Transcript ARIES: Fusion Power Core and Power Cycle Engineering

ARIES-AT Blanket and Divertor
A. R. Raffray1, L. El-Guebaly2, S. Malang3, I. Sviatoslavsky2,
M. S. Tillack1, X. Wang1, and the ARIES Team
1University
of California, San Diego, 460 EBU-II, La Jolla, CA 92093-0417, USA
2University of Wisconsin, Fusion Technology Institute, 1500 Engineering Drive,
Madison, WI 53706-1687, USA
3Forschungszentrum Karlsruhe, Postfach 3640, D-76021 Karlsruhe, Germany
Presented at the 14th ANS Topical Meeting on the Technology of Fusion
Energy
Park City, Utah
October 16-19, 2000
October 16-19, 2000
A. R. Raffray, et al., ARIES-AT Blanket and Divertor, ANS Top. Meet. On TOFE 2000
1
Presentation Highlights How Design Was
Developed to Meet Overall Objective
Overall Objective
Outline
Develop ARIES-AT Blanket and
Divertor Designs to Achieve High
Performance while Maintaining:
• Attractive safety features
• Simple design geometry
• Reasonable design margins as
an indication of reliability
• Credible maintenance and
fabrication processes
• Power Cycle
Design Utilizes High-Temperature
Pb-17Li as Breeder and Coolant
and SiCf/SiC Composite as
Structural Material
• Fabrication
October 16-19, 2000
• Material
• ARIES-AT Reactor
• Blanket Design and Analysis
• Divertor Design and Analysis
• Conclusions
A. R. Raffray, et al., ARIES-AT Blanket and Divertor, ANS Top. Meet. On TOFE 2000
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Brayton Cycle Offers Best Near-Term Possibility
of Power Conversion with High Efficiency*
• Maximize potential gain from hightemperature operation with SiCf/SiC
• Compatible with liquid metal blanket
through use of IHX
• High efficiency translates in lower
COE and lower heat load
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Min. He Temp. in cycle = 35°C
3-stage compression with 2 inter-coolers
Turbine efficiency = 0.93
Compressor efficiency = 0.88
Recuperator effectiveness = 0.96
Cycle He fractional DP = 0.03
Max. Cycle He Temperature = 1050°C
Cycle efficiency = 0.585
*R.
Schleicher, A. R. Raffray, C. P. Wong, "An Assessment of the Brayton Cycle
for High Performance Power Plant," 14th ANS Top. Meet. On TOFE
October 16-19, 2000
A. R. Raffray, et al., ARIES-AT Blanket and Divertor, ANS Top. Meet. On TOFE 2000
3
SiCf/SiC Enables High Temperature Operation and its Low
Decay Heat Helps Accommodate LOCA and LOFA Events
W/O Serious Consequences on In-Reactor Structure1,2
Properties Used for Design Analysis Consistent with Suggestions from International
Town Meeting on SiCf/SiC Held at Oak Ridge National Laboratory in Jan. 20003
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Density
Density Factor
Young's Modulus
Poisson's ratio
Thermal Expansion Coefficient
Thermal Conductivity in Plane
Therm. Conductivity through Thickness
Maximum Allowable Combined Stress
Maximum Allowable Operating Temperature
Max. Allowable SiC/LiPb Interface Temperature
Maximum Allowable SiC Burnup
≈ 3200 kg/m3
0.95
≈ 200-300 GPa
0.16-0.18
4 ppm/°C
≈ 20 W/m-K
≈ 20 W/m-K
≈ 190 MPa
≈ 1000 °C
≈ 1000°C
≈ 3%*
1D.
Henderson, et al, and the ARIES Team, ”Activation, Decay Heat, and Waste Disposal Analyses for ARIES-AT Power Plant,"
Mogahed, et al, and the ARIES Team, ”Loss of Coolant and Loss of Flow Analyses for ARIES-AT Power Plant," 14th ANS T. M. On TOFE
3See: http://aries.ucsd.edu/PUBLIC/SiCSiC/, also A. R. Raffray, et al., “Design Material Issues for SiC /SiC-Based Fusion Power Cores,”
f
submitted to Fusion Engineering & Design, August 2000
* From ARIES-I
2E.
October 16-19, 2000
A. R. Raffray, et al., ARIES-AT Blanket and Divertor, ANS Top. Meet. On TOFE 2000
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ARIES-AT Machine and Power Parameters1,2
Power and Neutronics3 Parameters
Fusion Power
Neutron Power
Alpha Power
Current Drive Power
Overall Energy Multiplicat.
Tritium Breeding Ratio
Total Thermal Power
Ave. FW Surf. Heat Flux
Max. FW Surf. Heat
Average Wall Load
Maximum O/B Wall Load
Maximum I/B Wall Load
1719 MW
1375 MW
344 MW
25 MW
1.1
1.1
1897 MW
0.26 MW/m2
0.34 MW/m2
3.2 MW/m2
4.8 MW/m2
3.1 MW/m2
Machine Geometry
Major Radius
Minor Radius
FW Location at O/B Midplane
FW Location at Lower O/B
I/B FW Location
5.2 m
1.3 m
6.5 m
4.9 m
3.9 m
Toroidal Magnetic Field
On-axis Magnetic Field
Magnetic Field at I/B FW
Magnetic Field at O/B FW
5.9 T
7.9 T
4.7 T
1F.
Najmabadi, et al.and the ARIES Team, “Impact of Advanced Technologies on Fusion Power Plant Characteristics,” 14th ANS Top. M.on TOFE
L. Miller and the ARIES Team, “Systems Context of the ARIES-AT Conceptual Fusion Power Plant,” 14th ANS Top. Meet. On TOFE
3L. A. El-Guebaly and the ARIES Team, “Nuclear Performance Assessment for ARIES-AT Power Plant,” 14th ANS Top. Meet. On TOFE
2R.
October 16-19, 2000
A. R. Raffray, et al., ARIES-AT Blanket and Divertor, ANS Top. Meet. On TOFE 2000
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Cross-Section and Plan View of ARIES-AT
Showing Power Core Components
October 16-19, 2000
A. R. Raffray, et al., ARIES-AT Blanket and Divertor, ANS Top. Meet. On TOFE 2000
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ARIES-AT Blanket Utilizes a 2-Pass Coolant
Approach to Uncouple Structure Temperature from
Outlet Coolant Temperature
ARIES-AT Outboard Blanket Segment Configuration
Maintain blanket
SiCf/SiC temperature
(~1000°C) < Pb-17Li
outlet temperature
(~1100°C)
October 16-19, 2000
A. R. Raffray, et al., ARIES-AT Blanket and Divertor, ANS Top. Meet. On TOFE 2000
7
Poloidal Distribution of Surface Heat Flux
and Neutron Wall Load
October 16-19, 2000
A. R. Raffray, et al., ARIES-AT Blanket and Divertor, ANS Top. Meet. On TOFE 2000
8
Moving Coordinate Analysis to Obtain Pb-17Li
Temperature Distribution in ARIES-AT First Wall
Channel and Inner Channel
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Assume MHD-flowlaminarization effect
Use plasma heat flux poloidal
profile
Use volumetric heat
generation poloidal and radial
profiles
Iterate for consistent
boundary conditions for heat
flux between Pb-17Li inner
channel zone and first wall
zone
Calibration with ANSYS 2-D
results
October 16-19, 2000
First Wall
Channel
vback
Pb-17Li
q''plasma
q''back
Inner
Channel
Poloidal
q'''LiPb
Radial
SiC/SiC
First Wall
vFW
Out
SiC/SiC Inner Wall
A. R. Raffray, et al., ARIES-AT Blanket and Divertor, ANS Top. Meet. On TOFE 2000
9
Temperature Distribution in ARIES-AT Blanket
Based on Moving Coordinate Analysis
Max. SiC/PbLi Interf.
Temp. = 994 °C
Pb-17Li Outlet
Pb-17Li Inlet
Temp. = 1100 °C
Temp. = 764 °C
• Pb-17Li Inlet Temp. = 764 °C
• Pb-17Li Outlet Temp. = 1100 °C
FW Max. CVD • From Plasma Side:
- CVD SiC Thickness = 1 mm
and SiC/SiC
- SiCf/SiC Thickness = 4 mm
Temp. =
1009°C° and
(SiCf/SiC k = 20 W/m-K)
996°C°
- Pb-17Li Channel Thick. = 4 mm
- SiC/SiC Separ. Wall Thick. = 5 mm
(SiCf/SiC k = 6 W/m-K)
• Pb-17Li Vel. in FW Channel= 4.2 m/s
• Pb-17Li Vel. in Inner Chan. = 0.1 m/s
• Plasma heat flux profile assuming no
radiation from divertor
October 16-19, 2000
A. R. Raffray, et al., ARIES-AT Blanket and Divertor, ANS Top. Meet. On TOFE 2000
10
Detailed Stress Analysis of Blanket Module to Maintain
Conservative Margins as Reliability Measure
e.g. Stress Analysis of Outboard Module
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6 modules per outboard segment
Side walls of all inner modules are pressure
balanced except for outer modules which
must be reinforced to accommodate the Pb17Li pressure (1 MPa)
For a 2-cm thick outer module side wall, the
maximum pressure stress = 85 MPa
The side wall can be tapered radially to
reduce the SiC volume fraction and benefit
tritium breeding while maintaining a uniform
stress
The thermal stress at this location is small
and the sum of the pressure and thermal
stresses is << 190 MPa
The maximum pressure stress + thermal
stress at the first wall ~60+113 MPa.
October 16-19, 2000
A. R. Raffray, et al., ARIES-AT Blanket and Divertor, ANS Top. Meet. On TOFE 2000
11
Reference Divertor Design Utilizes
Pb-17Li as Coolant
• Single power core cooling
system
• Low pressure and
pumping power
• Analysis indicates that
proposed configuration
can accommodate a
maximum heat flux of
~5-6 MW/m2
• Alternate Options
- He-Cooled Tungsten Porous
Heat Exchanger (ARIES-ST)
- Liquid Wall (Sn-Li)
October 16-19, 2000
Outlet Pb-17LiManifold
Outboard
Divertor Plate
SiCf/SiC Poloidal Channels
Tungsten Armor
Inlet Pb-17LiManifold
A. R. Raffray, et al., ARIES-AT Blanket and Divertor, ANS Top. Meet. On TOFE 2000
12
ARIES-AT Divertor Configuration and
Pb-17Li Cooling Scheme
Accommodating MHD Effects:
• Minimize Interaction Parameter (<1) (Strong Inertial Effects)
• Flow in High Heat Flux Region Parallel to Magnetic Field (Toroidal)
• Minimize Flow Length and Residence Time
• Heat Transfer Analysis Based on MHD-Laminarized Flow
LiPb Poloidal Flow in ARIES-AT
Divertor Header
Example schematic illustration
of 2-toroidal-pass scheme
for divertor PFC cooling
Plasma q''
Poloidal
Direction
A
A
Cross-Section A-A
Toroidal
Direction
October 16-19, 2000
A. R. Raffray, et al., ARIES-AT Blanket and Divertor, ANS Top. Meet. On TOFE 2000
13
Temperature Distribution in Outer Divertor PFC
Channel Assuming MHD-Laminarized LiPb Flow
BT
PFC

0
0.001
0.002
0.003
0.004
0.005
1200
1100
1000
1000
900
900
800
800
Temperature (°C)
1200
1100
700
700
600
0
0.005
0.01
Toroidal distance (m) 0.015
0.02
0.001
0.002
0.003
0.004 Radial distance (m)
0.005
0.006
Tungsten
SiC/SiC
LiPb
October 16-19, 2000
LiPb LiPb
1100
1000
900
800
700
600
• 2-D Moving Coordinate Analysis
• Inlet temperature = 653°C
• W thickness = 3 mm
• SiCf/ SiC Thickness = 0.5 mm
• Pb-17Li Channel Thickness = 2 mm
• SiCf/SiC Inner Wall Thick. = 0.5 mm
• LiPb Velocity = 0.35 m/s
• Surface Heat Flux = 5 MW/m2
Max. W Temp. = 1150°C
Max. SiCf/ SiC Temp. = 970°C
A. R. Raffray, et al., ARIES-AT Blanket and Divertor, ANS Top. Meet. On TOFE 2000
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Divertor Channel Geometry Optimized
for Acceptable Stress and Pressure Drop
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2-cm toroidal dimension and 2.5 mm minimum
W thickness selected (+ 1mm sacrificial layer)
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SiCf/SiC thermal pressure stress ~ 160+30 MPa
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DP minimized to ~0.55/0.7 MPa for lower/upper
divertor
PFC
BT

LiPb LiPb
Pressure Stress
2.00
Inner Channel
Pressure Drop (MPa)
Orifice
PFC Channel
1.50
Thermal Stress
Total
1.00
0.50
0.00
0
0.01
0.02
0.03
0.04
Toroidal Dimension of Divertor Channel (m)
October 16-19, 2000
0.05
A. R. Raffray, et al., ARIES-AT Blanket and Divertor, ANS Top. Meet. On TOFE 2000
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Develop Plausible Fabrication Procedures and
Minimize Joints in High Irradiation Region
E.g. First Outboard Region Blanket Segment
1. Manufacture separate halves of the
SiCf/SiC poloidal module by SiCf weaving
and SiC Chemical Vapor Infiltration
(CVI) or polymer process;
2. Manufacture curved section of inner shell
in one piece by SiCf weaving and SiC
Chemical Vapor Infiltration (CVI) or
polymer process;
3. Slide each outer shell half over the freefloating inner shell;
4. Braze the two half outer shells together at
the midplane;
Brazing
procedure
selected for
reliable
joint contact
area
Butt joint
Mortise and tenon joint
Lap joint
Tapered butt joint
Double lap joint
Tapered lap joint
5. Insert short straight sections of inner shell
at each end;
October 16-19, 2000
A. R. Raffray, et al., ARIES-AT Blanket and Divertor, ANS Top. Meet. On TOFE 2000
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ARIES-AT First Outboard Region Blanket
Segment Fabrication Procedure (cont.)
6. Form a segment by brazing six modules
together (this is a bond which is not in
contact with the coolant; and
7. Braze caps at upper end and annular
manifold connections at lower end of the
segment.
October 16-19, 2000
A. R. Raffray, et al., ARIES-AT Blanket and Divertor, ANS Top. Meet. On TOFE 2000
17
Maintenance Methods Allow for End-of-Life
Replacement of Individual Components*
* L. M. Waganer, “Comparing Maintenance Approaches for Tokamak Fusion Power Plants,” 14th ANS Topical Meeting on TOFE
October 16-19, 2000
A. R. Raffray, et al., ARIES-AT Blanket and Divertor, ANS Top. Meet. On TOFE 2000
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Typical Blanket and Divertor Parameters
for Design Point
Blanket Outboard Region 1
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No. of Segments
No. of Modules per Segment
Module Poloidal Dimension
Avg. Module Toroidal Dimen.
FW SiC/SiC Thickness
FW CVD SiC Thickness
FW Annular Channel Thickness
Avg. LiPb Velocity in FW
FW Channel Re
FW Channel Transverse Ha
MHD Turbulent Transition Re
FW MHD Pressure Drop
Maximum SiC/SiC Temp.
Maximum CVD SiC Temp. (°C)
Max. LiPb/SiC Interface Temp.
Avg. LiPb Vel. in Inner Channel
October 16-19, 2000
Divertor
32
6
6.8 m
0.19 m
4 mm
1 mm
4 mm
4.2 m/s
3.9 x 105
4340
2.2 x 106
0.19 MPa
996°C
1009 °C
994°C
0.11 m/s
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Poloidal Dimension (Outer/Inner)
1.5/1.0 m
Divertor Channel Toroidal Pitch
2.1 cm
Divertor Channel Radial Dimension
3.2 cm
No. of Divertor Channels (Outer/Inner)
1316/1167
SiC/Si Plasma-Side Thickness
0.5 mm
W Thickness
3.5 mm
PFC Channel Thickness
2 mm
Number of Toroidal Passes
2
Outer Div. PFC Channel V (Lower/Upper)
0.35/0.42 m/s
LiPb Inlet Temperature (Outer/Inner)
653/719 °C
Pressure Drop (Lower/Upper)
0.55/0.7 MPa
Max. SiC/SiC Temp. (Lower/Upper) 970/950°C
Maximum W Temp. (Lower/Upper)
1145/1125°C
W Pressure + Thermal Stress
~35+50 MPa
SiC/SiC Pressure + Thermal Stress
~35+160 MPa
Toroidal Dimension of Inlet and Outlet Slot
1 mm
Vel. in Inlet & Outlet Slot to PFC Channel
0.9-1.8 m/s
Interaction Parameter in Inlet/Outlet Slot
0.46-0.73
A. R. Raffray, et al., ARIES-AT Blanket and Divertor, ANS Top. Meet. On TOFE 2000
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Conclusions
• ARIES-AT Blanket and Divertor Design Based on High-Temperature
Pb-17Li as Breeder and Coolant and SiCf/SiC Composite as Structural
Material
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High performance
Attractive safety features
Simple design geometry
Reasonable design margins as an indication of reliability
Credible maintenance and fabrication processes
• Key R&D Issues
– SiCf/SiC fabrication/joining, and material properties at high temperature
and under irradiation including:
• Thermal conductivity, maximum temperature, lifetime
– MHD effects in particular for the divertor
October 16-19, 2000
A. R. Raffray, et al., ARIES-AT Blanket and Divertor, ANS Top. Meet. On TOFE 2000
20