Journal of Fusion Energy, VoL 11, No, 2, 1992

Status and Plans for I T E R Alexander J. Glass 1

under the auspices of the International Atomic Energy Agency (IAEA) in Vienna. The ITER project is conceived as operating in three stages. The first was the Conceptual Design Activity, completed in December 1990. In 1992, the responsibilities of the Soviet Union were assumed by the Russian Republic. The four Parties are now about to enter the second phase, the Engineering Design Activities (EDA), which is expected to last for 6 years, through 1998. To date, the Parties have made no committment to construct the machine, but only are preparing to complete an engineering design and develop the requisite technology. If they approve construction, a site will be chosen and the third stage, the Construction Activities, could begin as early as 1998 with possible first operation by 2005. The basic design parameters as developed in the CDA are shown in Table I. For comparison purposes, the operating parameters of the Joint European Torus (JET) facility in Culham, England, which is the largest tokamak operating today, are also shown. In the EDA, the design is expected to evolve from the one developed in the CDA. During the next 6 years, the four Parties are expected to spend approximately $1.5 billion on the design and technology development for ITER. During the CDA, an estimate was made of the cost of constructing

In 1987, the United States, Japan, Western Europe, and the Soviet Union combined forces to undertake the design, development, and construction of the world's first power-producing magnetic fusion reactor. This project is called the International Thermonuclear Experimental Reactor (ITER). The overall objective of the ITER project is to demonstrate the scientific and technological feasibility of fusion power for peaceful purposes. In order to accomplish this overall objective, ITER has a threefold mission. Thephysics mission is to demonstrate controlled ignition and extended burn of a deuterium-tritium (D-T) plasma with an ultimate goal of steady-state or continuous operation. The technology mission is to demonstrate technologies essential to the development of a demonstration reactor in an integrated system. The testing mission is to perform integrated testing of the high heat flux and nuclear components required for the use of fusion power for practical purposes. ITER is an international collaboration. It grew out of discussions between Presidents Reagan and Gorbachev at the Geneva Summit of 1985. After some discussion, the collaboration was broadened to include Western Europe (operating through Euratom) and Japan. In 1987, the four Parties established the terms of reference for the collaboration and entered the first phase of ITER activities, the so-called Conceptual Design Activities (CDA). The CDA was initiated in 1988 and completed in December 1990. ITER was organized as an international collaboration from the start. Each of the four Parties contributed equally to the effect. Currency transfers are kept to a minimum by having most of the technology R&D work associated with the project carried out in the domestic programs of the four participants. During the CDA, coordination was carried out

Table I. Basic Design Parameters from CDA

Fusion power, (MW) Major radius, R, (m) Minor radius, a, (m) Plasma current, I (MA) Volt-seconds to drive current, vS Toroidal field on-axis, Bt, (T) Pulse length, (s)

Lawrence Livermore National Laboratory, P.O. Box 808, L-7, Livermore, California 94551-9900.

ITER

JET

1000.0 6.0 2.15 22.0 325.0 4.85 200.0 = > Steady-state

10-20 2.96 1.25 2.6--4.8 25.0-34.0 2.8-3.4 20.0

59 0164-(]313/92](1600-0f159506,50/0 9 1992 Plenum Publishing Corporafioa

60 the device. The CDA estimate totaled $4.9 billion for capital costs to construct ITER, denominated in 1989 dollars. Operating costs for the facility were estimated to total $400 million annually, again in 1989 dollars. ITER plays a central role in the fusion program of the United States. Testifying before a congressional committee in February, Dr. William Happer, the DOE Director of Energy Research, identified four key issues for magnetic fusion energy. The first issue was to understand ignition physics. Here he said, "ITER will be our primary vehicle." ITER will be the first machine to achieve ignition conditions anywhere in the world, and, although some aspects of burning plasma physics will be investigated in DT experiments to be carried out on JET and TFTR, experiments on ITER will present the first opportunity for the scientific community to explore all aspects of the problem of confining a burning plasma. The second issue was the development of a fusion nuclear technology. Dr. Happer pointed out that the testing mission of ITER is intimately tied to the development of a practical technology for fusion reactors. He indicated that, with the cancellation of the BPX facility originally intended to be built at Princeton, the physics phase of ITER may take longer than originally expected. This will delay entry into the testing phase, and therefore delay the compilation of the necessary data on materials development required for the construction of a demonstration reactor. The third issue was the optimization of confinement configurations. Here Dr. Happer pointed out that other facilities would be required in addition to ITER and those facilities currently operating. These might include a superconducting machine such as the proposed TPX to address issues of profile control, improved operating modes, or second stability. He also indicated that for concepts which are alternatives to the tokamak, the United States would rely on participation in the programs of other nations. The fourth issue for magnetic fusion, in Dr. Happer's view, is the development of low-activation materials. Here a number of facilities are required. ITER can do a certain amount of testing, but does not have sufficient fluence to test components to the end of life. It is proposed to build an intense source of 14 MeV neutrons, as a further international collaboration, to provide a dedicated test facility for low activation materials. Even if all of these facilities are build over the next decade, the goal of starting the design of a demonstration power plant early in the twenty-first century, which is set forth in the U.S. National Energy Strategy, is extremely ambitious. In November 1991, the four Parties initialed an Agreement to enter into the EDA. According to this

Glass Agreement, the following activities will be carried out over the next 6 years: (a) design of the fusion device, (b) performance of the essential research and development needed to develop the requisite technologies, (c) development of a plan for construction, operation, maintenance, and decommissioning of the ITER facility, (d) preparation of a construction cost estimate and development of site requirements, including the characterization of candidate sites for the construction of ITER in each of the four Parties, and (e) agreement on policies for procurement, for task sharing, and for other administrative matters. The four Parties signed the. EDA Agreement on July 21, 1992, in Washington; D.C. The ITER organization is complex. The governing body for ITER is the ITER Council, which is headquartered in Moscow. The ITER Council is chaired by Dr. Eugeny Velikhov from Russia, and the co-chair of the Council is Dr. Masaji Yoshikawa from Japan. The Council consists of two representatives from the governments of each of the four participating nations. The Council is advised by two groups: the Technical Advisory Committee chaired by Dr. Paul Rutherford from Princeton Plasma Physics Laboratory, and a Management Advisory Committee which is chaired by Dr. Yoshikawa. The ITER design activities are supervised by the Joint Central Team. The Joint Central Team is responsible for design integration, coordination of R&D with design objectives, and for carrying out most of the required design activities. Each Party has organized its domestic effort into what is called a Home Team. The Home Teams will carry out the required technology R&D, and will also participate in design tasks under direction from the Joint Central Team. The director of the project is Dr. Paul-Henri Rebut, currently the director of JET. He is assisted by a principal deputy, Dr. Yasuo Shimomura from Japan, along with deputy directors, Dr. Valery Chuyanov from Russia, Dr. Ronald Parker from the United States, and Dr. Michel Huguet from the European Communities. The ITER Joint Central Team will occupy three sites: design integration and project direction will be located in San Diego, California, in-vessel component design will be located at Garching, near Munich in Germany, and out-of-vessel component design will be carried out at Naka, Japan. The site of the ITER building in San Diego is located on North Torrey Pines Road, just north of the General Atomics facilities and the campus of the University of California in San Diego. The site is managed by SAIC. The building is currently undergoing refurbishment to configure the offices to the desired layout. The executive offices are ready for occupancy, and ITER

Plans for ITER

meetings have already been held in the building. It is expected that the building will be fully ready for occupancy by the end of the summer of 1992. Each of the four Parties has completed a detailed national review of the CDA design, and all agree that although some aspects of the design require further work, that it does provide a suitable basis for continuing to the EDA. There is general acceptance on the part of the four Parties for having a staged approach to ITER, with an initial physics phase lasting between 6 and 10 years, followed by a technology and testing phase. It is probable that the machine will be designed in such a way that major modifications can be made on it between phases. Although the four Parties agree on these broad issues and accept the CDA design as the basis for further development, there remain substantive disagreements regarding the technical objectives for ITER. As soon as the Agreement was signed, a Special Working Group, SWG-1, was convened by the Council to examine the technical objectives of ITER. The EDA Agreement states the programmatic objective of ITER, "to demonstrate the scientific and technological feasibility of fusion power for peaceful purposes," and endorses the idea of a threefold mission for the facility--physics, technology, and testing--as previously described. These three missions stress different aspects of ITER technology. The physics mission places heavy emphasis on the requirements for achieving adequate ignition margin and stability of confinement. Ignition margin is sensitive to the physical parameters of the design such as the major radius, the plasma current, and the magnetic field. All the Parties agree that some form of heating technology will be needed for the plasma, and possibly techniques for current profile control. However, in the physics phase, particularly during the time the machine is operating in pulsed operation, it may not require external current drive or a tritium-breeding blanket. The technology mission requires reactor relevant technologies and high availability. This, in turn, requires a satisfactory solution of the divertor problem, and also requires extremely reliable superconducting magnets. These two issues, reliable superconducting magnets, and a divertor design capable of withstanding the high flux of heat and particles coming out of the machine at full power operation, have been identified by all the Parties as the two issues critical in the ITER design. Furthermore, since ITER will burn DT, it will clearly require remote maintenance which must be designed into the machine from the outset. In order to prove that a fusion device can be operated consistently over long periods of

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time, an adequate supply of tritium for extended operation must be provided. This in turn will probably require a functioning breeder blanket. Furthermore, if the machine is to operate in steady state, a demonstration of efficient external current drive is also required. Finally, the testing mission requires, above all else, adequate fluence. Therefore, high availability and an adequate supply of tritium through the provision of a breeder blanket are mandatory for the satisfactory completion of the testing mission. It is very likely that suitable nuclear testing will require steady-state operation for periods of up to several weeks. The detailed technical objectives for ITER must be resolved before the design can be defined. The SWG-1 will meet as soon as the Council is formed. The issues that it needs to resolve relate to the risk of the design, the scope, the schedule and construction, and ultimately to the cost of the machine. The Parties are beginning to discuss the issue of selecting a site for ITER construction. Experience in selecting the site for the ITER design causes concern because almost a year was spent in resolving the competition among the United States, Japan, and the European Communities, regarding the location of the ITER design activities, and the conclusion was a rather unwieldy compromise of dividing design activities among three sites. Clearly, such a compromise cannot be made for the construction site. Dr. Rebut has indicated his desire to make an early determination of the ITER site, and actually to construct some of the facilities required for the fabrication of machine components on the construction site, toward the end of the EDA. Thus, an early site collection could accelerate the schedule for the construction and ultimately the operation of ITER. However, that site selection would be tantamount to a commitment to construction of the machine. The decision to construct will be a lengthy process, and will include finding a site suitable for licensing for DT operation. It is clear that an early start on defining the site requirements and determining the process for negotiating a site agreement is needed. This item will undoubtedly be on the Council's agenda in the EDA. In conclusion, the prospects for moving forward on the ITER design activities are looking very promising. The EDA Agreement has been signed. ITER plays a central role not only in the U.S. program, but in the programs of each of the participating Parties. The international organization for ITER is taking shape, and in each of the Parties, Home Team organizations are aIso being formed to carry out the ITER-related work within the domestic programs. Shortly after the Agreement was signed, two Special Working Groups were convened:

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SWG-1, to resolve the issues relating to the technical objectives of the machine, and SWG-2, to establish a procedure for the process of sharing the technology R&D tasks to be distributed among the four Parties. The need to start ITER site characterization studies as soon as possible is widely recognized. The ITER project is technically very challenging. In addition, it is establishing a new format for international collaboration on scientific projects, and, as such,

Glass

is viewed as a model for international collaboration in large-scale science in the foreseeable future.

ACKNOWLEDGMENT This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract W-7405-ENG-48.