24P119RHistorical Review of Internationalization in Fusion Research in Japan-INTOR Workshop 核融合研究国際化の歴史経緯	 ̶INTORワークショップ-	 Harukazu Iguchi, Teruhiko Tazima, Keisuke Matsuoka, Chusei Namba and Kazue Kimura
井口春和, 田島輝彦，松岡啓介，難波忠清、木村一枝
National Institute for Fusion Science322-6 Oroshi-cho, Toki-shi, 509-5292, Japan
核融合科学研究所 〒509-5292	  土岐市下石町322-6
A real international collaboration in fusion research for Japan started in the late 1970s via two independentroutes. One is the United Nation’s INTOR workshop, which was an international design activity for thenext generation fusion device after the big tokamaks like TFTR, JET and JT-60 under the auspices ofIAEA (International Atomic Energy Agency). Another is the US-Japan collaboration program on energy
research, which was initiated by the Fukuda-Carter meeting in May 1977. Although the two international
collaborations in fusion researches started independently, they were strongly influenced by international
politics just after the “Oil Shock” several years before. In this report, start-up processes of the INTOR
workshop are described in detail based on the NIFS Fusion Science Archives (NIFS FSA).

1. Introduction
Successful T-3 tokamak experiment atKruchatov Institute in USSR in the late 1960s after
struggling phase of nuclear fusion research overtwo decades, and the world energy crisis, so-called
oil shock, triggered by the 4th Middle East War in
the early 1970s, attracted people’s attention to a
new energy resource all over the world. Nuclear
fusion energy was considered to be one of the most
attractiveenergyresources.
Immediately,
construction or proposal of large tokamaks (TFTRin USA, JET in European Communities, JT-60 inJapan, T-15 in USSR) started. It was a big jump forfusion research from both machine size and budget
points of view. In the same time, design study forthe experimental reactor as a next step device had
been promoted in each country. In Japan, forexample, design activity for Fusion Experimental
Reactor (FER) had been started at Japan Atomic
Energy Research Institute (JAERI). However,fusion research project is approaching a limit of abudget for a single country. In addition, a roadmap
to a commercial reactor was not clear. A common
recognition looking for international collaboration
was growing. Two international collaboration
programs had started in such background. They
were the INTOR Workshop under the International
Atomic Energy Agency (IAEA) and the US-Japan
Collaboration Program under bilateral agreement inthe late 1970s. In this report, start-up processes of theINTOR workshop is mainly described.

2. Establishment of INTOR Workshop
D. Rose of Massachusetts Institute ofTechnology (MIT), USA proposed an international
collaboration in the next phase fusion research in1977. A meeting (so-called Rose meeting) was heldat MIT in October of this year. An invitation letterto Japan was sent to the Director of JAERI. T.
Hiraoka attended the meeting as a representative of
the Director. Based on the discussion at the meeting,
D. Rose sent a letter to the Director General of
IAEA to promote an international collaboration.
The IAEA DG sent a letter (dated on January 17th,1978) to the member countries of International
Fusion Research Council (IFRC) asking forcomment to the Rose’s proposal. USSR was mostactive and immediately proposed construction of anext generation tokamak device under theinternational framework. At the IFRC meeting in
May 10th – 12th, 1978, a decision was made to helda “Sub-Committee Meeting on this internationalcollaboration”, which K. Husimi attended as aJapanese representative. The Advisory Committee
on Nuclear Fusion under the Japan Atomic Energy
Commission discussed on this issue and sent S.
Mori of JAERI to the IFRC Sub-Committee
Meeting in place of K. Husimi for the discussion,
especially on the Soviet proposal. The meeting
was held on June 26th – 28th at IAEA Headquarters
in Vienna. The members were S. Mori (JAERI,Japan), R. S. Pease (Chairperson, Culham
Laboratory, UK), E. E. Kintner (DOE, USA), E.
Velikhov (Kurchatov Institute, USSR), D. Palumbo(Commission of EC) and some IAEA staff
members including H. Kakihana as DDG. It wasrecommended to set up a periodic workshop, inwhich key issue is to crystallize technical objectives
and nature of the apparatus. The decision was madeat the IFRC meeting on August 21th – 22th toestablish the Zero Phase Workshop, which did notcommit machine construction. The IAEA DG
approved this decision in September. R. S. Pease,as a chairperson of IFRC, sent a telex to S. Mori tobe a chairperson of the workshop. Finally S. Mori
was pointed as a chairperson, and thus Japan
became the chair country. It was an epoch-making
event in this age that a Japanese took a leadershipfor the international big project, because Japan waslooked down as a latecomer in fusion research
before this age. This was the process of theestablishment of INTOR workshop as a first realinternational collaboration in fusion research.
2. The workshop procedure
The first steering committee meeting was held
on November 20th - 23 th. The members were W. M.
Stacy, Jr. (Georgia Institute of Technology, USA),B. B. Kadomtsev (Kuruchatov Institute, USSR), G.
Grieger (Max-Planck-Institute for Plasma Physics,EC), and S. Mori (JAERI, Japan). The tokamak
reactor to be examined was designated the United
Nations International Tokamak Reactor (UNITOR).
However, the name was changed later to INTOR.
The guideline for the machine design was decided:(1) The machine should be the maximum
reasonable step to a commercial reactor from thepresent large tokamaks. (2) All basic components as
a commercial reactor should be equipped. (3)System and component tests as a commercial
reactor should be carried out. A realistic machine toanswer these requests could be a D-T tokamakreactor with Q > 5. All engineering tests (material,tritium handling, superconducting coils, etc.) should
be available by carrying out long pulse operationand demonstration of electricity generation. The
final report has to be presented a year later.
The first session of the INTOR Workshop
started on February 5th – 16th, 1979. The members
are listed in the table I.
The workshop was held four times in a yearwith two-week intensive work for each time. Much
homework had been carried back to each homecountry, where many researchers contributed tosolve the issues for the next workshop. A year
later, a final report for the Zero Phase Workshop
was published, suggesting a necessity to continue
the international collaboration as a Definition Phase(later, it was called Phase One workshop).

Table I. Zero phase workshop members
Japan
S. Mori (Chair)T. Hiraoka
K. SakoT. Tazima
USA
W. M. Stacy (Vice-Chair)
J. R. Gilleland
G. L. Kulcinski
P. H. Rutherford

USSR
B. B. Kadomtsev
B. N. Kolbasov
V. I. Pistunovich
EC
G. Grieger
F. Engelman
D. Leger
R. Hancox
R. Verbeek (Secretary)

IAEA
J. A. Phillips
V. S. Vlasenkov

3. Fruits of the workshop
Finally the INTOR workshop continued for 10
years till 1988. The workshop played a role toestablish international partnership in fusion research.
S. Mori took a leadership for all these periods,
which raised the status of Japanese fusion researchamong international fusion research community.
The design parameters had been changed step bystep, but the machine size was kept compact
throughout the period, which was the principal
policy of the steering committee. They thought thatthe size and thus the cost of the machine have to belimited from the viewpoint of commercial purpose.
It is important to note that the workshop activity
became a basis of the international collaboration
framework in fusion research such as the ITER
(InternationalThermonuclearExperimentalReactor) project, although the INTOR machine
itself was not constructed. On the other hand, it isalso noted that the successful international
collaboration was due to the preliminary stage offusion research as a commercial energy
development, where international friction caused bynational interest of each country was not apparent.
It will not be promised in future when fusion energyapproaches commercial reality.
References[1] Workshop Report by S. Mori, 1978, NIFS FSA.
[2] Workshop Report by K. Saco and T. Tazima, 1979,
NIFS FSA.
[3] Interview to S. Mori, March 10, 2011, to beregistered as NIFS FSA.