Module 06Module 06BoilingBoiling Water Water ReactorsReactors

(BWR)(BWR)

Prof.DrProf.Dr. . H. H. BBööckckVienna University of Technology /AustriaVienna University of Technology /AustriaAtominstituteAtominstituteStadionalleeStadionallee 2, 2, 1020 Vienna, Austria1020 Vienna, Austriaboeck@ati.ac.atboeck@ati.ac.at

•• BWR BasicsBWR Basics•• Technical DataTechnical Data•• Safety FeaturesSafety Features•• Reactivity ControlReactivity Control•• Fuel AssembliesFuel Assemblies•• Reactor Pressure VesselReactor Pressure Vessel•• Development of Development of BWRBWR’’ss•• SWRSWR--10001000•• ABWRABWR

ContentsContents

•• HH22O as coolant O as coolant and and moderatormoderator•• Pressure in water/steam cycle: 70 bar (7 Pressure in water/steam cycle: 70 bar (7 MPaMPa))•• Boiling of water in the coreBoiling of water in the core•• Temperature about 300 Temperature about 300 ººCC•• Steam transferred directly from core to turbine Steam transferred directly from core to turbine

generator after passing steam/water separatorgenerator after passing steam/water separator•• AverageAverage power power densitydensity in in corecore: 50 : 50 kW/litrekW/litre•• BurnBurn--upup: ca. 55.000 : ca. 55.000 MWd/tMWd/t UU•• Thermal Thermal netnet efficiencyefficiency: 34.1%: 34.1%

BWR BasicsBWR Basics

BWR BWR GenerationsGenerations

ExampleExample: : TheThe BWR BWR KrKrüümmelmmel

•• BuiltBuilt–– 19841984–– byby KWUKWU

•• 1260 1260 MWMWee netnet

•• 3690 3690 MWMWthth

•• FuelFuel assembliesassemblies::–– NumberNumber of of fuelfuel assembliesassemblies: 840: 840–– Total Total lengthlength: 4.47 m: 4.47 m–– ActiveActive lengthlength: 3.71 m: 3.71 m–– LatticeLattice: 9 x 9 : 9 x 9 rodsrods–– WeightWeight withoutwithout shroudshroud: 276 kg: 276 kg–– NumberNumber of of rodsrods per per assemblyassembly: 81: 81–– PositionsPositions forfor absorberabsorber fingersfingers: 205: 205

•• FuelFuel rodsrods: : –– OuterOuter diameterdiameter 9.62 mm9.62 mm–– Wall Wall thicknessthickness 0.72 mm0.72 mm–– FuelFuel: up to 4.02 % : up to 4.02 % enrichedenriched UOUO22, , sinteredsintered to to ceramicceramic

pelletspellets of 92% of 92% theoreticaltheoretical densitydensity–– CladdingCladding material: material: ZircaloyZircaloy 4 (99% Zr, 4 (99% Zr, Sn,Fe,NiSn,Fe,Ni

TechnicalTechnical Data of Data of thethe BWR BWR KrKrüümmelmmel

•• ControlControl rodsrods::–– NumberNumber of of controlcontrol rodsrods: 205: 205–– Cross Cross shapedshaped absorberabsorber bladesblades–– Absorber material: BAbsorber material: B44C and HafniumC and Hafnium–– Absorber Absorber lengthlength: 3.66: 3.66 mm–– DrivenDriven byby electricalelectrical motormotor fromfrom bottombottom to to toptop in in -- out out

in normal in normal operationoperation ((speedspeed 3 cm/s), total 3 cm/s), total insertioninsertiontime 122 stime 122 s

–– Fast Fast shutshut down down hydraulicallyhydraulically: : SpeedSpeed 150 cm/s, total 150 cm/s, total insertioninsertion time 3.7 stime 3.7 s

TechnicalTechnical Data of Data of thethe BWR BWR KrKrüümmelmmel

SimplifiedSimplified Cross Cross SectionSection of a BWR of a BWR

FlowFlow Diagram of a BWRDiagram of a BWR

BWR Cross BWR Cross SectionSection -- DetailsDetails

•• In In BWRBWR’’ss steam bubbles have a negative steam bubbles have a negative reactivity feedback, if the steam fraction reactivity feedback, if the steam fraction increases in the core the reactor power increases in the core the reactor power decreasesdecreases

•• Two independent shut down systemsTwo independent shut down systems•• 3 x 100% redundancy in safety systems3 x 100% redundancy in safety systems•• Diverse functions for safety related actionsDiverse functions for safety related actions•• Physical separation of safety relevant systemsPhysical separation of safety relevant systems•• Five barriers between the fission products and Five barriers between the fission products and

the environment the environment

SafetySafety of of BWRsBWRs

Cross Cross SectionSection of a BWR Containmentof a BWR Containment

•• As As thethe pressurepressurevesselvessel isis 1/3 1/3 tallertallerthanthan withwith PWR a PWR a fullfull pressurepressurecontainementcontainementwouldwould bebe tootoo bigbig

•• ThereforeTherefore a a pressurepressuresuppressionsuppression systemsystemisis providedprovided

•• ControlControl rodsrods:: Are Are usedused forfor–– normal normal startstart--upup–– power power adjustmentadjustment–– operational operational shutshut downdownand and forfor emergencyemergency shutshut downdown

•• InternalInternal recirculationrecirculation pumpspumps::–– IncreasingIncreasing flowflow: : increasesincreases powerpower–– ReducingReducing flowflow: : reducesreduces power power withoutwithout movingmoving controlcontrol

rodsrods–– FlowFlow changeschanges thethe water/steamwater/steam ratioratio in in thethe corecore --

negative negative voidvoid coefficientcoefficient

ReacticityReacticity ControlControl of of BWRsBWRs

BWR BWR ControlControl RodsRods

•• Cross Cross shapedshaped blades blades containingcontaining BB44CC

•• EnterEnter thethe corecore fromfrombottombottom

BWR BWR RodRod--FuelFuel--AssembliesAssemblies

BWR BWR FuelFuel Rod Rod GeometryGeometry

BWR BWR FuelFuel Pellet DetailsPellet Details

Cross Cross SectionSection of BWR of BWR CoresCores

RefuellingRefuellingProcedureProcedure•• PV PV isis openedopened

and and internalsinternalsremovedremoved

•• Water Water levellevel isisincreasedincreased to to workingworkingplatformplatform

•• RefuellingRefuellingmachinemachinetransferstransfers fuelfuelassemblyassemblyunderunder waterwater

•• Basic Basic datadata::–– HeightHeight: 22.05 m: 22.05 m–– Inner Inner diameterdiameter: 6.78 m: 6.78 m–– Design Design pressurepressure: 87.3 bar: 87.3 bar–– Wall Wall thicknessthickness: 17 cm: 17 cm–– Wall Wall thicknessthickness bottombottom: 23,4 cm: 23,4 cm–– Total Total weightweight: 790 t: 790 t

ReactorReactor PressurePressure VesselVessel(BWR (BWR KrKrüümmelmmel) )

ReactorReactor PressurePressure VesselVessel Cross Cross SectionSection

ZwentendorfZwentendorf –– thethe AustrianAustrian BWR SolutionBWR Solution…….. ..

•• BWR BrunsbBWR Brunsbüüttel:ttel:–– Energy Energy productionproduction sincesince 7/76: 110.8 7/76: 110.8 TWhTWh–– life time life time availabiltyavailabilty: 55.1 % : 55.1 %

•• BWR Isar 1:BWR Isar 1:–– Energy Energy productionproduction sincesince 12/77: 161.7 12/77: 161.7 TWhTWh–– life time life time availabiltyavailabilty: 75.1 % : 75.1 %

•• BWR Philippsburg 1:BWR Philippsburg 1:–– Energy Energy productionproduction sincesince 7/79: 154 7/79: 154 TWhTWh

–– life time life time availabiltyavailabilty: 75.3 %: 75.3 %

Same Design as NPP Same Design as NPP ZwentendorfZwentendorf

•• Overall Overall datadata::–– Thermal power: 3370 Thermal power: 3370 MWMWthth–– ElectricalElectrical power: 1254 power: 1254 MWMWee–– EfficiencyEfficiency: 37,2 %: 37,2 %

•• ReactorReactor corecore::–– NumberNumber of of fuelfuel assembliesassemblies: 664: 664–– ActiveActive corecore heightheight: 3.0 m: 3.0 m–– Total Total uraniumuranium weightweight: 136 t: 136 t–– EnrichmentEnrichment: 3.5 %: 3.5 %–– DischargeDischarge burnburn--upup: 45 000 : 45 000 MWd/tMWd/t–– Power Power densitydensity: 51 : 51 kW/litrekW/litre

•• ReactorReactor pressurepressure vesselvessel::–– Inner Inner heightheight: 23.35 m: 23.35 m–– Inner Inner diameterdiameter: 7.12 m: 7.12 m–– Operational Operational pressurepressure: 75 bar: 75 bar–– Design Design pressurepressure: 88 bar: 88 bar–– RecirculationRecirculation pumpspumps: 8: 8

FramatomFramatom--ANPANP SWRSWR--10001000A New BWR GenerationA New BWR Generation

SWRSWR--1000 1000 SafetySafety

FeaturesFeatures•• EmergencyEmergency

condensorscondensors•• Containment Containment

coolingcoolingcondensorscondensors

•• CoreCore floodingfloodingsystemsystem

•• Passive Passive pressurepressure pulse pulse transmittertransmitter

•• EmergencyEmergency condensorscondensors: : –– IfIf thethe waterwater levellevel dropsdrops in in thethe PV, PV, waterwater fromfrom thethe

corecore floodingflooding poolpool flowsflows intointo thethe PV PV whilewhile steamsteam isiscondensedcondensed withoutwithout externalexternal powerpower

•• Containment Containment coolingcooling condenserscondensers::–– IfIf temperaturetemperature raisesraises, , heatheat isis removedremoved to to thethe

shielding/storageshielding/storage poolpool withoutwithout externalexternal powerpower

SWRSWR--1000 Passive 1000 Passive SafetySafety SystemsSystems

•• CoreCore floodingflooding systemsystem::–– WhenWhen reactorreactor pressurepressure isis lowlow waterwater fromfrom „„corecore

floodingflooding poolpool““ flowsflows byby gravitygravity intointo thethe PVPV

•• Passive Passive pressurepressure pulse pulse transmitterstransmitters::–– These These areare smallsmall heatheat exchangersexchangers: : –– IfIf waterwater levellevel dropsdrops pressurepressure increasesincreases on on secondarysecondary

sideside, , thisthis pressurepressure deliversdelivers safetysafety relatedrelated pulsespulses ((i.ei.e. . scramscram thethe reactorreactor) ) withoutwithout externalexternal powerpower

SWRSWR--1000 Passive 1000 Passive SafetySafety SystemsSystems

SWRSWR--1000 1000 ContainmentContainment

•• SafetySafety systemssystemsoperateoperate on on gravitygravity and and naturalnaturalconvectionconvection

•• ExtendedExtendedgracegrace periodperiodof 3 of 3 daysdayswithoutwithoutinterventionintervention

•• AnyAny corecore meltmeltremainsremains insideinsidecontainementcontainement

AdvancedAdvanced BoilingBoiling Water Water ReactorReactorABWR (GE, ABWR (GE, Hitachi,ToshibaHitachi,Toshiba))

•• SimplifiedSimplified constructionconstruction ((onlyonly 48 48 monthmonth))•• SimplifiedSimplified operationoperation•• MoreMore efficientefficient, , lessless wastewaste•• LicensedLicensed in USA Japan and Taiwanin USA Japan and Taiwan

•• Overall Overall datadata::–– Thermal power: 3926 Thermal power: 3926 MWMWthth

–– ElectricalElectrical power: 1356 power: 1356 MWMWee

–– EfficiencyEfficiency: 37,2 % : 37,2 %

ABWR ABWR TechnicalTechnical DataData•• ReactorReactor corecore::

–– NumberNumber of of fuelfuel assembliesassemblies: 872: 872–– ActiveActive corecore heightheight: 3.71 m: 3.71 m–– Total Total uraniumuranium weightweight: 136 t : 136 t –– EnrichmentEnrichment: 3.2 % : 3.2 % –– DischargeDischarge burnburn--upup: 32 000 : 32 000 MWd/tMWd/t–– Power Power densitydensity: 50.6 : 50.6 kW/litrekW/litre

•• ReactorReactor pressurepressure vesselvessel::–– Inner Inner heightheight: 21 m: 21 m–– Inner Inner diameterdiameter: 7.1 m: 7.1 m–– Operational Operational pressurepressure: 73.1 bar: 73.1 bar–– Design Design pressurepressure: 88 bar: 88 bar–– RecirculationRecirculation pumpspumps: 10: 10

ABWR ABWR SafetySafety FeaturesFeatures

•• InherentInherent safetysafety: Negative : Negative voidvoid and and Doppler Doppler coefficientcoefficient

•• High High operatingoperating performanceperformance, , loadloadfollowingfollowing possiblepossible

•• High plant High plant efficiencyefficiency, , shortshort constructionconstructionperiodperiod

•• MostlyMostly automatedautomated operationoperation

ABWR ABWR PressurePressure VesselVessel

In an ABWR, coolantwater is recirculatedinside the reactorpressure vessel (RPV) byreactor internal pumpsinstalled within thevessel itself.

ABWR ECCSABWR ECCS

••EmergencyEmergency CoreCore CoolingCoolingSystem (ECCS)System (ECCS)

••High High PressurePressure CoreCore FlooderFlooder(HPCF) and (HPCF) and ReactorReactor CoreCoreIsolation Isolation CoolingCooling (RCIC) (RCIC) SystemsSystems

••Low Low PressurePressure FlooderFlooder (LPFL) (LPFL) System System

••AutomaticAutomatic--DepressurizationDepressurizationSystem System

•• World Nuclear:World Nuclear:–– www.worldwww.world--nuclear.orgnuclear.org

•• KKW KKW KrKrüümmelmmel-- www.kernkraftwerkwww.kernkraftwerk--kruemmel.de/kraftwerk/index.htmlkruemmel.de/kraftwerk/index.html

•• TypesTypes of Nuclear of Nuclear ReactorsReactors::–– hyperphysics.phyhyperphysics.phy--astr.gsu.edu/hbase/nucene/reactor.html#c3astr.gsu.edu/hbase/nucene/reactor.html#c3

•• Nuclear Regulatory Commission:Nuclear Regulatory Commission:–– www.nrc.govwww.nrc.gov

•• Nuclear Energy Institute:Nuclear Energy Institute:–– www.nei.orgwww.nei.org

•• Mitsubishi Heavy Industry (Japan):Mitsubishi Heavy Industry (Japan):–– www.mhi.co.jp/atom/hq/atome_e/index.htmlwww.mhi.co.jp/atom/hq/atome_e/index.html

•• AtominstituteAtominstitute of the Austrian Universities: of the Austrian Universities: www.ati.ac.atwww.ati.ac.at

•• FramatomeFramatome -- ANPANPwww.www.framatomeframatome--anp.comanp.com

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