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Transcript of Fusion Power Plants: Visions and Development Pathway Farrokh Najmabadi UC San Diego 15 th ICENES May...
![Page 1: Fusion Power Plants: Visions and Development Pathway Farrokh Najmabadi UC San Diego 15 th ICENES May 15 – 19, 2011 San Francisco, CA You can download a.](https://reader031.fdocuments.net/reader031/viewer/2022032201/56649cfa5503460f949ccc46/html5/thumbnails/1.jpg)
Fusion Power Plants: Visions and Development Pathway
Farrokh NajmabadiUC San Diego
15th ICENESMay 15 – 19, 2011San Francisco, CA
You can download a copy of the paper and the presentation from the ARIES Web Site:
ARIES Web Site: http://aries.ucsd.edu/ARIES/
![Page 2: Fusion Power Plants: Visions and Development Pathway Farrokh Najmabadi UC San Diego 15 th ICENES May 15 – 19, 2011 San Francisco, CA You can download a.](https://reader031.fdocuments.net/reader031/viewer/2022032201/56649cfa5503460f949ccc46/html5/thumbnails/2.jpg)
The ARIES Team Has Examined Many Fusion Concepts As Power Plants
Focus of the talk is on Tokamak studies: ARIES-I first-stability tokamak (1990)
ARIES-III D-3He-fueled tokamak (1991)
ARIES-II and -IV second-stability tokamaks (1992)
Pulsar pulsed-plasma tokamak (1993)
Starlite study (1995) (goals & technical requirements for power plants & Demo)
ARIES-RS reversed-shear tokamak (1996)
ARIES-AT advanced technology and advanced tokamak (2000)
Criteria for power plant attractiveness were developed in consultation with Electric Utilities and Industry
![Page 3: Fusion Power Plants: Visions and Development Pathway Farrokh Najmabadi UC San Diego 15 th ICENES May 15 – 19, 2011 San Francisco, CA You can download a.](https://reader031.fdocuments.net/reader031/viewer/2022032201/56649cfa5503460f949ccc46/html5/thumbnails/3.jpg)
Nature of Power Plant Studies has evolved in time.
Concept Exploration (< 1990) Limited physics/engineering trade-offs due to lack of physic
understanding. The only credible vision was a large, expensive pulsed
tokamak with many engineering challenges (e.g., thermal energy storage).
Concept Definition ( ~ 1990-2005) Finding credible embodiments (Credible in a “global” sense). Better physics understanding allowed optimization of steady-
state plasma operation and physics/engineering trade-offs.
Concept Feasibility and Optimization (> 2010) Detailed analysis of subsystems to resolve feasibility issues. Trade-offs among extrapolation and attractiveness.
![Page 4: Fusion Power Plants: Visions and Development Pathway Farrokh Najmabadi UC San Diego 15 th ICENES May 15 – 19, 2011 San Francisco, CA You can download a.](https://reader031.fdocuments.net/reader031/viewer/2022032201/56649cfa5503460f949ccc46/html5/thumbnails/4.jpg)
For the same physics and technology basis, steady-state devices outperform pulsed tokamaks
ARIES-I’Pulsar*
Medium (~ 8 m major radius)High (~ 9 m major radius)Size and Cost
Non-inductive driveExpensive & inefficient
PF SystemVery expensive but efficientCurrent-drive system
HighLowRecirculating Power
High Bootstrap, High A, Low IHigh Bootstrap, High A, Low IOptimum Plasma Regime
Yes, 65-%-75% bootstrap fraction, bN~ 3.3, ~ 1.9%b
No, 30%-40% bootstrap fractionbN~ 3, ~ 2.1%bCurrent profile Control
Higher (B ~ 16 T on coil) Lower because of interaction with PF (B ~ 14 T on coil)
Toroidal-Field Strength
MediumLowPower Density
* Many engineering challenges such as thermal energy storage,lower performance of fusion core due to thermal cycling, etc.
![Page 5: Fusion Power Plants: Visions and Development Pathway Farrokh Najmabadi UC San Diego 15 th ICENES May 15 – 19, 2011 San Francisco, CA You can download a.](https://reader031.fdocuments.net/reader031/viewer/2022032201/56649cfa5503460f949ccc46/html5/thumbnails/5.jpg)
Improving Economic Competitiveness
Reducing life-cycle cost: 80s goals:
Low recirculating power; High power density;
Later Additions High thermal conversion
efficiency; Less-expensive systems.
Mass power density= net electric output / mass of fusion core
QE = net electric output / recirculating electric power
![Page 6: Fusion Power Plants: Visions and Development Pathway Farrokh Najmabadi UC San Diego 15 th ICENES May 15 – 19, 2011 San Francisco, CA You can download a.](https://reader031.fdocuments.net/reader031/viewer/2022032201/56649cfa5503460f949ccc46/html5/thumbnails/6.jpg)
Directions for Improvement
Increase Power Density (1/Vp)What we pay for,VFPC
rD
r > D r ~ D r < D Improvement “saturates” at ~5 MW/m2 peak wall loading
(for a 1GWe plant). A steady-state, first stability device with Nb3Sn
technology has a power density about 1/3 of this goal.
Big Win Little
Gain
Decrease Recirculating Power Fraction Improvement “saturates” at plasma Q ~ 40. A steady-state, first stability device with Nb3Sn Tech.
has a recirculating fraction about 1/3 of this goal.
High-Field Magnets ARIES-I with 19 T at
the coil (cryogenic). Advanced SSTR-2
with 21 T at the coil (HTS).
High bootstrap, High b 2nd Stability: ARIES-II/IV Reverse-shear: ARIES-
RS, ARIES-AT, A-SSRT2
![Page 7: Fusion Power Plants: Visions and Development Pathway Farrokh Najmabadi UC San Diego 15 th ICENES May 15 – 19, 2011 San Francisco, CA You can download a.](https://reader031.fdocuments.net/reader031/viewer/2022032201/56649cfa5503460f949ccc46/html5/thumbnails/7.jpg)
ARIES-AT
5.2
9.2% (5.4)
11.5
3.3
36
0.14
0.59
5
COE insensitive of current drive
COE insensitive of power density
Evolution of ARIES Tokamak Designs
1st Stability, Nb3Sn Tech.
ARIES-I’
Major radius (m) 8.0
(b bN) 2% (2.9)
Peak field (T) 16
Avg. Wall Load (MW/m2) 1.5
Current-driver power (MW) 237
Recirculating Power Fraction 0.29
Thermal efficiency 0.46
Cost of Electricity (c/kWh) 10
Reverse Shear Option
High-FieldOption
ARIES-I
6.75
2% (3.0)
19
2.5
202
0.28
0.49
8.2
ARIES-RS
5.5
5% (4.8)
16
4
81
0.17
0.46
7.5
![Page 8: Fusion Power Plants: Visions and Development Pathway Farrokh Najmabadi UC San Diego 15 th ICENES May 15 – 19, 2011 San Francisco, CA You can download a.](https://reader031.fdocuments.net/reader031/viewer/2022032201/56649cfa5503460f949ccc46/html5/thumbnails/8.jpg)
A range of attractive tokamak power plants is available.
Estimated Cost of Electricity
(1992 c/kWh)
0
2
4
6
8
10
12
14
Mid 80'sPhysics
Early 90'sPhysics
Late 90's Physics
AdvancedTechnology
Major radius (m)
0
1
2
3
4
5
6
7
8
9
10
Mid 80's Pulsar
Early 90'sARIES-I
Late 90'sARIES-RS
2000 ARIES-AT
Approaching COE insensitive of power density High Thermal Efficiency
High b is used to lower magnetic field
![Page 9: Fusion Power Plants: Visions and Development Pathway Farrokh Najmabadi UC San Diego 15 th ICENES May 15 – 19, 2011 San Francisco, CA You can download a.](https://reader031.fdocuments.net/reader031/viewer/2022032201/56649cfa5503460f949ccc46/html5/thumbnails/9.jpg)
Fusion Technologies Have a Dramatic Impact of Attractiveness of Fusion
![Page 10: Fusion Power Plants: Visions and Development Pathway Farrokh Najmabadi UC San Diego 15 th ICENES May 15 – 19, 2011 San Francisco, CA You can download a.](https://reader031.fdocuments.net/reader031/viewer/2022032201/56649cfa5503460f949ccc46/html5/thumbnails/10.jpg)
ARIES-I Introduced SiC Composites as A High-Performance Structural Material for Fusion
SiC composites are attractive structural material for fusion Excellent safety & environmental
characteristics (very low activation and very low afterheat).
High performance due to high strength at high temperatures (>1000
oC).
Large world-wide program in SiC: New SiC composite fibers with proper
stoichiometry and small O content. New manufacturing techniques based on
polymer infiltration or CVI result in much improved performance and cheaper components.
Recent results show composite thermal conductivity (under irradiation) close to 15 W/mK which was used for ARIES-I.
SiC composites are attractive structural material for fusion Excellent safety & environmental
characteristics (very low activation and very low afterheat).
High performance due to high strength at high temperatures (>1000
oC).
Large world-wide program in SiC: New SiC composite fibers with proper
stoichiometry and small O content. New manufacturing techniques based on
polymer infiltration or CVI result in much improved performance and cheaper components.
Recent results show composite thermal conductivity (under irradiation) close to 15 W/mK which was used for ARIES-I.
![Page 11: Fusion Power Plants: Visions and Development Pathway Farrokh Najmabadi UC San Diego 15 th ICENES May 15 – 19, 2011 San Francisco, CA You can download a.](https://reader031.fdocuments.net/reader031/viewer/2022032201/56649cfa5503460f949ccc46/html5/thumbnails/11.jpg)
Continuity of ARIES research has led to the progressive refinement of research
High efficiency with Brayton cycle at high temperature
Imp
rove
d B
lan
ket
Tech
no
log
y
ARIES-I: • SiC composite with solid breeders• Advanced Rankine cycle
ARIES-RS:• Li-cooled vanadium• Insulating coating
ARIES-ST: • Dual-cooled ferritic steel with SiC inserts• Advanced Brayton Cycle at 650 oC
ARIES-AT: • LiPb-cooled SiC composite • Advanced Brayton cycle with h = 59%
Many issues with solid breeders; Rankine cycle efficiency saturated at high temperature
Max. coolant temperature limited by maximum structure temperature
![Page 12: Fusion Power Plants: Visions and Development Pathway Farrokh Najmabadi UC San Diego 15 th ICENES May 15 – 19, 2011 San Francisco, CA You can download a.](https://reader031.fdocuments.net/reader031/viewer/2022032201/56649cfa5503460f949ccc46/html5/thumbnails/12.jpg)
Outboard blanket & first wall
ARIES-AT features a high-performance blanket
Simple, low pressure design with SiC structure and LiPb coolant and breeder.
Innovative design leads to high LiPb outlet temperature (~1,100oC) while keeping SiC structure temperature below 1,000oC leading to a high thermal efficiency of ~ 60%.
Simple manufacturing technique.
Very low afterheat.
Class C waste by a wide margin.
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Design leads to a LiPb Outlet Temperature of 1,100oC While Keeping SiC Temperature Below 1,000oC
• Two-pass PbLi flow, first pass to cool SiCf/SiC box second pass to superheat PbLi
q''plasma
Pb-17Li
q'''LiPb
Out
q''back
vback
vFW
Poloidal
Radial
Inner Channel
First Wall Channel
SiC/SiCFirst Wall SiC/SiC Inner Wall
700
800
900
1000
1100
1200800
900
1000
1100
1200
1
2
3
4
5
6
00.020.040.060.080.1
00.020.040.060.080.1
Radial distance (m)
Poloidaldistance(m)
SiC/SiC
Pb-17Li
Bottom
Top
PbLi Outlet Temp. = 1100 °C
Max. SiC/PbLi Interf. Temp. = 994 °C
Max. SiC/SiC Temp. = 996°C
PbLi Inlet Temp. = 764 °C
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Modular sector maintenance enables high availability
Full sectors removed horizontally on rails Transport through maintenance corridors to hot
cells Estimated maintenance time < 4 weeks
ARIES-AT elevation view
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10-7
10-6
10-5
10-4
10-3
10-2
10-1
100
101
104 105 106 107 108 109 1010 1011
ARIES-STARIES-RS
Act
ivit
y (C
i/W th
)
Time Following Shutdown (s)
1 mo 1 y 100 y1 d
After 100 years, only 10,000 Curies of radioactivity remain in the585 tonne ARIES-RS fusion core.
After 100 years, only 10,000 Curies of radioactivity remain in the585 tonne ARIES-RS fusion core.
SiC composites lead to a very low activation and afterheat.
All components of ARIES-AT qualify for Class-C disposal under NRC and Fetter Limits. 90% of components qualify for Class-A waste.
SiC composites lead to a very low activation and afterheat.
All components of ARIES-AT qualify for Class-C disposal under NRC and Fetter Limits. 90% of components qualify for Class-A waste.
Ferritic SteelVanadium
Radioactivity levels in fusion power plantsare very low and decay rapidly after shutdown
Level in Coal AshLevel in Coal Ash
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Fusion Core Is Segmented to Minimize the Rad-Waste
Only “blanket-1” and divertors are replaced every 5 years
Only “blanket-1” and divertors are replaced every 5 years
Blanket 1 (replaceable)
Blanket 2 (lifetime)
Shield (lifetime)
![Page 17: Fusion Power Plants: Visions and Development Pathway Farrokh Najmabadi UC San Diego 15 th ICENES May 15 – 19, 2011 San Francisco, CA You can download a.](https://reader031.fdocuments.net/reader031/viewer/2022032201/56649cfa5503460f949ccc46/html5/thumbnails/17.jpg)
Waste volume is not large
0
50
100
150
200
250
300
350
400
Blanket Shield VacuumVessel
Magnets Structure Cryostat
Cu
mu
lati
ve
Co
mp
ac
ted
Wa
ste
Vo
lum
e (
m3
)
1270 m3 of Waste is generated after 40 full-power year (FPY) of operation.Coolant is reused in other power plants 29 m3 every 4 years (component replacement), 993 m3 at end of service
Equivalent to ~ 30 m3 of waste per FPYEffective annual waste can be reduced by increasing plant service life.
1270 m3 of Waste is generated after 40 full-power year (FPY) of operation.Coolant is reused in other power plants 29 m3 every 4 years (component replacement), 993 m3 at end of service
Equivalent to ~ 30 m3 of waste per FPYEffective annual waste can be reduced by increasing plant service life.
0
200
400
600
800
1000
1200
1400
Class A Class C
Cumu
lative
Comp
acted
Was
te Vo
lume (
m3)
90% of waste qualifies for Class A disposal
90% of waste qualifies for Class A disposal
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Some thoughts on Fusion Development
![Page 19: Fusion Power Plants: Visions and Development Pathway Farrokh Najmabadi UC San Diego 15 th ICENES May 15 – 19, 2011 San Francisco, CA You can download a.](https://reader031.fdocuments.net/reader031/viewer/2022032201/56649cfa5503460f949ccc46/html5/thumbnails/19.jpg)
Nature of Power Plant Studies has evolved in time.
Concept Exploration (< 1990) Limited physics/engineering trade-offs due to lack of physic
understanding. The only credible vision was a large, expensive pulsed
tokamak with many engineering challenges (e.g., thermal energy storage).
Concept Definition ( ~ 1990-2005) Finding credible embodiments (Credible in a “global” sense). Better physics understanding allowed optimization of steady-
state plasma operation and physics/engineering trade-offs.
Concept Feasibility and Optimization (> 2010) Detailed analysis of subsystems to resolve feasibility issues. Trade-offs among extrapolation and attractiveness.
![Page 20: Fusion Power Plants: Visions and Development Pathway Farrokh Najmabadi UC San Diego 15 th ICENES May 15 – 19, 2011 San Francisco, CA You can download a.](https://reader031.fdocuments.net/reader031/viewer/2022032201/56649cfa5503460f949ccc46/html5/thumbnails/20.jpg)
ITER has changed the magnetic fusion landscape
ITER has heightened understanding of many subsystem issues: New sets of physics information/correlations has been
developed to define design requirements for many subsystems (e.g., in-vessel components, transients).
Realities of designing practical systems to be built.
Increased interest in fusion nuclear engineering and material Realization that new material and technologies have to be
developed now.
![Page 21: Fusion Power Plants: Visions and Development Pathway Farrokh Najmabadi UC San Diego 15 th ICENES May 15 – 19, 2011 San Francisco, CA You can download a.](https://reader031.fdocuments.net/reader031/viewer/2022032201/56649cfa5503460f949ccc46/html5/thumbnails/21.jpg)
New Paradigms for Power Plant Studies in the ITER area
Detailed design of subsystems in context of a power plant environment and constraints Can only be done one system at a time. Parametric surveys to understand physics/engineering trade-offs. Sophisticated computational tools are now widely available. Interaction with material and R&D community to indentify material
properties and R&D needs. Current ARIES project is focusing on detailed design of in-
vessel components.
System Tools to analyze trade-offs among R&D risks and benefits. A new System approach based on the survey of parameter
space as opposed to optimizing to a design point.
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Thank you!