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

Key Element Technology Phase (2000-2002)

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 (2003-2004)

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

EVEDA(Engineering Validation and

Engineering Design Activities)2005-2009