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by M. Takahashi1, S. Uchida2, K. Hata3, T. Matsuzawa2, H. Osada2, Y. Kasahara2, Y. Yamada2, N. Sawa2, Y. Okubo2, K. Koyama2,
M. Hirabayashi4, K. Ara4, T. Obara1, and E. Yusibani51Tokyo Institute of Technology (Tokyo Tech.)
2Advanced Reactor Technology Co., Ltd. (ARTECH)3Nuclear Development Corporation (NDC)
4Japan Nuclear Cycle Development Institute (JNC)
PbPb--Bi Cooled Direct Contact Boiling Bi Cooled Direct Contact Boiling Water Small ReactorWater Small Reactor
INES-1, Tokyo, Japan, November 1-4, 2004,
1. Energy park and small reactor2. Motivation3. Project4. Conceptual design of PBWFR 5. Lift pump in chimney6. Removal of Pb-Bi mists and polonium7. Concluding remarks
ContentsContents
Stable FP
Energy Park
Natural U or Th
Actinide
Long Life FP
FPPb, Bi
(Option)
(Leak)
Transmutation StorageSeparation
FP:Fission Products
Energy UtilizationWith Small Reactor
Outside of Park
Toxic sub.IN
Toxic sub.OUT
Energy Park and Small Reactors with Long Life
Long Life Small PFRLong Life Small PFR- Forced Convection- Gas Lift Pump
SelfSelf--controllable controllable NaNa--cooled Small FRcooled Small FR
HTGRHTGR(CANDLE Burning)
COCO22 Gas TurbineGas TurbineReactorReactor(HighEfficiency, LMFR)
Large PFR-Transmutation-CANDLE Burning
Self-controllable Na-cooled Large FR
Nuclear Energy Park
Outside of Park (Site)Production of Electricity, Heat and Hydrogen
CO2 Gas TurbineMedium Size Reactor
Transportationof Reactors
Long Life Small PFRLong Life Small LFR- Forced Convection- Gas Lift Pump
SelfSelf--controllable controllable NaNa--cooled Small FRcooled Small FR
HTGRHTGR(CANDLE Burning)
COCO22 Gas TurbineGas TurbineReactorReactor(HighEfficiency, LMFR)
Large LFR-Transmutation-CANDLE Burning
Self-controllable Na-cooled Large FR
Nuclear Energy Park
Outside of Park (Site)Production of Electricity, Heat and Hydrogen
CO2 Gas TurbineMedium Size Reactor
Transportationof Reactors
Reactors in Park and Sites
Safe Coolant: Inactive with air, water Void reactivity: Negative
Economic Simple or Reduction of material e. g., Elimination of
- Pumps- Steam generators- Intermediate loop
Efficient in uranium utilization Breeding ratio > 1Proliferation resistant Long life core > 10-15 yrs
Requirements of Innovative Small Reactors
Steam(296℃)
Direct contact BoilingGas Lift Pump
Pb-BiControl Rod
Feed Water(220℃)
Core
Direct Contact LFR (PBWR)
proposed by J. Buongiorno, N. E. Todreas, et al., at ANS Winter Meeting, Long Beach, USA, in 1999.
Steam Lift Pump (PBWFR)Φ5.1mx14.5mH
Forced ConvectionΦ5.2mx15.2mH
150MWe 50MWe
Reduction of component materialEconomy
Research Projects for Development of Innovative Nuclear Technologies
by MEXT (FY2002-2004)
Pb-Bi Cooled Direct Contact Boiling Water FR (PBWFR)
1. Conceptual design 2. Pb-Bi-water direct
boiling test3. Test of steam
injection into Pb-Bi/ O-control
4. Corrosion 5. Polonium measure
ThemeTheme
Direct contact boiling/Steam lift pump performance
Core
Steam with Pb-Bi mists
Polonium measure
Corrosion Water injection/
Oxygen control
1) Conceptual designLong life core, void reactivity and specific structural design,Safety evaluation.
2) Material and chemistryControl of oxygen potential in Pb-Bi,Compatibility of core and structural materials with Pb-Bi,Measure of Po transport into steam system.
Challenges of PBWFR Technology
3) HydraulicsLift pump performance,Suppression of carry-over of Pb-Bi mist/aerosol into steam system,Suppression of carry-under of steam bubbles into down-comer,Ultrasonic flow-meter.
4) Thermal effectDirect contact steam generation performance,Flow instability and vapor explosion.
Pb-Bi
Reaction with air, waterOxidationOxygen controlOxygen sensorAerosol
Core designVoid reactivityPo production
Metal solutionDiffusion PenetrationCorrosionMelting point
HydraulicsTransport
ChemicalMolecular
Nuclear
Mass transportTwo-phase voidMistErosion
Phenomena
Conceptual Design of 150MWe PBWFR
Reactor vessel炉心
Chimney
Fuel assembly
Guard vessel
Core
DHX
Supplywater
Steam
Separator/Dryer
CRDM
CRDM penetration
Ring header
Core barrel
Pipe
Pad
620˚CMax. cladding temp.
110 GWd/tBurnup
220 ˚CSupply water temperature
863 t/hSteam flow rate
1.05Breeding Ratio
450 MWtThermal power
310 ˚CCore inlet temp.
460 ˚CCore outlet temp.
15 yrsRefueling interval
296 ˚CSteam temperature
7 MPaSteam pressure
73970 t/hPb-Bi flow rate
Total 121
Control Rod 13
Pb-Bi Shielding 30
Outer Core Fuel Assembly 42
Inner Core Fuel Assembly 36
12
0.3 w/oContents of U235
in core fuel
15.8 w/oOuter zone11.5 w/oInner zonePu
enrichment
NonLower axial30 cmUpper axialNonRadialBlanket100 cmHeight267 cmDiameterCore
Pu-U nitride(N15 100%)
Fuel
Two enriched zones.
Zones
Homogeneous core
TypeCore
Core Design
Maximum linear power
keff
Fuel Assembly
14
Hex. 272.0Hex. 273.0
15.9
271-12.0
5.0
5.9
Fuel 1000Fuel rod 2360
Fuel Assembly 3975
B
B
A
A
Handling head
Wrapper tube
Fuel rods Entrance nozzle Ratch spring
$ 3 (EOL)Core, axial blanket and plenum
$ 7.4 (EOL)CoreVoid reactivity
>1.05Breeding ratio
1.5 %dk/kk’/15 yrsBurn-up reactivity loss
Breeding ratio
Fuel Assembly
16
272.0 mmFace distance of wrapper tube 15.9 mmPitch of rod arrangement12.0 mmOuter diameter of cladding 271Number of rods 80 %Pellet smear densityGrid spacerSpacer typeDuct typeType
0.04MPaFriction pressure drop in fuel bundle46.1 %coolant
14.1 %structure
39.8 %FuelVolumetric fraction 275 mmPitch of assembly arrangement
Additional Consideration Additional Consideration for Low Void Reactivity Corefor Low Void Reactivity Core
●Safety design demands negative void reactivity for the case of core and upper plenum region voided from considerations of core void pattern of PBWFR.
●Void reactivity (core +upper plenum) of core mentioned above is +3$.
●Considerations of core specification adequate for safety demands have been performed by core height adjustment with same core layout.
RelationRelation of Core Height and of Core Height and Coolant Void ReactivityCoolant Void Reactivity
-15.00
-10.00
-5.00
0.00
5.00
10.00
60 70 80 90 100 110
Core Height (cm)
Coolant Void Reactivity($)
Core
Core+ Lower Blanket+ Upper Plenum
Core+ Upper Plenum
EOL(10years) Vf = 39.8%
Vioded Region
75
Specification of Low Void Core
-5.33.0Void Reactivity(Core+Upper Plenum) ($)
5.67.4Void Reactivity(Core) ($)1.171.122Breeding Ratio (-)0.91.53Burn up Reactivity Loss (%ΔK/kk’)
3,2053,625Assembly Length (mm)331271Pin Number per Assembly (-)15.215.9Fuel Pin Pitch (mm)1212Fuel Pin Diameter (mm)
278267Core Equivalent Diameter (cm)75100Core Height (cm)1015Core Residence Time (years)
Low Void Reactivity Core
Reference CoreItem
15
Structure in Reactor Vessel20
4230
3500
5550
2000
427 5 3
625
2050
355040304440
3380
Chimney
Inner cylinder
Water pipe
Water supply header
Core barrel
Fuel assembly
Reactor vessel
33804440
5140
Core barrel
Inner cylinder
Reactor vessel
Guard vessel
DHX
Reactor Structure
Separatorand dryer
Support of vesselat gravity center
Guard vessel
Exchange of whole core
Upper CRDM
Core Support Structure
Core Support Structures and Core BarrelHung from upper flangein order to pull up when refuelingSupported horizontallyby earthquake-proof pads.
Control Rod Guide TubesGuide Control Rodsfrom Head Plate to CorePenetrate Upper Structures, such as Dryer, Separator and Chimney.Supported by penetrations
(CRGTs maintain CR insertion anytime)
111
111
11
111
11
1111
1
22
22222
22
22
22222
22
33
333
33
33
33
333
33
33
45
54
4554
45
54 4
55
4
4554
45
54
Flow AllocationFlow Allocation
Inner Core: 1,2
Outer Core : 3,4,5
10
Power of Fuel Rod and Max. Cladding Temperature
5
4
3
2
1
Region
12
12
18
18
18
Assemblies
527585619T18.423.226.1P225510565619T18.523.528.4P247563608619T24.929.230.3P264Outer
core
619579536T28.724.920.6P249618571496T31.126.218.4P272Inner
core
FinalMiddleInitialFlow rate(kg/s)
P: Power of fuel rod (kW), T: Cladding temperature (˚C); Initial: 0 days, Middle: 2737 days, Final: 5475 days
Plant System
RVACS
C/V
Separator/dryer
PRACS
Water supply
G/V
R/VCore
Pump
Heater
HP turbine
H2supply
Filter
LP turbine
GeneratorPump
Heater
Chimney
C/R DM
T: Temperature (°C)P: Pressure (MPa-G)W: Flow rate (t/h)
Turbine
Generator(150We)
Thermal power450Wt
Heat balance
Decay Heat Removal
Sectors
Water supply headers
Nozzles
Inner headerOuter header
Performance of lift pump in chimneyPerformance of lift pump in chimney
- Uniform distribution of void fraction -High void fraction, i. e.
Low slip ratio of steam velocity to Pb-Bi velocity
Requirement in sector-type chimney
Total lift pump head 0.198MPaChimney height 3,000mmAverage density 3,788kg/m3
(Void fraction 0.645)
Total pressure loss 0.156MPaBundle 0.081MPaAssembly 0.020MPaHD plate 0.029MPaChimney 0.025MPaDown-comer 0.00068MPa
OneOne--dimensional analysis of dimensional analysis of lift pump performancelift pump performance
Balance of head and pressure loss for Pb-Bi circuit
Experiment of Pb-Bi-Water Direct Contact Boiling Two-phase Flow
Dump tank
Condenser
Pump
Cooler
Dryer
Fuel bundle
DirectContactboiling
Pb-Bi
Flowmeter
P
Pb-Bi-Water Direct Contact Boiling Two-phase Flow Test Apparatus
1
2
3
5
6
7
8
4
ヒータピン(φ12×4本)
給水注入管
下降管(内径φ38.4)
下部プレナム(内径φ97.1)
四角管(内縁33×33)
チムニー管(1)(内径φ30)
チムニー管(2)(内径φ38.4)
鉛ビスマス液面
上部プレナム(内径φ283.7)
冷却コイル
9
10
図2 自然循環時の圧力損失計算モデル(鉛ビスマスのみの循環)
Pb-Bi free surface
Square duct
Lower plenum
Chimney (1)Chimney (2)
Heater pin bundle
Water supply
Upper plenumCooler
Downward pipe
Flow model
0102030405060708090
100110
Heater power Water flow rate Pb-Bi flow rateH
eate
r pow
er (k
W)
Wat
er fl
ow ra
te (k
g/h)
Pb-B
i flo
w ra
te (L
/min
)
0 60 120 180 240 300
200
300
400
500
Tem
pera
ture
(℃)
Outlet of heater pins Inlet of heater pins Outlet steam Chimney Injected waterTime (min)
7MPa
0.5 1.0 1.5 2.0
8.0
6.0
4.0
2.0
0.5 1.0 1.5 2.0
8.0
6.0
4.0
2.0
2mm 10mm
Analysis of Pb-Bi-steam flow
Bubble diameter
0.0 0.2 0.4 0.6 0.8 1.0
Void fraction
Pb-Bi-steam 2-d two-phase flow in chimney
Key issues:-Suppression of carry-under of bubbles-Estimate of bubble diameter
Removal of Pb-Bi mists
Dra
100500
500
2000 φ400
φ400
φ300
Dra
Sep
Dryer
Drain
Separator
Pb-Bi free suface
I.D.40
0
I.D.100
Steam flow
Steam flow
Porous plate
Steam flow
Dryer
Cyclone separator
Chevron dryer
Drain
Estimate of Pb-Bi mists and Pollonium
1.1×108Bq/sTransport into steam system
1.06×1011Bq/kg
Concentration in Pb-Bi
1.5×1017BqProduction
Requirement 1) Additional precipitation device2) Ceramic coated turbine blades
2.0x10-4% lower than 2.0%-5.0% in LWR
Ratio of mist flowrate to steam flowrate
4.8x10-4 kg/s or 15.2 t/y
Flow rate
Separator 95.5%, Dryer 2.6%
Removal efficiency
Mist flow rate Polonium
Steam flow in dryer
Flow velocity distribution [m/s]
Flow velocity vector
Droplet measurement and Electro-static precipitation
Design consideration is for a representative PBWFR condition
ESP System
PDA System
Comparison PBWFR Experiment
Velocity 0.6 m/s up to 0.1 m/sMedium Steam Argon GasPressure 7 Mpa 0.1 MpaTemperature 296 C 180 CFlowrate 329400 L/mnt 0.5 - 2 L/mnt
Glass wall
Dump Tank
Level meter tank
Test section
Ar gas injection
39
A design concept of PBWFR has been formulated with design parameters identified, and will be modified by the results of the following studies:
・ Two-phase flow test in the chimneyfor structure design of chimney with gas lift pump,
• Pb-Bi droplet removal testfor the reduction of carry-over and Po transport rate into steam system,
• Pb-Bi-water direct contact boiling testfor stable boiling and Pb-Bi circulation under
practical conditions,• Corrosion/steam injection tests
for corrosion-resistant steels, oxygen control/measurement method and the other Pb-Bi technology.
Concluding remarks