandthemaximumplasticstrainwas1.8timestheelasticstrainatyield.Therefore itisourconclusion thattheD.C.CookContainments aspresently designedandconstructed constitute abalanceddesign.Thatis,thetruepressureretaining capacityofthehatcheswhenthe1.5factordiscussed previously isappliedisapproximately thesameasthatoftheconcretelimitingportionofthecontainment, approximately 54.5psi.Onthisbasiswedonotrecommend anymodification oftheexistingD.C.Cook'ontainment hatches. 00 Figure1O.C.CookContainment Oimensions andGeneralArrangment Figure2ShearFailurePlanesandGeneralArrangment ofReinforcement inthe8basematFigure3GeneralArrangment oftheEquipment HatchClosurePlateFigure4GeneralArrangment oftheEquipment HatchClosurePlateSpliceFigure5FiniteElement51odelofEquipment HatchClosurePlateSpliceFigure6FiniteElementtlodeloftheEquipment HatchClosurePlate'Figure7OetailedFiniteElementi~lodeoftheEquipment HatchClosurePlateFigure8GeneralArrangement ofthePrsonnelHatchClosure,PlateFigure9FiniteElementi'lodelofthePersonnel HatchClosurePlateTable2ComputerCalculated Resultants ForcesintheContainment BaseSlabOue.toOeadl!eightTable3ComputerCalculated Resultant ForcesintheContainment BaseSlabOuetoaReference 12.0psiInternalPressure TABLE1SU&iARYOFtiItfIMUN SPECIFIED ANDASBUILTMATERIALPROPERTIES 1.LINERPLATE-SA442SAMPLESIZE=6S=2.27Cov.=0.0472.EgUIPMEiNT HATCH-SA516SAMPLESIZE=5S=2.74Cov.=0.051~GRADE60SPECIFIED MINIMUt1MEANSAMPLEVALUESi~lINIf'lUM SAMPLEVALUESGRADE70SPECIFIED MINIMUMi'lEAflSAtlPLEVALUESMIfIMUMSAiiPLEVALUESYIELD32.048.345.838.053.250.3ksiULTIMATE-60.064.762.470.081.280.23.e.5.BOLTING-SA193SAtiPLESIZE-2ea.1/2"x2-1/2"1"x5-1/2"(SPLICE)l-l/4"x10"(COVER)REINFORCING RODA1518SSAMPLESIZE9S=3.34Cov.=0.067CONCRETE-28DAYSTRENGTH-SAMiPLESIZE29S=0.508Cov.=0.103GRADE87SPECIFIEDilINIi~lUMi~lEANSAMPLEVALUESSPECIFIED MIiVIMUMi~iEAthSAMiPLEVALUES'PECIFIEDtlINIi~iUi~l flEANSAMPLEVALUESGRADE40SPECIFIEDtlINIMUMt1EANSAMPLEVALUESMINIMUMSAt'lPLEVALUESUflIT1and2SPECIFIED t'lINIflUil flEANSAt'1PLEVALUESYINItlUtl SAMPLEVALUE105.0119.0105.0121.3105.0120.140.049.844.3125.0137.0125.0141.0125.0140.370.081.875.5'.54.9564.112 WV64VJI140 ~409~i999)]l0lll974~~ii0viSOLUTIONFUNCTIONS IHSYSTEttREFEREHCE FRAttfTable2ComputerCalculated Resultant esintheContainment BaseSlabDuetoDeWeight10.207258K 04R0.220710K 0430.2340638K 040.249031E 0450.263875E 0460.279153E 0470.2940CEi50480.310?2'?E 0490.32737"E 04100.344161E04110.361263E 040.00.00.00.00.00.00.00.00.00.00.00.179783E 0.1816692E 0.183450E0.185155K 0.186704f0.188343E0.189335E 0.191265K 0.19263>>E 0.193942K0.195193K040.834138E 05040.548537K 05040.243167E 05040.8N924E04O4-O.42e949E 0504-0.796689E 0504-0.11C619E 0604-0.159789E 0604-0.20322lf 0604-0.24S953K 0604-0.29)069K 06-0.120054E"DR 0.00.148695C-OR 0.00.414161K-02 0.00.675165E-OR 0.00.9304051E DZ0,00~117869E-0 10.00.141846K-ol 0.00~164i827E-Dl 0'0.186456E-01 0.00.2071452-01 0.00.226201E-ol 0.0-0.719304E-DR 0.70479OE-OR -0'85N9E-02 -0.64346.7E-02 0'36066K-DR -0.603897K-OR 0.5646ii9E 02-0.56200034'.E-02 -0.4757042E-DR 0.421537K-DR -0.361094K-02 09163836.E030.16218iiE 030.159343E-03 0.156762E 030.152896E-030.148194"E-030.142618E-03 0.135108f-030.126616f-03 0.120092E-03 0.110472K-D3 ACTUALSTRESSRESULTAIITS-SIIELL REFERENCE FRAtlf-BODY 7%ATCEIITROIOc STATIOtlCEIITROIOS tlO;tlfRID~HOOPHllLB/IHtt12LB/IHH22LB/IN013LB/IHQ23LB/IHHllIH-LB/IHH12Itl-LB/IH tt22IH-LB/IN62.66262.BIIR62.86R62.811362.656.Sll62.85R62.811562.656262.811662.R6262.Cll762.8626".Sll0.179783E0.1S1662E0.183450K0.185155E0.166784E 0.160>>343K0.189335K 040.0040.0040.0040.0040.0040.0040.00.216753K 0.216602E 0.216593E0.216720E 0.R16971E0.217339E 0.217818E04-0.207258K Q4-0.220710K04-0.234638E 04-0.N9031E 04-0.626'3875E 04-0.279153E 04-0.2948ii E040.0040.0040.0040.0040.0040.0040.0-0.192634E 05-0.488963f 05-0.80454ioiE 05-0.113994E 06-0.149570E 06-0~187235E06-0.227037E 060.00.00900.00.00,0'~0060.0060.0060.0060.0862066R62.6110.1914"f040.00.218402E 04-0.310929K 040.0-0.269024K 962.86262.8110.192634if 040.00.219084K 04-0.327378E 040.0-0.313238E1060.06"610110;19W."E04"0;00:039060r04=0".344161E"04 D.E-0.359717E ll62.86262.8110.195193E 040.0-0.220726E 04-0.361263E 040.0-0.408547E 00,189855E 060~177062E060.163588E 060,149402E Ob0.134474E 060.11877ef 060.102285KOb0849739E050.668169E 050.47793if 050.278602K 05STATIONLAYERHO.HO.1234567STRESSSllINSIDE0.14413K01-0.46754E 02-0.1609iE-05 -0.465i7E 020.12971E01<<0.40609E 02"0.13917E-05 0.13126E01-0.46667E OR-O.16O44E-O5 -0.46276E 020~1113CEol0403r59E02-0.13820K-05 0.00.00.00.00.00.00.00.00.00.00.00.00.00.0RESULTANT STRESSES-PSI BOGYSSTRESSSllSTRESSS12STRESSS12OUTSIDEINSIDEOUTSIDESTRESSS22INSIDE0.36946K02I0.99142E-05 0.28696K030.9C645K-05 0~3>>4313K020.85744K050.24?obfD3STRESSS22OUTSIOE0.33971E020.98951E-05 0.28607E03093099E050.29374E020.85194K-05 0.24529E03

COOKPLAHTSOILPARAtlETER STUDYtIO.1LOAOItlG3DEADIIEIGIIT312-30-80ComputerCalculated. Resultant ForcesiContainment BaseSlabDuetoaReferen.0psiInternalPressureSOLUTIOII FUIICTIOIIS IHSYSTEtiREFfREtlcE FRAtiE10.362819E 20.300629E 3O.R40632E 40186rSZE50~126535E60.721415C 70.19$453E8-0.319680E 9-0.618996E 10-0.13054ZE ll-0.176029E 040.0040.0040.004Q.o040.0030.0-030.0030.0030.0040.0040.00.12<i021E 040.125169E 040.126290E 04012732rDE040.1"6295E 040.129201E 040.1300<>5E 0<i0.13OGReE O40.1315<>?E 040~132209f040~13261ZE040~197442E0.1477Z6E 0.108624E0.600810E 0.609194E0roQ246E0.493393E 0560519E0.705932E O.926286C ,0.121891E 06"0.181325E 0106-0.161004E Ol06-0.180663E Ol05-0.180361E 01050.1600<>OE 0105-0.179?RZE 0105-0.179405E 0105-0.179091E 0105-0.178760E 0105-0.1764i69E 0106-0.178159E 010.00.00.00.00.00.00.00.00.00.00.0-0.936208f-02 -0.9>0639E-02 -0.939061E-02 -0.93292QE-OZ -0.923599E-02 -O.912352E-02-0.90039<>E-02 -0.866667E-02 -0.878656E-02 "0.871393E-OR -0.667<i6<iE-02 0.193628E-03 0195016E030195358E030.1'94910E-03 0.193908E-03 0.1925?GE-03 0.191125E-03 0.18975<IE-03 0.166653E-03 0.180003E"030.187975E-03 ACTUALSTRESSRESULTAHTS-SIIELL REFEREtICE FRAtlE-BODY 7/ATCEIITROIO< STATIOIICEHIROIDS HO.ttCRIO.IIOOPtillLG/IHOI'>LG/IHll22R13LB/IHLB/IHO23LG/IHtillIH-LG/IHti12.IH-LB/IHti22IH-LG/IH162.66262.811262.66262.611362.86262.61162.66262.611562.66262.811662.6626"..811762.662GZ.I>110~124021E040.00.125169E 040.00.12629OE 040.00.12735E0<i0.00.126295E 040.00.129201E0<i0.00.13004.E0<i0.0862.652CR.GII0.13062of 0<i0.0962.66262.6110.1515<i?C040.01062.CGZ62.8110.132209E 0<i0.0ll62.66262.6110.13"612E 0<i0.00.163855E 0<>-0.362619E 040.00.16391<>E 04-0.3006 9E040.00.16320?E 04-0.2<i0632E 040.00.163539E 04-0.162652C 040.00163115E0<>-0.12653rSE 040.00.1625<>if 04-0.'/21<>15E 030.00.1616"1C 04-0.193<ir>3F 030.00.16095?E 040.3196QCE 030.00.159956E 040.81699GE 030.0O.l'>:GZOE 040.130542E 040.00.157549L 040~178029E040.00.126612E 060.7622GOE 050.3669?GC 050.736369E 04-0.123520E 05"0.2296<i2E 05-0.2<>9$14E050.00.00.00.00.00.00.0-0.166653E 050.0-0.453569E 040.001712"1E05000.460396E 050.00.250910E 060.236913E060.223955E 060~212269E060.202044E 060.193441E 06.0.186555F 0.161563E 060.17652ZE 060.177466E 060.178462E 06STATIOHLAYERIIO.IIO.STRESS511IH51DEREULTAHI'TRESSES-PSI STIIC55511Sll\L55SIROUTSJDEIl>SIDEBODY8STRESS512OUTSIDESTRESS522II>SIDESTRESS522OUTSIDE1235670.2<i416E 01-0.73659E 02-0.25338E-05 -0.?319QE 020.2)749E01-0.61216E 02-0.20934E-05 0.22035EOl-0.73<i81E 0202r5241E05-0.72691E 020.18357EOl-0.60709E 02-0.20738E-05 0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.60108E020.15811E-04 0.457<ilE 030.1571ZE"04 0.53466EOR0.131<ICE-04 0.37609E030.5419?E020~15773E-04 0.4556<if 03015603E040.45064EOR0.13037E-04 0'7<>56E03

TABLE4SUf1NARYOFLIHITINGINTERNALUNIFORt1PRESSURECAPACITYOFD.C.COOKCONTAINMENT INTERNALPRESSURECAPACITY(ELASTICANALYSIS) (SeeSubsection 4.0forPlasticAnalysis) CRITICALFAILURE110DESPECIFIED MINItlUNPROPERTIES LOlJESTii/EASURED SNlPLEPROPERTYMEANSAMPLEPROPERTYl.BendingShearingConcreteBaset1at2.MembraneHoopTensioninConcreteCylinder3.BendingCapacityofEquipment Hatch4.BendingCapacityofPersonnel Hatch-(a)ClosurePlate(b)Doorfc=3500psl;fc=59.16Limitinginternalpressure=45.8psify=40,000psiLimitinginternalpressure=50.2psif>=38,000psiLimitinginternalpressure=32.3psify=38.000psiLimitinginternalpressure=33.6psiLimitinginternalpressure=32.3psifc=4100psi;fc=6403Limitinginternalpressure=49.6psif>=44,300psiLimitinginternalpressure=61.2psif>=50,300psiLimitinginternalpressure=42.6fy=50,300psiLimiting.internal pressure=44.4psiLimitinginternalpressure=42.6psifc=4950psi;fc=7036Limitinginternalpressure=54.5psify=49,800psiLimitinginternalpressure=67.1psify=53,200psiLimiting-internal pressure45.1fy=53,200psiLimitinginternalpressure=47.0psiLimitinginternalpressure=45.1psiNote:InternalPressureCapacitywherevernotedas"psi"means"Psig" CCNTAILlHEMT QlQllSTEELLILlEll>/b"THICKSPRlHGLlNIAZSTEELLINER>io'HICK~g~~'II5ŽID.STRELLIQIR>/Z'HICK<ms'~rGROUQOFL."~QRAOK4'lo"pBASEf1~ToPopMATleo'-0"OD~.GFCTtohJA-AGECTIQN4,L F.LEYATIQQ Figure1D.C.CookContainment Dimensions andGeneralArrangment .CL.F.c,.I~IAllL'I'.I7a~h\~4Sa,I,4$.TCHI~'nv0'r;CgC...l.Y=fi//vi.IiIll~T~+II~~5-~n.)lc~gl"I."IICI-"Is)=i]I.~5~~'Lvg77!w!!IggNdcc14I)-:)rCl~I<I~'p->I"4AjI'I-LCIl-IO'2A~~le."'.=vI'Pell'c)),'4IAtf+JLC ~~5Av~Gse(cd~P.A><I3yQRI&poP,c)w~.NOT=1.iV:<~irL.ii; ~Ni<W=.(r.=)<IVEIlT'3TnEC"=tIT"-R JFC3llTHNr-II.c~-=r.TA:.-II:.,T"-G. Figure2ShearFailurePlanesandGeneralArrangement ofReinforcement intheContainment BaseMat 5'-31'i'-t5 YPh-32-!~/0"$HDLESON25O'I<"S.C.S4EQUALSPACES-BoLTS8+EQ0ALSppeES-..-SoLTS'.---~-~--------I=I0'-30'O-3/<" 4HOLCS,ONl24"S.C.Figure3GeneralArrangment oftheEquipment HatchClosurePlate I]II)Ie~SI~~0~>(

<<)rLO<<%Oral<< ~0~.I~5~4'F0514$145I~014014<<1%0I5I1%0)~0%Bot.TWal.bPIIOf:IIIL),It/It>I.ILCIt%ltklt)Ill%IIe<<)~l1~ClICTO5)SCSIItl10~5SSl~41010%OC5~CICt100I~I~5I~)5C5Cl~5<<55~)0%7<<g~iII~ClICt20)04~4~44$~5~1141%IItl~tlttt4~00-$.)l-4.15-4.Il-I~SC.<<.0$-5~)4tWC5100lhJOIST)Os4LVCIC0101140rOOCLI4)Ilt-.SleCIIltI))t)4CCOritev~v%1tIP)554IV4.v<<S~)0C.~004raaSLO)II>~~rI'1nltr.ElefnentHodelof'qulpmrntI%ItchClos>>rrI'intr'.Splice 31PREP7-PLOT 34227337283831342474819565351/6e01212891121,4131411151221818853767,128138151515815,gfg~QiI16151?PREP?EPLTANSYSFigure6FiniteFlementModeloftheEquipment HatchClosurePlate rgDI~SpealOF-'.21264o313312212142/1j'6125143156875128145154155Bc1291g1311301471481571562-~l"13213813914915815'52158161159160cotTANSY56Figure7DetailedFiniteElementMode(oftheEquipment HatchClosurePlate /63/i"g!DEPTH(y/'"DEPTH.(YVP)~I$~9'lz"DEPTHPLsrrEIIP/pIT'oY'RwPEPTICi"PLATEP./7)rF'CWEAS3DEPTH~4~!TVP3~4~>Figure8GeneralArrangement ofthePersonnel HatchClosurePlate

11172S916332982128147202'?1361926335323136393533373iQ12?4856314?5562046546120ea6915125182511417241031623QiS5360844525974351586<7167017691870.8-5'?.8-44.8-31.9-189-5'7.120.133.~46.0SQ0AlaLOCKPLAYPLAYSAtlALVSls CEO?1ETRVANSYS Figure9FiniteElementModelofthePersonnel HatchClosurePlate

SECTION2PhaseIIoftheD.C.CookInternalPressureContainment Analsis-Probabilistic AnalsisInthiseffortthevariability ofthe"as-built" materialparameters onthebestestimatecapacityofthecontainment tocarrystaticuniforminternalpressureisbeingevaluated. Fourpotential limitingfailuremodeshavebeenidentified bydeterministic analysis. 'woofthemodesinvolvepotential failurebyplatebendingoftheequip-mentandpersonnel hatchclosureplates.Theothertwopotentially limitingfailuremodesarebymembranetensionfailureofthemainsteelhoopreinforcement atthebaseof'hecontainment shellandshear(diagonal tension)failureoftheconcretebasemet.TheACI-359Codeequationgoverning diagonaltensionfailureisbasedontestresultshenceitisalsobeingevaluated inaprobabilistic manner.Resultsofthisstatistical analysiswillbeprobability densityfunctionofcontainment resistance definedforthetwodifferent contain-ment"as-built" materialproperties andinthecaseofshearinthebasematthestatistical natureofthecodedefinedfailureequation. Thisevaluation shouldbecompleted byMay15,1981.SECTION3PhaseIIIoftheD.C.CookInternalPressureContainment Analsis-LocalizeDnamicLoadsInthisevaluation dynamicanalytical modelsofthecontain-mentstructure assuminglocalizedynamicpressureloadinginputarebeingprepared. Thecontainment areaswherethedynamicmodelsarebeingde-velopedincludetheequipment andpersonnel hatchclosureplates,theshellportionofthecontainment shelladjacenttothebasematandthebisematadjacenttothecylindershelljuncture. Thedevelopment ofthedynamicmodelsshouldbecompletebyMay30,1981.Thenusingtheinternalpressuretimehistoryforcingfunctions, adynamicanalysiswillbedonetodetermine theforcesandmomentsatthecriticalsectionsofthecontainment.

DONALDC.COOKNUCLEARPLANTUNITNOS.tAND2ATTACHMENT NO.2TOAEP:NRC:00500A SECONDQUARTERLY REPORTONHYDROGENMITIGATION ANDCONTROL 0

2.0 Distributed

InitionSstem2.1Introduction Indiana5MichiganElectricCompany(ISMECo.) hasdecidedtoinstallaDistributed IgnitionSystem(DIS)inUnitNos.1and2oftheDonaldC.CookNuclearPlant.TheDISutilizesthermalresistance heatingelements(glowplugs)locatedthroughout thecontainment building. Operation oftheDISwillbeaccomplished bymeansofmanualcontrolswitcheslocatedinthemaincontrolroom.2.2Distributed InitionSstemDesinTheDISisatwo-train systememploying sixtyeight(68)igniterassemblies locatedthroughout thecontainment building. Eachtrainofthirtyfour(34)igniterassemblies isfurtherdividedintotwogroupsonegroupofsixteen(16)assemblies inthegenerallowervolumeareaandasecondgroupofeighteen(18)assemblies inthegeneraluppervolumearea-including theicecondenser upperplenumvolume.EachigniterassemblyconsistsofaGeneralMotorstype7GACglowplugandaDonganElectriccontrolpowertransformer (model52-20-435) mountedinasealedboxhousingasshowninFigure2.Theigniterboxisawatertightenclosure meetingNEMA-4specifications. Acopperplateisemployedasaheatshieldtominimizetemperature riseinsidetheigniterboxandadripshieldisutilizedtominimizedirectwaterimpingement onthethermalelement.Thetransformer isseismically mountedtotheigniterboxusingunistrut. Theentireigniterassemblyisseismically mountedsoastopreventanypossibleinterferences withsafety-related equipment during/after adesignbasisseismicevent. Thenormalandemergency powersourcesforeachtrainofignitersmeetsElectrical ClasslEspecifications andtheelectrical trainseparation criteriacommensurate withaClass1Esystemaremaintained intheDISdesign.TheDISwillbeamanualsystemcontrollable fromthemaincontrolroom.Twocontrolswitchespertrainwillbelocatedonauxiliary relaypanelsA7andA8inthemaincontrolroom.Thecontrolswitchesareofthetwo-position type,'off'nd'on',andredandgreenindicating. lightsareprovidedaboveeachswitch.Controlroomannunciation willbeprovidedtoindicatelossofpowerandfailuretooperateduetohypothetical controlcircuitequipment mal:functions. 2.3JIIAIAb1Theigniterassemblyisa16"x12"x8"enclosure meetingNET-4specifications. Theigniterisprotected fromdirectwaterimpingement bya1/8"steelplate(10"x18"galvanized steel)dripshieldweldedtothetopoftheenclosure. Theigniterismountedtotheenclosure througha6"x4"x1/4"copper,platetoreducethetemperature rise.insidetheenclosure during.periodsofcombustion. Allelectrical connections insidetheigniterassembly; itsassociated conduletbox,andthetwospliceboxespertrainutilizedintheDISareprotected withheatshrinktubingtoenhancesystemperformance inanadverseenvironment. Inaddition, allDIScablesinsidecontainment areroutedinconduitandhenceareprotected fromtheenvironment associ'ated withhydrogencombustion. Accesstotheinterioroftheigniter'3assemblyisthroughahingedcoverplatesecuredwithscrews.Abeadofsiliconerubberwillbeplacedaroundallboltholesintheigniterassembly. DetailsoftheigniterassemblyanditsconduletboxaregiveninFigureNos.1and2. 2.4IniterAssemblLocations Igniterassemblies aredistributed throughout thecontainment topromotecombustion ofleanhydrogen/air/steam mixtures. TheDISwillminimizethepotential forhydrogenaccumulation andprecludedetonations intheunlikelyeventofadegradedcorecoolingeventsimilarinnaturetotheTflI-2accidentinvolving substantive hydrogengeneration. Thecontainment airrecirculation/hydrogen skimmersystem,inconjunction withupperandlowervolumecontainment sprays,providessufficient mixingsoastopreventthestratification orpocketing ofhydrogeninthevariouscompartments ofthecontainment building. Approximate igniterassemblylocations arelistedinTable2-1.Ageneralviewof.thecontainment structure isprovidedinFigure3andapproximate ~~~~~~~~~~~~~~~igniterlocations showninFigureNos.4,5and6.Thelocations givenareforD.C.CookUnitNo.2andaretypicalforUnitNo.1.'inor'.variations'n ig-niterlocations mayberequiredin.UnitiVo.1'inconsideration ofphysicalinter-ferenceswith.existingequipment. A'schematic representation oftheDISelectrical networkinsidecontainment isprovidedinFigureNos.7and8.Oneofthequestions raisedbymembersoftheNRCstaffduringourmeetingofMarch18,1981dealtwiththeneed,orlackthereof,toinstalligniterassemblies intheinstrument, room.todateindicatethatexceptforpotential betweentheinstrument roomandeithertheTheresultsofourreviews.performed in-leakage thereisnocommunicatio'n generallowervolumeorthepipetunnel(annulusregion)withtheexception oftheflowpath-through thehydrogenskimmerductwork. Theabovenotwithstanding, itshouldbenotedthatanyleakageintotheinstrument roomwould,inallprobability, besignificantly lessthanthehydrogenskimmerflow(100CFt1pertrain)outoftheroom,thuspreventing Itheaccumulation ofhydrogentocombustible levels.Itshouldalsobenoted,thattheeffectsofhydrogencombustion on'required'quipment locatedintheinstrument room,pressurizer pressureandpressurizer leveltransmitters, is,forallintentsandpurposes, boundedbythecalculations contained inAttachment No.4ofthissubmittal. TABLE2-1IGNITERASSEMBLYLOCATIONS* Sheet1of2No.TRAIN'A'omartment/Area-El evationNoTRAIN'B'omartment/Area-El evationA-1A-2A-3A-6A-7A-8A-9A-10A-11A-12A-15A-16A-17A-18A-19A-20A-21A-22A-23A-24A-25A'-26A-27A-28A-29IceCond.UpperPlenumIceCond.UpperPlunumIceCond.UpperPlenumIceCond.UpperPlenumIceCond.UpperPlenumIceCond.UpperPlenumIceCond.UpperPlenumInside¹1SGEnclosure Inside¹2SGEnclosure Inside¹3SGEnclosure Inside¹4SGEnclosure InsidePZREnclosure Outside¹1SGEnclosure Outside¹2SGEnclosure Outside¹3SGEnclosure Outside¹4SGEnclosure OutsidePZREnclosure PrimaryShieldWallPrimary.ShieldHallPrimaryShieldWallPrimaryShieldHallPrimaryShieldWallPrimaryShieldWallEastFan/Accumulator RoomEastFan/Accumulator RoomWestFan/Accumulator RoomHestFan/Accumulator RoomVicinityofPRTUpperVolumeDomeAreaUpperVolumeDomeArea708'09'09'09'09'10'09'86'86'86'86' 686'59'662'62'62'62'47'48' 648'48'41'48'31'29'34'18'60'60'-1 B-2B-3B-4B-6B-7B-8B-9B-10B-11B-12B-13B-14B-15B-16B-17B-18B-19B-20B-21B-22B-23B-24B-25B-26B-27B-28B-29B-30IceCond.UpperPlenumIceCond.UpperPlenumIceCond.UpperPlenumIceCond.UpperPlenumIceCond.UpperPlenumIceCond.UpperPlenumIceCond.UpperPlenumInside¹1SGEnclosure Inside¹2SGEnclosure Inside¹3SGEnclosure Inside¹4SGEnclosure InsidePZREnclosure Outside¹1SGEnclosure Outside¹2SGEnclosure Outside¹3SGEnclosure Outside¹4SGEnclosure OutsidePZREnclosure PrimaryShieldWallPrimaryShieldWallPrimaryShieldHallPrimaryShieldWallPrimaryShieldWallPrimaryShieldWallEastFan/Accumulator RoomEastFan/Accumulator RoomWestFan/Accumulator RoomHestFan/Accumulator RoomVicinityofPRTUpperVolumeDomeAreaUpperVolumeDomeArea709'09'09'09'09'09'09'86'86'86'85'82'62'59'59'59'59'42'37'36'36'37'45'30'29'23'34'18'60'60'

Sheet2of2Ho.TRAIN'A'omartment/Area-El evationNo.TRAIN'B'omartment/Area-Elevation A-31A-32A-33A-34UpperVolumeDomeArea-760'pperVolumeDomeArea-748'pperVolumeDomeArea-748'pperVolumeDomeArea-748'-31B-32B-33B-34UpperVolumeDomeArea-760'pperVolumeDomeArea-748'pperVolumeDomeArea-748'pperVolumeDomeArea-748'EY:SG-SteamGenerator PZR-Pressurizer PRT-Pressurizer ReliefTanklocations givenareforDonaldC.CookUnitNo.2andaretypicalfor~~~~itNo.1.

'IL~

• <<~<<tII<<~<<tr(tl~~<<II'III~1/I<<'<<<<A1

NIfiIPI"~p't7 AEP:NRC:0500A768'pperVolumePolarCrane715'pperePlenumI)@drogenRecombiner 692'ceBedPressurizer LowerInletDoorsI(I(II1II'ZKf"1lSteamGenerators 650'7"Lower.VolumeInstrument RoomRecirculation FanPressurizer ReliefTank4q>'rReactorYesselI',FIGURE3 Section'A-A'levation 618FIGURE4gA-i<EastFan/Accumulator RoomPr,imaryShieldHa'ilCraneHallIl9-IA10XiInstrumentRoomLO8-2>g~--A>+VE'.HestFan/Accumulator Room48-2WQ-i7QID.C.CookUnitNo.2Containment. PlanBelovedElevation652'7"Pressurizer ReliefTankTrain'B"IgniterTrain'A'gniter FI6~A-Z8-c.IceCondenser p~lO~p,t5g~gP/j/~+M/Q/D.C.CookUnitNo.2Containment PlanAboveElevation 652'7"Train'B'gniter aTrain'A'gniter L~~ FIGURE50,PlatformElevation 748'5"PlatformElevation 759"32+33IIceCondenser TopDeckDoorsElevation 715'.C.CookUnitHo.2Containment PlanAboveElevation 715' 00 14IrtIIIIIIII4IIIIIII4I'IIII1IItI1II'I4~IIIII1I~I41I~IIIIII14'1tIi1i4I~II4~I'ti4i~I4II1'II-'4I1~~4I~I~'I'II!IIt111I4i4i~4I(~44~IIIIIfIIIIIII~IIIIIIIII.'I}'III'IIII~t!IIz7Bx4I4~jg'muzi!:Iiki7'L~~L.gIAZ~iQ~+ItI"4'1I1144I~~.~1'I4II~444441I~~III'II1~44l~~I4'II'~4f~I4'4I4I'4i4,1'}4I4iI44'I~~~f,'III+2Mzw&&U7-I1'~4~4tI~I~I'JI4~I1I'I~I1.-!4~,'(4',4~1I4III4I4!i*4'4'4Il~,~sI~.'~41~~,~4'IItI14~III~II~1I!IItII1~a~I4~~~4II~Ii;'4I4111II1II~1Itl'!I}I'iIII444~4I~I4iII'1IIIII~!}IIIIII;'4I}I4iIII~Is4II!~~t!I.IIIIii'iI~1,N~IIIII~I1III4I1II4i1IfIQII~I4tIIIi(IIIIIIII4II1/QIf/il441I~IIIii~14IIaII'II4x~mWAC2e~4I'441tt~'444I~t44~III~jkI4I1IIII~sI4tl4J~as~t44492-'ing~+71~'.4tIIi+(IWII}14IIiIIIa~41~t,~~~1I4-~4i1't441~I~it~~III*44~I~~fIII1'r4III1I*~}II'tI',III4II4II4-'4}Vat-='4w+~g4If~ts~I~441II444.1(.'I4ttettIIII4li~'I4ItI~IIIi~44II1III1IIIIIII(IIIIII~tII!1~I*aI'."}IIIII~~1I4I~JII41IIIIII6~AHsIIIkIII4II!I~'.~IIIi'II4~441III1~.II~}'IIeIII'i~.1I!I\.IIIIs1fI~4I~!III4II4I4IIkI!IIsI'14I11III1'I4I.II4sI"i:kII-I4f4~II';fi1~4-'II11i4*I4iIII4iJI4,t~.IIIti~444iI1i'II14"1k'.I!I4III~li~I'I','4Jk444414~~14s~Irv~EiddA.4~4(1k4:4'/T14IIIIIIIII'9aI4ItI's~41tP~~cfEAHLZIitIi11~II4~1iIeke~&44MMe4d~.~4I4I1~"'4-'4IIII4iI}iI!IIII"tIi~II.IIIIIIIiII4IIIII!IIIIIIII(I1'IIIIIIIIfI1II~4~I41~'4't4 4 'IcII1cIp1~1I~i~ItI'I~~~c1'icc1-1*r~1P',~1IIIItli,"icITI.~/~pgIt~III~chI1+cIcv.BE???:A&7&w7AJW vlt~IdC~i-cczxzemwII~III~rc~'I~IIII~~~Ig,cI1"/Q,ffIc~~tc'ItIII1II11-.1~iIccIS~vczw<WAX'~PfZ&7 CPS-:2.+W~7ERB i~lil~II*ctcXA'/WANEE2Ã/~A>..rr? I[~i~~cc,i~c~wciIci)cjt--.~~-i+ItI~IL'-Li'c=-~~~~c=~c*.=v1'~cP8z....f/'I+'~v1+c~cI1.IliiMJP>'1'{~'OP{:*<<,I~~I~+gj~IIi"I'II~uIII,~1~.~o1IIr,If'Gq.a~PCII~~1IMPIIIIII*~~:::&E?I?ER?rt~ ~:CJR+EW: Cr??WRIER7/YEnZ7:: YXFZe~im~RS:-.cde/.tlvI'~tItI*LZrr=Au'2CRa~~..rr&iHwWzd:NA'd mAl.z>-.~IIIV~;C~{?a;cInder~o.4;'507cz~MMJ&f', ~IvI1t'1II~ccIi~j+4'J'. DONALDC.COOKNUCLEARPLANTUNITNOS.1AND2ATTACHMENT NO.3TOAEP:NRC:00500A SECONDQUARTERLY REPORTONHYDROGENMITIGATION ANDCONTROL

3.0InadeuateCoreCoolinHdroenControlEuiment3.1Introduction Therearetwoprimaryconcernsassociated withaninadequate corecooling(ICC)eventsimilartotheTMI-2accidentinvolving thereleaseofsubstantive amountsofhydrogenandsubsequent combustion utilizingtheDistributed IgnitionSystem(DIS).Theseconcernsinvolve,(1)theabilitytoachieveandmaintainthereactorcoolantsysteminasafeshutdowncondition and(2)maintenance ofcontainment integrity throughadequatehydrogencontrol.Theequipment locatedinsidereactorcontainment requiredtoperformtheabovefunctions isidentified inthissection.Thesurvivability oftheequipment discussed hereinduringperiodsofhydrogencombustion isaddressed inAttachment No.4ofthissubmittal. Thecontainment responsetohydrogencombustion iscontained inOffshorePowerSystem(OPS)ReportNo.36A05previously transmitted totheCommission asAttachment No.2toourfirstquarterly reportonhydrogenissues(AEP:NRC:00500 dated12January1981).Theanalysesperformed byOPSutilizing theCLASIXcomputercodeclearlyindicatethatthepeakpressureresulting fromhydrogencombustion iswellbelowtheultimatestrengthoftheCookPlantcontainments. 3.2~EiEETable3-1liststheactivecomponents insidecontainment requiredtofunctionduringand(or)afterperiodsofhydrogencombustion. Thelocationofthesecomponents andtheirsusceptibility tohydrogencombustion effectsareaddressed below.

(1)SteamGenerator Narrow-Ran eLevelMonitors.Threesafety-grade differential pressuretransmitters (tLP)areemployedoneachsteamgenerator tomonitornarrow-range steamgenerator waterlevel.ThekPtransmitters, manufactured byITT8arton,arefullyqualified forpost-accident useinsidecontainment (LOCA/MSL8 qualification). Thesetransmitters arelocatedinthegenerallowervolume,withtwotransmitters persteamgenerator mountednearlyelevenfeetbelowthemaximumcontainment floodlevelof614'levation. ClasixrunJVAC4(seeAttachment No.2toourAEP:NRC:00500 submittal -OPSReportNo.36A05)represents theminimumtimeto'ombustion fortheS2Dcasesruntodate.andhencerepresents thecaseforwhichtheminimumcontainment waterlevelwouldexistatthetimeof'nitial combustion. FigureNo.32oftheOPSreportshowstheinitialcombustion tooccurinthelowercompartment approximately 4,600secondsintotheS2Deventsequence. Assumingthatwateristransferred tothecontainment fromtherefueling waterstoragetank(RWST)solelyviatwocontainment spraypumps,itiscle'arthattheminimumusableRl<STvolumespecified inthePlantTechnical Specifi-cations(350,000gallons)wouldhaveeffectively beendelivered tothecontainment pumplongbeforetheonsetofcombustion. Inaddition, theOPSreportshowsthatapproximately 22.4Xoftheinitialiceinventory hasbeenmeltedduringtheLOTICportionoftheanalysis; uptoatimeof3480seconds.Assumingtheinitialiceinventory tobetheTechnical Specification minimumvalueof2.37millionpounds; ~' itisthusshownthatinexcessof530,000poundsoficehasbeen.meltedpriortocombustion. Thisicemeltisequivalent toapproxi-.mately.80,000gallonsofadditional waterinthecontainment. Combining theicemeltwiththeRl<STwateryieldsatotalcontainment "waterinventory of430,000gallons,well-inexcessofthewaterinventory whichwouldresultinsubmergence oftwoleveltransmitters persteamgenerator. Thus,itisclearthatthesteamgenerator narrow-.rangelevelmonitoring functionwouldnotbesusceptible totheeffects.ofahydrogencombustion environment. '(2)Pressurizer PressureandPressurizer LevelMonitors-Thepressuretransmitters andthekPtransmitters utilizedfor.thepressurizer (PZR)pressureandlevelmonitoring functions, respectively arelocatedintheinstrument room.Thesetransmitters, -manufactured byITTBarton,arefullyqualified forpost-accident use-.insidecontainment (LOCA/MSLB qualification). AsstatedinSection'2.4ofAttachment No.2ofthissubmittal, ourreViewsperformed to'dateindicatethatthereisnocomnunication betweentheinstrument roomandeitherlowercompartment orthepipetunnel(annulusregion)-;otherthanthehydrogenskiomerductwork. Inaddition, theCLASIXH=analyses donotpredictcombustion inthedead-ended volume,ofwhichtheinstrument roomisapart.Hence,theinformation available at-thistimeindicates thatthePZRpressureandleveltransmitters wouldIInotbeexposedtoahydrogencombustion environment intheunlikelyeventofadegradedcorecoolingeventinvolving thegeneration ofsubstantive amountsofhydrogen. I~e (3(~333tll-33TTheRCSwide-range pressuretransmitters arelocatedinthelo.rercompartment nearlyelevenfeetbelowmaximumcontainment flooduplevel.Thetransmitters, manufactured byITTBarton,arefullyqualified forpost-accident useinsidecontainment (LOCA/MSLB qualifi-cation).ForreasonssetforthinItem(1)above,thesetransmitters wouldbesubmerged priortoinitiation'f combustion andhencewouldnotbeexposedtoahydrogencombustion environment intheunlikelyeventofadegradedcorecoolingeventinvolving thegeneration of,substantive amountsofhydrogen. (4)CoreExitThermocou lesTheeffectsofahydrogencombustion environment onthecore-exitthermocouple cableisaddressed inAttachment No.4tothissubmittal. (Ri~RCS(RTThehotlegandcoldlegRTQs,locatedinthelowercompartment, -arefullyqualified forpost-accident use(LOCA/MSLB qualification). 3Thecableassociated withtheRTDsisaddressed inAttachment No.4tothissubmittal. tl=(6)AirRecirculation HdroenSkimmerFans('heairrecirculation/hydrogen skimmerfansarelocatedintheuppe~cd.,partment andthePanmotorsarefullyqualified forpost-accidentuse'(LOCA/MSLB qualification). (7).Distributed InitionSstemDISComonentsTheDIScomponents insidecontainment aretheigniterassemblies; spliceboxesandconduletboxes,andtheancillary cable.AllDIScableinsidecontainment isroutedinconduitandthusisprotected

.fromahydrogenburn.Allelectrical connections insidetheigniter.assembly, itsassociated conduletbox,andthetwospliceboxespertrainutilizedintheDISareprotected withheatshrinktubingto.enhancesystemperformance inanadverseenvironment. Theigniterassemblyitselfisasealedenclosure meetingNEMA-4specifications. h

.Table3-1,;DonaldC.CookNuclearPlarltUnitNos.1and2.InadeuateCoreCoolin/HdroqenControlEuiment*-{1,)',Narrow-range SteamGenerator LevelMonitors.(2)Pressurizer LevelMonitors{3)Pressurizer PressureMonitors-':(4)RCSWide-Range PressureMonitors-.:{5):CoreExitThermocouples

-{6)RCSLoopsRTDs--{7)AirRecirculation/Hydrogen SkimmerFans=-.(8)Distributed IgnitionSystemComponents

• insidereactorcontainment

DONALDC.COOKNUCLEARPLANTUNITNOS.1AND2ATTACHMENT NO.4TOAEP:NRC:00500A SECONDQUARTERLY REPORTONHYDROGENMITIGATION AADCONTROL

4.0 EuimentSurvivabilit

Thisattachment tothequarterly reportaddresses theissueofthesurvivability ofequipment exposedtoahydrogencombustion atmosphere insidecontainment. Heat-transfer modelshavebeendeveloped todetermine theeffectsofhydrogenburnsoncriticalcomponents (seeTable3-1inAttachment 3).Themodelsarepresented inthisattachment followedbyacalculation madeforarepresentative pieceofequipment. Particular attention hasbeendevotedtoanumberofindividual piecesofequipment, eachofwhichisdiscussed separately. 4.1~G1AInordertocharacterize theenvironment towhichapieceofcritical~~~equipment issubjected duringandsubsequent toahydrogenburn,twoheat-transfermodelshavebeendeveloped. Thefirstheat-transfer modelisatimedependent heat-transfer analysiswhichcalculates thelowercompartment environ-mentasaresultofahydrogenburn.Thismodeltakesintoaccountthepresenceofstructural heatsinksandspraysinthelowercompartment andassumesthatduringahydrogenburnenergyisremovedbytheicecondenser. Theburnitselfismodelledbyanenergyinputratetothecompartment. Attheonsetofthecombustion, thelowercompartment isassumedtobeisothermal; energyisthenintroduced intothecompartment foradurationof20seconds,comparable tothetimeofahydrogenburninthecontainment. Asaresultoftheburn,thetemperature ofthecompartment atmosphere beginstoriserapidly;concurrently, heatisbeingtransferred tothestructural heatsinksandremovedbytheicecondenser andby)helowercompartment sprays.Heattransfertothecontainment sinksischaracterized bybothconvection and

radiation. Conservative assumptions havebeenmadeinthecalculation withregardtoparameters suchasgasemissivity andconfiguration factors.~~After20seconds,theatmosphere temperature isobservedtodecreaseexponentially, whereasthecontainment walltemperature continues toriseoverthenexttwentyseconds(seeFigure4-1)untilthetimewhentheatmosphere temperature fallsbelowthewalltemperature. Themaximumatmos-pheretemperature calculated doesnotexceed500F.Sensitivity studiesofvariousparameters usedintheanalysisarepresented inFigures4-2and4-3.Figure4-2depictstheresultsobtainedwhentheheattransfercoefficient,"h", fromatmosphere towallisvaried;as"h"vanishes, thepeakatmosphere temperature approaches theCLASIXresults.Itcanalsobenotedthat,ingeneral,thepeaktemperature isfairlyinsensitive tosmallvariations inthevaluesoftheheattransfercoefficient chosen.Perturbations inthesprayflowratealsorevealsmallincreases (n15Ã)inthepeaktemperature, seeFigure4-3.Theseanalysesclearlyshowthatifcontainment structural heatsinksareconsidered, thecontainment environment isnotexpectedtoexperience temperatures inexcessof500F.Theequipment includedinthecriticallistofcomponents (Table3-1)isqualified forLOCAandMSLBevents;whichincludesexposureto340Fforaperiodinexcessofonehour.Comparison betweentheMSLBconditions andthedatapresented inFigure4-1indicates thatequipment, whichis'subjdcted Ptoahydrogenburnofthemagnitude predicted byCLASIX,will*experience environmental conditions nomoreseverethanthoseofaMSLBevent.Thesecondheat-transfer modelattemptstodescribeanddefinetheenvironmental conditionsforequipmentwhichislocatedinthepathtraversed bythehydrogenflame.ABartonpressuretransmitter has.beenselectedasarepresentative pieceofequipment tobeinvestigated. Priortohydrogenignition, thetransmitter casinganditsinternals areassuredtobeinthermalequilibrium withthecontainment environment. Attheonsetofahydrogenburn,itispostulated thatignitionoccursin-thevicinityofthetransmitter andthecasingissubjected toaveryhighhydrogenflametemperature (~2000F)initially astheflamefrontmovesawayfromthecomponent. Thetemperature towhichthetransmitter surfaceisexposedwillthendecreasegradually andwilleventually approachlong-timeresultscalculated bythepreviousheat-transfer model.Thistemperature profilewillprovidetheoutsideboundarycondition neededtoevaluatethetemperature riseontheinsidesurfaceofthetransmitter. Theone-dimension .time-dependent conduction heattransferequationisevaluated assumingthattheinsidesurface-is anadiabatic boundary. Thismodeltreatsthetrans--.mittercasingasaone-dimensional slab.Thetimedependent temperature 'profiletobeusedontheoutsidesurfaceisimposedasaconvective boundarycondition. Twodifferent temperature

profiles, whichreflecttheenvironment temperature towhichthetransmitter isexposed,havebeenemployedinthiscalculation.

Thefirstprofilerepresents ahydrogenflametemperature of'2000Fforadurationofonesecondattheonsetpriortoalineardecayto-1000Finthenextsecond;temperature continues todecreaseto300Ffromtwotosixsecondsandeventually approaches 150Fafter10seconds(seeFigure4-4),curveA.Thistemperature profileissimilartotheoneusedbyTVAinitsequipment survivability calculations. Theotherprofile,seeFigure4-4,curve8,decaysexponentially from2000Fto150Foveraperiodof18secondsandissimilartotheoneusedintheDukeanalysis. Acomputercodewasusedtoanalyzethetemperature riseina1/4"carbonsteelcasinggiventheaforementioned boundaryconditions. Theheattransfercoefficient assumedinthecodeincludesbothconvective andradiative transport. 0 Thetemperature transients attheinsidesurfacecalculated fromthetwotemperature profilesaredepictedinFigure4-5.Curve(A)ofFigure4-5,-whichcorresponds tothecurve.AofFigure4-4,showedthattheinitial-temperature riseisveryabruptduringthefirstfewseconds;laterontheinsidesurfacereachesamaximumtemperature of171Fat10secondspriortoagradualdecrease. Thetemperature responsedepictedbycurve(B)of.Figure4-5indicates .thatthereisamoregradualriseovertheinitial15secondsandthatthetemperature reachesitsmaximumof175Fatabout30secondsbeforeaslowdecaybegins.Basedonthisanalysis, onecanassumethatforasinglehydrogenburn,theinsidecasingtemperature willrisenomorethan30F..Additionally, ifoneassumesthatthereisatotalofeightconsecutive burnsandthatbetweeneachburntheinsidecasingsurfacetemperature isheldconstant, thetemperature profilewillbeastepwisefunctionsimilartotheonepresented inFigure4-6.Eachtemperature increase(30oF.)canbeinterpreted astheheatupofthecasingresulting fromonehydrogenburn.Betweeneachburn,thetemperature Iattheinsidecasingisassumedtobeconstantwhichimpliesthatnocreditisgiventothecoolingofthecomponent subsequent toanyburn.Inaddition, thetimeintervalbetweencombustions isassumedtobesubstantially shorter'thanwhatispredicted byCLASIX;only100secondintervals areusedinthiscalculation. Basedonthestepwisecurve,aconservative linearheatuptemperature profileattheinsidesurfaceofthecasingisused,seeFigure4-6.Utilizing thislineartemperature responseattheinsideofthetrans-~mittercasing,aheattransferanalysishasbeenperformed to'evaluate theheatuprateoftheairandthesubcomponents insidethecasing.Results indicatethattheheatuprateoftheairinsideisslightlybelowthetemperature ofthecasingandthattheheatuprateofthesubcomponents isestimated tobeapproximately 50Foversevenburns,or,7Fperburn..Itisimportant tobearinmindthatconservative assumptions havebeen.usedinobtaining theaboveresults.The.heattransferanalysisclearlyindicates thatformostequipment -.whichisenvironmentally. qualified forLOCAorHSLBevents,elevatedtemperatures resultedfromhydrogenburnsofthemagnitude andduration:.discussed donotappeartoposeanythreattoitsabilitytosurviveina=~2D,-type event.-4e2Survivabilit ofParticular PiecesofEuiments~~ThissectionofAttachment 4discusses thesurvivabi lityofparticular -:piecesofequipment neededforthemitigation andcontrolofaS2D-typesequence. Thesepiecesofequipment requireeitherparticular evaluations or,else,theanalysispresented inSection4.1doesnotapplytothem..a)Cables'-Theburningofhydrogeninsidecontainment byuseofaDistributed IgnitionSystem(DIS)resultsinveryshortdurationexposurefiresandmay-involvecableswhichareexposedintrays.InsidetheCookcontainment buildings powerandcontrolcablesare-eitherinstalled inconduitsorincabletrays.Cablesinstalled inconduitsarenotlikelytoburnasaresultofexposuretoshort-duration exposurefires.Thesecablescannotpropagate a-fireeveniftheyburnsincetheflameresulting fromthe.combustion is-entirely confinedtotheconduitandcannotcausefailureofcables~~~~inadjacentenclosures. -Inthecaseofthecontrolcableswherethecurrentcarriedbytheconductors issmallrelativetothethermalratingoftheconductors, .thecablesareinstalled intrayswithsolidsteelsides,bottomsandcovers..Hence,itisnotlikelyforahydrogenburninsidecontainment toigniteanycontrolcablesinstalled intrays.However,uponexitingatray,eithermid-spanthroughaholeinthetraycoverorattheendofthetrayspan,aportionofthecablebecomesexposedforaveryshortlengthuntilthecableseitherenteraconduitwhichfacilitatesentryintoterminaldevices.oruntilthecablesareconnected tothedeviceorcontainment penetration

,(belowfloodlevel)..Allcontrolcablesinsidecontainment neededforinadequate corecoolingmitigation equipment arequalified forflameresistance inaccordance

.:witheitherIPCEAStandardS-19-81orIEEE-383. Hence,fortheexposedportions:ofthecontrolcablesandcablesentirelycontained intraysorconduits, itisextremely likelythatthecableswillsurvivehydrogenburnsinsidecontain-sment.Furthermore, thecablewillbewetduetotheactuation ofcontainment spraysmakingthepossibility ofignitionfromashortdurationexposureto,fireevenmorer'emote.Forthecaseofpowercables,theyareinstalled inconduitsorin-expanded metaltrayswithoutcoversandaresizedtoaccommodate thefull.loadcurrentofconnected equipment withoutexceeding theircontinuous rated.temperature. 1Jheninstalled inexpandedmetalcabletrays,'he cablesarelaidtypically onelayerdeepwithspacesbetweenadjacentcablesandsecuredtothebottomofthetraytomaintainthisspacing.ThepowercablesforICC'equipment maybeexposedtohydrogenburninginsidecontainment buttheyare qualifiedforflameresistance inaccordance withIEEE-383orS-19-81.Further,sincethepowercablesareexposed(opentrays)theywillbewetduetotheeffectofcontainment sprays.TestingresultshavebeenreportedbyL.J.KlamerusofSandiaonIEEE-383cables.Privatecommunication withNr.Klamerusrevealedthatthecablesusedintheexperiment wereX-linkpolyethylene cables.Theywereselectedf'rthetestbecausetheywerebelievedtobemostsusceptible toexposurefi.refailure.Reportedresultsindicatethatthetimetoelectrical shortforthesecablesrangesfromfivetonineminutes.ReviewofICCequipment powercablesatCookconfirmsthefactthattheyareeitherinsulated bygpalonorasynthetic compoundmadebyKerite.Bothtypesofmaterials arebelievedtoexhibitsuperiorfireresisting capability thanthosetestedbySandiaLaboratory. Therefore, despitethefactthatpowercablesatCookmightbeexposedtoatwotothreeminutestotaldurationofhydrogenburnsexperimental evidencesupportthecontention thatitisverylikelythattheywillbeabletosurvivehydrogenburnstypicalofthosediscussed foraS2D-typeevent.b)AirRecirculation FansTherearetwoairrecirculation fansatCookandbothofthemarelocatedintheuppercompartment. Thesetwocentri,fugal fanshaveatotalcapacityof80,000cfmanddischarge theflowintothetwofan/accumulator rooms.Attheexitofeachfanthereisabackdropdamperwhichopensasaresultofflowthroughthefan.Thedamperisgravityloadedandisexpectedtocloseifthereisan"overpressure inthefan/accumulator room.TheCLASIXresultspredictburnsintheuppercompartment withpressuredifferentials 1b unaccounted forinthedesignofthesystem.Fanintegrity isbeingevaluated bothfromthepointofviewofcasingdamageandoverspeeding -ofthewheelandmotor.c)SteamInertinandPolurethane. Insulation BurnInaSD-typeevent,hydrogenreleasebeginsapproximately 3800secondsaftertheonsetofasmallbreak.ResultsobtainedfromtheMarchcodeforSequoyahindicatethatduringtheinitial700seconds,thesteamcon'centration atthelowercompartmentreachesamaximumof78/priortodecayingto45/,seeFigure4-7.Subsequently, thesteamconcentration -continues todecreasetoapproximately 25/atonsetofthehydrogenrelease.DatareportedbytheU.S.BureauofNinesindicatethatlittlechange.tothelowerflammability limitofhydrogenisnotedwhensteamconcentration inthemixtureiskeptbelow308.Therefore, witha254steamconcentration -inthelowercompartment, theeffectsofsteamuponhydrogencombustion shouldbeminimal.'oreover, lowercompartment spraysatCookwouldfurtherservetoenhancecondensation ofsteamandtopromoterapidtemperature reductioninthe.lowercompartment. Thus,itisexpectedthatthesteamconcentration intheCooklowercompartment willbesubstantially lowerthan.whathasbeenpresented inFigure4-7.Therefore, itisunlikelythatCookwillexperience steam.inerting inaS2D-likeeventexceptpossiblyduringtheinitial1000seconds.Inaddition, datapresented byLawrenceLivermore Laboratory intheirignitertestprogramclearlyshowthatsteamconcentrations upto40Ãdonotinhibittheignitionofhydrogenbytheglowplugsnortheabilityoftheigniterstofunctionasdesigned. Inspiteofthefactthattherewouldbeahighersteamconcentration inthelowercompartment, evidenceindicates1

.thattheglowplugigniterswillperformtheirintendedfunctions as~~~~-required. Itisconceivable thatattheupperplenumofice-condenser, a:higherhydrogenconcentration maybepresentasaresultofsteamstripping bytheicecondenser. Ithasalsobeenpostulated thatcombustion mayfirst-occuratthatlocationandthatitmayevenburninacontinuous manner.However,itmustbepointedoutthatthelikelihood oftheabovescenario=diminishes iftheassumption onsteaminertingatthelowercompartment isconsidered unrealistic. Giventhecomplexity ofthisissue,thequestionofburninginthe.upperplenumoftheicecondenser willcontinuetobeinvestigated byAEP.'Moreover, upcomingresultsfromthemodifiedversionofCLASIXshouldbeabletoprovideadditional information onthissubject.Ifhydrogencombustion is-assumedtooccurattheupperplenumforanextendedperiodoftime,ithasbeenpostulated thattheintegrity ofthepolyurethane insulation maybethreatened bythepresenceofhotgases.Thisquestionisbeingaddressed -atAEPsimultaneously withtheupperplenumburnissue.Theresultsofourevaluations willbetransmitted totheNRCinthenextquarterly report. 0 4-.4~~=I~~~-.l~~~=4~~~~~\44~i-i44~'4=-4I444~-444~4~44~4~LON3~C.<i'!"-,-'kg44I4~=1'I4l44j"'pFt-5c4&-4I44':.ahk:kkkjki~.- -.4=-4.4:-=-=.~4~=-~4-4kX'4tpk($QQ)FIGURE4-1TEYiPERATURE RESPOi(SES OFLOMERCGlk1PARTHENT ATi)OSPHERE ANOMALL/ ,-Jooo.~-1ii.jit-l'0--.tjOo-I'i-~t~tI~ItIIi~jr'!ti"""'T"!e~!t~I)~~!,.1!l.,'t~~It~~~=-I~>>it~~~Ii~Ia1as~1~tI~<<~~~I~~wIIV1itIi-I1~jtIII-I41...>>Jji-!-!Lj0:;!!!1Tj:I-C~r~>XTPi=SRI'~!Ij--fk1/l.I;t..11T'JI,'".'~ijatjjIi~-~LI:,IL!1!Ij.-0II~~Ej1iI!j~-II,k!Ijkj~I~tjI1I-1II=~tI:1!I',!,1I1i;',I<<i',FIGUREI1-1!~Iift>>I'IIII1It1~tT-l~III'i.t'1I11lII!!HEISTVRI!NSFR.COhF-FICieJT I'I>>IT>>I>>'.(I'I/j',. ):;i'-2EFFECTSOF!IEATTRANSFERCOEFFICIENT YARIATIONS ONt1AXIt1UM ATMOSPHERE TEt1PERATURE'N LOWERCOt1PARTt1EttT 'lk"r.(0->>jI>>-I~-~-Tt...LLaEt~f~If>>~Ct-.t-lt:I-fi!fj~trrr't.jt,.ti),~~($qillIIIIII!!(UoI(i+pQQ/,P!I(QgQ,r(r/SIC)>>>>I>,r'rrrt,i'-( 'IFIGURE",4-'3, EFFECTSOFSPRAYFLO>>'tRATEVARIATIONS ONPEAKILILLLIl(iATNoSPHERE TENERATUREINLO((ER,CONPA(ITNENT 3!Ifttj1I 4iII+'.I.4~4=t-4tII44~=~~'\it~4.I'44~I4I=*t~I4~~t-~==444EM-:-':=3'*4*'I~-,-~~+:==+4*444ftt-Jm~-~-~~M444~~~*~l4>>=44=-+II~t=.4.l*~l~t~.j~=-~-~~-.-=-.~--t-s.-~J..~tt~-~-4-~.XE.~.4='-~!tt~tW+~~~4-I~+l4j3(2~tt4~f4<<tIIll~4~I*-J-~~4I4>>*444~*I444l444~~t4~=~4f-'4-~~'-l~l-4-~>>~4~*~i~~}=-I4}t~~J'!';~I+'13t4I4I~>>~CItt4200t*~IIt-~=~'I~4-~4~=I34t~}irF>>flan.~t-<<4>>-t.<<I-FiGURE-'tf-}}.-'TEMPERATURE PROFILESUSED-ASCONVECTIVE,:. BOUNDARYCONDITIONS

0 4h4III44I~~I4:.4~--~~~44il'=~:"14I-I=I-~~-=-41-I.~4~~r'IASSU11EDINSIDESORFACE-TEMPERATURE PROFILES=r~44~

VI1I)1!IiI~1Itfjff4j!IIt>i~IQQ'.;~I:&,.'~I,1~~~f'II.'gag<<I. III!~a4o~I~~!Ir'>>~.e'.-t~~~~~I<<t.aI~>~j4~~~l~-j>')',~/ljf1f=t"tIi.'it')!vIIV'r-j!LOT<<V.". Rfffd<<'Ia-ha)j',I-J->J;I\441l'~g0'OfACg,C-0f'~tP/.',PTg," (O'T~P~%/~I'j1f.,<~O";l.<<"-!!,Iff~if-4v:l[J'fl'jjr4ar.~AT!'-:3Fa1p*,RE:<<j-ONSef..o-1iBASE=j-tl.)jt~~~~~Q.>>-"~'ljt-~>1.'1t.,"<<'.i~!;--2-o-'-~~~~*Ij-tl'~a!I!!!Ilj'4!~afi41'tl"l~1'IIII,:illk-A,Ittf;JJ..'>~(jl.tfLLX-l~1IT[:t.lf-f<<'1tl)j"-tj:-,i:.~IL0l4ER.;!~i:li<<I-:lIItlll.ij!,.I1!II!!j'}-IQjh(pMTt.~~ lL'i4'1ji,;illtI~.0;4IIi~Il~fII~~~I,~1rl41~I~~il->11l~I~~~-tIijKO'0'0I",FIGURE4-ilII4I,O.t,.DaÃ;1ll;Qt-0f;l):WOO7STEANCONCENTRATION INLOWER<l',C011PARTt1EfNT ASAFUNCTIONOFTIt1Ejla11I14+me!','!'(2c.),'

References:

(1)Klamerus, L.J.,"FireProtection Research," quarterly ProgressReport,October-December1977,NUREG/CR-0366. (2)PrivateCommunication, L.J.KlamerustoK.K.Shiu,March1981.(3)Hertzberg, M.,"Flammability LimitsandPressureDevelopment inH2-AirMixtures," U.S.BureauofMines,PRCReportNo.4305,January1981.(4)Lowry,W.,"Preliminary ResultsofThermalIgniterExperiments inH2-AirSteamEnvironments," Paperpresented attheworkshopontheimpactofHydrogenonWaterReactorSafety,Albuquerque, NewMexico,January1981.(5)SequoyahNuclearPlant,CoreDegradation Program,Yolume2,ReportontheSafetyEvaluation oftheIDIS,December15,1980. 00 DONALDC.COOKNUCLEARPLANTUNITNOS.1AND2ATTACNENT NO.5TOAEP:NRC:00500A SECONDQUARTERLY REPORTONHYDROGENMITIGATION ANDCONTROL

5.0CurrentResearchProramsSeveralresearchprogramshavebeenundertaken byAEPtoinvestigate hydrogencontrolrelatedphenomena; someoftheseprogramswerediscussed inthelastquarterly report.Inthissectionanumberofthecurrentresearchprogramswillbereviewed; programstatus,revisedtestplanandprogramscheduleofeacheffortwillbediscussed individually. ~RPRIPAEP.,alongwithDukeandTYA,areco-sponsors off'ourEPRIresearchprogramsinwhichfundamental flamestudieswi11bemade;researchanddevelopment onvariousignitertypeswillbepursued;mixinganddistribution ofhydrogeninprototypic containment environments willbeinvestigated andadditional glowplugtestingwillbeperformed. a)Mhiteshell NuclearResearchEstablishment Thisresearchfacilityisoperatedby'AtomicEnergyofCanadaLimited.Tworesearchprogramswillbepursuedindependently atthisfacility; namely,thehydrogencombustion phenomena studyandtheresearchanddevelopment ofdifferent ignitertypes.Bothoftheseprogramswillbeundertaken withthecollaboration ofOntarioHydroasanadditional financial contributor tothework.IThefirstexperimental programisdesignedtoinvestigate varioushydrogencombustion phenomena andcan'bedividedintofourparts.Thefirstpartofthisexperimental effortentailsperforming nineteenignitiontestsonleanhydrogenmixtures. Thehydrogenconcentration tobeexaminedinthesetestswillvaryfrom5.05to30Ãbyvolume.Asparkignitionsourcewhichis

intheorderof0.5joulewillbeusedtoignitethemixture.Detailsoftheexperimental setupandtestvesseldimensions havebeenpresented inthepreviousquarterlysubmittal. Fastresponsepressuretransducers, thermo-couplesandionization probeswillbeemployedtomonitorandrecordvariousimportant testparameters. Ofthe=nineteentestsplannedthemajorityofthemwillbeconducted withtheignitionsparklocatednearthebottomofthespherical testvessel.Twotestsareplannedinwhichtheignitionsourcewillbelocatedatthecenterofthevesselandonetestisplannedwiththeignitionsourcenearthetopofthevessel.Thesethreetestswillbeusedtoassesstheeffectofigniterlocation. Thesetestsareanticipated torequireapproximately threeweekstocomplete. According tothelatestestimateprovidedbyHNRE,systemshakedown isbeingperformed onthetestvesselandonthedataacquisition system;itisexpectedthatdatacollection willbeginbyarlyNay.PartIIofthehydrogencombustion programincludesatotalofIIeighteentestswhichareintendedtostudyspherical deflagrations ofahydrogenflame.Thehydrogenconcentrations thatwillbeinvestigated rangefrom105to42Kwhereasthesteamconcentrations willvaryfrom0to30Ã.Withtheexception oftwotestsinwhichignitionwillbeinitiatedatthebottomofthetestvesselalltestswillbeperformed usingcenterignition. The'timerequiredtocompletethesetestsisapproximately onemonth.IISubsequent totheseteststhetestvesselwillbemodifiedforthestudyofturbulent effectsonhydrogencombustion. Twoweekshavebeenscheduled intheprogramplantoaccomplish thesemodifications. Theprimaryobjective ofthePartIIItestsistoinvestigate turbulent effectsuponcompleteness ofhydrogenburns,anduponpressureandtemperature responses. Turbulence inthesetestswillbecreatedbytwodifferent means:1)two16"diametervaniablespeedfansand,2)gratings. Thefansareratedat1500cfmeachandconsequently arecapableofcreatingaveryturbulent environment. Thegratingsaremadeof1/4"perforated platewith50%porosityandtheyareusedtosimulateobstacle-induced turbulence. Sixtestswillbedevotedtoexamining leanhydrogencombustion underturbulent conditions; ignitionwillbeinitiated atthebottomofthevessel.Fouradditional testswillbeconducted using14%and20/hydrogen-airmixtureswhentheignitionsourcewillbeplacedatthecenterofthetestvessel.Thetimeneededtocompletethesetestsisexpectedtobeaboutonemonth.PartIVofthehydrogencombustion programentailsatotalofsix7tests.Priortoperforming thesetests,aweek'stimeisneededtosetupthevestrigwhichincludesasphereusedintheprevioustests.Ignitionforthesetestswillbeinitiated ateitherthecenterofthesphereorattheendofthepipef'rhydrogenmixturesofeither8%or20%.Inadditiontocollecting thetemperature andpressuredata,ionization probeswillbeusedtorecordflamepropagation fromonecompartment to,another. Thefinaltwotestsusingthistestgeometryincludestudyinghydrogencombustion characteristics froma8%ora10%mixturetoa6%mixture.IntheseteststhepipewillbeIfilledwitha8/or'10%mixture,whilethesphereisfilledwitha6/mixture.Ignitionwillbeinitiated inthepipesection.Thedurationofthesetestsisanticipated tobeaboutthreeweeks.

-Thesecondexperimental programthatwillbecarriedthroughatthellhiteshell facilityinvolvesresearchanddevelopment effortonvariousignitertypes.Theobjective ofthisworkistoperformextensive benchmark testsinasixcubicfootspherical testvesseltoidentifyignitertypesandtodemonstrate theircombustion capability inaprototypic environment. ThetestingprogramwillbegininMayandlastaboutfourmonths.Basedontestdataobtained, a'selection ofigniterswillthenbefurthertestedinalargerscaletestvessel(600ft)atAcurex.Presently, besidestheGMAC7G3glowplugs,afewresistance-heating glowplugsdeveloped byTaycowillalsobeexamined. ,b)AcurexIntheAcurexprogram,thetestplancanalsobedividedintotwoparts;thefirstpartisdesignedtoexaminetheeffectiveness andtheperformance of.glowplugsinignitinghydrogenundervariousprototypic contain-&mentconditions .Intheseexperiments, hydrogenflowrate,steamflowrate,waterspraysparameters andignitorlocations will'evariedtoprovideparametric studiesontheabilityofglowplugs'oignitehydrogenmixtures.Theeffectofmicro-fog onglowplugignitionandpressuretransients willalsobeinvestigated. Anumberoftheexperiments willattempttoprovidedatatocorrelate foggingasapressuresuppressant withsprayvolume,spraydropsize,andhydrogenconcentrations. Astrongignitionsource,e.g.,electricmatch,willbeusedinallthefogging-related tests.Asecondpartofthetestplancallsfortestingaselectednumberofignitersdeveloped attheWhiteshell NuclearResearchEstablishment. Thesewillbelargescaleconfirmatory testsforignitiondeviceswhichhavedemonstrated asuperiorpotential inignitingleanhydrogenmixturesandin\ replacing theexistingglowplugdesignsinthefuture.Theireffectiveness ~~~~~~~~~~~inasprayenvironment willbeevaluated atAcurex's600ftvessel.Priortocarryingthroughtheabovedescribed test'plan,aseriesofshakedown testswillbeperformed toprovidechecksforconsistency andaccuracyofallinstrumentation; specifically, resultswillbecomparedwiththoseobtainedatMhiteshell andfromtheavailable literature. c)HanfordEnineerinDevelomentLaborator HEDLTheobjective ofthiseffortistoexperimentally investigate aspectsofhydrogenmixinganddistribution inasimulated icecondenser lowercompartment geometry. Hydrogenreleaseintothecompartment willbemodelledbytwoapproaches. Inthefirstapproach, steamandhydrogenareintroduced asajetintothecompartment simulating apipebreak;inthesecondapproach, hydrogenandsteamareaddedtothecompartment asadiffusesourcesimilartopressurizer relieftankrelease.Inordertoextendtherangofhydrogenconcentration beyond"4%%d,heliumwillbeusedasasimulation fluidinplaceofhydrogen. Confirmatory testswillbeperformed todemonstrate thatheliumcanindeedbeusedtosubstitute hydrogeninthesemixirigstudies.Thefirsttestisscheduled tobeginsometimeinmidJuneandthewholetestprogramisexpectedtolastapproximately twomonths.Inthemeantime, similitude andscalingcalculations arebeingdonesoastoproperlymodelthenecessary parameters thatarevitaltotheinvestigation ofmixinganddistribution. Someofthenon-dimensional groupsthatarebeingexaminedare:theRichardson number,theReynoldsnumber,andtheGrashofnumber.d)FactorMutualResearchAEP,Duke,TVAandEPRIrecentlycametotheconclusion thatinordertobetterunderstand foggingasameansofhydrogencontrolandtoeventually 0 renderadecisiononitsapplicability asaviablesolutiontohydrogenmitigation, theywouldcontractwithFactoryMutualResearchtoundertake aresearchprogramtoinvestigate fogging.Theobjective ofthisprogramistodetermine theeffectsofmicro-fog uponthelowerflammability limit(LFL)ofhydrogen, toprovidearelationship betweendropsizeandfoggingdensityonLFLandtocorrelate theconcentrations ofleanhydrogenairmixtureswithvariousfoggingparameters. InordertoensurethattheeffectsoffoggingonLFLareproperlyreproduced, astrongignitionsourcehasbeenproposedandislikelytobeusedtoinitiateignitiononallLFLtests.Therangeofdropletsizesthatisofinteresttotheutilities variesfromafewmicronstohundredsofmicrons,whereasthefoggingdensityvariesfromzerotoa.fewpercent.Test~~~~~~~parameters thatwillbemeasuredincludetemperature,

pressure, dropsizedistribution.and fog.density distribution.

Aschematic of.theexperimental setupisshowninFigure5-1.AdetailtestplanisbeingpreparedbyFactoryMutualResearchwithaidfromAEPandtheotherparticipants. Thetestvesselisscheduled tobecomeavailable fortestinapproximately threeweeks.Finally,itisalsotheintentofthisefforttoprovidethenecessary andpertinent information 'oassistintheselection oftestparameters intheAcurexfoggingtests.e)CLASIXIntheAEP-NRCmeetingonMarch18,1981,thestaffexpressed interestinreviewing a-numberofadditional CLASIXruns.Thefirstconcerncentersaroundtheuniquelowercontainment spraycapability atCookanditspossibleeffectuponothercompartment responses duringandsubsequent toahydrogenburn. 0 ReviewsatAEPindicatethatintheCLASIXsensitivity studysubmitted totheNRC,sprayparameters suchassprayflowrate,dropletsize,heattransfercharacteristi'cs tothedropandspraytemperature werevaried;minimaleffectsonthecontainment pressureandtemperature responses werenoted.Thus,theavailable information fromCLASIX,pointsoutthatvariations insprayparameters wouldnotsignificantly affectcontainment temperature andpressureresponse. AnotherpossibleCLASIXrundiscussed intheabovementioned meetinginvolvedinitiating hydrogencombustion at10%with50%burnfraction. Experimental measurements oncompleteness ofhy'drogen combustion reportedintheliterature showthatinspiteofthelargescattering indataaround5%to7%,aninitial10/concentration consistently resultsinanalmost100%(1)burn.Inaddition, ithasbeenshownthatturbulence willfurtherenhancecompleteness ofcombustion forleanhydrogenmixtures.Therefore, iftheprobability ofincomplete combustion of10%isindeednegligibly small,asitseemstobe,itseffectsuponthecontainment neednotbeinvestigated. Itwassuggested bythestaffthatacasewithignitioninitiated at10%andthenpropagating toa8%hydrogenconcentration regionshouldbestudied.Bothtypesofcombustion wouldassumea100%burnfraction. Closeexamination ofthevariouscasespresented intheCLASIXsensitivity studiesrevealsthatthereisonecase(JVD15)whichusestheexactinputparameters requested bythestaff.Oneburnwasobservedintheuppercompartment withanestimated maximumpressureof57psia(onlyoneairrecirculation fanwasassumedtobeoperational intherun).ThismaximumpressureisveryclosetotheCookcontainment elasticlimit.However,sinceheatsinkshavenotbeenincludedinthesesensitivity calculations, theresultsarelikely.tobeoverly~~conservative. Floivmeter-AirpressureMixer-Flowmeter -Regulator WaterFlashArrostorAir-SolonoldOporatedValveSolonold/OporatodValveFogNozzles/IX/I/I/H>-AirMixSupplyLineSparkGap~Eloctrodes lonizatlonProbosForFlamoSpoodlAoasuromonts 6"Dlcmeter~x~LongthIihr'(Iii/il/IIIiIII4-Thermocoeploe, bRopSfhE: hl~sug~NQ7) peal~DrainFIGURE5-1EXPERIMENTAL ARRANGEl1ENT OFFOGGINGTESTS

References:

(1)LiuD.D.S.,etal,"SomeResultsofWNREExperimentson,HydrogenCombustion," WaterReactorSafetyWorkshopontheImpactofHydrogen, Albuquerque, NewMexico,January1981.(2)Hertzbert, M.,"Flammability Limits'nd PressureDevelopment inH2-AirMixtures," U.S.BureauofMines,PRCReportNo.4305,January1981. DONALDC.COOKNUCLEARPLANTUNITNOS.1AND2ATTACNENT NO.5TOAEP:NRC:00500A SECONDQUARTERLY REPORTONHYDROGENMITIGATION ANDCONTROL t~ 5.0CurrentResearchProramsSeveralresearchprogramshavebeenundertaken byAEPtoinvestigate hydrogencontrolrelatedphenomena; someoftheseprogramsweredi.scussed inthelastquarterly report.Inthissectionanumberofthecurrentresearchprogramswillbereviewed; programstatus,revisedtestplanandprogramscheduleofeacheffortwillbediscussed individually. 1.1~EAEP,alongwithDukeandTVA,areco-sponsors offourEPRIresearchprogramsinwhichfundamental flamestudieswillbemade;researchanddevelopment onvariousignitertypeswillbepursued;mixinganddistribution ofhydrogeninprototypic containment environments willbeinvestigated andadditional glowplugtestingwillbeperformed. a)Whiteshell NuclearResearchEstablishment ThisresearchfacilityisoperatedbyAtomicEnergyofCanadaLimited.1Tworesearchprogramswillbepursuedindependently atthisfacility; namely,the'hydrogen combustion phenomena studyandtheresearchanddevelopment ofdifferent ignitertypes.Bothoftheseprogramswillbeundertaken withthecollaboration ofOntarioHydroasanadditional financial contributor tothework.Thefirstexperimental programisdesignedtoinvestigate varioushydrogencombustion phenomena andcanbedividedintofourparts.Thefirstpartofthisexperimental effortentailsperfororing nineteenignitiontestsonleanhydrogenmixtures. Thehydrogenconcentration tobeexaminedin'thesetestswillvaryfrom5.0$to305byvolume.Asparkignitionsourcewhichis 0 intheorderof0.5joulewillbeusedtoignitethemixture.Detailsoftheexperimental setupandtestvesseldimensions havebeenpresented inthepreviousquarterly submittal. Fastresponsepressuretransducers, thermo-couplesandionization probeswillbeemployedtomonitorandrecordvariousimportant testparameters. Ofthenineteentestsplannedthemajorityofthemwillbeconducted withtheignitionsparklocatednearthebottomofthespherical testvessel.Twotestsareplannedinwhichtheignitionsourcewillbelocatedatthecenterofthevesselandonetestisplannedwiththeignitionsourcenearthetopofthevessel.Thesethreetestswillbeusedtoassesstheeffectofigniterlocation. Thesetestsareanticipated torequireapproximately threeweekstocomplete. According tothelatestestimateprovidedbyWNRE,systemshakedown isbeingperformed onthetestvesselandonthedataacquisition system;itisexpectedthatdatacollection willbeginbyearlyNay.PartIIofthehydrogencombustion programincludesatotalofeighteentestswhichareintendedtostudyspherical deflagrations ofahydrogenflame.Thehydrogenconcentrations thatwillbeinvestigated rangefrom105to421whereasthesteamconcentrations willvaryfrom0to30Ã.Withtheexception oftwotestsinwhichignition.willbeinitiated atthebottomofthetestvesselalltestswillbeperformed usingcenterignition. Thetime'required tocompletethesetestsisapproximately onemonth.Subsequent totheseteststhetestvesselwillbemodifiedforthestudyofturbulent effectsonhydrogencombustion. Twoweekshavebeenscheduled jntheprogramplantoaccomplish thesemodifications.

Theprimaryobjective ofthePartIIItestsistoinvestigate turbulent effectsuponcompleteness ofhydrogenburns,anduponpressureandtemperature responses. Turbulence inthesetestswillbecreatedbytwodifferent means:1)two16"diametervariablespeedfansand,2)gratings. Thefansareratedat1500cfmeachandconsequently arecapableofcreatingaveryturbulent environment. Thegratingsaremadeof1/4"perforated platewith50/porosityandtheyareusedtosimulateobstacle-induced turbulence. Sixtestswillbedevotedtoexamining leanhydrogencombustion underturbulent conditions; ignitionwillbeinitiated atthebottomofthevessel.Fouradditional testswillbeconducted using14/and20/hydrogen-airmixtureswhentheignitionsourcewillbeplacedatthecenterofthetestvessel.Thetimeneededtocompletethesetestsisexpectedtobeaboutonemonth.PartIVofthehydrogencombustion programentailsatotalofsixtests.Priortoperforming thesetests,aweek'stimeisneededtosetupthetestrigwhichincludesasphereusedintheprevioustests.Ignitionforthesetestswillbeinitiatedateitherthecenterofthesphereorattheendofthepipeforhydrogenmixturesofeither8/or205.Inadditiontocollecting thetemperature andpressuredata,ionization probeswillbeusedtorecordflamepropagation fromonecompartment toanother.Thefinaltwotestsusingthistestgeometryincludestudyinghydrogencombustion characteristi csfroma8Ãora10Ãmixturetoa6Xmixture.Intheseteststhepipewillbefilledwitha8Ãor105mixture,whilethesphereisfilledwitha6Xmixture.Ignitionwillbeinitiated inthepipesection.Thedurationofthesetestsisanticipated tobeaboutthreeweeks' ~~ Thesecondexperimental programthatwi11becarried.throughattheWhiteshell facilityinvolvesresearchanddevelopment effortonvariousignitertypes.The.objective ofthisworkistoperformextensive benchmark testsinasixcubicfootspherical testvesseltoidentifyignitertypesandtodemonstrate theircombustion capability inaprototypi cenvironment. ThetestingprogramwillbegininMayandlastaboutfourmonths.Basedontestdataobtained, aselection ofigniterswillthenbefurthertestedinalargerscaletestvessel(600ft)atAcurex.Presently, besidestheGMAC7G3glowplugs,afewresistance-heating glowplugsdeveloped byTaycowillalsobeexamined. b)AcurexIntheAcurexprogram,thetestplancanalsobedividedintotwoparts;thefirstpartisdesignedtoexaminetheeffectiveness andtheperformance ofglowplugsinignitinghydrogenundervariousprototypic contain-mentconditions .Intheseexperiments, hydrogenflowrate,steamflowrate,waterspraysparameters andignitorlocations willbevariedtoprovideparametric studiesontheabilityofglowplugstoignitehydr'ogen mixtures.Theeffectofmicro-fogonglowplugignitionandpressuretransients wi11alsobeinvestigated. Anumber,oftheexperiments willattempttoprovidedatatocorrelate foggingasapressuresuppressant wi.thsprayvolume,spraydropsize,andhydrogenconcentrations. Astrongignitionsource,e.g.,electricmatch,willbeusedinallthefogging-related tests.Asecondpartofthetestplancallsfortestingaselectednumberofignitersdeveloped attheWhitqshell NuclearResearchEstablishment. Thesewillbelargescaleconfirmatory testsforignitiondeviceswhichhavedemonstrated a'uperior potential inignitingleanhydrogenmixturesandin h replacing theexistingglowplugdesignsinthefuture.Theireffectiveness inasprayenvironment willbe.evaluated atAcurex's600ftvessel.Priortocarryingthroughthe'above described testplan,aseriesofshakedown testswillbeperformed toprovidechecksforconsistency andaccuracyofallinstrumentation; specifically, resultswillbecomparedwiththoseobtainedatWhiteshell andfromtheavailable literature. c)HanfordEnineerinDevelomentLaborator HEDLTheobjective ofthiseffortistoexperimentally investigate aspectsofhydrogenmixinganddistribution inasimulated icecondenser lowercompartment geometry. Hydrogenreleaseintothecompartment willbemodelledbytwoapproaches. Inthefirstapproach, steamandhydrogenareintroduced asajetintothecompartment simulating apipebreak;inthesecondapproach, hydrogenandsteamareaddedtothecompartment asadiffusesourcesimilartopressurizer relieftankrelease.Inordertoextendtherangeofhydrogenconcentration beyond45,heliumwillbeusedasasimulation fluidinplaceofhydrogen. Confirmatory testswillbeperformed todemonstrate thatheliumcanindeedbeusedtosubstitute hydrogeninthesemixingstudies.Thefirsttestisscheduled tobeginsometimeinmidJuneandthewholetestprogramisexpectedtolastapproximately twomonths.Inthemeantime, similitude andscalingcalculations arebeingdonesoastoproperlymodelthenecessary parameters thatarevitaltotheinvestigation ofmixinganddistribution. Someofthenon-dimensional groupsthatarebeingexaminedare:theRichardson number,theReynoldsnumber,andtheGrashofnumber.d)FactorMutualResearchAEP,Duke,TVAandEPRIrecentlycametotheconclusion thatinordertobetterunderstand foggingasameansofhydrogencontrolandtoeventually

renderadecisiononitsapplicability asaviablesolution,to hydrogenmitigation, theywouldcontractwithFactoryMutualResearchtoundertake aresearchprogramtoinvestigate fogging.Theobjective ofthisprogramistodetermine theeffectsofmicro-fog uponthelowerflammability limit(LFL)ofhydrogen, toprovidearelationship betweendropsizeandfoggingdensityonLFLandtocorrelate theconcentrations ofleanhydrogenairmixtureswithvariousfoggingparameters. InordertoensurethattheeffectsoffoggingonLFLareproperlyreproduced, astrongignitionsourcehasbeenproposedandislikelytobeusedtoinitiateignitiononallLFLtests.Therangeofdropletsizesthatisofinteresttotheutilities variesfromafewmicronstohundredsofmicrons,whereasthefoggingdensityvariesfromzerotoafewpercent.Testparameters thatwillbemeasuredincludetemperature,

pressure, dropsizedistribution andfogdensitydistribution.

Asch'ematic oftheexperimental setupisshowninFigure5-1.AdetailtestplanisbeingpreparedbyFactoryMutualResearchwithaidfromAEPandtheotherparticipants. Thetestvesselisscheduled tobecomeavailable fortestinapproximately threeweeks.Finally,itisalsotheintentofthisefforttoprovidethenecessary andpertinent information toassistinthese1ection oftestparameters intheAcurexfoggingtests.e)CLASIXIntheAEP-HRCmeetingonMarch18,1981,thestaffexpressed interestinreviewing a.numberofadditional CLASIXruns.Thefirst.concerncentersaroundtheuniquelowercontainment spraycapability atCookanditspossibleffectuponothercompartment responses duringandsubsequent toahydrogenburn. ReviewsatAEPindicatethatintheCLASIXsensitivitystudysubmitted totheNRC,sprayparameters suchassprayflowrate,dropletsize,heattransfercharacteristics tothedropandspraytemperature werevaried;minimaleffectson,thecontainment pressureandtemperature responses werenoted.Thus,theavailable information fromCLASIX,pointsoutthatvariations insprayparameters wouldnotsignificantly affectcontainment temperature andpressureresponse. AnotherpossibleCLASIXrundiscussed intheabovementioned meetingin'volved initiating hydrogencombustion at10/with50%burnfraction. Experimental measurements oncompleteness ofhydrogencombustion reportedintheliterature showthatinspiteofthelargescattering indataaroundI5Xto7X,aninitial10Ãconcentration consistently resultsinanalmost100'5(1)burn.Inaddition, ithasbeenshownthatturbulence willfurtherenhancecompleteness ofcombustion forleanhydrogenmixtures.Therefore, iftheprobability ofincomplete combustion of105isindeednegligibly small,asitseemstobe,itseffectsuponthecontainment neednotbeinvestigated. Itwassuggested bythestaffthatacasewithignitioninitiated at10/andthenpropagating toa8/hydrogenconcentration regionshouldbestudied.Bothtypesofcombustion wouldassumea100/burnfraction. Closeexamination ofthevariouscasespresented intheCLASIXsensitivity studiesrevealsthatthereisonecase(JVD15)whichusestheexactinputparameters requested bythestaff.Oneburnwasobservedintheuppercompartment withanestimated maximumpressureof57psia(onlyoneairrecirculation fanwasassumedtobeoperational intherun).ThismaximumpressureisveryclosetotheCookcontainment elasticlimit.However,sinceheatsinkshavenotbeenincludedinthesesensitivity calculations, theresultsarelikelytobeoverlyconservative. ll~y!t Floemeter-AlrPror."ouroMixerFlowmetor-Regulator V/atorFlashArrostorAir-SolenoidOperatedValve/SolenoidOporatodValveFogNozzles/gii/IIH-AirMixSupplyLine2SparkGap~EioctrodoslonizatlonProbesForFlamoSpoodMoasuromantsO"nromolor~x~Lnnnth/iiia/(Iii/'lIIIIIIihermocouplos, bROPS!~MEAsuklNQPEVlcCDrainFIGURE5-1EXPERIMENTAL ARRANGEMENT OFFOGGINGTESTS

References:

(1)LiuD.D.S.,etal,"SomeResultsofWNREExperiments on-HydrogenCombustion," WaterReactorSafetyWorkshopontheImpactofHydrogen, Albuquerque, NewMexico,January1.981.(2)Hertzbert, M.,"Flammability LimitsandPressureDevelopment inH2-AirMixtures," U.S.BureauofMines,PRCReportNo.4305,.January1981. DONALDC.COOKNUCLEARPLANTUNITNOS.1AND2ATTACHMENT NO.6TOAEP:NRC:00500A SECONDQUARTERLY REPORTONHYDROGENMITIGATION ANDCONTROL I 6.0CoreCoolinCaabilitSubseuenttoHdroenCombustion 6.1'ntroduction Thewrite-upbelowaddresses theexistingcomponents necessary toachieveandmaintainasafeshutdowncondition subsequent toareactortripandtomaintainasafeshutdowncondition andcontain-mentintegrity viaadequatehydrogencontrolduringandafterahypothetical degradedcorecoolingevent.I6.2SafeShutdownThethreeprimaryfunctions tobeperformed inordertoachieveandmaintainasafeshutdowncondition subsequent toareactortripare:(1)circulation ofreactorcoolant(2)residualheatremoval(3)controlofRCSpressure'hemethods6ywhich.each.o$thesefunctions canbe'erformed,.-, andthenecessary equipment locatedinsidecontainment, arediscussed below.6.2.1-Circulation ofReactorCoolantCirculation ofreactorcoolantisprovidedbynatural*circulation withthereactorcoreservingastheheatsourceandthesteamgenerators servingastheheatsink.Waterisprovidedtothesteamgenerators viathesafety-grade Auxiliary Feedwater System(AFS)or,ifoffsitepowerisavailable andsufficient steamisavailable, viathenormalfeedwater system..TheAFScanbealignedtotakesuctionfromtheEssential ServiceWaterSyst'm,whichitself,takessuctionfromLakei

Michigan, thusassuringavirtually limitless supplyofcoolingwaterforthesteamgenerators.

Steamreleasepathsincludeturbinebypass(ifoffsitepowerisavailable) usingthemaincondenser, themainsteamsafetyvalves,andthemainsteampoweroperatedreliefvalves.Thoseportionsofthereactorcoolantsystem,mainfeed-watersystem,auxiliary feedwater system,andmainsteamsysteminsidecontainment containnoactivecomponents requiredtooperatetoassurecoolantcirculation andoperation ofsaidsystemswo'ul'.dnotbe.adversel'y -affected'y;"a hydrogencombustion environment. Theequipment locatedinsidecontainment neededto.assureadequatereactorcoolantcirculation islistedbelow.Thesusceptibility ofthisequipment toahydrogencombustion environment andtheeffectsofsuchanenvironment onequipment operation areaddressed inAttachment Nos.3and4ofthissubmittal, respectively. l.SteamGenerator Narrow-Range LevelMonitors2.Pressurizer WaterLevelMonitors3.Pressurizer PressureMonitors4.LoopRTDs5.CoreExitThermocouples 6.RCSWideRangePressureMonitors 1 6.2.2ResidualHeatRemovalResidualheatisremovedviathesteamgenerators utilizing themethodsandequipment described in6.2.1above.Forthesamereasonssetforthin6.2.1,thisfunctionisnotadversely affectedbyahydrogencombustion environment. 6.2.3RCSPressureControlSubsequent toareactortrip,RCSpressureismaintained utilizing the'.natural circulation'quipment described above,withthepressurizer (PZR)safetyvalvesservingashighpressureprotection. ThePZRsafetyvalvesareselfcontained, springloadedvalvesandwouldnotbeadversely affectedbyahydrogencombustion environment. AsecondaspectofRCSpressuremaintenance dealswithisolation ofthevariousbranchlinesattached.totheRCS.Eachofthesepotential leakagepaths,including themethodofisolation, isdiscussed below.(1)Pressurizer Power0cratedReliefValvesPORVsEachPORVisnormallyclosedandi.sdesignedtofailcloseduponlossofairorlossofpower.Inaddition, ablockvalveislocatedupstreamofeachPORVtoassureRCSisolation intheeventthatPORVleakageweretodevelop. (2)LetdownLineLetdownisolation isprovidedbythreeparallelfail-closed airoperatedvalveslocatedinsidecontain-mentandafail-'closed airoperatedvalveoutsidecontainment. Thesevalveswillautomatically closeonasafetyinjectionsignal.(3)ExcessLetdown/Seal MaterIn'ectionFlowfromtheexcessletdownheatexchanger isdirected. tothereactorcoolantpumpsealwaterreturnline(connection insidecontainment) whichisisolatedbytwomotoroperatedvalvesinseries,oneinsidereactorcontainment andoneoutsidecontainment. Thesevalveswillautomatically closeonasafetyinjection signal.(4)ResidualHeatRemovalRHRLetdown'he RHRletdownlineisisolatedbytwonormallyclosedmotoroperatedvalvesinserieslocatedinsidereactorcontainment. Bothvalvesareinterlocked withRCSwide-rangepressuretoautomatically closeonincreasing pressureabove600psigandcannotbeopeneduntilRCSpressurehasdecreased below426psig.Inaddition, thevalvecontrolswitchesareadministratively keylockedclosed'in themaincontrolroomduringpoweroperation. (5)ReactorVesselHeadVentThereactorvesselheadventsystemconsistsoftwo-.redundant parallelpaths,eachpathcontaining twonormallyclosed,solenoidactuatedvalvesinseriesforisolation. Thesevalvesaredesignedtofailcloseduponlossofpower.6.3HdroenControlEuimentOperation ofthecontainment airrecirculation/hydrogen .:skimmer (CAR/HYS) fansandtheDISinconjunction withthecontainment spraysystem(CTS)furtherassuresthecombustion of'leanhydrogenmixtureswithoutposingathreattothecontainment structure viaoverpressurization. TheportionoftheCTSinsidecontainment .xontains noactivecomponents andhenceCTSoperation isnotadversely

affected byahydrogencombustion environment.

Theactivecomponents insidecontainment usedforhydrogencontrolaretheCAR/HYSfans-,andtheDIS.Theelectrical hydrogenrecombiners wouldbeusedto'removeresidualhydrogen(lessthan4volumepercent)fromthe.containment subsequent toDISoperation.

6.4ECCSInjection SubseuenttoCombustion

Anevaluation hasbeenmadetoverifyECCSinjection capability subsequent tohydrogencombustion insidecontainment.

Theresultso'fthisevaluation indicated thathigh-head safetyinjection (SI)(charging pumps)flowpathviatheBITandtheintermediate/low head'SI(SIandRHRpumps)flowpathtotheRCScoldlegswillbeunaffected byhydrogencombustion. Theseflowpathscontainmotoroperatedvalvesinsidecontainment. ThesevalvesreceiveasignaltoopenonaSIsignaldespitethefacttheyarenormallyintheopenposition, thusproviding furtherassurance ofECCSinjection capability. Nomechanism hasbeenidentified wherebytheenvironment associated withhydrogencombustion wouldresultinclosureofthesevalves.Withtherefueling waterstoragetank(RWST)available, twelveweightpercentboricacidcanbedelivered totheRCSbyaligningthesuctionofthechargingpumpstotheRWSTandaligningthepump(s)discharge totheboroninjection tank(BIT).Asecondflowpathinvolvesalignment ofthechargingpumpsuctiontothedischarge oftheboricacidtransferpumps,whicharethemselves alignedtotakesuctionfromtheboricacidtankswiththedischarge ofthechargingpumpsagainalignedtotheBIT.Neitheroftheabovedescribed flowpathsutilizecomponents (eg.valves)insidecontainment whicharerequiredtochangeposition/function inahydrogenburnenvironment. IntheeventthatthecontentsoftheRWSThadalreadybeeninjectedcoolantinjection isachievedbyaligningthechargingpump(s)suctiontothedischarge oftheresidualheatremoval(RHR)pump(s);withtheRHRpump(s)takingsuctionfromthecontainment recirculation sump.Thisthirdflowpathdoesnotutilizeanyactivecomponents insidecontainment whicharesusceptible toahydrogencombustion environment.

Thesubjectvalvesarefullyqualified forpost-accident .useinsidecontainment (LOCA/MSLB qualification). Inaddition,

theanalysesdescribed inAttachment No.4tothisreportclearlyshowthattheenvironmental conditions associated withhydrogen.combustion arelessseverethantheenvironment to.whichtheyhave

beenqualified; thusassuringmaintenance oftheaforementioned

.flowpaths.Thenormallyclosedmotoroperatedvalvesinthe-intermediate/low headSIflowpathhavealsobeenqualified foruse-inaLOCA/NSLB environment andwouldbeexpectedtoremaininoperation

subsequent tohydrogencombustion; thusproviding anotherECCSinjection path.

DONALDC.COOKNUCLEARPLANTUNITNOS.1AND2ATTACHMENT NO.7TOAEP:NRC:00500A SECONDQUARTERLY REPORTONHYDROGENMITIGATION ANDCONTROL

7.0 Preliminar

SafetEvaluation ~~~Indiana5MichiganElectricCo.(IQ1ECo.)hasdecidedtoinstallaDistributed IgnitionSystem(DIS)intheDonaldC.CookNuclearPlantUnitNos.1and2.TheDISinconjunction withoperation ofexistingsafety-related equipment providesadditional hydrogencontrolcapability intheextremely unlikelyeventofadegradedcoreeventsimilarinnaturetotheTMI-2accidentinvolving thegeneration ofsubstantive amountsofhydrogen. TheDIS,described indetailinAttachment No.2ofthisreport,isdesignedtoassurecombustion ofleanhydrogen/air/steam mixturesandhencewillminimizethepressureandtemperature transients associated withhydrogencombustion. Conservative analysesofthecontainment responsehavepreviously beensubmitted viaourfirstquarterly report(AEP:NRC:00500). Theresultsoftheseanalysesindicatethatdeliberate ignitionofleanhydrogenmixturesusingtheDISwillresultinpressures belowtheultimatestrengthoftheCookPlantcontainments. Theeffectsofahydrogencombustion environment onnecessary equipment locatedinsidecontainment hasbeenevaluated andtheresultsofthisevaluation presented inAttachment No.4ofthisreport.Itisclearfromourevaluation thatthetemperature effectsoFdeliberate hydrogencombustion arelessseverethanthosetowhichmostofthenecessary equipment hasbeenqualified (LOCA/MSLB qualification). Ithasalsobeenshownthattheabilitytoinjectemergency corecoolingwaterisnotaffectedbyhydrogencombustion. Theextensive plantmodifications andenhancedoperatortrainingimplemented subsequently totheTNI-2accidenthaveeffectively reducedthealreadylowprobability ofoccurrence ofeventswhichcouldresultinthegeneration ofsubstantive amountsofhydrogenattheCookPlant'.TheDIS,inconjunction withexistingplantequipment>will provideanadditional levelofmitigation capability forhypothetical eventswellbeyondthedesignbasisoftheCookUnits,furtherenhancing thedefense-in-depth .philosophy. Installation oftheDISprovidesfurtherassurance thatoperation oftheCookPlantwillinnowayadversely effectthehealthandsafetyofthegeneralpublic. ah4}}