RE Nygren, Sandia ARIES Town Hall 1012dec2008 UCSD

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General Comments on the Development of Future
Fusion PFCs presented by Richard E.
Nygren Sandia National Laboratories ARIES
High Heat Flux Components Workshop UCSD 10-12
December 2008
Sandia is a multiprogram laboratory operated by
Sandia Corporation, a Lockheed Martin
Company,for the United States Department of
Energys National Nuclear Security
Administration under contract DE-AC04-94AL85000.
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BROAD SCOPE
Tokamak/AT
Focus 1. tokamak divertors 2. solid surface
PFCs 3. present/ITER-DEMO gap Other 4.
alternates 5. liquid surface 6. other fusion
pathways
Alternates
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BROAD SCOPE
Tokamak/AT
ITER divertor
JET
DIII-D
JT-60U
C-MOD
ASDEX-U
TEXTOR
Tore Supra
TFTR
Alternates
MAST
NSTX
LHD
W7X
Wendelstein
Non-electric or hybrid applications
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BROAD SCOPE
Tokamak/AT
DEMO-A divertor
DEMO-B divertor
ITER divertor
JET
DIII-D
???
JT-60U
???
C-MOD
ASDEX-U
TEXTOR
Tore Supra
TFTR
???/CTF
Alternates
MAST
?? primary alternate
NSTX
???
LHD
???
W7X
Wendelstein
Non-electric of hybrid applications
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BROAD SCOPE
Tokamak/AT
DEMO-A divertor
DEMO-B divertor
ITER divertor
JET
DIII-D
???
JT-60U
???
C-MOD
ASDEX-U
TEXTOR
Tore Supra
TFTR
???/CTF
Alternates
MAST
?? primary alternate
NSTX
???
LHD
???
W7X
Wendelstein

• ?liquid surface

Non-electric of hybrid applications
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WORKSHOP SCOPE
Tokamak/AT
DEMO-A divertor
DEMO-B divertor
ITER divertor
JET
DIII-D
???
JT-60U
???
C-MOD
ASDEX-U
TEXTOR
Tore Supra
TFTR
???/CTF
GAP 1
GAP 2
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WORKSHOP SCOPE
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OTHER SCOPE
GAP X
GAP Y
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SOURCES
Tokamak/AT
ITER divertor
DEMO-A divertor
JET
DEMO-B divertor
DIII-D
???
???
JT-60U
C-MOD
ASDEX-U
TEXTOR
Tore Supra
TFTR
D Maisonnier et al., DEMO and Fusion Power Plant
Conceptual Studies in Europe Nucl. Fusion 47
(2007) ISFNT7 K. Lackner SOFT2006
G Federici et al., Key ITER plasma edge and
plasmamaterial interaction issues, JNM 313316
(2003) PSI J Linke et al., High heat flux
testing of plasma facing materials , JNM 367370
(2007)
V Philipps Plasmawall interaction, a key issue
on the way to a steady state burning fusion
device, Phys. Scr. T123 (2006)
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Sources
Tokamak/AT
ITER divertor
DEMO-A divertor
JET
DEMO-B divertor
DIII-D
???
???
JT-60U
C-MOD
ASDEX-U
TEXTOR
Tore Supra
Greenwald Panel Report Priorities, Gaps and
Opportunities Towards A Long-Range Strategic
Plan For Magnetic Fusion Energy, FESAC Oct 2007
TFTR
D Whyte The Challenges of Plasma-Surface
Interactions for ITER Beyond, to FESAC Nov 2008
D Maisonnier et al., DEMO and Fusion Power Plant
Conceptual Studies in Europe Nucl. Fusion 47
(2007) ISFNT7 K Lackner SOFT2006
US ReNew Activity
G Federici et al., Key ITER plasma edge and
plasmamaterial interaction issues, JNM 313316
(2003) PSI J Linke et al., High heat flux
testing of plasma facing materials , JNM 367370
(2007)
V Philipps Plasmawall interaction, a key issue
on the way to a steady state burning fusion
device, Phys. Scr. T123 (2006)
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Greenwald Panel Report
The themes were defined in terms of knowledge
required prior to Demo. ... based on sound
scientific principles and rigorously tested in
the laboratory so that the step to a DEMO ..
taken with high confidence of success.
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Greenwald Panel Report
The themes were defined in terms of knowledge
required prior to Demo. ... based on sound
scientific principles and rigorously tested in
the laboratory so that the step to a DEMO ..
taken with high confidence of success.
Theme B. Taming the Plasma Material Interface
.. knowledge sufficient to design and build,
with high confidence, 8. PWI Understand and
control of all processes that couple the plasma
and nearby materials. 9. PFCs Understand ..
materials and processes that can be used to
design replaceable components that can survive
.. 10. .. Other .. .. necessary understanding
of plasma interactions, neutron loading and
materials to allow design of .. any other
diagnostic equipment that can survive ...
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Greenwald Panel Report
Theme C. Harnessing fusion power knowledge ..
sufficient to design and build, with high
confidence, 11. Fuel Cycle .. manage the flow
of tritium ... 12. Power .. temperatures
sufficiently high for efficient production of
electricity or hydrogen. 13. Materials ..
Understand the basic materials science for fusion
breeding blankets, structural components, plasma
diagnostics and heating components .. high
neutron fluence .. 14. Safety Demonstrate ..
safety .
minimize environmental burdens .. 15. RAMI
Reliability, Availability, Maintainability
Inspectability Demonstrate .. productive
capacity . validate
economic assumptions .
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Greenwald Panel Report
Finding 6. Evaluation of current and planned
programs and summary of gaps .. The most
significant gaps were G1. . G2. G-5. Ability
to predict and avoid, or detect and mitigate,
off-normal plasma events G-9. Sufficient
understanding of all plasma-wall interactions .
The science underlying the interaction of
plasma and material needs to be significantly
strengthened to .. G-10. Understanding of the use
of low activation solid and liquid materials,
joining technologies and cooling strategies
... G-11. Understanding .. the complete fuel
cycle, particularly .. G-12. An engineering
science base .. effective removal of heat
... G-13. Understanding .. low activation
materials .. G-14. .. guarantee safety over the
plant life cycle - including .. G-15. ..
efficient maintainability of in-vessel components
..
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Greenwald Panel Report
Recommendation 4. .... nine major initiatives.
I-1. .. predictive plasma modeling and
validation .., I-2. Extensions to ITER AT
capabilities .. burning AT regimes I-3.
Integrated advanced burning physics facility ..
dedicated I-4. Integrated experiment for
PWI/PFCs .. steady-state .. non-DT I-5. ..
disruption-free concepts .. performance extension
device .. I-6. .. advanced computer modeling and
laboratory testing .. single-effects science for
major fusion technology issues, I-7. Materials
qualification facility (IFMIF). I-8. Component
development/testing program multi-effect issues
in critical technology .. breeding/blanket ..
first wall I-9. Component qualification
facility.. high availability.. heat flux ..
neutron fluence .. DT device .... (CTF).
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D Whyte FESAC Presentation
The Challenges of PSI for ITER Beyond Nov 2008
Issue/Gap tokamaks ITER CTF DEMO now

• Quiescent energy exhaust
• Transient energy exhaust from plasma
  instabilities
• Yearly neutron damage in plasma-facing materials
• Max. gross material removal rate with 1 erosion
  yield
• Tritium consumption

greatly increasing parameters
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D Whyte FESAC Presentation
The Challenges of PSI for ITER Beyond Nov 2008

• Lack basic understanding and diagnosis of PSI
  processes in fusion devices ? Uncertain
  extrapolation
• Heat exhaust is primary design point for edge
  materials, since this Is directly related to
  fusion power density
• Thermal efficiency .. high ambient T ?
  Fundamentally different Physical Chemistry ..
  completely unexplored in fusion devices
• Energy sustainment chasm to CTF DEMO
• Rapid dissipation of plasma thermal energy poses
  major challenges in any Demo
• consequences of large particulate removal on ..
  plasma .. safety
• Tokamak edge plasmas feature extreme spatial
  gradients and fluctuations levels, .. erosion
  prediction control very difficult
• It is hard to overstate the importance of ambient
  temperature for fuel control T retention
• 30 years of experience .. we should be
  worried/excited .. in particular the
  effects of having hot walls

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Power plant conceptual studies in Europe
D. Maisonnier, D.
Campbell, I. Cook, Nucl. Fusion 47 (2007)
15241532 ISFNT7
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Power plant conceptual studies in Europe
D. Maisonnier, D.
Campbell, I. Cook, Nucl. Fusion 47 (2007)
15241532 ISFNT7
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Power plant conceptual studies in Europe
D. Maisonnier, D.
Campbell, I. Cook, Nucl. Fusion 47 (2007)
15241532 ISFNT7
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Power plant conceptual studies in Europe
D. Maisonnier, D.
Campbell, I. Cook, Nucl. Fusion 47 (2007)
15241532 ISFNT7
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High temperature He-cooled divertor
Need for work on divertor systems
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Whose DEMO?
In contrast to the rest of the world, a typical
preference of US technology people has been

• one step to high tech DEMO (reactor prototype)
• parallel RD for materials and blankets (CTF)

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Whose DEMO?
In contrast to the rest of the world, a typical
preference of US technology people has been

• one step to high tech DEMO (reactor prototype)
• parallel RD for materials and blankets (CTF)

We have a great challenge to develop the needed
technology! ITER activity is a revealing as we
observe the need for definition and integration
in the design along with the need to move
forward in building the machine!
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We develop PFCs using single effects tests
J. Linke et al., JNM 367370 (2007) 14221431
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We love issues
We are good at developing issues

• We tend to
• be optimistic (we are in fusion after all)
• enjoy identifying issues and pondering problems
• look toward RD programs

Congratulations on your new issue.
Hey nice issue
You rAPER Raised some important issues I
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GAP 3 Technology Culture
We develop one-of-a kind units with anecdotal
mockup tests.
PWI tests
tokamak coupons
test PFC
Material A
lab tests
lab tests
rad effects testing
properties 2
properties
Material A
PFC tests
mockups
prototypes
prototypes
joining
tests
tests
tests
Material B
scale up
manufacturing
manufacturing development
components
Vendor qual.
acceptance
design validation
QA development
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GAP 3 Technology Culture
Configuration d e v e l o p m e n t
STs, others
Ergodic div.
Super-X div.
Liquid PFCs
A realistic fully funded technology program,
will involve a strong winnowing of choices for
PFC materials and divertor technology simply
because of the time to develop and prove
specific robust components for a DEMO.
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PROGRAM DESIGN INTEGRATION
knowledge .. sufficient to design and build, with
high confidence, Recall some excerpts from the
Greenwald panel report
9. PFCs Understand .. materials and processes
design replaceable components that can survive
.. I-3. Integrated advanced burning physics
facility .. dedicated I-4. Integrated
experiment for PWI/PFCs .. steady-state .. non-DT
I-8. Component development/testing program
multi-effect issues in critical technology ..
breeding/blanket .. first wall
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