Fusion Technology 1986. Proceedings of the Fourteenth Symposium, Congress Center of the Palais Des Papes, Avignon, France, 8–12 September 1986

1777 Pages·1986·133.094 MB·1777\1777

SYMPOSIUM COMMITTEE
Organizing Committee
A. Torossian (Chairman) CEA Cadarache France
H. Conrads KFA Jiilich FRG
R. Hancox UKAEA Culham UK
A.M. Van Ingen FOM Jutphaas The Netherlands
A. Malein CEC Brussels Belgium
G. Rostagni CNR Padua Italy
P. Schiller JRC Ispra Italy
K.H. Schmitter IPP Garching FRG
Local Committee
A. Torossian (Chairman)
P. Libeyre (Scientific Secretary)
N. Barles (Organization)
A. Marc (Organization)
M. Block (Scientific)
LEGAL NOTICE
Neither the Commission of the European Communities, nor any person acting on behalf of the
Commission, is responsible for the use which might be made of the following information.
Association
European Atomic Energy Community — EURATOM
CEA-CEN Cadarache, France
FUSION TECHNOLOGY 1986
Proceedings of the fourteenth Symposium
Congress Center of the Palais des Papes
Avignon, France
8-12 September 1986
In Two Volumes
Volume 1
Published for the
COMMISSION OF THE EUROPEAN COMMUNITIES
by
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First edition 1986
EUR 10936 EN
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ISBN 0 08 034935 8
In order to make this volume available as economically and as
rapidly as possible the authors' typescripts have been reproduced
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graphical limitations but it is hoped that they in no way distract
the reader.
CHAIRMAN'S REMARKS
A. Torossian
Ladies and Gentlemen,
On behalf of the Organizing Committee I am very happy to welcome you here in Avignon to
the Fourteenth Symposium on Fusion Technology.
The present Symposium gathers more than five hundred participants coming from 13 different
countries and 270 contributed papers will be presented in spite of a very severe selection.
230 contributed papers will be presented as posters, the posters have been arranged in six
sessions of roughly 40 posters each.
14 contributed papers will be presented orally in parallel with poster sessions and twenty
seven invited lectures will be given during the Symposium.
They have been arranged in the following way :
- this morning and friday morning are entirely devoted to topics of general interest and
Large Experiments and Projects.
- on Wednesday morning, in parallel with the session E dealing with Blanket Technology,
Refuelling and Safety, we shall have a session gathering presentations of the nrogress
reports on :
Uendelstein VII AS
Asdex Upgrade
FTU
RFX
Tore Supra
- other invited lectures will be given at the beginning of each session. These invited
lectures will have the very difficult task of trying to give an overview of the topic which
will be dealt with during the appropriate session.
I would like to thank in advance all the sneakers arid especially Prof. Toschi who has
accepted to summarize and to point out, in the last lecture of this conference, the major
information gathered during the Symposium.
The programme of the Symposium also includes :
- a visit to the Cadarache center and Tore Supra experimental facilities
- several social events ·
Monday evening : cocktail at the City Hall of Avignon.
Wednesday evening : reception at the Guest House of Cadarache,
Our traditionnal conference dinner will be held at the Carrières de Lacoste on thursday
evening.
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On behalf of my colleagues of the Organizing Committee and of the Local Committee, I wish
you a pleasant stay in Avignon and I hope you will leave this beautiful city with the
feeling that we have the capability not only to overcome existing problems but also to
build and to put into operation a reactor in a safe and reliable way in spite of the
large amount of development work which still remains to be done.
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WELCOME ADDRESS AND OPENING REMARKS
F. Prévôt
Centre dfEtudes Nucléaires de Cadarache
Association Euratom-CEA
Département de Recherches sur la Fusion Contrôlée
13108 - SAINT PAUL LEZ DURANCE CEDEX (FRANCE)
It is a great pleasure for me to open the fourteenth Symposium on Fusion Techno­
logy.
First of all I like to welcome the participants and specially those who come from
abroad. I wish all of you a pleasant stay in Avignon, this old city so rich in tradition and
history, and a very successful work in this modern and difficult business of Fusion Techno­
logy.
As a responsible for the french fusion laboratory I am particularly glad the
place of the meeting offers you an opportunity to see our new fusion laboratory at Cadarache
and the new Tokamak under construction, I mean TORE SUPRA.
This symposium will give us the most recent advances and results in the various
fields of Fusion Technology. Let me begin now with some general remarks and ask questions
about the future of this work.
Fusion Technology is a vast area which covers numerous and distinct topics.
Traditionally we distinguish Plasma Technologies from Nuclear Technologies. This
distinction reflects a historical reality.
Plasma Technologies answer problems linked to plasma machines which today have
not reached the thermonuclear stage, it means without tritium and with a limited amount of
neutrons. Most of them are traditional technologies adapted to fusion (for instance magnetic
field, power supply, vacuum and so on), or more recent technologies specific to fusion (for
instance plasma heatings). They have been necessary since the beginning of fusion research
and they will continue on more and more large scales up to the reactor. Practically in all
countries they have been taken in charge by the plasma laboratories by relying more or less
on industry. They form a kind of world apart with only few little connections with the world
of nuclear research and industry.
The case is very different for nuclear technologies. They will have to play a
prominent part as soon as there is Tritium and there are very many neutrons. Let us hope it
will be soon. They will have to solve entirely new problems compared with the plasma machine
such as blanket, Tritium plant, irradiated materials, nuclear safety.
Historically the development of Nuclear Technologies for Fusion has begun broadly
after Plasma Technologies and so is today less advanced in the field of achievements.
In the Nuclear field, Fission has developed a huge amount of knowledge, tools and
facilities, which of course requires a considerable adaptation for fusion .But it is therefore
natural and wishable that the fission laboratories and industries now intervene in fusion.
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However these nuclear technologies cannot remain completely separate from plasma
technologies. On the one hand the border between these two technologies, very clear at the
beginning, is going to become more and more blurred. One good example is the first wall which
has to hold the constraints of the plasma as well as those of the neutrons. Indeed there are
many other ones.
On the other hand no particular technology as well as no particular scientific area
can alone progress and lead to a satisfactory solution. The reason is a fusion reactor is a
whole in which each part is closely connected with the others.
Here we deal with a new problem concerning fusion. The achievement of a fusion reac­
tor requires a choice of solutions for each scientific and technological specific problem.
These solutions must not only be satisfactory for each problem but also coherent and compa­
tible between them. So it appears that R and D in technology cannot be ignorant of constraints
of physics but it also is reciprocally true. Up to now plasma physicists have imposed speci­
fications to the technologists and they have little listened to their claims. In the future
the discussion would be better balanced and physicists would better take into account the
problems and constraints raised by technology.
Now there are many conferences, meetings, symposia dealing with fusion technology.
This one, the SOFT, is one of the most ancient. It was launched in 1960 at Culham. I hope
it belongs to the best ones.
Its evolution reflects I have just said. Firstly devoted mostly to Plasma Technologies
of research devices, it has gradually opened to Nuclear Technologies and to studies of whole
systems. However the dialogue between these various aspects remains difficult and insuffi­
cient in my opinion. Besides another difficulty appears. If no choice is made and if we
want to deal with everything and to keep on increasing the volume of work in each field, the
hugeness becomes a cause of ineffectiwness .I believe that for the first time at a SOFT the
selection committee had to reject papers vithout questionning their quality. It is there
fore the right time to make choices about the definition and the tread of this conference.
As for me I think there is an actual need for a general technology conference dea­
ling with all areas. We should set into relief the most significant results, deal with the
mutual connections between the different areas and find a proper balance between them. In
order to avoid hugeness topical meetings should take place on each particular field with
a synthesis account or a review at the general conference. This is a question to all of you
whose opinion must guide the work of the organization committee in the future. I think the
stake is important, although I realize it is difficult. If we could succeed along this line
the SOFT will not only give a very useful information but will also play an actual part in
research orientation.
Anyway beyond problems of communication we all, more or less, have a responsibility
and a part in the Fusion Technology R and D programs. I would like to devote the remaining
time of my talk to this problem.
The question is : how to optimize the whole R and D program ?
In my opinion, the four main arguments to take into account are :
- Time. There is no real pressure from the society or, in other words, there is no short
term energy crisis. But anyway much time, several decades, will be necessary and we must
progress as fast as possible.
- The diversity of solutions may appear as a great potential richness of fusion. It also is
a danger to both increase the duration and the cost of the development.
- The cost of development is very high and money is rare.
- International collaboration with its advantages and its difficulties
I am going to be more concrete.
Concerning diversity, what strikes me is the great number of proposed and studied solutions
for the technological problems of fusion. To give one sole instance here, for the Tritium
breeding blanket there are several substances with lithium in : metal, alloys, composites,
mixings, on different states : liquid or solid ; several coolings : water, gas or liquid
metal ; several kinds of architecture : in small modules, sectors or unique volume for the
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whole blanket. There are many possible arrangements between all these constituents. I acknow­
ledge myself very perturbed by this situation. Does that mean we have several good solutions
and that we must be glad of this and keep on working an a so broad scale to finally choose
the best one ? Or at the opposite does that mean no solution is really satisfactory and work
is going to be excessively difficult, long and expensive ? In one case as in the other case
how long must it take to choose the best solution and to bring it to a usable reality ? I
don't know the right answers to these questions. But I think the diversity of research must
be preserved in order to reach the best solution and up to that point. Beyond its cost is
excessive.
Concerning cost however the most acute problem comes from the experimental
fusion reactor. We need, in order to produce convincing proofs and progress, to build a
certain number of reactors, necessary steps before being able to propose fusion as a reliable
and competitive industrial product. Now each step is very expensive owed to the fact that,
contrary to fission, a zero power reactor does not exist in fusion. Resources being limited
we must therefore attempt to reduce the number of these steps. Each one must give the maxi­
mum answers. But is it possible without taking two high risks and arbitrary eliminate so­
lutions ?
A relaxation,at least partial, of these difficulties lies on international
collaboration. International Collaboration is very up to date for fusion and its streng­
thening seems indeed necessary. It offers numerous advantages, I mention here only two of
them. Firstly by a sharing of programs between different partners it permits a better keeping
of diversity. Then by sharing costs in a big common undertaking it lightens the burden for
each partner and can even permit a venture impossible for an isolated nation. In Europe
we have been cooperating for long ago and successfully I believe. However collaboration has
its own drawbacks and difficulties. It cannot accomplish a miracle and does not necessarily
create the best statements and the best technical decisions. It also has its heaviness which
is far from being negligible.
Finally I would like to briefly comment on the criticisms against fusion and
even denial. They can be summarized by the words : complicated technology - doubtful reliabi-
lity-too high final cost. These criticisms are too vague and too general to be refuted on a
firm basis today. However we cannot ignore and neglect them. Nobody is more aware than we
are of the difficulty of the task. Doubt is permitted, it is even stimulating, but not denial
As for me I am trustful the quality and the seriousness of our work will bring positive ans­
wers to the problems raised up by fusion. After all, we have already much progressed and
solved difficult problems.
As we say in french :
"C'est en marchant qu'on démontre la marche" *
* (only by walking can be proved the walk)
9
THE EVOLUTION OF THE EUROPEAN FUSION TECHNOLOGY PROGRAM
TOWARDS NET
H.H. Hennies
Kernforschungszentrum Karlsruhe
Postfach 364o, D-75oo Karlsruhe
1· Starting the Technology Program in 1983
Research work on plasma physics has been conducted at many places in Europe for
about 25 years. Today the funds spent for these studies amount to about 35o MEGU per
annum, the number of scientists working in this field is about 8oo and the total
staff concerned with this task is about 25oo. Since the Joint European Torus (JET)
has been completed, about 450 scientists and technicians working on this European
central large experiment and the budget has amounted to loo MECU per annum. These
fusion technology figures have to be added to the corresponding figures for the
plasma physics research work.
On the other hand, relatively little money had been spent for technological
development until 1983, although, obviously, the large physical experiments also
called for extensive and broad technological development. But work related to the
technology of tritium burning and radiation exposed machines provided with a blanket
was relatively moderate and not coordinated at all.
The situation changed in Europe in 1983 when the "Fusion Technology Program" was
initiated under the auspices of Euratom. The program is implemented in the associated
laboratories. Two goals have been pursued:
1. Building up a technology program in order to became able to give an answer
to all questions which are relevant in realizing a fusion reactor.
2. Planning a next large experiment in Europe which, after JET, should be a
reasonable interim step based on the Tokamak principle.
The first goal was pursued initially by extending current work (e.g., magnet
development, material development) and taking up development work in new fields
(detailed blanket R+D, tritium technology, remote handling, safety studies) conduc­
ted in the national laboratories.
The second goal is being pursued centrally by an international design team
located at Garching. This so-called NET team, NET being an acronym formed from Next
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^European Torus, presently employs about 5o persons, but grants quite a number of sub
contracts to national laboratories and to industrial firms.
Now, at the end of three years work, the NET team has become very efficient and
a lot of R+D groups have been formed within the laboratories. About 28o researchers
are presently working in the field of fusion technology (the NET team included).
The total budget amounts to about 80 MECU per annum.
Results obtained in the preceding three years are extremely encouraging:
- After initial parameter studies and many comparisons of the design concepts,
the NET team has decided in favor of a reference concept which, for the time being,
will serve as a basis for future work.
- The technology program now covers almost all fields to be treated and a large,
steadily growing part of it has been adapted to the NET design.
Unlike plans presently elaborated, e.g., in the U.S.A., to build only a "physics"
machine as the next generation, the NET concept is clearly geared to building an
Engineering Test Reactor at which essential questions can be studied, which are linked
to the construction of energy and tritium producing blankets. The idea is to test in
all fields, except for material development where inadequate fluence will preclude
testing, the technology to an extent which would provide the basis for the design of a
demonstration reactor after completion of the NET experiments.
According to the schedule, NET should be completed by the year 2ooo. Then a ten
years testing phase will follow. The prerequisite of this plan is not only the
successful performance of a complex technology program but also obtaining sufficiently
validated results of plasma physics (especially from JET) which will justify the
decision to start the construction of a large experiment which will cost several
thousend millions of ECU.
The long periods of development required are in our opinion an important reason
why plasma physics and technology should be promoted ^n parallel instead of starting
the technology only after evidence has been provided for the solution of the plasma
physics problems.
The development of blankets for producing useful energy and tritium is a complex,
time consuming task.
By attacking it parallel to the NET Project it should be avoided that after
successful completion of plasma physics experiments, e.g., in the year 2olo, no answer
can be given to the question how the neutrons generated can be converted into useful
energy and that one will be referred to another ten years R+D work in the technology
field.
Admittedly, the restriction must be made that material development plays a
special role and that also NET will not give adequate answers in this respect.
Also we are convinced that it will not suffice to develop technologies in
parallel to a physics experiment without close coupling to the specific design. When
there is lack of pressure to realize a planned project, one is tempted to study many
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