Transcript No Slide Title

EFDA
EUROPEAN FUSION
DEVELOPMENT AGREEMENT
TECHNOLOGY CHALLENGES ON THE
ROAD TO THE FUSION REACTOR
Roberto Andreani
EFDA Associate Leader for Technology
SOFT
Venezia 20-24 September 2004
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EFDA
EUROPEAN FUSION
DEVELOPMENT AGREEMENT
Content
• Present situation of the fusion programme
• Which are our (my) ideas about a DEMO (PROTO) reactor
• How does it compare with ITER and what we wish to
change/improve
• What then needs to be done
• Are we too, or too little optimistic?
SOFT
Venezia 20-24 September 2004
2
EFDA
EUROPEAN FUSION
DEVELOPMENT AGREEMENT
Present situation of the fusion programme (1)
• A positive decision on ITER construction has been taken, since a long
time, by the European council. The site decision is unfortunately still
on hold.
• The physics basis of ITER, established first in 1992 and then
confirmed in 1998, when proposing the reduced version of the
machine, has been very satisfactorily confirmed by the experiments.
• In particular JET and JT-60 have contributed but, like in a large
painting, a lot of details have been added on the basis of the results
obtained on many other experiments run worldwide.
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Venezia 20-24 September 2004
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EFDA
EUROPEAN FUSION
DEVELOPMENT AGREEMENT
Present situation of the fusion programme (2)
• The potential operating domain of ITER has been very appropriately
chosen to allow extrapolating the physics of ITER to a reactor in case
of successful performance of the experiment.
• The basic engineering design of ITER is complete. A number of design
details and some technological choices are still missing and will be
decided during the initial phases of construction as it always occur
with large projects. The new Director and the new International Team
will have to take responsibility.
• The materials and the technologies needed to build ITER with
reasonable confidence have been developed during the more than 10
years of R&D conducted by the ITER parties in view of the
construction.
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Venezia 20-24 September 2004
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EFDA
EUROPEAN FUSION
DEVELOPMENT AGREEMENT
Present situation of the fusion programme (3)
•
In Europe, in the framework of the EFDA technology programme, a number of
strategic objectives have been pursued:
- Review critically the new design of ITER in support to the International
Team
- Prepare technological and manufacturing solutions safely applicable to
the critical areas of the project, even independently from the
final configuration which
might be adopted.
Typical examples the radiation enduring magnet insulation, the
high heat flux resistant plasma facing components, the divertor,
the vacuum vessel, providing reliable recipes for the construction of
components of the machine.
- Build and test prototypes of crucial systems like the fuel cycle, the divertor
remote maintenance system, the cryogenic pumping system, in
view of assuring their reliability.
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Venezia 20-24 September 2004
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EFDA
EUROPEAN FUSION
DEVELOPMENT AGREEMENT
Present situation of the fusion programme (4)
- Conduct a comprehensive set of design and R&D activities, both in
physics and engineering, on the ITER day one Heating and
Current Drive systems. In ICRH integrate the JET experience
of manufacturing and testing an ITER relevant antenna.
- Prepare a set of essential facilities needed to test mock-ups and prototypes
and to allow quality control during series manufacturing.
- Assist the French Association in preparing the site to host ITER as a
true European site.
- All of these activities have been conducted putting great attention to
the need to train European industry in view of the manufacturing
phase.
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Venezia 20-24 September 2004
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EFDA
EUROPEAN FUSION
DEVELOPMENT AGREEMENT
Present situation of the fusion programme (5)
• All together, during the last three years of the
technology programme, about 160 M€ have been
spent by European Associations and Industry,
under coordination by EFDA, in preparation of
ITER.
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Venezia 20-24 September 2004
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EFDA
EUROPEAN FUSION
DEVELOPMENT AGREEMENT
Present situation of the fusion programme (6)
• In addition to the ITER activities, exploratory activities are
conducted in view of the design and construction of a
DEMO, especially, but not only, in those domains, like the
materials, where we already know that, beyond ITER, we
will need new better suited solutions.
• A debate has been taking place, since somewhat more than
a year, about the possibility of adopting and following a
“fast track” in our quest for fusion power. This requires an
agreement amongst a number of international partners to
properly share the different elements of a broader approach
to fusion. We hope that this agreement materialises soon.
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Venezia 20-24 September 2004
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EFDA
EUROPEAN FUSION
DEVELOPMENT AGREEMENT
Which are our (my) ideas about a DEMO
(PROTO) reactor (1)
• A DEMO should likely demonstrate that a fusion reactor
can indeed produce a significant amount of energy,
delivered to the electrical grid. No guarantee could be
provided before hand on the availability of the machine but
it is expected that the quality of operation and the load
factor would be acceptable and improving with time.
• An electric power of the order of 1000 MW seems
appropriate considering that the size of the machine would
have to be large enough to allow reaching a value of the
gain Q (= P fusion/ P heat&CD) of the order of 30. By
simple considerations, one recognises that the size of ITER
is of the same order of the size needed for a reactor.
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Venezia 20-24 September 2004
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EFDA
EUROPEAN FUSION
DEVELOPMENT AGREEMENT
Which are our (my) ideas about a DEMO
(PROTO) reactor (2)
SOFT
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A
Z(m)
• Considering the most advanced
concept of reactor studied in the
Power Plant Conceptual Study,
the size of a 1500 MWe reactor
approximately coincides with
the size of ITER. This implies
extremely
high
operating
temperatures (> 1000 0C) and
efficiency, and then advanced
materials still in the early stage
of development. But also
considering a water cooled
1000 MWe reactor and modest
extrapolations in physics and
technology, the linear size
would be only 30-50 % larger
than ITER.
6
B
C
D
4
ITER
2
R(m)
0
0
5
10
15
-2
-4
-6
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Venezia 20-24 September 2004
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EFDA
EUROPEAN FUSION
DEVELOPMENT AGREEMENT
How does DEMO compare with ITER and
what would we wish to change or improve (1)
• There are a number of critical areas in which we do not have yet a
consolidated design choice : the coolant, the main structural material,
the first wall, the blanket and the divertor, the remote handling system.
• Additional problems, like the choice of the superconductor for the
magnets (which might have a strong impact on the cost) or the
decision on the type of additional heating and current drive systems are
not so crucial for the success of DEMO.
• The coolant. A preference for helium has been already expressed in
the European programme when helium cooling was chosen for the two
European blanket concepts to be tested in ITER. Helium presents
advantages in operating temperature (thermodynamic efficiency of the
reactor) and safety (due to the absence of chemical reactivity with the
materials present in DEMO).
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Venezia 20-24 September 2004
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EFDA
EUROPEAN FUSION
DEVELOPMENT AGREEMENT
How does DEMO compare with ITER and
what would we wish to change or improve (2)
•
Structural material. The austenitic steel used for ITER would undergo an
excessive swelling when subject to the fluences foreseen in DEMO (an
equivalent damage of 80-120 dpa compared with 3 dpa in ITER) and would
present the problem of high activation, high nuclear heating and long decay
time. Europe is developing EUROFER, a 9 Cr ferritic martensitic steel which
looks rather promising. This type of steels has already performed well in fast
breeder reactors at that level of fission neutrons fluence. It is in the same
category of steel to which the Japanese F82H belongs.The operating
temperature of EUROFER (500-550 0C) sets the limit to the thermodynamic
efficiency of the reactor. A problem to be properly accounted for is that
martensitic steels are ferro-magnetic.
The fusion variety has to account for the high neutron energy and the need to
reduce the level of activation and minimize the radioactivity decay time of the
irradiated material. The first irradiation results with fission neutrons, although
up to a limited number of dpa, are promising. The validation of these results
using the right breed of neutrons is however a must before adopting
EUROFER for DEMO. This implies to start as soon as possible, in parallel
with ITER construction, with the construction of IFMIF.
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Venezia 20-24 September 2004
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EFDA
EUROPEAN FUSION
DEVELOPMENT AGREEMENT
How does DEMO compare with ITER and
what would we wish to change or improve (3)
• First wall. DEMO first wall could not provide an acceptable lifetime
using graphite or beryllium as in ITER and in the present machines. A
metallic first wall would be desirable, tungsten or, even better, steel to
reduce activation. Experimentation on the existing machines needs to
be pursued in order to establish the compatibility of the plasma
regimes with these types of solutions.
• Blanket. Experimentation with ITER is essential in order to test
blanket solutions. Two concepts, both helium cooled, one with a
pebble bed of lithium ceramic as a solid breeder and beryllium
multiplier, the second with a liquid lithium lead eutectic, are being
developed in Europe. A helium cooled, lithium lead blanket avoids the
presence of beryllium. Hopefully the engineering and technological
problems related with both solutions will be solved in the framework
of the ITER test programme.
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Venezia 20-24 September 2004
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EFDA
EUROPEAN FUSION
DEVELOPMENT AGREEMENT
How does DEMO compare with ITER and
what would we wish to change or improve (4)
• Divertor. A helium cooled divertor would be highly desirable. The
relevant R&D programme is already under way inside EFDA and
appears well oriented although there is a long way to go.
• Superconducting materials. The success of ITER operation would
provide an assurance for the use of Nb3-Sn as the superconducting
material. In the mean time the fusion programme is going to carefully
monitor the industrial developments in the field of high temperature
superconductors applications and an exploratory R&D will be
conducted also by EFDA in view of their application to fusion specific
needs.
• Heating & CD systems. The choice of the best solutions in this
respect will be likely dictated by the results obtained in ITER.
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Venezia 20-24 September 2004
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EFDA
EUROPEAN FUSION
DEVELOPMENT AGREEMENT
What then needs to be done (1)
• We are moving towards a transition from a strongly physics oriented
programme to a physics based, large, industrial type programme to
build the reactor.
• The European fusion programme is still predominantly physics
oriented. There are in the programme about 2000 professionals, out of
them, one third between technologists and engineers. The financial
resources spent on technology during the VIth Framework Programme
are about 1/7th of the financial resources assigned by the Commission
to the entire fusion programme.
• In the mean time there is also a diffused scarcity of experienced
personnel. No machine has been built in Europe and in the world
during the last 15 years.
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Venezia 20-24 September 2004
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EFDA
EUROPEAN FUSION
DEVELOPMENT AGREEMENT
What then needs to be done (2)
• All this translates in the fact that more or less all the European
Associations, involved in technology activities, are working at present
at the limit of their capabilities.
• Definitely, in my opinion, to move on a fast track towards the reactor,
we need a strong enhancement in the human and financial resources
devoted to fusion technology and engineering in the European
programme.
• The broadening of the human basis of the programme in the
Associations is also absolutely necessary to prepare new generations of
fusion scientists and engineers.
• In the mean time ITER will require a very strong involvement of the
most qualified European industry.
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Venezia 20-24 September 2004
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EFDA
EUROPEAN FUSION
DEVELOPMENT AGREEMENT
Are we too or too little optimistic? (1)
Success of the programme (of DEMO) will depend on a number of
factors:
• A steady state operation of ITER according to the expectations.
• An in-depth understanding of the physics regimes of ITER, obtained
through the experimentation, allowing to produce a reliable model of
the plasma of DEMO, which should not be an experiment in this
respect.
• A successful operation of the remote handling systems in ITER, to
guarantee the needed availability of this machine for experimentation
and to design a DEMO with confidence.
• A strong investment in qualified human resources in the Associations.
• A solid industrial involvement throughout the construction and
operation of ITER to prepare a well qualified European “fusion”
industry to play a crucial role in DEMO.
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Venezia 20-24 September 2004
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EFDA
EUROPEAN FUSION
DEVELOPMENT AGREEMENT
Are we too or too little optimistic? (2)
In conclusion:
I personally feel that we have prepared a good basis
from which to proceed.
Of course we cannot be sure of the success,
but
The game and the potential results are worth playing.
SOFT
Venezia 20-24 September 2004
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