Chamber Technology (CT)
and Why Now?
Mohamed Abdou
Presented to:
VLT-PAC
General Atomics, San Diego
February 25, 2003
Note: specifics are for MFE Chamber. See Wayne Meier for specifics on IFE Chamber
1
Outline
•
What is Chamber Technology? and its central role in fusion
devices, burning plasma devices, and fusion energy systems
•
Past achievements and tremendous impact on plasma physics
research and fusion energy development (prior to Restructuring)
•
Recent achievements and Impact on fusion program (post
restructuring)
•
Critical Technical Issues for Chamber Technology and their
Central Role in the Fusion Program for the next few years and
beyond.
•
Plans for immediate future FY04/05/06 and Role of Chamber
Technology in Recent Initiatives: ITER, Energy-Based Policy, and
35-yr Plan
•
Disastrous consequences to the Fusion Program of “close out” of
CT
Note: Prior to the Restructuring of the Fusion Program of 1997, Chamber
Technology was divided into several programs (Neutrons, Blanket/FW, Fuel
Cycle, etc.) After restructuring, these programs were combined under a Chamber
Technology Program.
2
Scope of Chamber Technology Research
Chamber Technology (CT) Research
embodies the scientific and engineering
disciplines required to understand,
design, develop, test, build, and
operate safely and reliably the systems
that surround a burning plasma.
CT includes all components and
functions from the edge of the plasma
to the magnets, including:
• first wall
• blanket (breeding
and non-breeding)
• conducting shells
• vacuum vessel
• cooling systems
• radiation shielding
• tritium fuel cycle
• nuclear part of RF
antenna, etc.
• support structure &
remote maintenance
• electric/thermal
insulators
• tritium barriers and
processing
CT also includes design and integration for Chamber Components
•
3
Chamber Technology Embodies Two of the Three
Fundamental Functions of Fusion Energy Systems
Fusion Energy Systems Fundamental Functions:
1- Producing energy from the DT fusion reaction in the
plasma
2- High-temperature power extraction in a practical, safe,
and economical fusion energy system (extracting heat
in any plasma device)
3- Breeding sufficient tritium to assure that the plasma is
self-sustained and that fusion is a “renewable” energy
source with a closed fuel cycle
• The Chamber Technology Program includes all
components required to achieve functions #2 and #3
• Chamber Technology also embodies the systems that
hold, provide the vacuum and fuel the plasma, which are
essential to achieving function #1
4
The CT Program is responsible for
advancing and providing state-of-the-art
predictive capabilities for many technical
disciplines required for the fusion program
(to support, for example, Safety, Materials, PFC, Advanced
Design Studies, fusion devices, burning plasma experiments, etc.)
Modeling, experiments, codes and analysis for:
•
•
•
•
•
•
neutron/photon transport
neutron-material interactions
heat/mass transfer
thermofluid physics and MHD
thermal hydraulics
Tritium release, extraction,
inventory and control
• structural mechanics
• thermomechanics
• chemistry
• radioactivity and decay heat
• engineering scaling
• reliability analysis methods
5
R&D for Chamber Technology is a “Grand Challenge” not only
because of the multi-function, multi-physics, multi-engineering
requirements and issues but also because of the complex and
unique thermo-magneto-vacu-tritu-nuclear environment of fusion
Neutrons (fluence, spectrum, spatial and temporal gradients)
-
Radiation Effects (at relevant temperatures, stresses, and loading)
Bulk Heating
Tritium Production
Activation and Decay Heat
The kind of training
Heat Sources (magnitude, gradient)
- Bulk (from neutrons)
- Surface (from particles and radiation)
Particle Flux (energy, density, gradients)
Magnetic Field (3-component with gradients)
- Steady Field
- Time-Varying Field
Mechanical Forces
- Normal (steady, cyclic)
- Off-Normal (pulsed)
needed to perform
research and
engineering within this
highly constrained
fusion chamber system
takes many years of
education and
experience.
Thermal/Chemical/Mechanical/Electrical/Magnetic/Nuclear
Interactions
and Synergistic Effects
- Combined environmental loading conditions
- Interactions among physical elements of components
6
Technology Programs are Highly Interrelated and Interactive
(Take as an analogy a “three-legged stool”: PFC, Chamber Tech, and Materials) (Many Other “3-legged stool” examples
can be shown with other parts of the fusion program, e.g. with Safety and Design Studies Programs)
Area
Plasma Technology
Fusion
Technology
PFC
Chamber Tech
Tritium breeding and neutron multiplier materials R&D
Radiation shielding (components and personnel radiation protection, design and R&D)
Neutronics, photonics, and neutron material interactions (transport, DPA, He, H, transmutation,
etc.)
Blanket structural materials (development, properties and irradiation)
S
P
P
P
S
S
S
P
Coolant/Multiplier/Breeder/Structure interactions and compatibility
S
P
P
Tritium extraction, inventory, and control
S
P
S
S
P
P
S
Configuration and engineering design
Vacuum Vessel
P
S
Structural material (development, properties and irradiation)
S
P
Configuration and engineering design
P
S
Key Issue
Materials
Program
Fusion Materials
First Wall/Blanket/Shield
Thermofluid effects (heat transfer, fluid mechanics, MHD)
Heat removal and thermal efficiency
Plasma Facing Components
Plasma materials interactions R&D (effects of PFM on core plasma)
P
S
Erosion of PFM and impurity control
P
S
Joining of Plasma Facing Materials (PFM) to heat sink, thermal fatigue life
P
S
PFC heat sink development and heat removal, coolant compatibility
P
S
Thermofluid MHD
S
P
S
PFM and heat sink materials (development, properties and irradiation)
S
Tritium retention
P
S
P
S
Methods, analysis, and R&D (failure modes, effects, and rates; reliability growth; maintenance
and availability; etc.)
S
P
S
Remote maintenance technology
S
P
S
Reliability, Availability, and Maintainability
P - Primary role for resolving issue,
S - Supporting role in resolving issue
7
Why Chamber Technology Research Now?
“Why Now?!”
It is not just needed now!
It was needed 30 years ago!
It was started 30 years ago!
• It would have been impossible for the fusion program to make
the progress we have made without Chamber Technology
Research over the past 30 years.
• No Credible plans for future fusion development are possible
without Chamber Technology Research NOW.
• One way to understand “why now” is to learn how Chamber
Technology Research was crucial in making progress over the
past 30 years.
8
Since the Early 1970’s, Chamber
Technology Research has had a
Fundamental and Major Impact on:
1. The Direction and Emphasis of Plasma Physics
R&D
2. The Direction and Emphasis of other Fusion
Technology Programs
3. Identifying and Resolving Critical Issues in
Fusion, many of which are “Go, No-Go” issues
4. Shaping our vision today of a burning plasma
device and fusion power plant
This impact is illustrated by some “historical” examples given
in a separate handout.
9
Remaining Critical R&D Issues for Chamber Technology (FNT)
1.
2.
3.
Remaining Engineering Feasibility Issues, e.g.
• feasibility, reliability and MHD crack tolerance of electric insulators
• tritium permeation barriers and tritium control
• tritium extraction and inventory in the solid/liquid breeders
• thermomechanics interactions of material systems
• materials interactions and compatibility
• synergistic effects and response to transients
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, and many more variables. A related issue is how to supply Tritium for
burning plasma experiments, such as ITER.
Reliability/Maintainability/Availability: failure modes, effects, and
rates in blankets and PFC’s under nuclear/thermal/mechanical/electrical/
magnetic/integrated loadings with high temperature and stress gradients.
Maintainability with acceptable shutdown time.
4.
Lifetime of blanket, PFC, and other FNT components
10
NOW is the time to develop tritium breeding blanket
for extended ITER Operation and beyond
 Tritium Supply considerations are a critical factor in Fusion
Energy Development
 Experimental DT Devices for Fusion Energy Development Will
Need a Tritium Breeding Blanket
The world maximum tritium supply (from CANDU) over the next 40 years is 27 kg. This tritium decays
at 5.47% per year. Cost is high ($30M-$200M/kg)
A DT facility with 1000 MW fusion power burns tritium at a rate of 55.8 kg/yr. Large power DT
facilities must breed their own tritium.
(It is ironic that our major problem is “tritium fuel supply”,
while the fundamental premise of Fusion is an “inexhaustible”
energy source)
 This is why testing of breeding blanket module is Planned in ITER
from Day 1 of Operation (2013), since ITER can not run in the
extended phase without breeding
 The Fusion Program needs to show that “tritium self sufficiency
in a practical engineering system” is indeed attainable in a real
fusion device. This is a challenge, involves > 20 physics,
engineering, and material variables.
11
The Lack of Adequate Tritium Supply and the Need for Tritium Breeding
Blanket are Already Having a Major Impact NOW on ITER Operational
Plans and Fusion Energy Development Plans
Projected Ontario (OPG) Tritium Inventory (kg)
30
CTF
5 yr, 100 MW, 20% Avail, TBR 0.6
5 yr, 120 MW, 30% Avail, TBR 1.15
10 yr, 150 MW, 30% Avail, TBR 1.3
25
20
Candu Supply
w/o Fusion
15
1000 MW Fusion,
10% Avail, TBR 0.0
ITER-FEAT (2004
start) + CTF
10
5
0
1995
ITER-FEAT
(2004 start)
See calculation assumptions in
Table S/Z
2000
2005
2010
2015
2020
Year
2025
2030
2035
2040
2045
• Without a tritium breeding capability, ITER cannot run in an extended phase.
• Large power DT facilities must breed their own tritium
• Breeding Blanket must be developed NOW - We cannot wait very long for
blanket development even if we want to delay DEMO
12
We must proceed quickly to participate in
ITER Technology Testing Program
 ITER was conceived not only as a burning plasma
experiment but also as an experiment to test fusion
technologies in a real fusion environment.
 The Chamber Technology Program has a leading
role in both the basic device and the blanket test
module missions.
 ITER can provide important functional and screening
tests for vital tritium breeding technologies
Notion:
It doesn’t make sense to pay billions to build ITER,
and not spend millions to utilize ITER to acquire key
technology data and experience
13
ITER Operational Plan Calls for Testing Breeding
Blankets from Day 1 of Operation
H-Plasma Phase
D Phase
First DT plasma phase
Accumulated
fluence =
0.09 MWa/m2
Blanket
Test
14
TBM Roll Back from ITER 1st Plasma
Shows CT R&D must be accelerated now for TBM Selection in
EU schedule for Helium-Cooled
Pebble Bed TBM (1 of 4 TBMs Planned)
02 03 04 05 06 07 08 09 10 11 12
2005
ITER First Plasma
13 14 15 16 17 18 19 20 21 22 23 24 25
HCPB Programme
PB Material Fabrication and
Char. (mech., chem, etc)
Out-of-pile pebble bed
experiments
Pebble bed Irradiation
Programme
Modelling on Pebble beds
including irradiation effects
Key issues of Blanket
Structure Fabr. Tech.
HCPB Programme for ITER
Develop. and testing of
instrumentation for TBM
Develop. and testing of
components of Ext. Loops
TBM and Ext. Loop Mock-up
Design
TBM and Ext. Loops Mock-up
Fabrication
Operation of TBM and Ext.
Loop Mock-ups
a final decision on blanket test
modules selection by 2005 in order
to initiate design, fabrication and
out-of-pile testing
Final Design of TBM
Fabrication and qualification of
TBM and Ext. Loops
Operation in the Basic
Performance Phase of ITER
(Reference: S. Malang, L.V. Boccaccini, ANNEX 2, "EFDA Technology Workprogramme 2002 Field: Tritium
Breeding and Materials 2002 activities- Task Area: Breeding Blanket (HCPB), Sep. 2000)
15
Reliability/Maintainability/Availability is one of the remaining
“Grand Challenges” to Fusion Energy Development. Chamber
Technology R&D is necessary to meet this Grand Challenge.
Need High Power Density/Physics-Technology Partnership
- High-Performance Plasma
- Chamber Technology Capabilities
Need Low
Failure Rate
C  i + replacement cost + O & M
COE =
P fusion  Availability  M  h th
Energy
Multiplication
Need High Temp.
Energy Extraction
Need High Availability / Simpler Technological and Material Constraints
(1 / failure rate )
1 / failure rate + replacemen t time
 Need Low Failure Rate:
- Innovative Chamber Technology
 Need Short Maintenance Time:
- Simple Configuration Confinement
- Easier to Maintain Chamber Technology
16
The reliability requirements on the Blanket/FW (in current confinement concepts that
have long MTTR > 1 week) are most challenging and pose critical concerns. These must
be seriously addressed as an integral part of the R&D pathway to DEMO. Impact on
ITER is predicted to be serious. It is a DRIVER for CTF.
800
ed
(R
)
600
5
400
200
0
Expected
0
1
2
C
A
0
3
MTBF per Blanket Segment(FPY)
10
N
ee
d
MTBF per Blanket System(FPY)
The Chamber Technology Program NOW is
leading the way to resolving this challenge.
MTTR (Months)
A = Expected with extensive R&D (based on mature technology and no fusion-specific failure modes
C = Potential improvements with aggressive R&D
17
Why do research now on
Chamber Technology?
 Utilization of ITER technology testing environment
 Develop needed tritium breeding and recovery technologies for
burning plasma experiments and to demonstrate fusion fuel selfsufficiency
 Impact on current and future physics program
 Vital Interactions with other technology programs
 Key predictive capabilities needed by all programs
 Access to the broader international technology research / data
though existing collaborations
 Training young technology researchers that will be running ITER
and CTF experiments in 10 years
 Tough technology problems require long testing and
development times – e.g. Reliability Growth
18
CT Plans for FY 04/05
A Chamber Technology Program is Essential to
the New Presidential Initiatives to join ITER and
Implement an Energy-Based Policy for Fusion
The Chamber Technology Community is
ready to move to a new emphasis:
Learn from proven successful
APEX Features
1. Re-Start ITER Test Blanket Module Program
1) Multidisciplinary, multiinstitution integrated TEAM
2. Support ITER Basic Device in the FNT area
2) Close Coupling to the
Plasma Community
3. Continue research on Advanced Chamber
Configurations with re-adjusted scope
4. Maintain vital efforts to advance fundamental
Predictive Capabilities and tools needed by
other Fusion Programs
5. FNT Experimental Techniques and testing to
support the energy development plans
3) Direct Participation of
Scientists from Materials,
PFC, Safety, and AD
Programs
4) Direct Coupling to IFE CT
Community
5) Direct participation with
International programs
6) Encourage Innovation
Note: Balance among these elements in a constrained budget will be derived from community
deliberations.
19
CT Plans for FY 04/05 (cont’d)
Chamber Technology Plan for FY 04/05
1. Blanket Test Module Program (for ITER and other devices)
- Lead US community to evaluate blanket options for DEMO,
evaluate R&D results for key issues to select TWO Primary
Blanket Concepts for testing in ITER (must reach a decision by
2005). [This effort will also involve interactions with EU, Japan,
and China for coordinated, cost effective efforts]. In addition to
the CT community, this effort will involve participation by many
US programs (e.g. Materials, Safety, PFC, and Advanced
Design Studies Programs and industry)
- Perform concurrently R&D on the most critical issues required
to make prudent selection by 2005 (e.g. self-healing coatings
and other types of MHD insulators, tritium permeation barriers,
SiC inserts, solid breeder/multiplier/structure/coolant
interactions)
20
Blanket Test Module Program (cont’d)
-
Enhance and focus current international collaborative
R&D to provide data to ITER Blanket Test Module
Selection:
a) Thermomechanics material interactions for
SB/multiplier/structure/coolant (ongoing under IEA)
b) Enhanced heat transfer techniques for molten salts to determine
if there is a temperature window with ferritic steel structure
and/or advanced high-temperature ferritic steel (ongoing under
JUPITER-II)
-
Participate in international “unit cell” experiment in fission
reactors (tritium release and breeder/multiplier/structure/purge
interactions)
-
Develop Engineering Scaling and design blanket test
articles in the ITER environment for the blanket concepts
selected for testing in ITER
21
CT Plans for FY 04/05 (cont’d)
2. FNT Support for the ITER Basic Device
- As ITER moves toward construction it will need more accurate
predictions in the nuclear area
e.g. computation of radiation field, radiation shielding, nuclear heating,
penetrations, materials radiation damage, dose to insulators in
superconducting magnets, decay heat, radwaste, maintenance dose,
tritium fuel cycle, tritium permeation and inventories, basic device nonbreeding blanket issues and performance
- Help resolve remaining issues in ITER design e.g
- flexibility in non-breeding blanket design to ensure feasibility for change to
breeding blanket in the extended phase
- providing for auxiliary and ancillary equipment to support the ITER
Blanket test module program
- diagnostics to monitor in-situ FW/Blanket operating conditions
22
CT Plans for FY 04/05 (cont’d)
3. Advanced Chamber Configurations and High Pay-Off
Concepts
(Emphasis on Innovation and Engineering Sciences - Similar to
Plasma Confinement Alternate Concepts and Configuration
Optimization)
- Thin liquid wall concepts: R&D on critical issues to evaluate
feasibility, attractiveness (including plasma-chamber interactions)
- Provide thermofluid MHD and design support for the NSTX liquidsurface test module (joint activity between PFC/ALPS and
Chamber Technology) and MHD channel flow tests
- Evaluate the potential of advanced blanket concepts with
attractive combinations of materials and configurations.
- This activity will be aimed at GEN-II in US DEMO (see 35-yr plan)
and possibly hydrogen production, but successful results may
have profound near-term impact on the fusion program
23
CT Plans for FY 04/05 (cont’d)
4. Fundamental Predictive Capabilities
(Computational Models and Codes and Tools Needed by Other Key
Fusion Programs, e.g. Safety, Materials, PFC, Advanced Design Studies)
- Heat Transfer/Fluid Mechanics/MHD
- Radioactivity and Decay Heat
- Tritium Transport/Recovery/Control, Tritium Fuel Cycle Dynamics
- Reliability and Availability
- Neutronics and Neutron-Material Interactions
5. FNT Experimental Techniques and Diagnostics
- Develop experimental techniques and engineering scaling for testing Chamber
Technology on fusion devices
- Develop diagnostic techniques for operation in the magneto-nuclear
environment of fusion devices (ITER, CTF, etc.)
- Evolve technical and programmatic strategies for Fusion Nuclear Technology
testing and development on ITER, CTF, and other devices leading to DEMO
(support the 35-yr Plan)
24
Consequences of Terminating
Chamber Technology Program
• Loss of Credibility to the fusion program and to any fusion
energy plan
- It undermines the initiative to rejoin ITER
- It makes the “35-yr” US Plan “dead on arrival”
- At odds with the President’s New Policy for Fusion
- Demoralizing to fusion’s advocates
Heartening to fusion’s critics
- Confusing and frustrating message to the International Fusion
Programs
• Devastating consequences to the US Fusion Program’s
ability to make progress
25
Consequences of Terminating Chamber
Technology Program (cont’d)
• Moving forward with fusion requires many diverse skills
in Chamber Technology.
After the 1996 restructuring, only a “bare minimum” of critical skills
remain – skills that took 30 years to develop.
Termination of the CT Program will set fusion energy back by
decades.
• Loss of FNT “headlights”: Enormous risk that near term
fusion research may not ultimately bear the fruit of a
practical fusion energy source.
26
Specific and Immediate Consequences:
- No participation in ITER test program or possibility to test US blanket
modules. Loss of ability to influence ITER decisions on the test program,
scheduled to be finalized in 2005.
- Loss of capability for timely demonstration of tritium self sufficiency - the
fundamental premise of fusion as an “inexhaustible” energy source.
- Loss of vital expertise needed to design and test in ITER, CTF, and DEMO.
- Great harm to important elements of the US fusion technology program. CT
Research, Materials, Safety, and Advanced Design studies interact very
strongly.
 How can we do safety analysis without radioactivity calculations
and technologies for tritium containment?
 How do we develop structural materials for the blanket if we do not
know what the blanket is?
 How do we predict MHD induced motion of lithium in DiMES/DIIID
during plasma operation?
- Loss of critical interaction with the plasma community to solve the plasmachamber interface issues and to provide innovative Chamber solutions to
improve plasma performance.
27
Specific and Immediate Consequences (Cont.):
- No research on innovative technology ideas that may have the most
significant impact on the attractiveness of fusion energy or hydrogen producing
systems.
- Loss of access to foreign research/data from existing CT international
collaborations. (also loss of funding from Japan)
- Loss of investment in unique new experimental facilities recently constructed.
- Drastic reduction in university involvement and serious impact on many
Professors, Fusion Researchers and PhD students
- Loss of training for the “seed of the future” – graduate students and young
researchers. CT Research provides training and development of skills for people that
go on to lead other programs. The head of the US Safety Program, the Head of the
Vacuum Vessel Division in KSTAR, and the Head of the PFC components in Europe and
ITER, for example, were all students trained in the US Chamber Technology Research
Program. Many fusion leaders and university professors in the US, Europe and Japan
were trained as part of the US CT Research Program.
- Loss of current CT leadership at a time when the program needs more
technology emphasis as we move toward ITER, CTF, and demonstration.
28