Upload
others
View
4
Download
0
Embed Size (px)
Citation preview
Liquid lithium Targetin IFMIF
(International Fusion Materials Irradiation Facility)
Hiroo NakamuraJapan Atomic Energy Research Institute
WS on High-power Targetry for Future Accelerators September 8–12, 2003, Marriott Courtyard, NY
What is IFMIF
International Fusion Materials Iraddiation Facility
2000 - 2002 KEP(Key Element Technology )
2003 - 2004 Transition Phase2005 - 2009 EVEDA
(Engineering Validation and EngineeringDesign Activitiy)
2010 - 2016 Construction 2017 - Operation
IFMIF OrganizationIFMIF Organization
USJAEU
RF
IEA-Fusion Material Irradiation Research
IFMIF sub-Exco
IFMIFI team
Users Group
Acceleratior GrTarget GrTest Facility GrDesign Integration Gr
Requirements of Neutron Source for Requirements of Neutron Source for Development of Fusion MaterialsDevelopment of Fusion Materials
•• 14MeV neutron14MeV neutron•• Neutron intensityNeutron intensity
100100--200dpa200dpa(20dpa/year, 2MW/m(20dpa/year, 2MW/m22))
•• He production/damageHe production/damage~10appm/~10appm/dpadpa
•• Irradiation volumeIrradiation volume500cc500cc(LAF steel, V(LAF steel, V--alloy, alloy, SiCSiC//SiCSiC))
DD--Li neutron source has Li neutron source has been selected.been selected.
1014
1016
1018
1020Fusion Reactor
D-Li(IFMIF)
Spallation(LASREF)N
eutro
n Fl
ux(n
/m2 /s
/Let
harg
y)
HFIR
FBR
10-3 10-2 10-1 100 101 102
Neutron Energy (MeV)
0
200
400
600
0 20 50
Spallation(5MW, 20%-availability)
Fission Reactor
Fusion ReactorIFMIF
Irradiation Damage (dpa/y)
He
Prod
uctio
n (a
ppm
/y)
3010 40
500
300
100
Concept of DConcept of D--Li Neutron SourceLi Neutron SourceHighHigh--speed liquid Li flow along concave backspeed liquid Li flow along concave back--wall is selected as Li target to handle high heat wall is selected as Li target to handle high heat load (1GW/mload (1GW/m22) of 10MW D) of 10MW D++ beams.beams.
D+ Accelerator
Liquid Li TargetLi Flow
Specimen
Neutron(1x1017n/s)
Li FreeSurface
HX
EMP
Injector
D+ Beam(10MW)
Vacuum10-3Pa
Concave Back-wallto Increase Boiling Point beyond 340℃by Centrifugal Force
Major Issues of Target System
D + B eam
40 M eV,
250 m A ,
10 M W
Liquid Lithium
T arget
Im purity Trap
E lectro M agnetic P um p
Flow meter
V=20 m /sec
Tin=250 oC
C old T rap
H ot T rap
Liquid Li th ium Target: (1 0 MW in to 20 c m w ide x 5c m ) ー>St able and High Sp eed Flow ー>Good Com p ati bi l i ty of n ozzle m ate r ial w i th Li f l ow ー>Easy Rem ot e Maint en anc e
Im puri ty Trap: ー>Rem ov al of pr odu c t s (T、7Be) ー>Redu c ti o n o f im p uri t i es (N2, O2, etc )
Safety: ー>Con ef in em ent o f radi oac t i ve p rod uc t ー>Pre vent i on of L i f i reQ uench
Tank
N eutron
Proof of principal in FMIT Need data in IFMIF conditions
Electro Magnetic Pump: ー>Stable and Cavitation less operation
ThermalThermal--hydraulic Analysishydraulic AnalysisCalculation codeCalculation code : FLOW: FLOW--3D3DViscosity estimationViscosity estimation : k: k--εε turbulent modelturbulent modelMesh sizeMesh size : 0.2mm x 1mm: 0.2mm x 1mmAverage velocity (UAverage velocity (U0 0 ) : 10, 20m/s) : 10, 20m/sBackBack--wall radius (Rwall radius (RWW) : 100, 250, 1000mm) : 100, 250, 1000mmJet thicknessJet thickness : 25mm: 25mmInlet temperatureInlet temperature : 250: 250℃℃
Calculation ModelCalculation Model50
mm
Temperature was calculated using input data Temperature was calculated using input data of beam deposition.of beam deposition.
Li Flow
D+ Beam
Free Surface
Li Flow
Back-wallHeated RegionLi Region (t=0)Empty Region (t=0)
Energy Deposition Profile
BackWall
FreeSurface
6
0 5 10 15 20 25
4
2
0
Depth from Surface (mm)
Ener
gy D
epos
ition
(GW
/A•m
) 40MeV D+ → Li(σ=0.5MeV)
Calculated Temperature & PressureCalculated Temperature & Pressure(Case : U(Case : U00=20m/s, R=20m/s, RWW=250mm)=250mm)
0 5 10 15 20 250
5
10
15
20
25
Depth from Surface (mm)Pr
essu
re (
kPa
) Centrifugal Force~160G
Max. temperature is given at lower edge of beam.Max. temperature is given at lower edge of beam.Pressure increases with depth by centrifugal force.Pressure increases with depth by centrifugal force.
Boiling Point=Boiling Point= 179001790022.722.7--logP(Pa)logP(Pa)
-- 262262
(230-1230°C, JSME, Engineering data of heat transfer, Edit.4)
270℃
290℃
250℃
310℃
Beam
Hei
ght (
50m
m)
250.1℃
Flow
FreeSurface
Distribution of Li Temperature, Boiling Distribution of Li Temperature, Boiling Point and Boiling MarginPoint and Boiling Margin
Velocity of 20m/s gives enough margin.Velocity of 20m/s gives enough margin.Spatial margin > 3mm on backSpatial margin > 3mm on back--wall side.wall side.
200 25
1000
600
1400
20151050Depth (mm)
Boiling PointRW=100 mm
1000
Li
250
344°C
280°C
408°C
Temperatures Distribution in Li Flow (U0=20m/s)
3mm
712°C
Tem
pera
ture
(°C
)
252015105Average Velocity : U0 (m/s)
250
300
350
400
Surfa
ce T
empe
ratu
re (°
C)
Boiling Point at Free Surface
Velocity Dependence on Surface Temperature
30°C40°C∆T= 61°C
54°C
SimulatingSimulating ExperimentsExperiments byby Water Water
Objectives :Objectives :•• To verify stable flow generation by To verify stable flow generation by
double reducer nozzledouble reducer nozzle•• To clarify effect of nozzle wallTo clarify effect of nozzle wall
roughness on surface wavesroughness on surface waves
Advantages of Water Experiment :Advantages of Water Experiment :•• Well simulation of Li flow with fittingWell simulation of Li flow with fitting
Reynolds numberReynolds number•• Convenience at velocity measurementConvenience at velocity measurement
EffectivenessEffectiveness ofof SimulationSimulation byby Water Water
Li flow(250℃)
Water flow(20℃)
Kinem atic viscosity (m2/s) 0.98x10 -6 1.01x10 -6
Reynol ds number (L=25mm) 510,000 495,000Density (kg/m3) 510 998Viscosity (Pa•s) 5.01x10 -4 1.00x10 -3
Surface tension (N/m) 0.386 0.0728
Flow Parameters at Velocity of 20m/s
Water experiments can simulate Li flows with same Water experiments can simulate Li flows with same kinematic kinematic viscosity and Reynolds number.viscosity and Reynolds number.
Effect of Test Section ArrangementEffect of Test Section ArrangementWater experiments with horizontal, straight wall are Water experiments with horizontal, straight wall are expected to well simulate surface of Li flow with expected to well simulate surface of Li flow with vertical, concave wall.vertical, concave wall.
Force Effect(m/s2)
Surfacetension (σK2ρ)
30,000
Centrifugalforce (U0
2/RW)1,600
Gravit y (g) 9.8
Wave amplitude Wave amplitude ∝∝ (g+U(g+U00
22/R/RWW++σσKK22//ρρ))--0.50.5
~ (~ (σσKK22//ρρ) ) --0.50.5
σσ : Surface tension: Surface tensionρρ : Density: DensityK : Wave numberK : Wave number
(2(2ππ/ / λλ ~2~2ππ/1mm)/1mm)
Effect of Forces on Surface Wave StabilityEffect of Forces on Surface Wave Stability
U0
RRWW
λλ
Experimental SetupExperimental Setup
150 150
100
10
25
U : 2.4~20 m/s
P : 0.15, 1.0 atm
Viewing Port (80x50) Surface Roughness
6.3, 100 µm
10
10cm
2019 21
Surface Observation(High-speed Camera)
Wall Roughness6.3, 100µm
Free Surface
Double Reducer Nozzle
15cm
1cm
Velocity Measurement(Laser Doppler Velocimeter)
XYVX
VY
Wave Height Measurement
20m/s
Laser Beam andPosition Sensitive Detector
3D View of Test Section3D View of Test Section(Test Operation without Measuring Devise)(Test Operation without Measuring Devise)
Double Reducer NozzleFlow Surface
10cm
1cm
Flow velocity & RoughnessFlow velocity & Roughness•• Double reducer nozzle generates stable flows Double reducer nozzle generates stable flows with surface deviation < 1mm.with surface deviation < 1mm.R
ough
ness
: 10
0µm
50m
mFlow
Flow Flow
•• Rough (100Rough (100µµm) wall nozzle generated waves in m) wall nozzle generated waves in IFMIF velocity range of 10IFMIF velocity range of 10--20m/s20m/s
U0=5m/s U0=10m/s U0=20m/s
Rou
ghne
ss :
6.3µ
m Flow
Flow
Flow
50m
m
Wave Height~0.2mm (r.m.s.)
Characteristic Change of Boundary Layer at Characteristic Change of Boundary Layer at Nozzle ExitNozzle Exit
Change of boundary layer from laminar to turbulent Change of boundary layer from laminar to turbulent occurred at Uoccurred at U00>5m/s in case of rough (100>5m/s in case of rough (100µµm) wall m) wall nozzle.nozzle.
Velo
city
: U
(m/S
)
0
5
10
15
20
25
0 0.1 0.2 0.3 0.4 0.5Distance from Wall : y (mm)
U0=20m/s
5m/s
10m/s
0 10 20Average Velocity : U0 (m/s)
30
0.10
0
0.05
Laminar Flow (δ∝U0-0.5)
Mom
entu
m T
hick
ness
(mm
)
Momentum thickness :δ =∫(U/U0(1-U/U0)dy
Wall Roughness6.3µm
Wall Roughness6.3µm
100µm100µm
Selection of Target ParametersSelection of Target Parameters
Double ReducerNozzle(Roughness : 6.3µm)
Concave Back-wall(RW=25cm)
Li Flow( U0=10-20m/s
T25mm x W260mm )
D+ Beams
Quench Tank
Pump
Shie
ldin
gW
all
IFMIF Li target has been designed utilizing IFMIF Li target has been designed utilizing results of analyses and experiments.results of analyses and experiments.
Transition phase in Japan
JAERI / JNC Osaka Li loop
2.2 m/s 13 m/s
70 mm
Side wall
Side wall
System design of Li target
H.Nakamura, IFMIF DI meeting, Tokyo, March 17-18 2003
Transition phase in ENEA-EU
Water Experiment Remote Handling
Schedule in 2003-Joint gap:0, -0.05,- 0.1, +0.05,+ 0.1 mm-Curvature : 25 cm,45 cm
Schedule in 2003-RH Experiment : March - June-Report : July
H.Nakamura, IFMIF DI meeting, Tokyo, March 17-18 2003
3 year Li target program (June 2002-June 2005) is on going under ISTC project.
Transition phase in IPPE-RF
2m
Li Loop for Impurity Monitor andLi Purification System
Rotating Target forCorrosion Test(15 cm φ for 20 m/s)
H.Nakamura, IFMIF DI meeting, Tokyo, March 17-18 2003