Overview of Fusion, ITER, and
Fusion Nuclear Technology
Mohamed Abdou
Distinguished Professor of Engineering and Applied Science
Director, Center for Energy Science and Technology (CESTAR)
Director, Fusion Science and Technology Center
University of California, Los Angeles (UCLA)
web: http://www.fusion.ucla.edu/abdou/
Lecture at the symposium "Towards a Mexican Fusion Programme"
21-22 June, 2007
held at Universidad Nacional Autonoma de Mexico
Outline
• World Energy Scene
• What is fusion and Why we need it
• ITER
• Fusion Nuclear Technology (FNT)
– Principles
– Concepts
– Issues
• Facilities for FNT Development
– ITER Test Blanket
– CTF/VNS
• Framework for FNT Development
Global Economics and Energy
Population
GDP
Energy Demand
Billions
Trillion (2000$)
10
80
Average Growth / Yr.
2000 - 2030
70
8
0.9%
60
MBDOE
350
2.8%
1.6%
300
250
50
6
4.7%
40
4
2
1.1%
OECD
0
1950
1990
0.4%
100
2030
2.2%
10
0
1950
2.4%
150
30
20
Non-OECD
200
0.7%
50
1990
2030
0
1950
1990
2030
Carbon dioxide levels over the last 60,000 years - we are
provoking the atmosphere!
Source:
University of Berne and
US National Oceanic and Atmospheric Administration
Energy Situation
•
The world uses a lot of energy
– Average power consumption = 13.6 TW (2.2 KW per person)
– World energy market ~ $3 trillion / yr (electricity ~ $1 trillion / yr)
•
The world energy use is growing
- to lift people out of poverty, to improve standard of living, and to
meet population growth
•
Climate change and debilitating pollution Concerns are on
the rise
– 80% of energy is generated by fossil fuels
– CO2 emission is increasing at an alarming rate
•
Oil supplies are dwindling
– Special problem for transportation sector (need alternative fuel)
Solving the Energy Problem Requires a
Diversified Portfolio and
Pursuing Several Approaches
•
Develop major new (clean) energy sources
(e.g. fusion)
•
Expand use of existing “clean” energy sources
(e.g. nuclear, solar, wind)
•
Develop technologies to reduce impact of fossil
fuels use (e.g. carbon capture and sequestration)
•
Improve energy efficiency
•
Develop alternate (synthetic) fuels for
transportation
Nuclear energy Must be significantly
expanded over the next century
• Large scale deployment of fusion is needed by mid-century but
significant challenges remain
– Physics and engineering maturation
– Confidence in the private sector
• Economics require both capital investment and O&M (Utilities
will look to >90% capacity factors)
• Advanced Fission can be the bridge
– Improved reactors are required and do exist!
• Better fuel utilization and reduced waste generation
• An integrated transition path from Fission to Fusion needs to be
developed
– Fusion must learn from fission experience and synergy needs to be
developed
• Fusion Nuclear Technology and Materials
• End use applications
• The long term nuclear options are limited
– Generation IV thermal and breeder reactors
– fusion
Incentives for Developing Fusion
Fusion powers the Sun and the stars
 It is now within reach for use on Earth
In the fusion process lighter elements are “fused” together,
making heavier elements and producing prodigious amounts
of energy
Fusion offers very attractive features:
 Sustainable energy source
(for DT cycle; provided that Breeding Blankets are successfully
developed)
 No emission of Greenhouse or other polluting gases
 No risk of a severe accident
 No long-lived radioactive waste
Fusion energy can be used to produce electricity and
hydrogen, and for desalination
The world needs large scale
deployment of fusion by mid-century!
• 1950-2010
– The Physics of Plasmas
• 2010-2030
– The Physics of Fusion
– The “Fermi Demonstration” - Fusion-heated and sustained
• Q = (Ef / Einput )~10
• 2010-2040
– Fusion Nuclear Technology for Fusion
– DEMO by 2040
• 2050 ?
– Large scale deployment!
The World Fusion Program has a Goal for a
Demonstration Power Plant (DEMO) by ~2040
Poloidal Ring Coil
Cryostat
Coil Gap
Rib Panel
Blanket
Maint.
Port
Plasma
Vacuum
Vessel
Center Solenoid Coil
Toroidal Coil
JAEA DEMO Design
ITER
• The World is about to construct the next
step in fusion development, a device
called ITER
• ITER will demonstrate the scientific and
technological feasibility of fusion energy
for peaceful purposes
• ITER will produce 500 MW of fusion power
• Cost, including R&D, is 15 billion dollars
ITER Objectives
Programmatic
• Demonstrate the scientific and technological feasibility
of fusion energy for peaceful purposes.
Technical
• Demonstrate extended burn of DT plasmas, with steady
state as the ultimate goal.
• Integrate and test fusion technologies
• Demonstrate safety and environmental acceptability of
fusion.
ITER is a collaborative effort among Europe,
Japan, US, Russia, China, South Korea, and India
ITER Design - Main Features
Central
Solenoid
Outer Intercoil
Structure
Blanket
Module
Vacuum Vessel
Cryostat
Toroidal Field Coil
Port Plug (IC Heating
Poloidal Field Coil
Divertor
Machine Gravity Supports
Torus Cryopump
ITER Magnet System
The magnet system for ITER consists of 18 toroidal field (TF) coils, a central
solenoid (CS), six poloidal field (PF) coils and 18 correction coils (CCs).
The magnet system creates
a doughnut-shaped
magnetic field to confine
charged particles plasma.
ITER Blanket System
The basic function of the
blanket system is to provide
the main thermal and nuclear
shielding to the vessel and
external machine components.
FW Panel
Total number of
blanket modules: 421
Shield module
FW leg
Coaxial connector
ITER Divertor Cassette
(Total: 54 Cassettes in ITER)
The main function of the divertor system is to
exhaust the major part of the alpha particle power
as well as He and impurities from the plasma.
Dome
Schedule
LICENSE TO
CONSTRUCT
ITER IO
2005
2006
2007
2008
TOKAMAK
ASSEMBLY STARTS
2009
2010
2011
2012
FIRST
PLASMA
2013
2014
2015
2016
EXCAVATE
Bid
Contract
TOKAMAK BUILDING
OTHER BUILDINGS
Construction License Process
First sector Complete VV
TOKAMAK ASSEMBLY
Install PFC
cryostat
MAGNET
Bid
Install CS
COMMISSIONING
Vendor’s Design
Contract
VESSEL
Complete
blanket/divertor
Bid
Contract
PFC
TFC CS
fabrication start
First sector
Last TFC
Last sector
Last CS
First D-T Burning Plasma in ITER in 2021
ITER Schedule
1st 10 yrs
Hybrid
operation
Phase
Flat top pulse length (s)
Equivalent number of
nominal burn pulses
Neutron fluence at TBM
FW (MW-y/m2) PER YR
1~3
4
5
6
7
8
9
10
H-H
D-D
D-T
D-T
D-T
D-T
D-T
D-T
400
400
400
 3000
3000
3000
100-200
0
1
750
1000
1500
2500
3000
3000
0.0
0.0
0.008
0.011
0.017
0.028
0.033
0.033
New Long-Pulse Confinement and Other Facilities
World-wide will Complement ITER
Japan (w/EU)
China
EAST
JT-60SA
(also LHD)
Europe
South Korea
W7-X
(also
JT-60SA)
India
SST-1
ITER Operations:
34% Europe
13% Japan
13% U.S.
10% China
10% India
10% Russia
10% S. Korea
KSTAR
U.S.
Being planned
Likely Fusion
Nuclear Technology
Testing Facility
The Deuterium-Tritium (D-T) Cycle
• World Program is focused on the D-T cycle (easiest to
ignite):
D + T → n + α + 17.58 MeV
• The fusion energy (17.58 MeV per reaction) appears as
Kinetic Energy of neutrons (14.06 MeV) and alphas (3.52
MeV)
• Tritium does not exist in nature! Decay half-life is 12.3 years
(Tritium must be generated inside the fusion system to
have a sustainable fuel cycle)
• The only possibility to adequately breed tritium is through
neutron interactions with lithium
– Lithium, in some form, must be used in the fusion system
Tritium Breeding
Li-6(n,alpha)t and Li-7(n,n,alpha)t Cross-Section
1000
Natural lithium contains
7.42% 6Li and 92.58% 7Li.
100
6Li
(n,a) t
Li-6(n,a) t
Li-7(n,na)t
10
6
Li  n  t  a  4.78MeV
7
Li  n  t  a  n  2.47 MeV
1
The 7Li(n;n’a)t reaction is a
threshold reaction and
requires an incident neutron
energy in excess of 2.8 MeV.
0.1
7Li
(n;n’a) t
0.01
1
10
100
1000
10
4
10
Neutron Energy (eV)
5
10
6
10
7
Blanket (including first wall)
Blanket Functions:
A. Power Extraction
–
Convert kinetic energy of neutrons and secondary gamma rays into heat
–
Absorb plasma radiation on the first wall
–
Extract the heat (at high temperature, for energy conversion)
B. Tritium Breeding
–
Tritium breeding, extraction, and control
–
Must have lithium in some form for tritium breeding
C. Physical Boundary for the Plasma
–
Physical boundary surrounding the plasma, inside the vacuum vessel
–
Provide access for plasma heating, fueling
–
Must be compatible with plasma operation
–
Innovative blanket concepts can improve plasma stability and confinement
D. Radiation Shielding of the Vacuum Vessel
Shield
Blanket
Vacuum vessel
Radiation
Plasma
Neutrons
First Wall
Tritium breeding zone
Coolant for energy
conversion
Magnets
Blanket Concepts
A.
B.
(many concepts proposed worldwide)
Solid Breeder Concepts
–
Always separately cooled
–
Solid Breeder: Lithium Ceramic (Li2O, Li4SiO4, Li2TiO3, Li2ZrO3)
–
Coolant: Helium or Water
Liquid Breeder Concepts
Liquid breeder can be:
a) Liquid metal (high conductivity, low Pr): Li, or 83Pb 17Li
b) Molten salt (low conductivity, high Pr): Flibe (LiF)n · (BeF2),
Flinabe (LiF-BeF2-NaF)
B.1. Self-Cooled
–
Liquid breeder is circulated at high enough speed to also serve as coolant
B.2. Separately Cooled
–
A separate coolant is used (e.g., helium)
–
The breeder is circulated only at low speed for tritium extraction
B.3. Dual Coolant
–
FW and structure are cooled with separate coolant (He)
–
Breeding zone is self-cooled
Tritium self-sufficiency condition:
Λa > Λ r
Λr = Required tritium breeding ratio
Λr is 1 + G, where G is the margin required to account
for tritium losses, radioactive decay, tritium inventory in
plant components, and supply inventory for start-up of
other plants.
Λr is dependent on many system physics and
technology parameters.
Λa = Achievable tritium breeding ratio
Λa is a function of technology, material and physics.
Λa = Achievable tritium breeding ratio
Λa is a function of technology, material and physics.
– FW thickness, amount of structure in the blanket, blanket concept.
30% reduction in Λa could result from using 20% structure in the blanket.
(ITER detailed engineering design is showing FW may have to be much
thicker than we want for T self sufficiency)
– Presence of stabilizing/conducting shell materials/coils for plasma
control and attaining advanced plasma physics modes
– Plasma heating/fueling/exhaust, PFC coating/materials/geometry
– Plasma configuration (tokamak, stellerator, etc.)
Integral neutronics experiments in Japan and the EU showed
that calculations consistently OVERESTIMATE experiments
by an average factor of ~ 1.14
Analysis* of current worldwide FW/Blanket concepts
shows that achievable TBR Λa ≤ 1.15
* See, for example, Sawan and Abdou
Dynamic fuel cycle models were developed to calculate
time-dependent tritium flow rates and inventories
Such models are essential to predict the required TBR
(Dynamic Fuel Cycle Modelling: Abdou/Kuan et al. 1986, 1999)
Simplified Schematic of Fuel Cycle
To new
plants
Startup
Inventory
T storage and
management
Impurity separation
and
Isotope separation system
T waste
treatment
Fueling
system
DT
plasma
Exhaust Processing
(primary vacuum pumping)
T processing
for blanket
and PFC
depends on
design option
PFC
Blanket
physics and technology considerations lead to defining a
“window” for attaining Tritium self-sufficiency
This “window” must be the focus of fusion R&D
Required TBR
td = doubling time
td=1 yr
td=5 yr
Fusion power
1.5GW
Reserve time
2 days
Waste removal efficiency 0.9
(See paper for details)
Max achievable
TBR ≤ 1.15
td=10 yr
“Window” for
Tritium self
sufficiency
Fractional burn-up [%]
Physics and Technology R&D needs to assess the
potential for achieving “Tritium Self-Sufficiency”
1. Establish the conditions governing the scientific
feasibility of the D-T cycle, i.e., determine the
“phase-space” of plasma, nuclear, material, and
technological conditions in which tritium selfsufficiency can be attained
– The D-T cycle is the basis of the current world plasma physics and
technology program. There is only a “window” of physics and
technology parameters in which the D-T cycle is feasible. We need
to determine this “window.” (If the D-T cycle is not feasible the
plasma physics and technology research would be very different.)
– Examples of questions to be answered:
–
–
–
–
Can we achieve tritium fractional burn-up of >5%?
Can we allow low plasma-edge recycling?
Are advanced physics modes acceptable?
Is the “temperature window” for tritium release from solid
breeders sufficient for adequate TBR?
– Is there a blanket/material system that can exist in this phasespace?
R&D for Tritium Self-Sufficiency (cont’d)
2.
Develop and test FW/Blankets/PFC that can operate in
the integrated fusion environment under reactorrelevant conditions
–
3.
R&D on FW/Blanket/PFC and Tritium Processing
Systems that emphasize:
–
–
–
4.
The ITER Test Blanket Module (TBM) is essential for
experimental verification of several principles necessary for
assessing tritium self-sufficiency
Minimizing Tritium inventory in components
“Much faster” tritium processing system, particularly processing
of the “plasma exhaust”
Improve reliability of tritium-producing (blanket) and tritium
processing systems
R&D on physics concepts that improve the tritium
fractional burn-up in the plasma to > 5%
Comparison of Advanced Fission and
Fusion Structural Materials Requirements
US ITER TBM
Fission
(Gen. IV)
Fusion
(ITER/TBM)
Fusion
(Demo)
Structural alloy
maximum temperature
600 - 850˚C
(~1000˚C for
GFRs
350 - 550˚C
550 - 700˚C
(~1000˚C for SiC)
Max dose for core
internal structures
~30-100 dpa
<2 dpa
~150 dpa
Max transmutation
helium concentration
~3-10 appm
~20 appm
~1500 appm
(~120 appm SiC) (~10,000 appm SiC)
Structural Materials
• Key issues include thermal stress capacity, coolant compatibility,
waste disposal, and radiation damage effects
• The 3 leading candidates are ferritic/martensitic steel, V alloys and
SiC/SiC (based on safety, waste disposal, and performance
considerations)
• The ferritic/martensitic steel is the reference
structural material for DEMO
(Commercial alloys (Ti alloys, Ni base superalloys, refractory alloys, etc.) have been
shown to be unacceptable for fusion for various technical reasons)
Structural
Materia l
Coolant/Tritium Breeding Material
Li/Li
Ferritic steel
V alloy
SiC/SiC
He/PbLi
H2O/PbLi
He/Li ceramic H2O/Li ceramic FLiBe/FLiBe
Fission (PWR)
Fusion structure
Coal
Tritium in fusion
Fusion Nuclear Technology (FNT)
Fusion Power & Fuel Cycle Technology
FNT Components from the edge of the
Plasma to TF Coils (Reactor “Core”)
1. Blanket Components (includ. FW)
2. Plasma Interactive and High Heat Flux
Components
a. divertor, limiter
b. rf antennas, launchers, wave guides, etc.
3. Vacuum Vessel & Shield Components
Other Systems / Components affected
by the Nuclear Environment
4. Tritium Processing Systems
5. Instrumentation and Control Systems
6. Remote Maintenance Components
7. Heat Transport and Power Conversion
Systems
Summary of Critical R&D Issues for Fusion Nuclear Technology
1.
D-T fuel cycle tritium self-sufficiency in a practical system
depends on many physics and engineering parameters / details: e.g. fractional burn-up
in plasma, tritium inventories, FW thickness, penetrations, passive coils, doubling time
2. Tritium extraction and inventory in the solid/liquid breeders
under actual operating conditions
3. Thermomechanical loadings and response of blanket and PFC
components under normal and off-normal operation
4. Materials interactions and compatibility
5. Identification and characterization of failure modes, effects, and
rates in blankets and PFC’s
6. Engineering feasibility and reliability of electric (MHD) insulators
and tritium permeation barriers under thermal / mechanical /
electrical / magnetic / nuclear loadings with high temperature and
stress gradients
7. Tritium permeation, control and inventory in blanket and PFC
8. Remote maintenance with acceptable machine shutdown time.
9. Lifetime of blanket, PFC, and other FNT components
Blanket systems are complex and have many
integrated functions, materials, and interfaces
[18-54] mm/s
[0.5-1.5] mm/s
Neutron Multiplier
Be, Be12Ti (<2mm)
Tritium Breeder
Li2TiO3 (<2mm)
PbLi flow
scheme
First Wall
(RAFS, F82H)
Surface Heat Flux
Neutron Wall Load
Fusion environment is unique and complex:
multi-component fields with gradients

Neutrons (fluence, spectrum, temporal and

spatial gradients)
• Radiation Effects (at relevant temperatures, 
stresses, loading conditions)
• Bulk Heating
• Tritium Production
• Activation

Heat Sources (magnitude, gradient)
•
•

Bulk (from neutrons and gammas)
Surface
Synergistic Effects
•
•

Particle Flux (energy and density,
gradients)
Magnetic Field (3-component with
gradients)
• Steady Field
• Time-Varying Field
Mechanical Forces
• Normal/Off-Normal

Thermal/Chemical/Mechanical/
Electrical/Magnetic Interactions
Combined environmental loading conditions
Interactions among physical elements of components
Multi-function blanket in multi-component field environment leads to:
- Multi-Physics, Multi-Scale Phenomena
Rich Science to Study
- Synergistic effects that cannot be anticipated from simulations & separate effects
tests.
A true fusion environment is ESSENTIAL to activate mechanisms that
cause prototypical coupled phenomena and integrated behavior
Tritium Breeding Blankets must be developed in the near
term to solve the serious issue of external tritium supply
Production & Cost:
CANDU Reactors: 27 kg from over 40 years,
$30M/kg (current)
Fission reactors: 2–3 kg/year
$84M-$130M/kg (per DOE Inspector General*)
*www.ig.energy.gov/documents/CalendarYear2003/ig-0632.pdf
 A Successful ITER will exhaust most
of the world supply of tritium, but
5-10 kg will be needed to start DEMO
 Any future long pulse burning plasma
device (including ITER Extended
Phase) will need tritium breeding
technology
 The availability and cost of external
tritium supply is a serious issue for
FNT development
 Engineering development and reliability
growth stages must be done in a small
fusion power device; only fusion break-in
stage can be done in ITER
Projected Ontario (OPG) Tritium Inventory (kg)
Tritium Consumption in Fusion is HUGE! Unprecedented!
55.8 kg per 1000 MW fusion power per year
30
CANDU
Supply
w/o Fusion
25
20
15
10
1000 MW Fusion
10% Avail,
TBR 0.0
5
0
1995 2000 2005
ITER-FEAT
(2004 start)
2010 2015 2020 2025 2030 2035 2040 2045
Year
We cannot wait very long for
blanket development
DEMO Availability of 50% Requires Blanket Availability >85%
(Table based on information from J. Sheffield’s memo to the Dev Path Panel)
Component Num
Failure
rate in
hr-1
MTBF in MTTR
for
years
Outage Risk Component
16
5 x10-6
23
Major
failure,
hr
104
MTTR
Fraction of
for Minor failures that
failure, hr are Major
240
0.1
0.098
0.91
8
5 x10-6
23
5x103
240
0.1
0.025
0.97
4
1 x10-4
1.14
72
10
0.1
0.007
0.99
2
100
32
4
1
1
2 x10-4
1 x10-5
2 x10-5
2 x10-4
3 x10-5
1 x10-4
0.57
11.4
5.7
0.57
3.8
1.14
300
800
500
500
72
180
24
100
200
20
-24
0.1
0.05
0.1
0.3
1.0
0.1
0.022
0.135
0.147
0.131
0.002
0.005
0.978
0.881
0.871
0.884
0.998
0.995
3
5 x10-5
72
6
0.1
2.28
Conventional equipment- instrumentation, cooling, turbines, electrical plant ---
0.002
0.05
0.624
0.998
0.952
0.615
ber
Toroidal
Coils
Poloidal
Coils
Magnet
supplies
Cryogenics
Blanket
Divertor
Htg/CD
Fueling
Tritium
System
Vacuum
TOTAL SYSTEM
Availability
Assuming 0.2 as a fraction of year scheduled for regular maintenance.
Demo Availability = 0.8* [1/(1+0.624)] = 0.49 (Blanket Availability must be .88)
Obtainable Blanket System Availability (%)
Obtainable Blanket System Availability with 50%
Confidence for Different Testing Fluences and Test Areas
MTTR = 1 month
1 failure during the test
80 blanket modules in
blanket system
70
60
6 MW.yr/m2
Experience factor =0.8
3 MW.yr/m2
50
40
30
1 MW.yr/m2
20
Neutron wall load = 2 MW/m2
10
0
0
2
4
6
Test Area (m2)
8
10
Level of Confidence based on Figure 15-2.2 in "FINESSE: A Study of the Issues, experiments and Facilities for Fusion Nuclear
Technology Research & Development, Chapter 15 Reliability Development Testing Impact on Fusion Reactor Availability", Interim
report, Vol. IV, PPG-821, UCLA, 1984.
Types of experiments, facilities and modeling for FNT
Theory/Modeling
Basic
Separate
Effects
Property
Measurement
Multiple
Interactions
Design Codes
Partially
Integrated
Phenomena Exploration
Integrated
Component
•Fusion Env. Exploration Design
Verification &
•Concept Screening
•Performance Verification Reliability Data
Non-Fusion Facilities
(non neutron test stands,
fission reactors and accelerator-based
neutron sources)
Testing in Fusion Facilities
• Non fusion facilities (e.g. non-neutron test stands, fission reactors and neutron
sources) have important roles
• Testing in Fusion Facilities is NECESSARY for multiple interactions, partially
integrated, integrated, and component tests
R&D Tasks to be Accomplished Prior to Demo
1) Plasma
- Confinement/Burn
- Disruption Control
- Current Drive/Steady State
- Edge Control
2) Plasma Support Systems
- Superconducting Magnets
- Fueling
- Heating
3) Fusion Nuclear Technology Components and Materials
[Blanket (including First Wall), Divertors, rf Launchers]
- Materials combination selection and configuration optimization
- Performance verification and concept validation
- Show that the fuel cycle can be closed (tritium self-sufficiency)
- Failure modes and effects
- Remote maintenance demonstration
- Reliability growth
- Component lifetime
4) Systems Integration
Where Will These Tasks be Done?!
• Burning Plasma Facility (ITER) and other plasma devices will address 1, 2, & much of 4
• How and Where Will Fusion Nuclear Technology (FNT) be developed?
(ITER alone?, another device?, both?)
Stages of FNT Testing in Fusion Facilities
Fusion “Break-in” &
Scientific Exploration
Engineering Feasibility
& Performance
Verification
Component Engineering
Development &
Reliability Growth
Stage I
Stage II
Stage III
0.1 – 0.3 MW-y/m2
1 - 3 MW-y/m2
> 4 - 6 MW-y/m2
1-2 MW/m2,
steady state or long pulse
COT ~ 1-2 weeks
1-2 MW/m2,
steady state or long burn
COT ~ 1-2 weeks
 0.5 MW/m2, burn > 200 s
Sub-Modules/Modules
• Initial exploration of coupled
phenomena in a fusion environment
• Uncover unexpected synergistic effects,
Calibrate non-fusion tests
• Impact of rapid property changes in
early life
• Integrated environmental data for
model improvement and simulation
benchmarking
• Develop experimental techniques and
test instrumentation
• Screen and narrow the many material
combinations, design choices, and
blanket design concepts
Modules
• Uncover unexpected synergistic
effects coupled to radiation
interactions in materials, interfaces,
and configurations
• Verify performance beyond beginning
of life and until changes in properties
become small (changes are substantial
2
up to ~ 1-2 MW · y/m )
• Initial data on failure modes & effects
• Establish engineering feasibility of
blankets (satisfy basic functions &
performance, up to 10 to 20 % of
lifetime)
• Select 2 or 3 concepts for further
development
Modules/Sectors
• Identify lifetime limiting failure modes
and effects based on full environment
coupled interactions
• Failure rate data: Develop a data base
sufficient to predict mean-timebetween-failure with confidence
• Iterative design / test / fail / analyze /
improve programs aimed at reliability
growth and safety
• Obtain data to predict mean-time-toreplace (MTTR) for both planned
outage and random failure
• Develop a database to predict overall
availability of FNT components in
DEMO
D
E
M
O
What is CTF (VNS)?
• The idea of CTF is to build a small size, low fusion power
DT plasma-based device in which Fusion Nuclear
Technology experiments (for engineering development and
reliability growth) can be performed in the relevant fusion
environment: 1- at the smallest possible scale, cost, and
risk, and 2- with practical strategy for solving the tritium
consumption and supply issues for FNT development.
- In MFE: small-size, low fusion power can be obtained in a driven, low-Q,
plasma device. (But the minimum fusion power for tokamak is >100MW.)
• This is a faster, much less expensive approach than
testing in a large, ignited/high Q plasma device for which
tritium consumption, and cost of operating to high fluence
are very high (unaffordable!, not practical).
Major Activities and Approximate Timeline* for
Fusion Nuclear Technology Development
YEAR:
R&D
ITER
TBM
CTF
07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
Experiments in Non-Fusion Facilities: Thermal, MHD, Tritium, Fission, Accelerator Neutron Sources, etc.
Theory, Modeling and Computer Simulation
Machine Construction
Phase I: H-H/D-D/D-T
TBM Preparation
TBM (Fusion “break-in”)
Exploration & Decision
Engr. Design
Construction
?? Extended Phase ??
H-H
FNT Testing:
Engineering Feasibility
and Reliability Growth
System Analysis / Design Studies
 R&D Activities are critical to support effective FNT/Blanket
testing in ITER and CTF
 ITER TBM Provides Timely Information to CTF
* Based on FESAC 2003 Panel with adjusting ITER Schedule by 2 years
Arrows indicate
major points of FNT
information flow
through ITER TBM
Challenging
Fusion Nuclear Technology Issues
1. Tritium Supply &
Tritium Self-Sufficiency
2. High Power Density
3. High Temperature
4. MHD for Liquid Breeders / Coolants
5. Tritium Control (Permeation)
6. Reliability / Maintainability / Availability
7. Testing in Fusion Facilities
Fusion has made substantial progress, but
many challenging tasks remain ahead
• 1950-2010
– The Physics of Plasmas
• 2010-2030
– The Physics of Fusion
– The “Fermi Demonstration” - Fusion-heated and sustained
• Q = (Ef / Einput )~10
• 2010-2040
– Fusion Nuclear Technology for Fusion
– DEMO by 2040
Resolving the Fusion Nuclear Technology Issues is the most Critical
Remaining Challenge in the Development of Fusion as a Practical,
Safe, and Economically Competitive Energy Source
Thank You!