Sagara 1

R&D activities on flibe blanketin Japan

Akio SAGARANIFS

ITER TBM Project Meeting at UCLAFebruary 23-25, 2004

Sagara 2

�FFHR design �with R&D

�JUPITER-II

R&D/LHD�TNT loop�Ultrahigh HT

FY1993 1997 2001 2004 2007

Molten salt R & D activities in Japan Molten salt R & D activities in Japan

2015

$

$

$

Sagara 3

Advantages in LHD• current-less • Steady state• no CD power• Intrinsic divertor

Force Free Helical ReactorPhase I ----- Concept definition 1993 Design of FFHR-1 (l=3) 1994 ---> NIFS Collaboration 1995 Design of FFHR-2 (l=2) 1998 ---> Fusion Eng. Network 2001 ---> Liq. Blanket in JUPITER-II 2002 ---> Concept improvements

Sagara 4

FFHRDesign Concept& Optimization

Molten-salt blanket with low MHD effect

Enhancing inherent safety & Thermal efficiency

Plasma

100 cm0

Self-cooled T breeder

Radiation shield Vacuum vessel

SCmagnet

LCFS

First wall

550°Ccoolant out

SOL

Thermal shield 450°Ccoolant in

20°C

7 53

T boundary&

Flibe

217 5

JLF-1(30vol. %)

1 1

&

Carbon10 ~ 20

JLF-1 + B4C(30 vol.%)

Be (60 vol.%)

Simplification of supporting structure

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3

< f

a >

/ (

B0

I H)

ac/H=4

2

LHD

FFHR-142

W

H

ac

= 3

@W/H=2

= 2 l

coil cross-section

NIFS-960812 / S.I.

l

Coil pitch parameter c =(m/ )( acg /R) l

FFHR-2

a c/H W/H < f a > (MN/m)

LHD 3.4 1.74 10.7FFHR-1 2.3 2.0 96.7FFHR-2 3.0 2.0 124.5

Reduction of magnetic force

case C: Ti(0)=29keV, n(0)=1.5x1020m-3, < b> =4.5 %, hH=3.5

case B: Ti(0)=24keV, n(0)=1.9x1020m-3, < b> =2.2 %, hH=2.25

Ignition conditions for the 3GW fusion outputcase A: Ti(0)=22keV, n(0)=2.0x1020m-3, < b> =0.7 %, h

H=1.5

0

5

10

15

20

0 5 10 15 20 25 30Mag

netic

fiel

d on

axi

s B

0

(T)

C

10T

Major radius R (m)

B

12T

8T

D=0.5m 1m 1.5m

=3 m =18R/a

p=10

R/ac= 6

NIFS-930901 / K.W & O.Mi

j=27A/mm2

A

B^ max

= 15T l

B^max µ (IHJ)1/2

High B design

- 2

- 1

0

1

2

2 3 4 5 6

Z (

m)

R (m)

g=1.18g=1.33

LHD Rax=3.6m, Bq=100%, F = 0∞

Expansion of blanket area

g = ÊË

ˆ¯

ml

aR

c

decrease

Continuos windinghelical coil

issue

SC materials &Current density

issue

MHD stabilityissue

Heat transfer & structure materials

issue

Sagara 5

SCmagnet

Self-cooled T breeder TBRlocal > 1.2

Radiation shield reduction > 5 orders Thermal shield

20°C

Vacuum vessel

T boundary&

Protection wall Ph =0.2 MW/mPn =1.5 MW/m Nd =450 dpa/30y

22

Be

T storage

Pump

Pump

Tank

HXPurifier

T-disengager

14MeV neutron

Turbine

Liquid / Gas

Structural Materials

In-vesselComponents

Blanket

Thermo-fluid

Tritium

June 6. 2003, A.Sagara

Safety& Cost

Chemistry

shielding materials.

high temp.surface heat flux

CorePlasma

Ignition access & heat fluxO.Mitarai(Kyusyu Tokai Univ.)

Helical core plasmaK.Yamazaki(NIFS)

Blanket systemS,Tanaka(Univ. of Tokyo)

Thermo-mechanical analysisH.Matsui(Tohoku Univ.)

Helical reactor design / Sytem IntegrationA.Sagara(NIFS)

Thermofluid systemK.Yuki(Tohoku Univ.)

Advanced thermofluid T.Kunugi(Kyoto Univ.)

Heat exchanger & gas turbine systemA.Shimizu(Kyusyu Univ.)

T-disengager systemS.Fukada, M.Nishikawa(Kyusyu Univ.)

Device system codeH.Hashizume(Tohoku Univ.)

Thermofluid MHD S.Satake(Tokyo Univ. Sci.)

Advanced first wallT.Norimatsu(Osaka Univ.)

Reactor design activity in NIFS collaborationReactor design activity in NIFS collaboration

• on goingcf. NIFS annual repo.

Flibe related

Sagara 6

Evaluation of tritium leak and permeation barrierEvaluation of tritium leak and permeation barrier( by S. ( by S. FukadaFukada ) )

He purge gas flow

W=2.2x10-4m3/s, Re=100, Sh=10

Flibe flow, W=2.1m3/s,Re=9x105, Sh=2x104

• With barrier of He sweep gas(W=220cc/s) and/or Flibe stagnant(t=0.5m) in double wall (100m2), theleak level is 1.6Ci/day < 10Ci/day.

Heat exchanger

pump

TritiumrecoveryFlibe blanket

Tritiumstorage

Flow rate2.3m3/s

Tritium generation rate (1 GWt)190 g-T/day = 1.8 MCi/day

Permeationbarrier

Double tube

Flibe/He gasPlasma

100 cm0

Self-cooled T breeder

Radiation shield Vacuum vessel

SCmagnet

LCFS

First wall

550°Ccoolant out

SOL

Thermal shield 450°Ccoolant in

20°C

7 53

T boundary&

Flibe

217 5

JLF-1(30vol. %)

1 1

&

Carbon10 ~ 20

JLF-1 + B4C(30 vol.%)

Be (60 vol.%)

• W/O barrier, 200Ci/m/day from ss316 tube ( t=5mm, f=0.7m)

100

101

102

103

104

105

106

Tri

tium

per

mea

tion

rate

per

leng

th [

Ci/m

day]

10-12

10-11

10-10

10-9

10-8

10-7

10-6

Tritium concentration in Flibe [weight fraction]

101

102

103

104

105

106

Tritium partial pressure in Flibe [Pa]

j/z=pdrFlibekM(xT-xoutside)

j/z=pdKp(xT0.5-xoutside

0.5)/tKH0.5

diffusion-in-Flibe controlling

permeation-through-wall controlling

Flibe, 600C, sus316tube

W=2.1m3/s, Re=8.5x10

5, Sc=870, Sh=1.9x10

4

corresponding to 190g/day

However, leakageinto the secondaryflow ~ 34kCi/day

Sagara 7

Permeation window system for Tritium RecoveryPermeation window system for Tritium Recovery

10-8

10-7

10-6

10-5

10-4

Tri

tiu

m m

ola

r fr

acti

on

in

Fli

be

[-]

101

102

103

104

105

Permeation area [m2]

103

104

105

106

Tri

tiu

m p

arti

al p

ress

ure

[P

a]

Fluid-film diffusion + permeation

ferrite-steel permeation window

T=843K, QT=190g-T/day, WFlibe=2.3m3/s

Permeation controlling

Fluid film diffusion controlling

Permeation window area [m2] (a=1, t=1mm)

Tritium leak

Large apparatus

By S. Fukada et al., Fusion Sci. Tech.41 (2002) 1054.

With the barrier for T leakage,operation at CT > 0.3ppm(PT2~ 20 kPa) is optimum

Diffusion of T2 in Flibe is therate-limiting process.

Recovery systems ofa realistic-scale ( the total <a few 100 m2) are possiblefor permeation windowdisengager systems.

Sagara 8A.Sagara

Japan-US joint project JUPITER-IIFrom FY2001 to 2006

����������������������������

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1-1-B: FLiBe Thermofluid Flow Simulation2-2 : SiC System Thermomechanics

1-2-A: Coatings for MHD Reduction

1-2-B: V Alloy Capsule Irradiation2-1 : SiC Fundamental Issues, Fabrication, and Materials Supply2-3 : SiC Capsule Irradiation

1-1-A: FLiBe Handling/Tritium.Chemistry������������

��� ��� ��� ���

3-1: Design-based Integration Modeling3-2: Materials Systems Modeling

Sagara 9

R & D collaboration program in LHD project R & D collaboration program in LHD project1. Development of the Molten Salt Forced

Circulation Loop Unit and Investigationon the High Heat Flux Removal Devicefor Divertor and Blanket Technologies

Tohoku Univ., Prof.S.Toda / A.Sagara(NIFS)

(FY1997 - 2000 - )

TNT loop

2. Ultrahigh Heat Transfer Enhancementusing Nano-Particle Porous Surface forDivertor and Blanket Technologies

Kyoto Univ., Prof.T.Kunugi / A.Sagara(NIFS)

(FY2004 - 2006 - )

Ultrahigh HT

July 4, ‘03

“2 timesenhancedby Kunugi”

High Pr fluid

Sagara 10

TTTTTTTToooohhhhooookkkkuuuuoooohhhhooookkkkuuuu----NNNN----NNNNIIIIFFFFSSSSIIIIFFFFSSSS TTTTTTTThhhheeeerrrrmmmmoooofffflllluuuuiiiiddddhhhheeeerrrrmmmmoooofffflllluuuuiiiidddd lllloooooooopppp lllloooooooopppp ffffoooorrrr mmmmoooolllltttteeeennnn ssssaaaallllttttffffoooorrrr mmmmoooolllltttteeeennnn ssssaaaalllltttt

TNT loopTNT loop�� u ~ Max.20 L/minu ~ Max.20 L/min

�� T ~ 600 T ~ 600°°CC

�� V ~ 0.1m V ~ 0.1m33

�� P ~ 0.7 P ~ 0.7 MPa MPa..

40 kW

Now HTS (simulant for Flibe) is used.

Sagara 11System diagram of TNT loop

• S.Toda, S.Chiba, K.Yuki, A. Sagara, “Experimental research on molten salt thermofluid technologyusing a high-temperature molten salt loop applied for a fusion reactor Flibe blanket”, Fusion. Eng.Des., 63-64, 405 (2002)

• M.Omae, “Experimental study about heat transfer enhancement for high temperature molten salt”,Master thesis of Tohoku Univ. (2003) [In Japanese]

• S.Chiba, “Study on improvement of thermofluid characteristics with optimization of flow field forhigh Prandtle-number fluid”, Doctoral thesis of Tohoku Univ. (2003) [In Japanese]

Sagara 12

Bird’s eye view of TNT loop

(Fabricated by IHI Co., Ltd.)

Upper Tank

Main Pump

Dump Tank

Air CoolerTestSection

ControlRoom

Sagara 13

Side view of TNT loop

Upper TankMain Pump

Dump Tank

Air Cooler

Sagara 14Elapsed time vs Temperature at each point of TNT loop (Heater Test)

0

100

200

300

400

500

600

700

0 5 10 15 20 25 30

Elapsed time (hr)

Te

mp

era

ture

(�

)TE11 Bottom of Dump Tank

TE12 Lateral of Dump Tank

TE27 Pipe connected at inlet of Upper Tank

TE22 Pipe to supply gas for flow meter

TE32 Inlet of Air Cooler

TE29 Heat transfer pipe (Upper row at Air Cooler)

TE14 Heat transfer pipe (Upper row at Air Cooler)

TE15 Heat transfer pipe (Upper row at Air Cooler)

TE16 Heat transfer pipe (Middle row at Air Cooler)

TE17 Heat transfer pipe (Middle row at Air Cooler)

TE18 Heat transfer pipe (Lower row at Air Cooler)

TE30 Heat transfer pipe (Lower row at Air Cooler)

TE19 Bottom of Upper Tank

TE02 Outlet of Air Cooler

TE13 Orifice flange

TE24 Pipe (Between Dump Tank and Main Pump)

TE23 Pipe (Between Dump Tank and flow meter)

TE31 Pipe (Betwenn Main Pump and Test Section)

TE25 Flange at outlet of Main Pump

TE03 Pipe connected at inlet of Test Section

TE21 Pipe (Between Test Section and Upper Tank)

TE01 Pipe connected at outlet of Test Section

TE20 Flange at outlet of Test Section

TE26 Test Section (dummy)

TE28 Main Pump

Sagara 15

pipe Insulatort=25 mm

Insulatort= 6 mm

Coppert= 0.5 mm

Insulatort= 25mm

Thermal insulator at Test Section and Schematic view of cross section

g

Sagara 16

Heat transfer enhancer at Heat transfer enhancer at low flow ratelow flow rate…… Packed-bed tube in TNT loop Packed-bed tube in TNT loop

Fig.Re vs heat transfer characteristics (at 300 mm)

Fig.Pump frequency vs heat transfer coefficient (at 300 mm)

About About 33 times higher than times higher thanturbulent heat transferturbulent heat transfer

300 mm

HERE

Flow

Fig. Flow structure near wall(Result of 2D numerical simulation)

19.5mm

5mm

Sagara 18

�FFHR design �with R&D

�JUPITER-II

R&D/LHD�TNT loop�Ultrahigh HT

FY1993 1997 2001 2004 2007

Molten salt R & D activities in Japan Molten salt R & D activities in Japan

2015

�ITER-TBM

$

$

$

Presented by A.Sagara(NIFS), Feb.’04