Starpower: the U.S. and the International Quest for Fusion Energy

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Starpower: The U.S. and the International Quest for Fusion Energy

October 1987

NTIS order #PB88-128731 Recommended Citation: U.S. Congress, Office of Technology Assessment, Starpower: The U.S. and the Internna- tional Quest for Fusion Energy, OTA-E-338 (Washington, DC: U.S. Government Printing Office, October 1987).

Library of Congress Catalog Card Number 87-619854

For sale by the Superintendent of Documents U.S. Government Printing Office, Washington, DC 20402-9325 (order form can be found in the back of this report) .

Foreword

Fusion research, offering the hope of an energy technology with an essentially unlimited supply of fuel and relatively attractive environmental impacts, has been conducted worldwide for over three decades. In the United States, increased budgetary pressures, along with a decreased sense of urgency, have sharpened the competition for funding between one research program and another and between energy research programs and other components of the Federal budget. This report, requested by the House Committee on Science, Space, and Technology and endorsed by the Senate Committee on Energy and Natural Resources, reviews the status of magnetic confinement fusion research and compares its progress with the requirements for development of a usefuI energy technology. The report does not analyze inertial confinement fusion research, which is overseen by the House and Senate Armed Services Committees. OTA analyzed the magnetic fusion research program in three ways: (1) as an energy program, by identifying important features of the technology and discussing its possible role in the energy supply mix; (2) as a research program, by discussing its role in training scientists and developing new fields of science and technology; and (3) as an international program, by reviewing its history of international cooperation and its prospects for even more extensive collaboration in the future. OTA could not have conducted this work without the valuable assistance it received from many organizations and individuals. I n particular, we would like to thank the advisory panel members, workshop participants, and outside reviewers, who provided guidance and extensive critical reviews to ensure the accuracy of the report. Responsibility for the final report, however, rests solely with the Office of Technology Assessment. Magnetic Fusion Research Advisory Panel William Carey, Panel Chair Executive Officer, American Association for the Advancement of Science Ellen Berman Betty Jensen Executive Director Nuclear and Environmental Program Manager Consumer Energy Council of America Research and Development Public Service Electric & Gas Co. Linda Cohen Assistant Visiting Professor of Economics Hans Landsberg University of Washington Senior Fellow Emeritus Resources for the Future Paul Craig professor of Physics Lawrence Lidsky Department of Applied Science Professor of Nuclear Engineering University of California, Davis Massachusetts Institute of Technology Harold Forsen Irving Mintzer Manger of Research and Development Senior Associate Bechtel National, Inc. World Resources Institute T. Kenneth Fowler Robert park Associate Director Executive Director Magnetic Fusion Energy Office of Public Affairs Lawrence Livermore National Laboratory American Physical Society Melvin Gottlieb Murray Rosenthal Director Emeritus Associate Laboratory Director for Advanced Princeton Plasma Physics Laboratory Energy Systems Oak Ridge National Laboratory L. Charles Hebel Manager, Research Planning Eugene Skolnikoff Corporate Research Technical Staff Director Xerox Corp. Center for International Studies Massachusetts Institute of Technology Robert Hirsch Vice President Herbert Woodson Arco Oil & Gas Co. Director Center for Energy Studies Leonard Hyman University of Texas, Austin Vice President Merrill Lynch Capital Markets

NOTE: OTA appreciates and is grateful for the valuable assistance and thoughtful critiques provided by the advisory panel members. The panel does not, however, necessarily approve, disapprove, or endorse this report. OTA assumes full responsibility for the report and the accuracy of its contents.

iv OTA Project Staff on Magnetic Fusion Research

Lionel S. Johns, Assistant Director, OTA Energy, Materials, and International Security Division

Peter D. Blair, Energy and Materials Program Manager

Gerald L. Epstein, Project Director

Dina K. Washburn

Contractors

Wilfrid Kohl Leonard Lynn Paul Josephson Lynn Powers Fusion Power Associates Battelle Pacific Northwest Laboratories

Administrative Staff Lillian Chapman Linda Long Barbara J. Carter Workshop Participants and Other Outside Reviewers

Workshop 1: Fusion Research Chuan Sheng Liu Judy Bostock Chairman Operations Research Analyst Panelists Department of Physics and U.S. Office of Management and Robert Seamans, Workshop Chair Astronomy Budget Senior Lecturer University of Maryland, College Melvin Gottlieb Aeronautics and Astronautics Park Director Emeritus Department Thomas Ratchford Princeton Plasma Physics Massachusetts Institute of Associate Executive Officer Laboratory Technology American Association for the Paul Huray Sibley Burnett Advancement of Science Senior Policy Analyst General Manager John Sheffield General Science Applied Superconetics Division Associate Director for U.S. Office of Science and GA Technologies Confinement Technology Policy Ronald Davidson Fusion Energy Division Paul Josephson Director Oak Ridge National Laboratory Program in Science, Technology Plasma Fusion Center Herbert Woodson and Society Massachusetts Institute of Director Massachusetts Institute of Technology Center for Energy Studies Technology Stephen Dean University of Texas, Austin Wilfrid Kohl President Director Fusion Power Associates Contributor International Energy Program Harold Forsen N. Anne Davies Johns Hopkins School of Manager of Research and Assistant Director Advanced International Studies Development Office of Fusion Energy Linda Lubrano Bechtel National, Inc. U.S. Department of Energy Professor T. Kenneth Fowler School of International Service Workshop II: International Associate Director The American University Cooperation Magnetic Fusion Energy Leonard Lynn Lawrence Livermore National Eugene Skolnikoff, Workshop Assistant Professor Laboratory Chair Department of Social and Director Harold Furth Decision Sciences Center for International Studies Carnegie-Mellon University Director Massachusetts Institute of Princeton Plasma Physics Technology Charles Newstead Laboratory Foreign Affairs Officer Harold Benglesdorf Melvin Gottlieb Bureau of Oceans and Vice President International Environmental and Director Emeritus International Group Princeton Plasma Physics Scientific Affairs International Energy Associates Laboratory U.S. Department of State Limited Robert Hirsch Douglas R. Norton Diana Bieliauskas Chief of International Planning Vice President Program Officer Arco Oil & Gas Co. and Program Office Office of Soviet and East European U.S. National Aeronautics and Robert Krakowski Affairs Space Administration Group Leader National Academy of Sciences Systems Study Group Herman Pollack Justin Bloom Los Alamos National Laboratory Research Professor President Department of International Affairs Lawrence Lidsky Technology International, Inc. George Washington University Professor of Nuclear Engineering Massachusetts Institute of Technology

vi Michael Roberts Harold Feiveson Richard Barnes Director Center for Energy and U.S. National Aeronautics and International Programs Environmental Studies Space Administration Office of Fusion Energy Princeton University Lee Berry U.S. Department of Energy Bill Keepin Oak Ridge National Laboratory Richard Samuels School of Engineering and Applied Joan Lisa Bromberg Professor of Political Science Science Laser History Project Massachusetts Institute of Princeton University Technology Daniel Chavardes Carlo La Porta Embassy of France U. John Sakss Director of Research Chief of International Program Solar Energy Industries Association Daniel Cohn Support Office René MaIès Massachusetts Institute of U.S. National Aeronautics and Technology Senior Vice President and Space Administration Principal Donald L. Cook Decision Focus, Inc. Sandia National Laboratories Workshop Ill: Energy Context Michael Mauel Tony Cox Robert Fri, Workshop Chair Assistant Professor Embassy of the United Kingdom President Department of Applied Physics Resources for the Future and Nuclear Engineering John Deutch Truman Anderson Columbia University Massachusetts Institute of Technology Director Irving Mintzer Program Planning and Analysis Senior Associate Thomas J. Fessenden Oak Ridge National Laboratory World Resources Institute Lawrence Berkeley Laboratory Charles Backus Eric Reichl Thomas G. Finn Assistant Dean Retired, Conoco Coal Corp. U.S. Department of Energy College of Engineering and Applied Science Arthur Rosenfeld William Hogan Arizona State University Director Lawrence Livermore National Center for Building Science Laboratory Charles Berg Lawrence Berkeley Laboratory Professor and Head of Department John Holdren Department of Mechanical John Siegel University of California, Berkeley Engineering Vice President Paul Koloc Northeastern University Atomic Industrial Forum Phaser Corp. Jan Beyea Don Steiner Dennis Mahlum Vice President of Science Institute Professor Battelle Pacific Northwest National Audubon Society Department of Nuclear Laboratories Engineering and Engineering Paul Craig Physics George Miley Professor of Physics Rensselaer Polytechnic Institute University Fusion Associates Department of Applied Science University of California, Davis David Overskei Other Outside Reviewers GA Technologies Daniel Dreyfus Mohamed Abdou Vice President John Richardson University of California, Los Strategic Analysis and Energy National Research Council Angeles Forecasting Marshall Rosenbluth Gas Research Institute Charles Baker University of Texas, Austin Argonne National Laboratory James A. Edmonds Richard Rowberg Senior Research Economist David Baldwin Congressional Research Service Battelle Pacific Northwest Lawrence Livermore National Laboratories Laboratory Mike Saltmarsh Oak Ridge National Laboratory

vii John Santarius F. Robert Scott Albert Teich University of Wisconsin, Madison Retired, Electric Power Research American Association for the Institute Advancement of Science Winfried Schmidt Richard Siemons Robert W. Turner Karlsruhe Nuclear Research Center Los Alamos National Laboratory U.S. Department of Defense Ken Schultz Joel Snow Wim Van Deelen GA Technologies U.S. Department of Energy European Communities Delegation

viii .

Contents

Chapter Page I, Executive Summary...... 3 2. Introduction and Overview ...... 29 3. History of Fusion Research ...... 39 4. Fusion Science and Technology ...... 57 5. Fusion as an Energy Program...... , ...... 105 6. Fusion as a Research Program ...... , ...... 131 7. Fusion as an International Program ...... , . , .155 8. Future Magnetic Fusion Program ...... 189

Appendixes Page A. Non-Electric Applications for Fusion ...... 201 B. Other Approaches to Fusion...... 205 c. Data for Figures ...... 209 D. List of Acronyms and Glossary ...... 213

Index ...... 227

ix Chapter 1

Executive Summary CONTENTS

Page Overview...... 3 Potential Role of Fusion ...... 3 The Policy Context ...... 3 Findings ...... 4 A Quick Fusion Primer...... 6 The Fusion Reaction ...... 6 The Feasibility of Fusion ...... 8 Probability of Success ...... 8 History of Magnetic Confinement Fusion Research ...... 8 1950s and 1960s ...... 8 1970s and 1980s ...... 9 Fusion Science and Technology ...... 11 Confinement Concepts ...... 11 Reactor Development ...... 12 Future Plans and Facilities ...... 12 Schedules and Budgets ...... 15 Status of the World Programs...... 16 Fusion as an Energy Program ...... 16 Safety ...... 17 Environmental Characteristics...... 18 Nuclear Proliferation Potential ...... 18 Resource Supplies ...... 19 cost...... 19 Fusion’s Energy Context ...... 19 Fusion as a Research Program ...... 20 Near-Term Benefits ...... 20 Near-Term Financial and Personnel Needs ...... 21 Participation in the Magnetic Fusion Program , ...... 21 Fusion as an International Program...... 24 Opportunities for Increased Collaboration ., ...... 24 Benefits and Liabilities of Cooperation ...... 25 Obstacles to International Cooperation ...... 25 The International Thermonuclear Experimental Reactor ...... 26

Figures Figure No. Page l-1. Historical Magnetic Fusion R&D Funding, 1951-87 (in 1986 dollars) ...... 4 1-2, Historical Magnetic Fusion R&D Funding, 1951-87 (in current dollars) . . . . 5 1-3.The D-T Fusion Reaction and a Fission Reaction ...... 7 1-4. Systems in a Fusion Electric Generating Station ...... 13 1-5. Systems in the Fusion Power Core...... 14 l-6. Annual Appropriations of DOE Civilian R&D Programs ...... 22

Table Table No. Page l-1.Classification of Confinement Concepts...... 12 Chapter 1 Executive Summary

OVERVIEW Potential Role of Fusion tial funding increases required for next-generation facilities. In fact, due to funding constraints, the If successfully developed, nuclear fusion could program has been unable to complete and oper- provide humanity with an effectively unlimited ate some of its existing facilities. source of electricity that has environmental and safety advantages over other electric energy tech- The Department of Energy (DOE) manages the nologies. However, it is too early to tell whether U.S. fusion program, and its goal is to evaluate these advantages, which could be significant, can fusion’s technological feasibility–to determine be economically realized. Research aimed at de- whether or not a fusion reactor can be designed veloping fusion as an energy source has been and built—early in the 21st century. A positive vigorously pursued since the 1950S, and, despite evaluation would enable a decision to be made considerable progress in recent years, it appears at that time to construct a prototype commercial that at least three decades of additional research reactor. However, this schedule cannot be met arid development will be required before a pro- under existing U.S. fusion budgets. The DOE totype commercial fusion reactor can be dem- plan requires either that U.S. budgets be in- onstrated. creased substantially or that the world fusion programs collaborate much more closely on fusion research. The Policy Context Choices made over the next several years can The budget for fusion research increased more place the U.S. fusion program on one of four fun- than tenfold in the 1970s, due largely to grow- damentally different paths, which are discussed ing public concern about environmental protec- more thoroughly in chapter 8 of this report: tion and uncertainty in long-range energy sup- 1 With substantial funding increases, the fu- ply. However, a much-reduced sense of public sion program could complete its currently urgency in the 1980s, coupled with the mount- mapped-out research effort domestically, per- ing Federal budget deficit, halted and then mitting decisions to be made early in the reversed the growth of the fusion budget. Today, next century concerning fusion’s potential the fusion program is being funded (in 1986 dol- for commercialization. lars) at about half of its peak level of a decade 2. At only moderate increases in U.S. funding ago (see figures 1-1 and 1-2). levels, the same results as above might be attainable—although possibly somewhat The change in the fusion program’s status over delayed–if the United States can work with the past 10 years has not resulted from poor tech- some or all of the world’s other major fu- nical performance or a more pessimistic evalua- sion programs (Western Europe, Japan, and tion of fusion’s prospects. On the contrary, the the Soviet Union) at an unprecedented level program has made substantial progress. How- of collaboration. ever, the disappearance of a perceived need for 3. Decreased funding levels, or current fund- near-term commercialization has reduced the ing levels in the absence of extensive col- impetus to develop commercial fusion energy laboration, would require modification of and has tightened pressure on fusion research the program’s overall goals. At these con- budgets. Over the past decade, the fusion pro- strained funding levels, U.S. evaluation of gram has been unable to maintain a constant fusion as an energy technology would be funding level, much less command the substan- delayed.

4 ● Starpower: The u.s. and the International Quest for Fusion Energy

Figure 1-1 .—Historical Magnetic Fusion R&D Funding, 1951087 (in 1986 dollars)

1955 1960 1965 1970 1975 1980 1985

Year SOURCE: U.S. Department of Energy, Office of Energy Research, letter to OTA project staff, Aug. 15, 1986.

4. If fusion research ceased in the United ments do not uncover major surprises, it is States, the possibility of domestically devel- likely–although by no means certain–that oping fusion as an energy technology would the engineering work necessary to build an be foreclosed unless and until funding were electricity-producing fusion reactor can be restored. Work would probably continue completed successfully. abroad, although possibly at a reduced pace; ● Additional scientific understanding and tech- resumption of research at a later time in the nological development is required before fu- United States would be possible but difficult. sion’s potential can be assessed. It will take at least 20 years, under the best circumstances, to determine whether construction Findings of a prototype commercial fusion reactor will Here are some of the overall findings from be possible or desirable; additional time be- OTA’s analysis: yond then will be required to build, operate, and evaluate such a device. ● Experiments now built or proposed should, ● It is now too early to tell whether fusion re- over the next few years, resolve most of the actors, once developed, can be economi- major remaining scientific uncertainties re- cally competitive with other energy tech- garding the fusion process. If those experi- nologies.

C/7. I.—Executive Summary “ 5

Figure 1-2.—Historical Magnetic Fusion R&D Funding, 1951-87 (In current dollars)

150

100

0 1955 1960 1965 1970 1975 1980 1985

Year SOURCE: U.S. Department of Energy, Office of Energy Research, letter to OTA project staff, Aug. 15, 1986.

● Demonstration and commercialization of fu- not produce high-level, long-lived radio- sion power will take several decades after active wastes. completion of the research program. Even ● One of the most attractive features of fusion under the most favorable circumstances, it is its essentially unlimited fuel supply. The does not appear likely that fusion will be able only resources possibly constraining fusion’s to satisfy a significant fraction of the Nation’s development might be the materials needed electricity demand before the middle of the to build fusion reactors. At this stage of de- 21st century. velopment, it is impossible to determine what materials will eventually be developed • With appropriate design, fusion reactors and selected for fusion reactor construction. could be environmentally superior to other ● If fusion technology is developed success- nuclear and fossil energy production tech- fully, it should be possible to design fusion nologies. Unlike fossil fuel combustion, fu- reactors with a higher degree of safety as- sion reactors do not produce carbon dioxide surance than fission reactors. It may be possi- gas, whose accumulation in the atmosphere ble to design fusion reactors that are incapa- could affect world climate. Unlike nuclear ble of causing any immediate off-site fatalities fission–the process utilized in existing nu- in the event of malfunction, natural disaster, clear powerplants—fusion reactors should or operator error. ● 6 Starpower : The us and the Intemational Quest for fusion Energy

● potential problems with other major sources near-term benefits such as development of of electricity—fossil fuels and nuclear plasma physics, education of trained re- fission–provide incentives to develop alter- searchers, contribution to “spin-off” tech- nate energy technologies as well as to sub- nologies, and support of the scientific stat- stantially improve the efficiency of energy ure of the United States. However, fusion’s use. Fusion is one of several technologies be- contributions to these areas do not imply that ing explored. devoting the same resources to other fields ● It is unlikely that major, irreversible energy of study would not produce equivalent ben- shortages will occur early in the next cen- efits. Therefore, while near-term benefits do tury that could only be ameliorated by the provide additional justification for conduct- crash development of fusion power. There ing research, it is difficult to use them to is little to be gained—and a great deal to be justify one field of study over another. lost–by introducing fusion before its poten- ● Fusion research has a long history of success- tial economic, environmental, and safety ca- ful and mutually beneficial international co- pabilities are attained. Even if difficulties with operation, If this tradition can be extrapo- other energy technologies are encountered lated in the future to an unprecedented level that call for the urgent development of an of collaboration, much of the remaining cost alternative source of energy supply, that of developing fusion power can be shared alternative must be preferable in order to be among the world’s major fusion programs. accepted. It would be unwise to emphasize ● International collaboration cannot substitute one fusion feature—economics or safety or for a strong domestic research program. If environmental advantages—over the others the domestic program is sacrificed to sup- before we know which aspect will be most port international projects, the rationale for important for fusion’s eventual acceptance. collaboration will be lost and the ability to ● Due to the high risk and the long time be- conduct it successfully will be compromised. fore any return can be expected, private in- ● Agreeing to collaborate on fusion research, dustry has not invested appreciably in fusion both within the U.S. Government and be- research and cannot be expected to do so tween the U.S. Government and potential in the near future. But, unless the govern- partners, will require sustained support at the ment decides to own and operate fusion highest levels of government. A variety of po- generating stations, the responsibility for fu- tential difficulties associated with large-scale sion research, development, and commer- collaborative projects will have to be re- cialization must be transferred to private in- solved, and presidential support will be re- dustry at some stage. The nature and timing quired. If these difficulties can be resolved, of this transition are highly controversial. the benefits of successful collaboration are ● Fusion research has provided a number of substantial.

A QUICK FUSION

The Fusion Reaction isotopes; two of them—deuterium (D) and tritium (T)–in combination work the best in fusion re- in a fusion reaction, the nuclei–or central actions. The kinetic energy released in the D-T cores—of light atoms combine or. .fuse together; reaction can be converted to heat, which in turn when they do, energy is released. In a sense, tu- can be used to make steam to drive a turbine to sion is the opposite of fission, the process utilized generate electricity. in existing nuclear powerplants (see figure 1 -3), in which energy is released when a heavy nucleus But a fusion reaction cannot happen unless cer- splits into smaller pieces. tain conditions are met. To fuse hydrogen nuclei The lightest atom, hydrogen, is the easiest one together, the nuclei must be heated to approxi- to use for fusion. Hydrogen has three forms, or mately 100 million degrees Celsius (C). At these .

Ch. I.—Executive Summary ● 7

Figure 1-3. —The D-T Fusion Reaction and a Fission Reaction

I).T fusion reaction

Neutron Tritium 14.1 MeV r. + Helium Deuterium 3.5 MeV

Fuel Reaction conditions (density, temperature, time) ProdUCIS'"

Neutron 0--'" Neutron

Neutron FIssion fuel nUcleus

;~*;,:'! ,':,:,I!~lUM -;''''_ ~ V-tP'~JL·~~t 2 nucleus r

e Proton Kev: o Neutron

MeV: million electron volts SOURCE: Adapted from Princeton Plasma Physics Laboratory, Information Bulletin NT·1: Fusion Power, 1984, p. 2; Office of Technology Assessment (fission), 1987. 8 ● Starpower: The U.S. and the International Quest for Fusion Energy temperatures, matter exists as plasrna, a state in Once scientific feasibility of fusion as a poten- which atoms are broken down into electrons and tial energy source is established, the engineer- nuclei. Keeping a plasma hot enough for a long ing development necessary to develop fusion re- enough period of time, and effectively confining actors must be completed. Engineering feasibility it, are crucial for generating fusion power. denotes the successful development of reliable components, systems, and subsystems for oper- While no solid container can withstand the ating fusion reactors. heat of a plasma, magnetic fields may be able to confine a plasma successfully. This assessment Scientific and engineering feasibility, although discusses magnetic confinement research and the involving different issues, are interdependent. various magnetic field configurations that look Demonstrating either one will require advances promising for producing fusion power. to be made in basic scientific understanding as well as in technological capability. More detail on the basics of fusion power can be found in chapter 2. The goal of fusion research is to prove fusion’s technological feasibility so that its commercial The Feasibility of Fusion feasibility is likely. To be marketable, fusion power must be socially and environmentally accept- Before fusion powerplants can generate elec- able and economically attractive compared to its tricity, fusion must be proven technologically and competitors, and it must meet regulatory and commercially feasible. licensing requirements. Technological feasibility will require that both scientific feasibility and engineering feasibility be Probability of Success shown. Scientists must bring fusion reactions to Experiments now existing or proposed to be breakeven, the point at which at least as much built should be sufficient, within the next few energy is produced as must be input to maintain years, to demonstrate fusion’s scientific feasibil- the reaction. Existing experiments are expected ity. If these experiments do not uncover unfavora- to reach this long-elusive milestone by 1990. Be- ble surprises, it appears likely–although not cer- yond breakeven, scientists have an even harder tain—that fusion’s engineering feasibility can be but more important task of creating high energy subsequently established. Most of the technologi- gain–energy output that is many times higher cal and engineering challenges to designing and than the energy input. Only when high-gain re- building a reactor have been identified. How- actions are produced will the scientific feasibility ever, it cannot yet be determined whether or not of the fusion process be demonstrated. If a high- a fusion reactor will be commercially attractive. gain reaction reaches ignition, it will sustain itself even when the external heat is turned off.

HISTORY OF MAGNETIC CONFINEMENT FUSION RESEARCH

1950s and 1960s were thought to be capable of leading directly to a commercial reactor. From 1951 until 1958, fusion research was conducted by the U.S. Atomic Energy Commission In reality, however, very little was known about (AEC) in a secret program code-named “Project the behavior of plasma in experiments and even Sherwood.” Many different magnetic confine- less about how it would act under the conditions ment concepts were explored during the early required for fusion reactors. Experimental results 1950s. Although researchers were careful to note were often ambiguous or misinterpreted, and the that practical applications lay at least 10 to 20 theoretical understanding underlying the research years in the future, the devices being studied was not well established. By 1958—as people Ch. I.—Executive Summary ● 9

tion, the growth of the environmental movement and increasing opposition to nuclear fission technology drew public support to fusion as an energy technology that might prove more environmentally acceptable than other energy technologies.

The fusion program capitalized on this public support; program leadership placed a high priority on developing a research plan that could lead to a demonstration reactor. Planning began for the Tokamak Fusion Test Reactor, a new experiment using D-T fuel that would reach breakeven. By 1974, the funding increases necessary to pursue accelerated development of fusion were appropriated.

Photo credtt: Los Alamos National Laboratory Program organization changed twice during the Perhapsatron, built and operated in the 1950s at Los 1970s. In 1974, Congress abolished the AEC and Alamos Scientific Laboratory. transferred its energy research programs to the newly created Energy Research and Develop- realized that harnessing magnetic fusion was go- ment Administration (ERDA). ERDA assumed ing to be difficuIt and that national security con- management of the AEC’s nuclear fission and fu- siderations were less immediate—the research sion programs, as well as programs in solar and was declassified. This action made widespread renewable technologies, fossil fuels, and conser- international cooperation in fusion research pos- vation. Three years later, President Carter incor- sible, particularly since the countries involved porated the functions of ERDA into a new agency, realized that the state of their research programs the Department of Energy (DOE). was more or less equivalent. Under DOE, the fusion program did not have With the optimism of the 1950s tempered, fu- the same sense of urgency. Fusion could not mit- sion researchers in the United States proceeded igate the short-term oil and gas crisis facing the at a steady pace throughout the 1960s. In 1968, United States. Furthermore, as a potentially in- Soviet scientists announced a major breakthrough exhaustible energy source (along with solar energy in plasma confinement in a device called a “toka- and the fission breeder reactor), fusion was not mak. ” After verifying Soviet results, the other expected to be needed until well into the next world fusion programs redirected their efforts century. Therefore, there appeared to be no com- toward development of the tokamak. pelling reasons to rapidly develop a fusion demonstration plant. 1970s and 1980s Nevertheless, the Magnetic Fusion Energy Engi- With the identification of the tokamak as a con- neering Act of 1980 urged acceleration of the na- finement concept likely to reach reactor-level tional effort in magnetic fusion research, devel- conditions, the U.S. fusion program grew rapidly. opment, and demonstration activities. The act Between 1972 and 1979, the fusion program’s recommended that funding levels for magnetic budget increased more than tenfold. This growth fusion double (in constant dollars) within 7 years. was due in part to uncertainty in the early 1970s However, Congress did not appropriate these in- concerning long-range energy supply; fusion creases, and there was no follow-up. Actual ap- energy, with its potentially inexhaustible fuel sup- propriations in the 1980s have not grown at the ply, appeared to be an attractive alternative to levels specified in the act; in fact, since 1977, they exhaustible resources such as oil and gas. In addi- have continued to drop in constant dollars.

10 ● Starpower: The U.S. and the International Quest for Fusion Energy

Photo credit: Princeton Plasrna Physics Laboratory

Model C Stellarator at Princeton Plasma Physics Laboratory. Designed and built in the late 1950s, the Model C was converted into the United States’ first tokamak in 1970.

Despite constrained funding, the U.S. fusion sion principle have not diminished, there is less program has made significant advances in plasma urgency to develop such a system. ’ physics and fusion technology throughout the The plan emphasizes the importance of interna- 1980s. However, DOE has had to adjust its long- tional collaboration if the United States is to estab- range planning to the new fiscal situation. In lish fusion’s technological feasibility during the 1985, it issued the Magnetic Fusion Program Plan early 21st century. (MFPP), which states that the goal of the fusion program is to establish the scientific and techno- The history of U.S. magnetic confinement fu- logical base required for fusion energy. This plan sion research is discussed in chapter 3 of this explicitly recognizes that: report.

. . . although the need for and desirability of an U.S. Department of Energy, Office of Energy Research, Magnetic energy supply system based on the nuclear fu- Program P/an, DOE/ER-0214, February 1985, preface.

Ch. 1.—Executive Summary ● 11

FUSION SCIENCE AND TECHNOLOGY

Great scientific progress has been made in the realized under breakeven conditions. An ignited field of fusion research over the past 35 years. plasma, or at least one with high energy gain, The fusion program appears to be within a few must be studied. Issues to be resolved before fu- years of demonstrating breakeven, an event that sion’s technological feasibility can be established will show an impressive degree of understand- are discussed more fully in chapter 4. ing and technical capability. Nevertheless, many scientific and technological issues must be resolved before fusion reactors can be designed and Confinement Concepts built. The principal scientific uncertainties involve what happens to a plasma when it generates ap- Besides the behavior of ignited plasmas, the preciable amounts of fusion power. Because no characteristics, advantages, and disadvantages of existing devices can produce significant amounts various confinement concepts need further study. of power, this uncertainty currently cannot be ex- Several different concepts, utilizing different con- plored. Simply reaching breakeven will not re- figurations of magnetic fields and different meth- solve the uncertainties, since the effects of inter- ods of generating the fields, are being studied nally generating fusion power will not be fully (table l-l).

Photo credit: Princeton Plasma Physics Laboratory The Tokamak Fusion Test Reactor at Princeton Plasma Physics Laboratory, where breakeven experiments are scheduled for 1990. 12 ● Starpower The U.S. and the International Quest for Fusion Energy

Table 1-1.—Classification of Confinement Concepts

Well-developed Moderately developed Developing knowledge base knowledge base knowledge base Conventional Tokamak Advanced Tokamak Spheromak Tandem Mirror Field-Reversed Configuration Stellarator Dense Z-Pinch Reversed-Field Pinch SOURCE: Adapted from Argonne National Laboratory, Fusion Power Program, Technical Planning Activity: Final Report, commissioned by the U.S. Department of Energy, Office of Fusion Energy, ANL/FPP-87-1, 1987, p. 15.

At this stage of the research program, it is not ensure safe, environmentally acceptable opera- known which confinement concepts can form tion. Developing and building these associated the basis of an attractive fusion reactor. The toka- systems and integrating them into a reactor will mak is the most developed concept, and it has require a technological development effort at attained plasma conditions closest to those re- least as impressive as the scientific challenge of quired in a fusion reactor. Its experimental per- understanding and confining fusion plasmas. formance has been encouraging, and it provides The overall fusion generating station (figure 1-4) a standard for comparison to other concepts. consists of a fusion power core, which contains Studies of reactor-like plasmas must be done in the systems that support and recover energy from tokamaks because no other concept has yet dem- the fusion reaction, and the balance of p/ant, onstrated the potential to reach reactor condi- which converts this energy to electricity. Fusion tions. Most fusion technology development takes reactor conceptual designs typically have balance place in tokamaks as well. Although tokamak be- of plant systems similar to those found in exist- havior has not yet been fully explained theoreti- ing electricity generating stations. However, fusion cally, it may well be possible to design reactor- technology may permit more advanced systems scale tokamaks on the basis of experimental per- to generate electricity in a manner that is qualita- formance in smaller tokamaks. tively different from the methods in use today. Research on alternatives to the tokamak con- The fusion power core, shown schematically tinues because it is not clear that the tokamak in figure 1-5, is the heart of a fusion generating will result in the most attractive or acceptable fu- station. The systems in the core create and main- sion reactor. Moreover, research conducted on tain the plasma conditions required for fusion re- different concepts provides important insights actions to occur. These technologies confine the into the fusion process. It remains to be seen plasma, heat and fuel it, remove wastes and im- which alternate concepts will be able to reach purities, and, in some cases, drive electric cur- the level of performance already attained by the rents within the plasma. Other systems in the fu- tokamak, whether their relative strengths will be sion power core recover heat from the fusion preserved in the development process, and what reactions, breed fuel, and provide shielding. One the costs of developing these concepts to reactor of the key requirements for many of these fusion scale will be. Nor is it known what the ultimate power core systems is the development of suit- capability of the tokamak concept will be. able materials that are resistant to the intense neutron radiation generated by the plasma. The envi- Reactor Development ronmental and safety aspects of fusion reactors depend significantly on materials choice. Just as an automobile is much more than spark plugs and cylinders, a fusion reactor will contain Future Plans and Facilities many systems besides those that heat and confine the plasma. Fusion’s overall feasibility will Many additional experiments and facilities will depend on all of the “engineering details” that be required to investigate both scientific and tech- support the fusion reaction, convert the power nological aspects of fusion. Preliminary experi- released in the reaction into usable energy, and ments that investigate the basic characteristics of

Ch. I.—Executive Summary c 13

Figure 1=4.—Systems in a Fusion Electric Generating Station

Rejected heat

Electric power out to grid

new confinement concepts can be done for a few and it has requested funds in its 1988 budget to miIlion dollars or less. As concepts approach rebuild a short-pulse ignition facility, called the actor capability, successively larger facilities are Compact Ignition Tokamak (CIT). Total costs for required, with reactor-scale experiments costing this device are estimated at about $360 million. hundreds of millions of dollars each. Obviously, CIT cannot satisfy the requirements for long the U.S. fusion program cannot afford to inves- pulses, materials studies, or nuclear technology tigate every confinement concept at the reactor testing. These needs could be addressed in sep- scale; choices must be made on the basis of in- arate facilities and later combined (except for ma- formation gathered at earlier stages. terials testing) in a device that would integrate Additional facilities will be required to resolve all the systems for the first time. Alternatively, general issues not identified with specific confine- many of these issues could be addressed and in- ment concepts. In particular, facilities will be tegrated simultaneously in a next-generation engi- needed to address the scientific issues associated neering test reactor. Satisfying a number of pur- with ignited plasmas. Many physical processes poses simultaneously would complicate an associated with ignition can be studied in ignited engineering test reactor’s design and could force plasmas that only last for a few seconds; other trade-offs between the different objectives. More- aspects, such as fueling and removal of reaction over, it is likely that each additional requirement products, will require a facility that can produce will increase the price of the machine. Even so, ignited plasmas lasting hundreds of seconds. a general-purpose engineering test reactor would Short- and long-burn ignition questions can be presumably cost less than the combination of sev- studied either in a single device or in two sepa- eral single-purpose facilities and a subsequent rate devices. DOE has chosen to separate them, system-integration device.

14 ● Starpower: The U.S. and the International Quest for Fusion Energy

DOE has not yet determined the features to be Thermonuclear Experimental Reactor (ITER), be included in an engineering test reactor. It is com- undertaken. mitted to investigating the possibility for international cooperation on the device; the U.S. Gov- Materials testing will require a dedicated de- ernment has proposed to the other major world vice even if a general-purpose engineering test fusion programs that collaborative conceptual de- reactor is built. To complete lifetime irradiation sign of such a device, called the International testing of reactor materials in a reasonable

Ch. I.—Executive Summary “ 75

Photo credit” GA Technologies

View inside vacuum vessel of D II I-D fusion device at GA Technologies, San Diego, CA. The plasma is contained within this vessel. amount of time, a source of fusion neutrons sev- The study estimated that the worldwide cost of eral times more intense than expected from a this research effort would be about $20 billion. commercial reactor is required. While an engi- As mentioned earlier, developing fusion on this neering test reactor wouId duplicate conditions schedule will require either substantially in- expected in a reactor, it would not be able to con- creased U.S. funding or wide-scale collaboration duct accelerated materials tests at several times among the world fusion programs. the radiation levels to be found in a reactor. The requirements and schedule for establishing fusion’s subsequent commercial feasibility are Schedules and Budgets more difficult to project, and they depend on fac- A major fusion-communitywide study has iden- tors other than fusion research funding. Conceiv- tified the technical tasks and facilities required ably, if the research program provides the infor- to establish fusion’s technological feasibility and mation necessary to design and build a reactor enable a decision to be made early in the next prototype, such a device could be started early century to start the commercialization process,2 in the next century. After several years of construction and several more years of qualification

2 and operation, a base of operating experience Argon ne National Laboratory, Fusion Power Program, f’/anning Activity: Report, commissioned by DOE, Office could be acquired that would be sufficient for the of Fusion Energy AN L/FPP-87-l, 1987, design and construction of commercial devices.

● 16 Starpower: The us. and the Internatjonal Quest for Fusion Energy

If the regulatory and licensing process proceeded concurrently, vendors and users could begin to consider manufacture and sale of commercial fusion reactors sometime during the middle of the first half of the next century. From that point, it will take decades for fusion to penetrate energy markets. Even under the most favorable circumstances, it does not appear likely that fusion will be able to satisfy a significant fraction of the Na- tion’s electricity demand before the middle of the 21st century. This schedule for demonstrating technological and commercial feasibility requires a number of assumptions. Sufficient financial support or international coordination must be attained so that the research needed to establish technological feasibility can be completed early in the next century. Research must proceed without major difficulty and must lead to a decision to build a reactor prototype. The prototype must operate as expected and prove convincingly that fusion is both feasible and preferable to its alternatives.

Status of the World Programs The United States, Western Europe, Japan, and the Soviet Union all have major programs in fusion research that are at similar stages of development. Each program has built or is building a Photo credit: JET Joint Undertaking major tokamak experiment. The U.S. Tokamak The Joint European Torus, located in Abingdon, Fusion Test Reactor and the European Commu- United Kingdom. nity’s Joint European Torus are operating and are ultimately intended to reach breakeven conditions with D-T fuel. Japan’s JT-60 tokamak, also tion. In addition to these major devices, each of operational, will not use tritium fuel; it is intended the programs operates several smaller fusion ex- to generate a “breakeven-equivalent” plasma periments that explore the tokamak and other using ordinary hydrogen and deuterium. The So- confinement concepts. Each program is also de- viet Union’s T-1 5 experiment is under construc- veloping other aspects of fusion technology.

FUSION AS AN ENERGY PROGRAM

The long-term goal of the fusion program in the oriented towards producing fuel for fission re- United States is to produce electricity. Fusion reactors .)3 actors can also produce fuel for fission reactors by irradiating suitable materials with neutrons, 3 A fusion reactor that produces fissionable fuel, or one that gen - but this ability is not seen as fusion’s primary ap- erates part of its energy from fission reactions that are induced by plication in the United States, Western Europe, fusion-generated neutrons, is called a reactor. Although the applications and characteristics of hybrid reactors are or Japan. (The Soviet fusion effort does appear different from those of “pure fusion” reactors that do use or

Ch. I.—Executive Summary . 17

Photo credit; Japanese Atomic Energy Research Institule The JT-60 tokamak, located in Naki-machi, Japan.

Hypothetical designs for fusion reactors that possible characteristics of fusion reactors. These produce electricity have been studied for a num- projections will improve as additional knowledge bet of years. Since the research program is far and understanding enable scientists and engi- from complete, however, current systems studies neers to better model the reactor systems. Chap- are necessarily tentative. Although these studies ter 5 of this report discusses projected charac- have been especially valuable in identifying im- teristics of fusion reactors, along with the factors provements in fusion physics or technology that that will determine the degree to which fusion appear to have the greatest potential for making is accepted in the energy marketplace. fusion reactors attractive and competitive, they cannot provide a firm basis for assessing fusion’s Safety potential as a future energy source. Nevertheless, the studies do provide a basis for projecting the If fusion development is successful, it maybe possible to ensure that accidents due to mal- functions, operator error, or natural disasters produce fissionable materials, there is little difference at present could not result in immediate public fatalities. I n the research requ I red to develop the two. Differences wil I arise at subsequent stages of research and development. This safety would depend on passive systems or This assessment focuses on pure fusion reactors; hybrid reactors on materials properties, rather than on active sys- are discussed briefly in app. A of the full report, tems that could fail or be overridden. A number 18 . Starpower: The U.S. and the International Quest for Fusion Energy

of attributes of the fusion process should make include fuels and byproducts that are inherent safety assurance easier for fusion reactors than to the technology. While the tritium fuel required for fission reactors: by a D-T fusion reactor is a potential hazard, the byproducts of fusion are not in themselves haz- ● Fusion reactions cannot run away. Fuel will ardous, Since there is much greater freedom to be continuously injected, and the amount choose materials that minimize safety hazards for contained inside the reactor chamber will fusion reactors than there is in fission reactor de- only operate the reactor for a short period sign, a higher degree of safety assurance should of time. Energy stored in the plasma at any be attainable with fusion. given time can be dissipated by the vacuum chamber in which the fusion reactions take place. Environmental Characteristics ● With appropriate choice of materials, the amount of heat produced by the decay of Fusion reactors will not be free of radioactive radioactive materials in the reactor after the wastes, although the wastes that they produce reactor has been shut down should be less should be easier to dispose of than fission for fusion reactors than for fission reactors. wastes. Fusion reactors will not generate the long- Fusion reactors should therefore require sim- Iived and highly radioactive wastes contained in pler post-shutdown or emergency cooling the spent fuel rods of fission reactors. Fusion systems, if any such systems are required at wastes may have a greater physical volume than all. fission wastes, but they should be substantially ● The radioactive inventory of a fusion reactor less radioactive and orders of magnitude less —in terms of both the total amount present harmful. The amount of radioactive waste antic- in the reactor and the fraction that would be ipated from different fusion designs ranges over likely to be released in an accident–should several orders of magnitude because it depends be smaller than that of a fission reactor. Fu- on the choice of materials with which the reactor sion will not generate long-lived wastes such is made. Special materials that do not generate as those produced by fission reactors. Except intense or long-lived radioactive wastes may be for tritium gas, the radioactive substances developed that would make it possible to sub- present in fusion reactors will generally be stantially reduce the radioactive waste produced bound as metallic structural elements. by a fusion reactor. ● in the event of accidental release, fusion reactors should not contain radioactive elements Nuclear Proliferation Potential —except tritium —that would tend to be absorbed in biological systems. Tritium is an The ability of a fusion reactor to breed fission- inherent potential hazard, but the risk it able fuel could increase the risk of nuclear poses is much smaller than that of the gase- proliferation. Proliferation concerns relate to the ous or volatile radioactive byproducts pres- possibility of constructing fission-based or atomic ent in fission reactors, Active tritium inven- weapons. Although fusion reactors contain tritium, tories in current fusion reactor designs are a material that could be used in principle to make small enough that even their complete re- thermonuclear weapons such as the hydrogen lease should not produce any prompt fatal- bomb, such weapons cannot be built by parties ities off-site. Moreover, fusion reactors oper- who do not already possess fission weapons. ating on advanced fuel cycles would not A reactor deriving all its energy from fusion and need tritium. producing only electricity would not contain ma- This discussion does not imply that fission re- terials usable in fission-based nuclear weapons, actors are unsafe. Indeed, efforts are underway and it would be impossible to produce such ma- to develop fission reactors whose safety does not terials by manipulating the reactor’s normal fuel depend on active safety systems. However, the cycle. However, material usable in fission weap- potentially hazardous materials in fission reactors ons could be produced by placing other materi- Ch. I.—Executive Summary “ 19

als inside the reactor and irradiating them with Fusion’s Energy Context fusion neutrons. This procedure, in effect, would convert a pure fusion reactor into a fission/fusion The factors that influence how successfully hybrid reactor (see note 3, above). If such modifi- fusion technology will compete against other cations to the reactor structure were easily de- energy technologies include how well its char- tected or were extremely difficult and expensive, acteristics meet the requirements of potential cus- pure fusion reactors would be easier to safeguard tomers (most likely electric utilities) and how well against surreptitious production of nuclear weap- fusion compares to alternate electricity-generating ons material than existing fission reactors, and fu- technologies. A more detailed look at these fac- sion reactors would therefore pose less of a tors makes a number of points clear: proliferation risk. ● The overall size and composition of electricity demand, by itself, should neither re- Resource Supplies quire nor eliminate fusion as a supply option. Supplies of both coal and uranium Shortage of fuels will not constrain fusion’s appear adequate at reasonable prices to prospects for the foreseeable future. Enough meet high future demand in the absence of deuterium is contained in the earth’s waters to fusion.4 It will be overall economics and satisfy energy needs through fusion for billions acceptability, rather than total demand or of years at present consumption rates. Domes- fuel availability, which will determine the tic lithium supplies should offer thousands of mix of energy technologies. years worth of fuel, with vastly greater amounts ● It is unlikely that any one technology will of potentially recoverable lithium contained in take over the electricity supply market, bar- the oceans. ring major difficulties with the others. Materials required to build fusion reactors may ● Potential problems with currently foreseen pose more of a constraint on fusion’s develop- future sources of electricity provide incen- ment than fuel supply, but at this stage of research tives to develop alternate energy technol- it is impossible to determine what materials will ogies and/or substantially improve the effi- eventually be developed and selected for fusion ciency of energy use. Combustion of coal reactor construction. No particular materials releases carbon dioxide, whose accumula- other than the fuels appear at present to be in- tion in the atmosphere may affect world cli- dispensable for fusion reactors. mate; this problem may make increased reliance on coal undesirable. Safety, nuclear cost waste, or nuclear proliferation concerns may continue to impair expansion of the nuclear It is currently impossible to determine fission option. The urgency for developing whether a fusion reactor, once developed, will fusion, therefore, depends on assumptions be economically competitive with other energy of the likelihood that existing energy tech- technologies. The competitiveness of fusion nologies will prove undesirable in the power will depend not only on successful com- future. pletion of the remaining research program but also on additional factors that are impossible to predict—e.g., plant licensability, construction 4Coal supplies are adequate to provide power for centuries at time, and reliability, not to mention factors less current rates of use. Uranium supplies should be available at a rea- directly related to fusion technology such as in- sonable price until well into the next century without requiring ei- terest rates. Fusion’s competitiveness will also de- ther breeder reactors or reprocessing. Advanced, more efficient fission reactors could delay the need for breeders or reprocessing pend on technical progress made with other still further. With the use of breeders, uranium depos}ts become energy technologies. adequate for centuries. 20 ● Starpower: The U.S. and the International Quest for Fusion Energy

● There is little to be gained and a great deal supply, that alternative must be preferable to be lost if fusion is prematurely intro- in order to be accepted, It would be unwise duced without attaining its potential eco- to emphasize one fusion feature—economics nomic, environmental, and safety capabil- or safety or environmental advantages—over ities. Even in a situation where problems the others before we know which aspect will with other energy technologies urgently call be most important for fusion’s eventual for development of an alternative source of acceptance.

FUSION AS A RESEARCH PROGRAM The ultimate objective of fusion research is to plied mathematics, computer science, and other produce a commercially viable energy source. fields. Yet, because the research program is exploring new realms of science and technology, it also pro- 3. Advancing Science and Technology vides near-term, non-energy benefits. These ben- Many high-technology research and develop- efits fall in four major categories. ment (R&D) programs produce secondary benefits or “spin -offs.” Over the years, the magnetic Near-Term Benefits fusion energy program has contributed to a va- 1. Development of Plasma Physics riety of spin-off technologies with wide-ranging applications in other fields. Among them are su- Plasma physics as a branch of science began perconducting magnet technology, high-quality in the 1950s, driven by the needs of scientists vacuums, high-temperature materials, high- working on controlled thermonuclear fusion and, frequency and high-power radiofrequency waves, later, by the needs of space science and expir- electronics, diagnostics and tools for scientific ation. The field of plasma physics has developed analysis, high-speed mainframe computers, and rapidly and has synthesized many areas of physics particle beams. Although spin-offs may benefit previously considered distinct disciplines. Mag- society, they are unanticipated results of research netic fusion research funding is crucial to the con- and should not be viewed as a rationale for con- tinuation of plasma physics research; over half tinuing or modifying high-technology research of all Federal plasma physics research is funded programs. It is impossible to predict before-the- by the magnetic fusion program. fact which research investments will have the greatest spin-off return. 2. Educating Scientists 4. Stature Educating scientists and engineers is one of the most widely acknowledged benefits of the fusion The stature of the United States abroad bene- program. Over the last decade, DOE’s magnetic fits from conducting high-technology research. fusion energy program has financed the educa- The United States has been at the forefront of fu- tion of most of the plasma physicists produced sion R&D since the program began in the 1950s. in the United States. DOE, through its magnetic Maintaining a first-rate fusion program has placed fusion program, directly supports university fu- the United States in a strong bargaining position sion programs and provides 37 fusion fellowships when arranging international projects, has at- annually to qualified doctoral students. Training tracted top scientists from other fusion programs in plasma physics enables these scientists to con- to the United States, and has enhanced the repu- tribute to defense applications, space and as- tation of the United States in scientific and tech- trophysical plasma physics, materials science, ap- nical programs other than magnetic fusion. Ch. I.—Executive Summary ● 21

Near-Term Financial and Participation in the Magnetic Personnel Needs Fusion Program Financial Resources The Department of Energy’s Office of Fusion Energy (OFE) conducts research through three The Federal R&D budget has grown steadily in different groups: national laboratories, colleges the 1980s. The bulk of this growth has been and universities, and private industry. Each of driven by increases in defense spending, but non- these groups has different characteristics, and defense R&D has also grown. The fraction of the each plays a unique role in the fusion program. Federal R&D budget devoted to energy, however, has been steadily declining during the 1980s. In National Laboratories fiscal year 1987, energy R&D is estimated to account for less than 4 percent of the Federal R&D It is estimated that national laboratories will budget. conduct over 70 percent of the magnetic fusion R&D effort in fiscal year 1987. According to DOE, virtually all fusion research is funded by the the laboratories are “a unique tool that the United Federal Government; due to fusion’s long-term, States has available to carry on the kind of large high-risk nature, there is little private sector in- science that is required to address certain prob- vestment. Even though the fusion budget has lems in fusion.” G Four laboratories conduct the fallen, in constant dollars, to less than half of its bulk of the Nation’s fusion research: Lawrence 1977 peak, magnetic fusion has fared better than Livermore National Laboratory in Livermore, CA; many other energy programs. DOE’s energy pro- Los Alamos National Laboratory in Los Alamos, grams in nuclear fission, fossil fuels, conservation, NM; Oak Ridge National Laboratory in Oak Ridge, and renewable energy technologies have lost TN; and Princeton Plasma Physics Laboratory in proportionately more of their Federal support be- Princeton, NJ. cause it is believed that private sector financing is more appropriate in these cases. Figure 1-6 Universities and Colleges shows the budgets of DOE’s larger energy R&D programs during the 1980s. Within the fusion program, universities and colleges provide education and training and histori- Personnel Resources cally have been a major source of innovative ideas as well as scientific and technical advances. The fusion program currently supports approx- It is estimated that the university and college pro- imately 850 scientists, 700 engineers, and 770 grams will receive about 11 percent of the Fed- technicians. s These researchers work primarily eral fusion budget directly in fiscal year 1987. I n at national laboratories and in university and col- addition, they will probably receive another 2 or lege fusion programs. According to estimates by 3 percent through the national laboratories. DOE, the number of Ph.D. staff positions in the fusion program has declined by almost 20 per- Recent budget cuts have seriously affected cent since 1983. Most of the fusion researchers university and college fusion programs. Over 80 who have left the fusion program have found percent of these programs have budgets of less work in other research programs within DOE and than $1 million, and there are no other sources the Department of Defense. Many former fusion of Federal funding for fusion research to replace researchers, for example, are working on Strate- DOE appropriations. Since 1983, two-thirds of the gic Defense Initiative projects, university and college fusion programs have reduced or eliminated their programs. The Univer-

SThOnlas G. Finn, Department of Energy, Office of Fusion Energy, sity Fusion Associates, an informal grouping of letter to the Office of Technology Assessment, Mar. 12, 1987. The individual researchers from universities and col- number of technicians represents only full-time staff associated with experiments; shop people and administrative staff are not included. Figures for scientists and engineers include university professors bJOhn F. clarke, Director of the DOE Office of Fusion Energy, and post-doctoral appointments; graduate student employees are “Planning for the Future, ” Journal of Fusion Energy, vol. 4, Nos. not included. 2/3, June 1985, p. 202.

22 ● Starpower: The U.S. and the international Quest for Fusion Energy

Figure l-6.—Annual Appropriations of DOE Civilian R&D Programs (in currant dollars)

3.2

3.0

Ieges, anticipates that as many as half of the in- laboratories. As the research approaches the engi- stitutions represented by its members will elimi- neering stage, industry can begin to participate nate their fusion programs between 1986 and directly by supplying components or contracting 1989 if the university fusion budgets are not main- with DOE. Ultimately, it is anticipated that in- tained. DOE, however, disputes this claim and dustry will sponsor research and development projects constant budgets (corrected for inflation) activities. for the university programs. To date, industry and utility involvement in magnetic fusion R&D has been advisory, with Private Industry limited cases of direct participation. This is due private industry can take a variety of different largely to fusion’s long time horizon and the lack roles in fusion research, depending on its level of predictable, easily commercializable “spin-off” of interest in the program and the status of fu- technologies. Most current industrial participa- sion development. At the lowest level, industry tion is facilitated through subcontracts from na- can serve as an advisor to DOE and the national tional laboratories.

Ch. I.—Executive Summary ● 23

Photo credit: Plasma Fusion Center, MIT The Alcator C tokamak at the Massachusetts Institute of Technology.

The transition of responsibility for fusion re- ment of industry in fusion research is necessary search and development from government to in- to ensure that the technology will be attractive dustry is a significant hurdle to be cleared before to its eventual users and marketable by the pri- fusion can be commercialized. Current DOE pol- vate sector. Others counter that, given present icy calls for any demonstration fusion reactor to and foreseeable future research budgets, there be built and operated by the private sector. In- are not enough opportunities for the private sec- dustries and utilities, on the other hand, may be tor to develop and maintain a standing capabil- unwilling to risk a major investment in a new and ity in fusion. These individuals believe that indus- unproven technology. try’s limited participation in fusion research in the near-term will not preclude its eventual role in There is considerable controversy over the demonstration and commercialization. appropriate time for the private sector to become more involved in the research program. Some argue that the willingness of industry to in- Chapter 6 of this report describes characteris- vest in fusion technology should not be used as tics of fusion as a near-term research program—its a criterion for determining its appropriate degree near-term benefits, its financial and personnel of involvement. They maintain that early involve- needs, and its principal participants.

24 ● Starpower: The U.S.. and the International Quest for Fusion Energy

Photo credit: GA Technologies The Ohmically Heated Toroidal Experiment at GA Technologies, Inc., which is the only major fusion experiment constructed and operated largely with private funds.

FUSION AS AN INTERNATIONAL PROGRAM

The field of magnetic fusion research has a 30- grams to become significantly interdependent: year history of international cooperation. The indeed, DOE now sees more extensive interna- leaders of the U.S. fusion community continue tional cooperation as a financial necessity. to support cooperation, as does DOE. In the past, the United States cooperated internationally in Opportunities for Increased a variety of exchanges that have produced use- Collaboration ful information without seriously jeopardizing the autonomy of the domestic fusion program. In re- Cooperation among the major world fusion cent years, in response to budgetary constraints programs can be expected to continue at its cur- and the technical and scientific benefits of co- rent level, at the least, as long as each of the ma- operation, DOE has begun cooperating more in- jor fusion programs maintains a level of effort tensively in fusion, and the major fusion programs sufficient to make it an attractive partner to the have become more interdependent. For the fu- others. In the future, it is also possible that a sub- ture, DOE proposes undertaking cooperative proj- stantially expanded degree of collaboration may ects that will require the participating fusion pro- take place. Such collaboration may take two forms: Ch. I.—Executive Summary s 25 joint construction and operation of major facil- usual circumstances each partner should ities on a scale not yet attempted among the four spend less through collaboration than it programs, and substantial additional joint plan- would to duplicate the research by itself. ning among the world programs to minimize redun- ● Risk Sharing. The financial and program- dant research and to maximize the transfer of in- matic costs of a collaborative project are formation and expertise among the programs. spread among a number of participants, minimizing the exposure of any one of them in Those who favor increased levels of collabo- the event of failure. On the other hand, ration believe that there will be important oppor- through collaboration, each party opens it- tunities over the next decade. At the same time self up to the risk that withdrawal of any of that similarities in the status and goals of the ma- the other partners may jeopardize the suc- jor international fusion programs provide a tech- cess of the entire project. A partner may also nical basis for expanded cooperation, the com- become dependent on others for the con- parable levels of achievement ensure that each tinuation of its own program. Finally, some program can contribute to and benefit from col- observers feel that the absence of competi- laboration. Moreover, commercial applications tion and duplication among experimental fa- of fusion technology are sufficiently far off that cilities may increase the risk of technical competitive concerns should be minimal. Since failure. the programs may not remain comparable over ● Diplomatic and Political Implications. Col- the long term, these pro-collaboration observers laboration can be diplomatically motivated, maintain that the timing may not be as advanta- because it may improve relations and in- geous for collaboration in the future as it is now. crease familiarity between the partners. In particular, they worry that if recent funding Some analysts welcome this additional as- trends continue, the U.S. fusion program may fall pect of collaboration; others fear that diplo- behind the other programs and might no longer matic motivations may override technical be viewed as a desirable partner. ones, causing a project to be undertaken that might not be judged attractive on its techni- Benefits and Liabilities cal merits alone. of Cooperation ● Domestic Implications. If the domestic program is neglected in order to support the col- International collaboration introduces a num- laboration, both the ability of the partner to ber of potential benefits and liabilities to the par- collaborate and the value of collaboration ticipants. Observers will weigh these features to that partner may be compromised. Even differently, arriving at different conclusions about if the domestic program is not damaged, it the value of collaboration: will be influenced by participation in col- ● Knowledge Sharing. All forms of coopera- laboration. Becoming dependent on collabo- tion involve sharing knowledge. Research- ration lessens the flexibility of the partners ers can take advantage of one another’s ex- to change research direction and emphasis. perience, greatly aiding their own progress. On the other hand, collaboration can stabi- Some observers, however, are concerned lize domestic efforts; the additional commit- that collaboration could lead to exchange of ment given to a collaborative effort makes information that has adverse implications for it more difficult for domestic contributions national security or technological competi- to that effort to be cut back. tiveness. ● Cost Sharing. Cooperation can save the part- Obstacles to International ners money by spreading out the costs of ex- Cooperation periments among the participants and avoiding duplication of effort. Some additional The process of organizing and executing large- costs may be added as a result of increased scale collaboration presents challenges that must administrative complexity, but barring un- be overcome by each of the partners. Among the 26 ● Starpower: The U.S. and the International Quest for Fusion Energy

challenges will be siting the facility, resolving the million and $20 million annually over the 3-year technology transfer concerns of the parties and program. making them compatible with an open exchange Since the U.S. Government proposal addresses of research results, resolving technical differences only the conceptual design phase of ITER, it among the parties, and overcoming a variety of makes no commitment to future construction of administrative obstacles including different in- a collaborative experiment. Therefore, current stitutional frameworks, different budget cycles, negotiations will not address the obstacles to in- different legal systems, and personnel needs. ternational collaboration that would arise if and Negotiating and executing workable agree- when the decision were made to jointly construct ments for international collaboration will un- and operate the device. At the completion of the doubtedly be a difficult and time-consuming conceptual design phase, interested parties process. Legal and institutional frameworks must would be in a position to begin negotiations on be devised that address the issues in a manner whether or not to proceed with construction. The acceptable to participants in the project. existence of a conceptual design would make it easier to resolve many of the questions that would The International Thermonuclear arise should a subsequent decision be made to Experimental Reactor build and operate ITER. In particular, it should be possible to analyze concerns about technol- Currently, most of the effort in international col- ogy transfer specificalIy and determine their im- laboration is focused on a proposal to develop plications for national security or industrial com- a conceptual design for an international engineer- petitiveness. ing test reactor, called the International Thermo- International cooperation on the scale re- nuclear Experimental Reactor (ITER). Estimates in- quired for ITER is unprecedented for the United dicate that building an engineering test reactor States. Reaching agreement within the U.S. Gov- will cost well over $1 billion and possibly sev- ernment to initiate and maintain support for ITER eral times this amount, which is far more than over the lifetime of the project will probably re- the U.S. fusion program has spent on any one quire a presidential decision. Even that, by itself, facility in the past and is too expensive for the is insufficient to guarantee the viability of a project United States to undertake alone without substan- involving all branches of the U.S. Government tial increases in fusion funding. Therefore, DOE and extending over several presidential adminis involved in discussions with the other world- istrations. wide fusion programs to jointly design, construct, and operate ITER. At this time, DOE considers international collaboration on the scale of ITER to be crucial. At this stage, only the conceptual design of ITER Given the seriousness of the obstacles, however, is being considered by the potential collabora- it is possible that such collaboration may not oc- tors; the U.S. Government recently issued a pro- cur, In the event that no major collaboration posal to begin a joint planning activity on a con- takes place, either the U.S. fusion program will ceptual design for the experiment, along with have to be funded at a higher level or its sched- supporting R&D. It is anticipated that the con- ule will have to be slowed down and revised. ceptual design phase of ITER will occur between 1988 and 1990 at a total estimated cost ranging International issues are discussed in chapter from $150 million to $200 million. The U.S. cost 7 of this report. of the undertaking is projected to be between $15 Chapter 2

Introduction and Overview Chapter 2 Introduction and Overview

FUSION POWER

To geologists and physicists at the turn of the ogy is perfect. Since the 1950s, the potential pay- century, the term “energy problem” referred not off of fusion energy has motivated a worldwide to finding sources of energy for society, but to research effort. identifying the one used by the sun. Most physi- The previous decades of research have shown cists believed that the source of the sun’s energy that fusion energy is extremely difficult to pro- was heat released as the sun slowly shrank un- duce. Experiments planned for the next few years der its own gravity, a process that would burn shouId be able to assess fusion’s scientific feasi- out no more than 20 million years after the sun bility as an energy source, but several decades was formed. Geologists, however, argued that of additional research and development, and bil- geological and fossil evidence showed that the lions of additional dollars, will be needed to see earth-assumed to be no older than the sun— whether a marketable fusion reactor can be de- was in fact many times more than 20 million years veloped. Researchers in the United States, West- old. ern Europe, Japan, and the Soviet Union generally agree on the technical tasks yet to be done Although many hypotheses were developed to to evaluate fusion’s potential. Policy makers in reconcile the two positions, it was not until 1938 these nations must now decide if, when, and how that one explanation received virtually instantane- to allocate the resources necessary to accomplish ous and universal acclaim: the sun’s “energy these tasks. problem” was solved when nuclear fusion was identified as its energy source. Through fusion, The Allure the sun has been able to shine for nearly 5 billion years using only about half of its original fuel. In the future, fusion power could bean attractive source of energy because it might offer a Nuclear fusion is the process by which the combination of benefits unmatched by other nuclei—or central cores—of two atoms combine fuels. Compared to other energy technologies, or fuse together. The total mass of the final prod- fusion could be: ucts is slightly less than the total mass of the original nuclei, and the difference—less than 1 per- Unlimited. A form of hydrogen found natu- cent of the original mass—is released as energy. rally in water is a potential fusion fuel, and Nuclear fusion, in a sense, is the opposite of nu- every gallon of water on earth contains the clear fission, the process utilized in existing nu- fusion energy equivalent of 300 gallons of clear powerplants. In a fission reaction, energy gasoline. is released when a heavy nuclei splits into smaller Clean. Using fusion reactions to generate pieces whose total mass is slightly less than that power may be significantly cleaner than ei- of the original nucleus. ther fossil fuels or nuclear fission. Fusion, unlike coal combustion, does not produce Nuclear fusion may be applicable to the energy carbon dioxide whose accumulation in the needs of humans. If the fusion process can be atmosphere may affect world climate. More- utilized economically, it has the potential to pro- over, fusion will not contribute to acid rain vide society with an essentially unlimited source or other potential environmental damage of electricity. It may also offer significant environ- associated with fossiI fuels. Although fusion mental and safety advantages over other energy reactors themselves will become radioactive, technologies, characteristics that are particularly the products of the fusion reaction are not appealing in a world where no energy technol- radioactive. With appropriate choice of struc-

29 —

30 . Starpower: The U.S. and the International Quest for Fusion Energy

tural materials, fusion reactors will produce be demonstrated. This accomplishment will en- far less radioactive waste than fission re- tail developing future reactor systems, subsystems, actors. and components that can function reliably un- ● Safe. It may be possible to design fusion re- der reactor operating conditions. Demonstrating actors in which “safe operation is assured by engineering feasibility will require an extensive physical properties, rather than by active amount of research and development, and it will safety systems that might fail due to malfunc- be a technical achievement at least as impressive tion, operator error, or natural disaster. as the scientific accomplishment of harnessing controlled fusion reactions. Substantial further scientific and technological development is required to see whether these ben- Although scientific feasibility and engineering efits can be attained, feasibility involve different issues, fusion science and fusion engineering are interdependent: ad- Establishing Fusion’s Feasibility vancing scientific understanding of the fusion process requires improved technological capa- Two requirements must be met before fusion bilities in experimental facilities, just as solving can be an attractive source of energy. First, fu- the engineering problems posed by fusion reactor sion’s technological feasibility must be demon- design requires additional basic understanding in strated by establishing the scientific and engineer- a number of areas. Demonstrating both the sci- ing understanding necessary to build an operating entific and engineering feasibility of fusion power fusion reactor. Second, fusion’s commercial fea- requires advances to be made in basic scientific sibility must be demonstrated. understanding as well as in technological capability. Technological feasibility is usually considered in two stages: scientific feasibility and engineer- The goal of fusion research is to establish fu- ing feasibility. Scientific feasibility requires gen- sion’s technological feasibility in a manner that erating a fusion reaction that produces at least makes commercial feasibility likely. If and when as much energy as must be input into the plasma it becomes clear that generating electricity in a to maintain the reaction. This milestone, called fusion reactor is possible, such a reactor must breakeven, has not yet been reached, but it is prove socially and environmentally acceptable expected that breakeven will be accomplished and economically attractive compared to its alter- in existing machines by 1990. natives. Although dependent on the technical results of fusion research, fusion’s commercial fea- Simply breaking even, however, does not show sibility also involves factors unrelated to the that fusion can serve as a useful source of energy. technology itself, such as the status of other in addition, a fusion reaction must be created that energy technologies and the regulatory and li- has high energy gain, producing an energy out- censing structure. Commercial feasibility ulti- put many times higher than its energy input. No mately will be determined by individuals and in- existing experiment has the capability to produce stitutions that are not involved directly in fusion such a reaction, a task that is more significant and research. more difficult to achieve than breakeven. How- ever, the Department of Energy (DOE) has requested funds in its fiscal year 1988 budget to be- The Fusion Reaction gin construction of an experiment to generate a Only light elements can release energy through reaction with such high-gain that it should be- fusion. While many different fusion reactions take come self-sustaining, or ignited. At ignition, replace in the stars, the one that can be used most actions will generate enough power to sustain the easily to generate power on earth involves hydro- fusion process even after external heating power gen (H), the lightest element. Three forms, or iso- has been shut off. topes, of hydrogen exist: protium, which is usu- After high gain or ignition has shown fusion’s ally referred to simply as hydrogen, deuterium scientific feasibility, its engineering feasibility must (D), and tritium (T). The nuclei of these isotopes Ch. 2.—Introduction and Overview “ 31 consist of a single proton and zero, one, or two characteristics of fusion reactors used to produce neutrons, respectively. Over 99.98 percent of all electricity are discussed in chapter 5; other pos- hydrogen found in nature is the protium isotope. sible applications of fusion are discussed in ap- Less than 0.02 percent (one part in 6,700) is com- pendix A. posed of deuterium. Tritium is radioactive, with 1 The D-T reaction is not the only one that can a half-life of 121/4 years; it is practically nonexist- generate fusion energy. One deuterium nucleus ent in nature, but it can be manufactured.2 can fuse with another in a D-D reaction. It is also The easiest fusion reaction to initiate combines possible to use other light elements besides hy- deuterium and tritium to form helium and a free drogen as fuel. However, it is much harder to ini- neutron, as shown in figure 2-1; a fission reaction tiate fusion reactions with fuels other than deu- is also shown for comparison. The fusion reaction terium and tritium, and many of these alternate shown—called a D-T reaction—liberates 17.6 mil- fuels produce less power for a given amount of lion electron volts3 of energy. By way of compar- fuel than the D-T reaction does. Reactors using ison, burning a single atom of carbon (the com- alternate fuels would be more difficult to design bustible material in coal) releases only about 4 and build than D-T reactors producing the same electron volts. Therefore, a single D-T fusion re- amount of energy. On the other hand, these alter- action is over 4 million times more energetic. nate reactions may not require tritium production and/or may not generate as many neutrons Four-fifths of the energy released in a D-T fu- as the D-T reaction. Both tritium production and sion reaction is carried off by the neutron as ki- neutron generation increase the amount of radio- netic energy. I n a fusion reactor, it is anticipated active material contained in a reactor, a situation that neutrons would be captured in the material that complicates the reactor’s design and can surrounding the reaction chamber, where their raise environmental and safety issues. kinetic energy would be converted into heat. One-fifth of the reaction energy, carried off by the helium nucleus, would remain inside the re- Requirements for Fusion Reactions action chamber, heating up the fuel and making Fusion reactions can only occur when the re- additional reactions possible. quirements of temperature, confinement time, The primary application of fusion will probably and density are simultaneously met. The mini- be for electric power generation, using heat from mum temperatures, confinement times, and den- the fusion reaction to boil water to drive a steam sities needed to produce fusion power have been turbine that generates electricity. Advanced sys- known for decades. Achieving these conditions tems for converting fusion energy more directly in experiments, however, has proven extremely into electricity may also be possible. Other ap- difficult. plications of fusion might use the neutrons themselves for various purposes, rather than just ex- Temperature tracting their energy. It is also possible that, as Because the nuclei that must fuse have the fusion development progresses, additional uses same electrical charge, they must be heated to of the technology might be found. The potential extremely high temperatures to overcome their

I Radioactive materials decay over time as the nuclei of radioactive natural repulsion. Temperatures on the order of atoms emit radiation and transform into other nuclei. The decay 100 million degrees Celsius (C) are required. No rate is measured by the substance’s ha/f-/ife, which is the time re- matter exists in solid form at these temperatures; quired for half of the nuclei to be transformed. 2 individual atoms are broken down—ionized— Trace amounts of tritium are continually produced by cosmic rays in the upper atmosphere. Most of the tritium now in the envi- into their constituent electrons and nuclei. With ronment, however, was produced by atmospheric nuclear weap- their outside electrons missing, the nuclei have ons tests In the 1950s. 30ne electron volt (eV) is the energy that a single electron can a positive electric charge and are called ions. pick up from a 1 -volt battery. It is equal to 1.6 X 10-’9 joules, 1.52 x 10”22 Btu, or 4.45 x 10-26 kilowatt-hours. One thousand elec- Matter in this state is called plasrna (figure 2- tron volts is called a kiloelectron volt, or keV. 2). Plasma is considered a fourth state of matter

32 . Starpower: The U.S. and the International Quest for Fusion Energy

Figure 2-1 .—The D-T Fusion Reaction and a Fission Reaction

● Proton Key: o Neutron MeV: million electron volts

SOURCE: Adapted from Princeton Plasma Physics Laboratory, Information Bulletin NT-1: Fusion Power, 1984, p. 2 (fusion); Office of Technology Assessment (fission), 1987, Ch. 2.—Introduction and Overview “ 33

Figure 2-2.— Gas and Plasma

because it has properties unlike solids, liquids, ings, and the temperature difference between the or gases. Fusion research, critically dependent on two. The ability of a plasma to stay hot is repre- understanding plasmas, has led to the develop- sented by its confinement time, which is a meas- ment of a new field of science called plasrna ure of the time it would take to cool down to a physics. certain fraction of its initial temperature if no additional heat were added. The temperature of a plasma is a measure of the average energy of the plasma particles and With an insufficient confinement time, it is im- is usually expressed in units of electron volts. A possible to reach breakeven or ignition. Even if plasma temperature of 1 electron volt, which is the plasma is heated hot enough for fusion re- about 11 ,600° C, corresponds roughly to each actions to start, heat would be lost faster than it particle in the plasma having an average energy would be generated in those reactions, and the of 1 electron volt. In a plasma, the ions and the reactions would not produce any net power. electrons can have different temperatures; ion Confinement times on the order of one second temperature is most important and must exceed are generally considered necessary for an ignited about 10,000 electron volts for enough of the ions plasma. to overcome their mutual repulsion to produce appreciable amounts of fusion power. Density The exact confinement time requirement de- Confinement Time pends on plasma density. The fusion reaction The goal of fusion research is not only to cre- rate, and therefore the amount of fusion power ate a hot plasma but also to keep it hot long produced by the plasma, goes down rapidly as enough to produce fusion power. [t is not suffi- density drops. A plasma that is not dense enough cient simply to heat the fuel, because any sub- will not be able to generate power even if it is stance that is hotter than its surroundings will cool very hot and retains its heat very well. The den- off. The rate at which the substance cools de- sity required to reach breakeven or ignition in- pends on its physical characteristics, its surround- creases as confinement time decreases. The prod- —

34 . Starpower: The U.S. and the International Quest for Fusion Energy

uct of density and confinement time (called the by magnetic fields. A charged particle moving in Lawson parameter) must exceed a minimum a magnetic field will be bent at right angles to threshold in order for a fusion plasma to ignite.4 both the direction of the field and its direction of motion, with the result that the energetic par- Confining Fusion Plasmas ticles making up a fusion plasma will trace spiral orbits around magnetic field lines (figure 2-3). A fusion plasma cannot be contained in an or- Magnetically confined plasmas will tend to flow dinary vessel no matter how hot the vessel is along field lines but not across them, and a suit- heated, because the plasma will be instantly able configuration of magnetic fields can there- cooled far below the minimum temperature re- fore confine a plasma. Many different kinds of quired for fusion whenever it comes into contact magnetic-confinement configurations are u rider with the vessel walls. There are three primary investigation, as described in chapter 4. In this ways to hold a plasma that avoid this obstacle. report, the word fusion refers to magnetic confine- Only one of these–magnetic confinement-is ment fusion unless specifically noted otherwise. discussed to any appreciable extent in this report.

Magnetic Confinement Gravitational Confinement Magnetic confinement relies on the fact that A sufficiently large plasma can produce fusion because individual particles in a plasma are elec- power while holding itself together with its own trically charged, their motion is strongly affected gravitational field. This process, called gravitational confinement, permits fusion to take place 4The minimum threshold for ignition, as defined by the Lawson in the sun and other stars. It is impossible, how- parameter, is 3 X 10~4 second-particles per cubic centimeter. This means that a plasma with a density of 3 X 10’4 particles per cubic ever, to utilize gravitational confinement for fu- centimeter must be confined for one second in order to ignite. As sion processes on earth. Even the planet Jupiter, mentioned above, if the density were increased to 3 x 1015 parti- which is over 300 times more massive than earth, cles per cubic centimeter, then the confinement time requirement would decrease to one-tenth (O. 1 ) of a second. does not have sufficient mass to produce gravita- tionally confined fusion.

SOURCE: Princeton Plasma Physics Laboratory, Information Bulletin NT-1: Fusion Power, 1984, p. 3, Ch. 2.—Introduction and Overview “ 35

Inertial Confinement its close connection with weapons physics, and may have longer term energy applications as well. In a hydrogen bomb, fusion fuel is heated and The energy applications of inertial confinement compressed to such high densities that it need fusion are generally considered less developed be confined only for a very short time in order than those of the magnetic confinement process. to generate fusion power. The fuel’s own inertia Because of the direct links between this approach keeps it confined long enough for fusion reactions and hydrogen bomb design, much of the research to occur. A research effort is now underway to in inertial confinement fusion is classified. The study this inertial confinement process i n a con- inertial confinement approach is discussed in ap- trolled manner on a laboratory scale. This pro- pendix B. gram has near-term military applications, due to

THE PURPOSE OF THIS STUDY

Increasing budgetary pressures, along with a the program from three different, but related, per- decreasing sense of urgency regarding energy spectives: supply, have sharpened the competition for fund- 1. It considers the issues related to fusion’s role ing between one research program and another as an energy research and development pro- and, perhaps more significantly, between energy gram, in particular those related to develop- research programs and other components of the ing an attractive energy supply technology. Federal budget. At the same time, issues such as 2. It analyzes the near-term, non-energy ben- the implications of increased fossil fuel usage on efits of the fusion program and the financial the global climate and the long-term acceptabil- and personnel resources necessary to sup- ity of nuclear power have raised serious concerns port the program. about future energy supply. 3. It examines the increasing role of interna- In balancing the long-term potential of fusion tional collaboration in magnetic fusion re- energy against shorter term, more immediate search. pressures, the congressional committees with OTA’s assessment was carried out with the jurisdiction over DOE’s magnetic fusion program assistance of a large number of experts reflect- requested this study. In 1986, the House Com- ing different perspectives on the fusion program mittee on Science and Technology requested that –fusion scientists and engineers, nuclear engi- OTA review the magnetic fusion energy program, neers, environmental scientists, international re- citing that “. . . a number of factors have served lations experts, industry and utility executives, to decrease the sense of urgency with which the consumer groups, economists, financial planners, DOE management and many members of the and energy policy analysts. As with all OTA studies, Congress view the development of fusion power.” an advisory panel representing these interests and Shortly afterward, the Senate Committee on fields of expertise met periodically throughout the Energy and Natural Resources endorsed this re- course of the assessment to review and critique quest. These committees are faced with setting interim products and proposals, to discuss fun- policy for the fusion program, and they were in- damental issues affecting the analyses, and to re- terested in an independent analysis of the fusion view drafts of the report. Contractors and con- program as input to their budget authorization sultants also provided material in support of the deliberations. 5 assessment. in response, OTA undertook this assessment of the magnetic fusion research and development program in March 1986. The assessment exam- 5Advlsory panel members, workshop participants, contractors, ines the technical and scientific achievements and and other contributors to this assessment are listed in the front of objectives of the fusion program. It also analyzes this report. 36 . Starpower: The U.S. and the International Quest for Fusion Energy

Finally, OTA convened three workshops to ● Chapter 4 explains the technical underpin- clarify important issues considered in the assess- nings of fusion research and sets out the re- ment and to review and expand upon contrac- quirements for demonstrating fusion’s tech- tors’ analysis. The first workshop dealt with gen- nological feasibility. Fusion research is one eral issues involved in fusion research. It focused of the Federal Government’s most futuristic on the nature of the fusion research program, the and technically complex undertakings. Phys- implications of current funding cuts on the pro- ical theory and experimentation must ad- gram, and the main issues involved in decisions vance the present state of the art if the goal about future courses of action. is to be reached; forefront technology must be developed not only in the long-run, to The second workshop addressed issues in in- harness fusion, but in the short-run to con- ternational collaboration in fusion research. Three struct each successive experiment. contractor reports, detailing the characteristics of ● Chapter 5 addresses the long-range energy the major non-U.S. fusion programs and their applications of fusion research. The antici- views of collaboration, were reviewed at the pated characteristics of future fusion reactors workshop. The principal issues addressed were are discussed, including projected plant eco- the motivations and goals of foreign fusion pro- nomic, safety, and environmental features. grams, national security and competitiveness risks Issues involved in commercializing the tech- of technology transfer through collaboration, and nology are also examined. In addition, fac- other potential obstacles to collaboration, tors that will be important in determining The final workshop addressed fusion’s energy whether and when fusion will penetrate context. Projections of electricity demand in the energy markets as a source of electricity are 21st century and their relevance to fusion were discussed. presented by OTA consultants and reviewed. In ● Chapter 6 discusses the character of current addition, the uncertainties inherent in forecast- fusion research and analyzes the value of the ing supply and demand over times relevant to fu- fusion program in terms of its near-term, sion were discussed. Alternative energy supply non-energy benefits. Data on program par- technologies that might compete with fusion ticipants, funding levels, and personnel levels were addressed, as were the implications of po- are summarized. tential difficulties such as global climate change ● Chapter 7 examines the extremely important and nuclear fission safety or environmental issues. role that international cooperation in fusion research has had in the past and may have The material in this report is based on OTA staff in the future. Motivations for and obstacles research, site visits, workshop discussions, advi- to future large-scale collaboration are assessed, sory panel recommendations, and contractor and as well as possible models for such collabo- consultant reports. The report is organized as ration. follows: ● Finally, chapter 8 summarizes the critical issues facing the fusion program and presents ● Chapter 3 provides a brief history of the U.S. a series of policy paths for Congress to con- fusion program, which, since its inception sider as it makes decisions on funding fusion in the 195os, has been almost entirely funded research. The implications of pursuing the by the U.S. Government. different paths are discussed. Chapter 3

Fusion Research CONTENTS

Page Research Beginnings ...... 39 Nuclear Physics ...... 39 Plasma Physics ...... 39 Early Fusion Research ...... 39 The U.S. Fusion Program Through the Decades ...... 40 The 1950s: Era of Optimism and Disillusionment...... 40 The 1960s:A Plateau ...... 44 The 1970s: Rapid Growth ...... 46 The 1980s: Leveling Off ...... 50

Figures Figure No. Page 3-1. Historical Magnetic Fusion R&D Funding, 1951-87 (in 1986 dollars) ...... 41 3-2. Historical Magnetic Fusion R&D Funding, 1951-87 (in current dollars) .,.. 42 Chapter 3 History of Fusion Research

RESEARCH BEGINNINGS

Fusion research draws on two independent Plasma Physics branches of physics–nuclear physics and plasma physics. Studying the fusion reaction itself is the Plasma physics, according to the same National domain of nuclear physics. Studying the behavior Academy review panel, is “the only major branch of matter u rider conditions necessary for fusion of physics to come largely into being in the past reactions to take place is the focus of plasma generation.”3 Its development drew upon a num- physics. ber of previously distinct and independent disciplines, pulling them together into a unified Nuclear Physics methodology for the study of the plasma state. Explaining plasmas could not begin until the Early in this century, the search for the causes discovery of the electron in 1895 and the devel- of radioactivity revealed that vast amounts of opment of the atomic theory of matter. Between energy were stored in an atom’s nucleus. As early 1930 and 1950, the foundations of plasma physics as 1920, this energy was hypothesized to be the were laid, largely as a byproduct of investigations heat source that powered the sun and other stars. on topics such as the earth’s outer atmosphere, With the discovery of the neutron in 1932 these the sun, and various astrophysical phenomena. nuclear processes began to be understood, and The advent of space exploration and controlled by the time efforts to control fusion reactions in fusion research–the two major experimental the laboratory began in the 195os, the nuclear arenas for modern plasma physics—firmly estab- physics underlying laboratory fusion reactions lished the field. were well known. “Then, as now, ” noted a recent National Academy of Sciences panel review- Early Fusion Research ing physics research, “the obstacles to achieving controlled fusion lay not in our ignorance of The first probe into harnessing fusion power 2 nuclear physics, but of plasma physics. ” took place during the Manhattan Project, the effort during World War II dedicated to developing an atomic bomb. Some physicists working on the Manhattan Project in Los Alamos, New Mex- ico, began to consider whether the fusion process could be utilized in nuclear weapons. Such

I Most of the historical material in this chapter is based on Fu- investigations were not a high priority during the sion: Science, Politics, and the Invention of a New Energy Source war, however, because the national effort was (Cambridge, MA: MIT Press, 1982), a comprehensive and exten- focused on developing weapons that utilized the sively documented history of the U.S. fusion program written by Joan Lisa Bromberg under contract with the U.S. Department of more immediately promising fission process. Energy. The book is restricted almost entirely to magnetic confinement fusion and covers a period ending in 1978. While Bromberg In 1949, largely in response to the first Soviet was given access to unclassified and declassified DOE and national nuclear detonation, senior U.S. scientists and pol- laboratory records, the book does not represent the official posi- icymakers conducted an extensive, classified tion of DOE. A more popularized history of the fusion program, covering in- (secret) debate about whether hydrogen bombs– ertial fusion as well as magnetic fusion and extending until 1983, weapons that use the fusion process instead of is found i n T.A. Heppenheimer, The Man-Made Sun: Hre Quest the fission process—could and should be devel- for Fusion Power (Boston, MA: Little, Brown & Co., 1984), 2Natlonal Research Council, Panel on the Physics of Plasmas and oped. In 19s0, the debate ended when president Fluids, Physics Survey Committee, Physics Through the 1990s: Truman approved a crash program to build such P/asrnas and F/uids (Washington, DC: National Academy Press, 1986), p. 4, jlbid., p, 6.

72-678 0 - 87 - 2 40 . Starpower: The U.S. and the International Quest for Fusion Energy

a weapon. The United States detonated its first “use of special nuclear material in the produc- H-bomb in 1952.4 tion of energy,” remain classified indefinitely unless specific action was taken to declassify its In the beginning, most research in thermonuclear fusion was weapons-related and classi- Over the years, some of the emphasis in fusion fied. This research fell under the constraints of research shifted from weapons to reactors. Fu- the Atomic Energy Act of 1954, which mandated sion reactors were sought not only to produce that data concerning the “design, manufacture, “special nuclear materials’’—tritium and pluto- or utilization of atomic weapons, ” as well as “the nium—needed for nuclear weapons, but also to production of special nuclear material” and the produce electricity. At the time, both energy production and materials production fell under the restrictions of the Atomic Energy Act that man- 4 Herbert York, “The Debate Over the Hydrogen Bomb, ” Scien- dated continued classification. tific American, October 1975. There are many names for bombs that use the fusion process: hydrogen bombs, H-bombs, and thermonuclear or hydrogen weapons. Such weapons can have many “’Special nuclear material,” as defined in the Atomic Energy Act times the explosive power of fission weapons. of 1954, is material capable of undergoing nuclear explosions.

THE U.S. FUSION PROGRAM THROUGH THE DECADES

The nature of the U.S. fusion research program to supply future electricity needs. In pursuing fu- through each decade from its conception to the sion, scientists and AEC commissioners sought to present is summarized below. The funding pro- maintain U.S. scientific supremacy; there could file for U.S. fusion research, both in constant and be significant political and economic advantage current dollars, is shown in figures 3-1 and 3-2. should fusion lead to a commercially competi- Data for these figures is provided in appendix C; tive new energy technology. Fusion research for more information on funding for magnetic fu- would also support the U.S. weapons program. sion research, see chapter 6. The potential use of fusion reactors for generating weapons materials, as well as the possibility The U.S. Atomic Energy Commission (AEC) was of other military applications, was important to responsible for magnetic fusion research from the AEC; thus, during the early 1950s, fusion re- 1951, when the program was formally under- search grew along with military atomic research. taken, until 1974, when the AEC was disbanded and replaced by the Energy Research and Devel- project Sherwood began optimistically in 1951. opment Administration (ERDA). In 1977, ERDA At that time, it was estimated that spending about in turn was disbanded and its responsibilities $1 million over a period of 3 to 4 years would transferred to the new Department of Energy be sufficient to learn whether a high-temperature (DOE). Since 1977, DOE has managed the mag- plasma could be confined by a magnetic field. netic fusion research program. About that amount was budgeted for fusion research from 1951 to 1953. However, the prob- The 1950s: Era of Optimism lem proved harder than originally anticipated, and Disillusionment and in 1953 the fusion research program expanded. The personnel level increased from 8 in Project Sherwood 1952 to 110 in 1955 and rose to over 200 people in 1956. Annual budgets increased from under From 1951 until 1958, fusion research was clas- $1 million to $7 million over the same period.6 sified; during these years, the program was conducted under the code name “Project Sherwood.” The United States established several fusion re- At the outset of Project Sherwood, both field sci- search centers. Federally funded efforts were con- entists and program managers at the AEC believed that fusion could yield an important technology 6Bromberg, Fusion, Op. Cit., P. 30.

Ch. 3.—History of Fusion Research ● 41

Figure 3-1 .—Historical Magnetic Fusion R&D Funding, 1951-87 (in 1988 dollars)

. . 1955 1960 1965 1970 1975 1980 1985

Year SOURCE: U.S. Department of Energy, Office of Energy Research, letter to OTA project staff, Aug. 15, 1986. ducted at Oak Ridge National Laboratory in Ten- thought to be capable of leading, in a straight- nessee, Los Alamos Scientific Laboratory in New forward process of extrapolation, to a commer- Mexico, Lawrence Livermore Laboratory in Cali- cial reactor. One report concluded in 1958: fornia, and a number of universities, including With ingenuity, hard work, and a sprinkling of a major plasma physics laboratory at Princeton good luck, it even seems reasonable to hope that University in New Jersey established primarily to a full-scale power-producing thermonuclear de- conduct fusion research. Private or corporate- vice may be built within the next decade or two.7 sponsored research began in 1956 at the Gen- eral Electric Co. (GE) in New York and at the In reality, very little was known about the be- newly created General Atomic Corp. in Califor- havior of matter under the conditions being stud- nia. Several other companies dedicated a few staff ied, much less under reactor-like conditions. Ex- members to monitor the field. periments were trial-and-error operations, and each one charted new ground. Results were often Many different confinement schemes were explored during the early 1950s. Although proponents of the various schemes were careful to note 7Amasa S. Bishop, Project Sherwood.” The U.S. Program (Reading, MA: Addison-Wesley Publishing Co., Inc., that practical applications lay at least 10 or 20 1958), p. 170. Bishop managed the AEC fusion program from 1953 years in the future, the devices under study were to 1956 and again from 1965 to 1970.

42 . Starpower: The U.S. and the International Quest for Fusion Energy

Figure 3-2.—Historical Magnetic Fusion R&D Funding, 1951-87 (in currant dollars)

0 L 1955 1980 1985 1970 1975 1980 1985 Year SOURCE: U.S. Department of Energy, Office of Energy Research, letter to OTA project staff, Aug. 15, 1986.

ambiguous or misinterpreted, and the theoreti- Temperatures attained were about 100 electron cal underpinnings of the research were not well volts, in comparison to the minimum requirement established. All devices investigated showed evi- of 10,000 electron volts.9 dence of “instabilities,” or disturbances that grew to the point where the plasma escaped confine- Declassification ment faster than expected. The devices studied By the mid to late 1950s, the advantages of in the 1950s could not attain Lawson parameters declassifying Project Sherwood were recognized, higher than about 1010 second-particles per cu- both within the AEC and among scientists in the bic centimeter, a factor of about 10,000 less than field. Some U.S. scientists had sought to delay the minimum required to make net fusion power.8 declassification of fusion research because they were optimistic about harnessing controlled fusion reactions in the near future, and they rea- ‘The Lawson parameter is the product of density and confinement time (see 2, note 4). The units in which the Lawson parameter is expressed represent a density (particles per cubic centimeter) multiplied by a time (seconds), and have no immediate 9An electron volt is a unit of energy. It is also used as a measure physical significance. A product of 3 X second-particles per of temperature, representing that temperature at which the aver- cubic centimeter is considered the minimum for ignition in a D-T age energy of plasma particles is roughly electron volt. (See reaction. (See discussion of “energy gain” in 4, pp. 67-68. ) 2, note 3.) H ry R

P 9 A m S

d h d o wo dh mo m p g on pow w db m p me w h 0 eme 0 h ph o ope mm d wo do he u e pod one he mon h g m d po b b d e 0 Mo e he how e A he me m h d og ed h g 0 o d on h h h d ed b m m bo 0 w go gob m h h d h p rt New upp 0 m w p g p d h d pp w d d Mo 0 AEC omm m b h d h g wh h d b d g p m d m w p w b gd d dd m 44 ● Starpower: The U.S. and the International Quest for Fusion Energy sense to classify fusion research, whose applica- sion electricity station being developed in the tion in producing weapons material was still foreseeable future is small.”14 GE proposed that hypothetical, after fission technology that was ac- the AEC finance its research through a joint ef- tually being used for that purpose was declassi- fort, but the AEC refused and GE phased out its fied.11 fusion program. While GE was reconsidering its fusion program, the consortium of Texas utilities U.S. magnetic fusion research was declassified that funded fusion research at General Atomic in 1958 at the Second Geneva Conference on the 15 in California withdrew its support. The AEC re- Peaceful Uses of Atomic Energy. Following declas- sponded to this decision by funding much of sification, it was apparent that the American, Brit- General Atomic’s fusion research itself in order ish, and Soviet programs were at more or less the to preserve the expertise assembled there. In ef- same level and were pursuing similar approaches fect, this response created an additional national toward confining plasmas. Declassification opened laboratory. the door to widespread international cooperation in fusion. In 1965, a prestigious outside review committee evaluated the fusion program. The commit- The 1960s: A Plateau tee found that the magnetic fusion program had made significant progress, that the United States Fusion research in the United States proceeded needed to support research in order to develop at a steady pace throughout the 1960s. The theo- the technology, and that the program produced retical framework advanced, but discrepancies “spin-off” technologies that could benefit the between theoretical predictions and experimental economy. Moreover, the committee stated that results were common. By the mid-1960s, Con- the United States would suffer a great loss of in- gress became impatient. In the late 1950s, mem- ternational stature if another country demon- bers of Congress had believed that the Federal strated the feasibility of fusion first. The commit- program would beat the reactor prototype level tee recommended that the fusion budget increase in 5 or 6 years. Since that time, fusion research- by 15 percent annually and that a new genera- ers realized that they had seriously underesti- tion of experiments be funded to replace obso- mated the complexity of the problem. Therefore, lete ones.16 After considerable deliberation within the researchers concentrated on studying plasma the AEC and the Bureau of the Budget, an in- behavior rather than on building reactor proto- crease in funding was recommended, though not types. Congress, however, worried that the re- of the magnitude suggested by the committee. searchers were building an array of different experiments that did not appear to be leading to The Tokamak an attractive reactor.12 Thus, in 1963, the House Appropriations Committee recommended a 16 By 1968, the highest temperatures that had percent cut in the program’s operating budget. been achieved in a magnetic confinement fusion Much of the cut was restored, but the program device were only about 100 electron volts–not ended up with a budget of 7 percent less than appreciably higher than they were in the 1950s. requested. The quality of confinement, as measured by the Lawson parameter, had increased by an order of Enthusiasm for the fusion program cooled out- magnitude (factor of 10) to about 1011 second- side of Congress as well. While remaining sup- particles per cubic centimeter. In 1968, however, portive of fusion, AEC commissioners were more Soviet scientists announced that they had ex- interested in expanding the fission breeder re- ceeded the previous best values of each of these actor program .13 GE reviewed its corporate in- parameters by an additional order of magnitude. volvement in fusion in 1965 and concluded that “the likelihood of an economically successful fu- “1bid., p. 137. 1 I Ibid., pp. 69, 72-73. I tThis consortium has continued to fund a modest level of fu- Izlbid., pp. 118-119. sion research at the University of Texas. IJlbid., p. 136. lbBromberg, Fusion, op. cit., pp. 138-139.

Ch. 3.—History of Fusion Research w 45

Photo credit: Princeton Plasma Physics Laboratory

Model C Stellarator at Princeton Plasma Physics Laboratory. Designed and built in the late 1950s, the Model C was converted into the United States’ first tokamak in 1970.

Using a device named the “tokamak,” a Russian strating fusion’s feasibility. Some U.S. scientists acronym taken from the words for “toroidal submitted proposals to build tokamaks in the chamber with magnetic coil,” the Soviets claimed United States, while others argued that previous to have generated ion temperatures of 500 elec- plans to upgrade existing devices were more im- tron volts, electron temperatures of twice that, portant. Many scientists were skeptical of Soviet and a Lawson parameter of 1012 second-particles data, contending that it was ambiguous and not per cubic centimeter. sufficiently compelling to change the emphasis of the U.S. program. The Soviet announcement both excited and troubled the U.S. fusion community. U.S. pro- Early in 1969, the director of the Soviet fusion gram administrators worried that the Soviet effort invited a British team of scientists to bring Union would beat the United States to demon- its own diagnostic equipment to Moscow to verify —

46 . Starpower: The us. and the International Quest for Fusion Energy

Soviet research results. During the summer of During much of the 1970s, the director of the 1969, the British team in Moscow announced its fusion program was largely responsible for re- preliminary findings: the Soviet results were gen- orienting the program toward the use of tritium uine, and, in fact, the tokamak performed even in an experimental device. He sought to attain better than the Soviets had claimed. This announce- breakeven with tritium for a number of reasons:18 ment came shortly after the American scientific ● Physics. The energy released in actual fusion community had decided to convert the premier reactions involving tritium introduced a new Princeton machine, the Model C stellarator, into complication in device operation that could a tokamak. In addition, funds had been allocated significantly affect experimental behavior. for the development of another tokamak at Oak The director thought it was essential to study Ridge National Laboratory. After publication of the physical consequences of releasing fu- the British findings, the U.S. program Iaunc ed sion energy in a plasma. three more experimental tokamaks. ● Psychology. He also believed that too many fusion scientists were interested in plasma The 1970s: Rapid Growth physics as a research enterprise, not as an With the identification of the tokamak as the energy technology. Burning D-T, he thought, confinement concept most likely to reach reactor- wouId force them to come to grips with the Ievel conditions, the U.S. fusion program grew realities of fusion power instead of the ab- rapidly. Between 1972 and 1979, the fusion pro- stractions of plasma physics. ● gram’s budget increased more than tenfold. Engineering. A D-T experiment would in- Three forces spurred this growth. First, uncer- crease the amount of attention given to the tainty over long-range energy supply mobilized engineering aspects of a fusion reactor, de- public concern for finding new energy technol- parting from the near-total emphasis on ogies. Second, fusion energy, with its potentially plasma physics in fusion research to date. ● inexhaustible fuel supply, looked especially at- Politics. A D-T experiment would generate tractive. Third, the growth of the environmental actual fusion power for the first time. This movement and increasing opposition to nuclear demonstration would dramatize to the pub- fission technology drew public attention to fusion lic the capabilities of fusion in a more direct as an energy technology that might prove more way than simply achieving “breakeven-equiv- 19 environmentally acceptable. The fusion program alent” conditions. Moreover, this demon- capitalized on this public support; program leader- stration had to take place soon enough so ship placed a very high priority on developing that the fission breeder reactor would not be- a research plan that could lead to a demonstra- come established as the long-run energy option reactor. tion of choice. Many members of the fusion community op- From Research to Development? posed a D-T machine. They questioned whether The emphasis on building a demonstration re- the scientific principles underlying tokamak oper- actor dramatically changed the fusion program. ation were sufficiently known to take such a ma- Previous fusion program plans had called for jor step. Moreover, many felt that it was not nec- “breakeven-equivalent” to be demonstrated in essary to construct an experiment at this point a device containing only deuterium, to avoid the in the research program that would involve radio- complications introduced by use of tritium.17 The activity and thus more complications and more new plans called for an experiment fueled with expense. deuterium and tritium (D-T), which would reach breakeven by actually generating fusion power. 18 Bromberg, Fusion, op. cit., PP. 204-205. 19’’Breakeven-equivaIent” is the attainment of plasma conditions in a deuterium-only plasma equivalent to those that, in a D-T 1 ~ritiu m is radioactive and difficu It to work with. More signifi- plasma, would produce breakeven. Breakeven-equivalent does not cantly, its use in fusion experiments generates neutrons that make require use of radioactive tritium and does not produce the neu- materials in the device radioactive. tron radiation generated in a breakeven D-T plasma.

Ch. 3.—History of Fusion Research ● 47

Photo credit: Princeton Plasma Physics Laboratory

The Tokamak Fusion Test Reactor at Princeton Plasma Physics Laboratory.

In mid-1 973, senior fusion researchers, fusion breakeven experiment, the Tokamak Fusion Test program managers, and outside observers evalu- Reactor (TFTR), to be constructed at the Prince- ated the plans to accelerate building a D-T ma- ton Plasma Physics Laboratory. chine. They concluded: 1 ) that scientific questions program organization also changed when Con- should be answered in deuterium experiments, gress abolished the AEC in 1974 and transferred which would be simpler and cheaper to build its energy research programs to the Energy Re- than machines using tritium, but 2) that a search and Development Administration. ERDA burning experiment should be conducted on an was a new agency with a broad mission in energy accelerated schedule. research. It assumed management of AEC’s nu- During this period, congressional and public clear fission and fusion programs, as well as pro- concern about energy supply was increasing, grams in solar and renewable technologies, fos- and, in June 1973, president Nixon announced sil fuels, and conservation. his intention to nearly double the budget proposed for energy research over the next 5 years. Concept Competition By June 1974, the funding increases necessary to pursue accelerated development of fusion were The expansion of the tokamak program in- appropriated. Planning began for a D-T burning creased competition for funds among proponents 48 ● Starpower: The U.S. and the International Quest for Fusion Energy of alternate confinement concepts. Most fusion Systems Studies community leaders believed that the fusion pro- In addition to experiments on confinement gram could not command the budget required concepts, fusion program managers in the 1970s to construct more than one additional TFTR-class began to consider design attributes of fusion re- experiment. Thus, there was some concern about actors in a systematic way. Scientists and engi- the role of the three remaining major fusion lab- neers began to address the engineering problems oratories. Oak Ridge National Laboratory, which that various confinement methods posed for re- had competed unsuccessfully with Princeton to actor design, and “reactor relevance” soon be- construct the tokamak breakeven experiment, came a driving force for additional research. Sus- had tokamak experience that would be needed tained and serious interest in these design studies, to support the Princeton experiment. The future also called systems studies, attracted the atten- was more uncertain for the non-tokamak re- tion of people outside the fusion community. search programs at Los Alamos and Lawrence Several individuals in electric utilities began to Livermore national laboratories. follow fusion closely, and the utility research con- Between the major concepts investigated at sortium, the Electric Power Research Institute these two labs, the “magnetic mirror” at Liver- (EPRI), established a Fusion Advisory Committee. more was selected over the “theta pinch” at Los Alamos to become the principal alternative to the World Effort tokamak. Livermore had constructed a series of During the 1970s, the U.S. fusion program led mirror devices during the 1960s and 1970s, and, the world. It had the greatest breadth and depth in 1976, its proposal to build a greatly scaled-up of confinement concepts under investigation, and Mirror Fusion Test Facility (MFTF) was approved. its attention to fusion systems and technology was After design and construction of MFTF were unmatched. However, programs in the Soviet underway, researchers developed a design inno- Union, Japan, and Western Europe grew during vation that could improve the performance of the the 1970s. Each program made plans to build a mirror concept. This idea was tested by building TFTR-class tokamak to reach breakeven-equiva- the Tandem Mirror Experiment (TMX) and found Ient conditions: the Joint European Torus (JET) in to be valid. Even so, the improvement was too Europe, JT-60 in Japan, and the T-15 tokamak in small to justify changing the MFTF design, so con- the Soviet Union. All of these machines except struction proceeded as originally planned. the T-1 5 are now operational. The international Livermore scientists then proposed another in- aspects of fusion research are discussed more novation that seemed to have the potential to fully in chapter 7. make a mirror reactor a viable competitor to a tokamak reactor. This time, the gain appeared Program Reorientation to be sufficiently great to warrant modifying the In 1977, president Carter incorporated the func- MFTF design, more than tripling its size. More- tions of ERDA, including the fusion program, into over, Livermore scientists had so much confi- a new agency, the Department of Energy. DOE dence in the theory that they proposed to start reemphasized support for nuclear fission, primar- modifications to MFTF before testing the new ily due to concern over the proliferation aspects concept experimentally. In 1979, they proposed of breeder reactors, and it increased support for to modify both TMX and MFTF in parallel, with solar energy, conversion from oil and gas to coal, the smaller TMX-Upgrade (TMX-U) to be com- and conservation .*0 pleted and operated to verify the new concept at a time when substantial work still remained to The first director of the DOE Office of Energy be done on the revised MFTF (now called MFTF- Research believed that the budget for the fusion B). In this way, any changes found to be neces- program was too large for fusion’s uncertain pros- sary as a result of tests on TMX-U could be in- pects. In his capacity as scientific advisor to the corporated directly into MFTF-B during its construction. Construction of MFTF-B began in 1981. 2oBrom&rg, Fusion, op. cit., P. 235.

Ch. 3.—History of Fusion Research . 49

Photo credit: Lawrence Livermore National Laboratory Installation of one of the end cell magnets for MFTF-B. Another view of this magnet is shown on p. 87.

Secretary of Energy, he commissioned a high- suit of the panel’s findings, the Secretary of Energy Ievel outside review of the program, a review that subsequently reaffirmed the near-term planning he expected would recommend cutting the bud- of the fusion program. With few modifications, get and relaxing the program’s emphasis on an DOE management supported maintaining current early demonstration reactor.21 On the contrary, budget levels, pushing towards early completion the review panel praised the management and and operation of TFTR, maintaining ongoing fu- scientific achievements of the fusion program and sion system studies, and accelerating fusion tech- did not recommend budget cuts. Mostly as a re- nology development. Although the short-term fusion program plans Z’ Ibid., p. 236. continued much as before, the long-term strat- 50 . Starpower: The U.S. and the International Quest for Fusion Energy egy under DOE in the late 1970s differed from program over the previous few years and found the ERDA strategy earlier in the decade. The re- many accomplishments that justified the panel’s view panel stated in its report that “the first ob- confidence that breakeven was near. The panel jective of the program must be to determine the concluded that: highest potential of fusion as a practical source . . . the United States is now ready to embark on of energy.” This meant not proceeding with con- the next step toward the goal of achieving eco- struction of a tokamak device to succeed TFTR nomic fusion power: Exploration of the engineer- until “a convincing case should be made that ing feasibility of fusion .25 Tokamaks can be engineered into attractive energy producers.” 22 In effect, the committee recom- The panel proposed that the program begin mended that the tokamak program be held up planning a Fusion Engineering Device (FED), at the TFTR stage until other devices, such as the which would provide a focus for development mirror, could be compared to it at relatively of reactor-relevant technologies and components, equivalent stages of development. enable researchers to evaluate safety issues associated with fusion power, and facilitate investi- Under DOE, the fusion program did not have gation of additional plasma physics issues. This the sense of urgency that was so important earlier device would be built and operated as part of a in the decade. Fusion could not mitigate the broad program of engineering experimentation short-term oil and gas crisis facing the United and analysis to be conducted by a new fusion States. Furthermore, as a potentially inexhausti- engineering center. The ERAB panel recognized ble long-range energy source (along with solar that planning and constructing FED would require energy and the fission breeder reactor), fusion a doubling of the fusion budget over the next 5 was not thought needed until well into the next to 7 years, and it recommended this budget in- century. Therefore, there appeared to be no com- crease. pelling reasons to develop a fusion demonstration plant rapidly .23 The Magnetic Fusion Energy Engineering Act, 1980 The 1980s: Leveling Off Many of the recommendations of the ERAB The fusion program has continued to make panel were incorporated into the Magnetic Fu- substantial technical progress during the 1980s. sion Energy Engineering Act (MFEE Act), passed Several world machines have the potential to by Congress in September 1980.26 Passage of the achieve breakeven, or breakeven-equivalent con- MFEE Act was largely a result of Representative ditions, within the decade; in addition, significant Mike McCormack’s (D-Washington) efforts. It advances in plasma physics and fusion technol- urged acceleration of the national effort in mag- ogy continue.24 netic fusion research, development, and demonstration activities. Like the ERAB report, the act ERAB Review of the Fusion Program, recommended creation of a Magnetic Fusion 1980 Engineering Center to coordinate major magnetic fusion engineering devices. In 1980, the Energy Research Advisory Board (ERAB), a standing committee that advises the The MFEE Act recommended that funding lev- Secretary of Energy, established a committee to els for magnetic fusion be doubled (in constant review DOE’s fusion program. The committee’s dollars) within 7 years. However, it did not ap- report evaluated technical progress in the fusion 2t’’Report on the Department of Energy’s Magnetic Fusion Pro- gram,” prepared by the Fusion Review Panel of the Energy Research zzFOster Committee, Final Report (DOE/ER-OO08, June 1978). Advisory Board, August 1980, as quoted in Fusion Energy: An Over- Quoted in T,A. Heppenheimer, The Man-Made Sun, op. cit., pp. view of the Magnetic Confinement Approach, /ts Objectives, and 201-202. Pace, a report prepared for the Subcommittee on Energy Research zjBromberg, Fusion, op. cit., p. 247. and Production, House Committee on Science and Technology, 24ManY of the technica[ accomplishments in the fusion program 96th Cong., 2d sess., Serial GGG, December 1980, p. 133. and the tasks still to be done are discussed in ch. 4 of this assessment. Zbpublic Law 96-386, signed into law on OCt. 7, 1980. Ch. 3.—History of fusion Research ● 51

propriate these increases, and there was no fol- phases of the MFEE Act within the fiscal con- low-up. in effect, the act indicated that Congress straints imposed by the Reagan Administration. considered the fusion program worthwhile and The plan also sought to preserve the role of in- deserving of support but was unable or unwilling ternational leadership in fusion for the United to make a long-term commitment to substantially States. increase expenditures. Actual appropriations in The CPMP had a clear reactor emphasis, but the 1980s did not grow at the level specified in it was also consistent with Reagan Administration the act and in fact continued the drop in con- philosophy towards development. The plan ex- stant dollar funding that began in 1977. plicitly ruled out government construction of a demonstration reactor, stating that: Reagan Administration Budgets and Philosophy The primary objectives of the [fusion] program are designed to provide a technical basis for de- Energy R&D budgets underwent radical cuts in cisions by the private sector on whether to pro- 1981 at the beginning of the Reagan Administra- ceed with the commercial development of fusion tion. The Reagan Administration stated that de- energy. Proceeding with a Federally funded dem- velopment activity belonged in the private sec- onstration plant is not part of this plan .28 tor and that the government could encourage this The CPMP stated that within the next decade, activity most effectively by staying out of it. Ac- the fusion program would select a plasma con- cordingly, DOE research budgets for solar energy, finement concept to undergo further develop- fossil fuel technology, fission technology, and ment as a power reactor core. The plan defined energy conservation—those energy areas most two stages that would permit a decision to be heavily weighted towards development or dem- made to build a demonstration reactor by the onstration, as opposed to research—were sub- year 2000. stantially reduced. In contrast, the Reagan Ad- ministration continued to support government funding for long-term, high-risk programs–e.g., ERAB Review of the Fusion Program, fusion research–that would not attract private 1983 investment. Therefore, although the fusion re- An additional provision of the MFEE Act estab- search budget has decreased in the 1980s, it has lished a technical panel on magnetic fusion as not been cut as severely as some of DOE’s other an ERAB subcommittee. The subcommittee was energy R&D programs. mandated to conduct a triennial review of the fusion program, with the first such review to be With annual budget appropriations falling, the conducted in 1983. ambitious plans of the 1970s, which culminated in the MFEE Act of 1980, could not be imple- The subcommittee’s report29 recognized that mented. Thus, the fusion program has had to budgetary constraints had made it impossible to modify its program strategy; subsequent plans at- accomplish the goals of the MFEE Act on the time- tempted to identify the most important aspects scale envisioned. The panel recommended that of the fusion program to pursue. DOE abandon the CPMP, stating that it would force the program to make a choice between tan- The Comprehensive Program Management Plan, 1983 z7Compreben5;ve Program Management Plan (CPMP) for Mag- The MFEE Act required that the Secretary of netic Fusion Energy, June 1983. Submitted to the House Science and Technology Committee by the Secretary of Energy pursuant Energy prepare a Comprehensive Program Man- to the Magnetic Fusion Energy Engineering Act. agement Plan (CPMP) outlining the fusion pro- Zslbid., p. 2. gram’s strategy and schedule. This plan was com- 29 Energy Research Advisory Board, Magnetic Fusion Energy Re- search and ~eve/opment, Final Report prepared by the Technical pleted by DOE and transmitted to Congress in Panel on Magnetic Fusion of the Energy Research Advisory Board, 1983.27 The CPMP attempted to satisfy the em- DOE/S-0026, January 1984. 52 ● Starpower: The U.S. and the International Quest for Fusion Energy

dem mirror and tokamak confinement concepts international leadership, for the U.S. fusion before constructing another major device, a choice program. that in turn would require delaying progress on the tokamak. The paneI also noted that the CPMP’s ERAB Review of the Fusion Program, schedule called for construction of a next-gen- 1986 eration engineering test reactor—a major facility The second triennial review of the magnetic fu- intended to explore engineering aspects of fusion sion program was completed by the ERAB sub- –before necessary technology development committee on magnetic fusion in November could be completed. 1986. 32 The subcommittee endorsed the fusion As a revised program strategy, the ERAB panel program’s direction, strategy, and plan and re- recommended that a tokamak follow-up device affirmed the need to investigate fusion energy as to TFTR be built to study scientific issues. The “an attractive energy source of great potential for panel recommended that the reactor engineer- the future.” The panel specifically considered two ing efforts be postponed until additional resources issues of great importance to the future direction were available, and that a strong and innovative of the program: 1 ) the construction of a Compact base program be maintained in plasma physics, Ignition Tokamak (CIT) as an experiment that technology development, and alternative con- would extend scientific understanding beyond finement concepts. that obtainable in TFTR; and 2) the role of international collaboration in an engineering test re- The Magnetic Fusion Program Plan, 1985 actor project. DOE revised its program plan in response to The Compact Ignition Tokamak.–Several the criticisms of the ERAB subcommittee. In 1985, years of TFTR operation have shown continued DOE issued the Magnetic Fusion Program Plan progress both in understanding and in achieving (MFPP), which stated that “the goal of the mag- confinement. TFTR has attained Lawson param- netic fusion program is to establish the scientific eters above 1014 second-particles per cubic centi- and technological base required for fusion meter (a factor of 10,000 improvement over energy. ”3° Unlike the CPMP, however, the MFPP 1950’s results) and ion temperatures of 20,000 lessened the reactor emphasis, concentrated electron volts (a factor of 200 improvement). At- more on the science and engineering require- tainment of actual breakeven when tritium is in- ments, and relaxed the schedule for fusion de- troduced seems highly probable, and the fusion velopment: community has been actively exploring options for a next step beyond TFTR. This has led to DOE The schedule for completing magnetic fusion recommendations for CIT construction. development is directly related to the technical, economic, and political uncertainties associated CIT will explore the physics associated with ig- with energy supply, which are likely to exist for nited plasmas. The ERAB subcommittee concluded several decades. The Magnetic Fusion Program that CIT is “an essential and timely project,”33 Plan is a strategy for solving fusion’s technical both because it will address a fundamental physics problems within a time frame keyed to resolution 31 issue and because it will provide technical infor- of other areas of energy development. mation and experience valuable to the engineer- Like the CPMP, the MFPP did not extend to ing test reactor. ERAB recommended providing construction of a fusion demonstration reactor. an increment to the magnetic fusion program The plan laid out key technical issues that must budget to prevent funding for CIT from being be resolved by the fusion program and set out taken from other program areas. The construc- a goal of international collaboration, rather than tion cost of CIT, in 1986 dollars, has been esti-

30U. S. Department of Energy, Office of Energy Research, A4ag- 32 Energy Research Advisory Board, Repofl of the Technical pane/ rretic Fusion Program Han, DOE/ER-0214, February 1985, Execu- on Magnetic Fusion of the Energy Research Advisory Board, pre- tive Summary. pared for the U.S. Department of Energy, November 1986. 311 bid . JJlbid,, p. 1. Ch. 3.—History of Fusion Research . 53 mated at $300 million for the facility, plus about experimental facility designed to explore engi- $60 million for diagnostic equipment and asso- neering and technological issues relevant to fu- ciated R&D. This estimate assumes that the fa- sion reactors. The ERAB subcommittee stated that cility will be located at Princeton Plasma Physics “the United States should consider reaching out Laboratory, where, according to DOE, site credits to other nations to establish a multinational struc- will save about $200 million.34 ture for fusion relationships. ”35 However, ERAB also recognized the inherent complexity and un- The Role of International Collaboration.–The certainty of major international collaborations, subcommittee endorsed current DOE efforts in pointing out that “some realistic consideration international collaboration. In particular, the must be given to the possibility that international panel supported the idea of constructing an inter- collaboration on a large scale may not come national engineering test reactor. As envisioned, 36 about.” At present, DOE is investigating the po- this device—called the International Thermonu- tential of undertaking a joint planning activity clear Experimental Reactor (lTER)—will be a large with the other major fusion powers on a conceptual design for ITER, along with supporting R&D. ldlbid., p. 11, site credits refer to the savings that result from constructing the project at a location that already has some of the Jslbid., p. 14. needed equipment in place. By constructing CIT at Princeton, the JGlbid,, p. 1 T. A detailed discussion of international collabora- experiment will be able to take advantage of the existing T~R power tion on ITER and other projects can be found in ch. 7 of this supplles and other equipment. assessment. Chapter 4

Fusion Science and Technology Chapter 4 Fusion Science and Technology

Great progress has been made over the past for lack of funds; science had a higher funding 35 years of fusion research. Nevertheless, many priority. In addition, fusion technologies that re- scientific and technological issues have yet to be quire a source of fusion power to be tested and resolved before fusion reactors can be designed developed have had to await a device that could and built. Fundamental questions in plasma sci- supply the power. Until recently, the fusion science remain, especially involving the behavior ence database has not been sufficient to permit of plasmas that actually produce fusion power. such a device to be designed with confidence. Other plasma science questions involve the be- This chapter discusses the various confinement havior and operation of the various confinement concepts under study, the systems required in a concepts that might be used to hold fusion fusion reactor, and the issues that must be re- plasmas. solved before such systems can be built. It then To date, engineering issues have not been stud- outlines the research plan required to resolve ied as extensively as plasma science issues. For these issues and estimates the amount of time and many years, engineering studies were deferred money that such a research plan will take.

CONFINEMENT CONCEPTS’

Most of the fusion program’s research has fo- Table 4-1 lists the principal confinement schemes cused on different magnetic confinement con- presently under investigation in the United States cepts that can be used to create, confine, and and classifies them according to their level of de- understand the behavior of plasmas. In all of velopment. The concepts are described in the fol- these concepts, magnetic fields are used to con- lowing section. fine the plasma; the concepts differ in the shape At this stage of the research program, it is not of the fields and the manner in which they are known which confinement concept can best generated. These differences have implications form the basis of a fusion reactor. The tokamak for the requirements, complexity, and cost of the is much more developed than the others, and engineering systems that surround the plasma. tokamaks are expected to demonstrate the basic scientific requirements for fusion within a few

1 Th is chapter d Iscusses on Iy magnetic confinement approaches. years. However, several alternate concepts are Other approaches to fusion are discussed In app. B. The concepts under investigation in order to gain a better un- mentioned In this section are described in greater detail in pp. 156- derstanding of the confinement process and to 204 ot’ Physics Through the 19905: P/asmas and F/uids, by the Na- tional Research Council (Wa~hington, DC: National Academy Press, explore possibilities for improving reactor per- 1 986). formance.

Table 4-1 .—Classification of Confinement Concepts

Well-developed Moderately developed Developing knowledge base knowledge base knowledge base Conventional tokamak Advanced tokamak Spheromak Tandem mirror Field-reversed configuration Stellarator Dense Z-pinch Reversed-field pinch SOURCE Adapted from Argonne National Laboratory, Fusion Power Program, Technical Planning Activity Final Report, commissioned by the U S Department of Energy, Off Ice of Fusion Energy, AN UFPP-87-1, January 1987, p 15

57 58 ● Starpower: The U.S. and the International Quest for Fusion Energy

The major scientific questions to be answered Figure 4-1 .—Tokamak Magnetic Fields for each confinement approach are whether and with what confidence the conditions necessary for a sustained, power-producing fusion reaction can be simultaneously satisfied in a commercial- scale reactor. Much of the experimental and theoretical work in confinement studies involves the identification and testing of scaling relationships that predict the performance of future devices from the results of previous experiments. ideally, such scaling models should be derivable from the basic laws of physics. However, the behavior of plasmas confined in magnetic fields is so complicated that a general theory has not yet been found. With some simplifying assumptions, limited theoretical models have been developed, but they are not broad enough to extrapolate the behavior of a concept to an unexplored range. Without a sound theoretical base, the risk of taking too large a step is great. A series of intermediate-scale experiments is needed to bridge the gap between concept development and a full- scale reactor. Even with the tokamak—the most studied confinement concept–scaling properties are not fully understood. Although tokamaks have attained by far the best experimental performance of any confinement concept, no proven theoretical explanation of how that performance scales with parameters such as size, magnetic field, and plasma current has yet been derived. Without a complete theoretical basis, “empirical” scaling relationships deduced from past observations must be used. Such empirical relationships may well prove sufficient for designing a machine capable of forming reactor-scale plasmas before a fundamental theoretical understanding of tokamak behavior is reached.

SOURCE: Princeton Plasma Physics Laboratory Information Bulletin NT-1: Fu- “Closed” Concepts sion Power, 1984, p. 4. In “closed” magnetic confinement configura- field. This field is generally created by external tions, the plasma is contained by magnetic lines magnet coils, called toroidal field coils, through of force that do not lead out of the device. Closed which the plasma torus passes. A magnetic field configurations all have the basic shape of a dough- perpendicular to the toroidal field, encircling the nut or inner tube, which is called a “torus. ” A torus the short way, is called a “poloidal” field. magnetic field can encircle a torus in two differ- This field is generated by electrical currents in- ent directions (figure 4-1 ). A field running the long duced to flow within the plasma itself. Together, way around the torus, in the direction that the toroidal and poloidal magnetic fields form the to- tread runs around a tire, is called a “toroidal” tal magnetic field that confines the plasma. Ch. 4.—Fusion Science and Technology ● 59

Conventional Tokamak shaped plasmas according to this principle, Other variants on tokamak design would permit more In a tokamak, the principal confining magnetic compact fusion cores to be constructed, which field is toroidal, and it is generated by large ex- could lead to less expensive reactors; these im- ternal magnets encircling the plasma. This field provements are under study. alone, however, is not sufficient to confine the plasma. A secondary poloidal field, generated by Still other improvements would permit toka- plasma currents, is also required. The combina- maks to run continuously. The technique typi- tion of poloidal and toroidal fields produces a to- cally used today to drive the plasma current in tal field that twists around the torus and is able a tokamak can be run only in pulses. Technol- to confine the plasma (figure 4-1). ogies for driving continuous, or steady-state, plasma currents are being investigated at a num- The tokamak concept was developed in the So- ber of different experimental facilities. viet Union, and, since the Iate 1960s, it has been the primary confinement concept in all four of the world’s major fusion research programs. It Stellarator has also served as the principal workhorse for The stellarator is a toroidal device in which developing plasma technology. The scientific both the toroidal and poloidal confining fields are progress of the tokamak is far ahead of any other generated by external magnets and do not de- concept. Major world tokamaks are listed in ta- pend on electric currents within the plasma. The ble 4-2. external magnets are consequently more complicated than those of a tokamak (figure 4-2). Advanced Tokamak However, the absence of plasma current in a stel- Various features now under investigation may Iarator enables steady-state operation to be substantially improve tokamak performance. Mod- achieved more directly without the need for cur- ifying the shape of the plasma cross-section can rent drive. increase the maximum plasma pressure that can be confined with a given magnetic field. The The stellarator concept was invented in the Doublet II I-D (D III-D) tokamak at GA Technol- United States. After the discovery of the tokamak ogies and the Princeton Beta Experiment Modifi- in the late 1960s, however, the United States con- cation (PBX-M) tokamak at Princeton Plasma verted its stellarators into tokamaks. The stella- Physics Laboratory are being used to investigate rator concept was kept alive primarily by research

Table 4-2.—Major World Tokamaksa

Device Location Status JET ...... European Community (United Kingdom) Operating D III-D ...... United States (GA Technologies) Operating Alcator C-Mod ...... i ...... United States (MIT) Under construction T-14 ...... U.S.S.R. (Kurchatov) Under construction TFTR ...... United States (PPPL) Operating JT-60 ...... Japan (Naka-machi) Operating T-15 ...... U.S.S.R. (Kurchatov) Under construction ASDEX-Upgrade ...... Federal Republic of Germany (Garching) Under construction Tore Supra...... France (Cadarache) Under construction Frascati Tokamak Upgrade ...... Italy (Frascati) Under construction PBX-M ...... United States (PPPL) Under construction TEXTOR ...... Federal Republic of Germany (Julich) Operating aListed in decreaing order of plasma current, one of the many parameters that determines tokamak capability. NO single factor by itself measures capability well; current is used here only to give a rough distinction between those devices at the top of the list and those at the bottom. Ranking by size, magnetic field, or other parameter would rearrange the list somewhat. NOTE: This table includes only the largest tokamaks. The World Survey of Activities in Corrtrolled Fusion Research, 1986 Edition (published in Nuclear Fusion, Special Supplement 1966) lists a total of 77 existing and proposed tokamaks at 54 sites in 26 countries. SOURCE Office of Technology Assessment, 1987

60 ● Starpower: The U.S. and the International Quest for Fusion Energy

Figure 4-2. —Magnet Coils for the Advanced Toroidal Facility, A Stellarator

SOURCE Oak Ridge National Laboratory

in the Soviet Union, Europe, and Japan, and, due the new Japanese device would be the largest to good results, the United States has recently re- operational non-tokamak fusion experiment, vived its stellarator effort. Stellarators today perform as well as comparably sized tokamaks. Reversed-Field Pinch Major world stellarator facilities that are oper- In a reversed-field pinch, the toroidal magnetic ating or under construction are listed in table 4-3. field is generated primarily by external magnets Not shown on the table is the Large Helical Sys- and the poloidal field primarily by plasma cur- tem proposed to be built in Japan at a cost sev- rents. The toroidal and poloidal fields are com- eral times that of the largest stellarator machine parable in strength, and the toroidal field reverses now u nder construction; if built and operated, direction near the outside of the plasma, giving

Table 4-3.—Major World Stellaratorsa

Device Location Status ATF ...... United States (ORNL) Under construction Wendelstein VII-AS ...... Federal Republic of Germany (Garching) Under construction URAGAN-2M ...... U.S.S.R. (Kharkov) Under construction Heliotron-E...... Japan (Kyoto University) Operating URAGAN-3 ...... U.S.S.R. (Kharkov) Operating CHS ...... Japan (Nagoya University) Under construction L-2 ...... U.S.S.R. (Lebedev) Operating H-1 ...... Australia (Canberra) Under construction aListed in order of decreasing stored magnetic energy, a parameter which in turn depends both on magnetic field strength and plasma

SOURCE Office of Technology Assessment, 1987; from data provided by Oak Ridge National Laboratory,

Ch. 4.—Fusion Science and Technology “ 61

Figure 4-3.— Reversed. Field Pinch without the complex and costly external heating Toroidal field systems required by tokamaks. windings Los AIamos National Laboratory in New Mex- ico is the center of U.S. reversed-field pinch research. The Confinement Physics Research Fa- cility (CPRF) to be built there will hold the largest reversed-field pinch device in the United States. A variant of the reversed-field pinch, the Ohmi- cally Heated Toroidal Experiment, or OHTE, was built at GA Technologies in San Diego, Califor- nia. Reversed-field pinch research is also conducted in both Europe and Japan. Table 4-4 lists the major world reversed-field pinches.

Spheromak The spheromak is one of a class of less developed confinement concepts called “compact toroids,” which do not have toroidal field coils SOURCE: Adapted from National Research Council, Physics Through the 1990s: Plasmas and FluIds (Washington, DC: National Academy Press, 1988). linking the plasma loop and therefore avoid the engineering problem of constructing rings locked within rings. Conceptually, if the torodial field the concept its name (see figure 4-3). In a toka- coils and inner walls of a reversed-field pinch mak, the toroidal field dominates and points in were removed and the central hole were shrunk the same direction throughout the plasma. to nothing, the resultant plasma would be that The reversed-field pinch generates more of its of the spheromak. Its overall shape is spherical; magnetic field from plasma currents and less from although the internal magnetic field has both external magnets, permitting its external magnets toroidal and poloidal components, the device has to be smaller than those of a comparably per- no central hole or external field coil linking the forming tokamak. The nature of the magnetic plasma (figure 4-4). The plasma chamber lies en- fields in a reversed-field pinch may also permit tirely within the external magnets. If the sphero- steady-state plasma currents to be driven in a mak can progress to reactor scale, its small size much simpler manner than is applicable in a toka- and simplicity may lead to considerable engineer- mak. Moreover, a reversed-field pinch plasma ing advantages. However, the present state of may be able to heat itself to reactor temperatures knowledge of spheromak physics is rudimentary.

Table 4.4.—Major World Reversed-Field Pinchesa

Device Location Status CPRF ...... United States (LANL) Under construction RFX ...... Italy (Padua) Under construction OHTE ...... United States (GA Technologies) Operating HBTX 1-B ...... United Kingdom (Culham) Operating ZT-40M . . . ! ...... United States (LANL) Operating MST ...... United States (University of Wisconsin) Under construction ETA BETA 11 ...... , Italy (Padua) Operating Repute I...... Japan (Tokyo University) Operating TPE-1RM(15) ...... Japan (Tsukuba University) Operating STP-3M ...... Japan (Nagoya University) Operating aListed in order of decreasing plasma current, a rough measure of reversed-field pinch performance. SOURCE: Office of Technology Assessment, 1987; from data supplied by the Los Alamos National Laboratory.

62 “ Starpower: The U.S. and the International Quest for Fusion Energy

Figure 4-4.—Spheromak spheromak research effort takes place at the Uni- versity of Maryland. Spheromaks also are being studied in Japan and the United Kingdom. Ma- jor world spheromak devices are listed in table 4-5.

Field= Reversed Configuration The field-reversed configuration (FRC) is another form of compact toroid. Despite the similar name, it does not resemble the reversed-field pinch. It is unusual among closed magnetic confinement concepts in providing confinement with only poloidal fields; the FRC has no toroidal field. The plasma is greatly elongated in the poloidal direction and from the outside has a cylindrical shape (figure 4-5). Like the spheromak, the FRC does not have external magnets penetrating a hole in its center; all the magnets are located outside the cylindrical plasma. The FRC also has the particular vir- tue of providing extremely high plasma pressure for a given amount of magnetic field strength. if its confining field is increased in strength, the FRC plasma will be compressed and heated. Such heating may be sufficient to reach reactor conditions, eliminating the need for external heating. Existing FRC plasmas are stable, but whether stability can be achieved in reactor-sized FRC plasmas is uncertain. A new facility, LSX, is under construction at Spectra Technologies in Bellevue, Washington, to investigate the stability of larger plasmas. U.S. FRC research started at the Naval Research Spheromak research at Los Alamos National Laboratory in Washington, D. C., in the late 1960s. Laboratory was terminated in 1987 due to fiscal Increased effort in the United States in the late constraints, and another major U.S. device at 1970s, centered at Los Alamos, was undertaken Princeton Plasma Physics Laboratory is to be ter- largely in response to experimental results ob- minated in fiscal year 1988. The remaining U.S. tained earlier in the decade from the Soviet Union

Table 4-5.—Major World Spheromaksa

Device Location Status Ch. 4.—Fusion Science and Technology “ 63

Figure 4-5.— Field-Reversed Configuration Magnetic Mirrors Fusion plasmas can be confined in an open- ended tube by strengthening, and thereby compressing, the magnetic fields near the ends. Strengthening the magnetic field near the ends “reflects” plasma particles back into the center much as narrowing the ends of a sausage helps keep in the meat. However, the ends of a sim- p/e magnetic mirror (figure 4-6a) are not otherwise sealed. Just as the meat eventually forces its way out of an unsealed sausage when squeezed, a simple magnetic mirror cannot confine a plasma well enough to generate fusion power. In addition, simple mirrors are usually unstable, with the plasma as a whole tending to slip out sideways. A variation of the simple mirror is the minimum-B mirror (figure 4-6 b), one version of which SOURCE: National Research Council, Physics Through the 1990s: Plasmas and Fluids (Washington, DC National Academy Press, 1988), uses a coil shaped like the seam on a baseball to create a magnetic field that is lowest in strength at the center and increases in strength towards the outside. Particles leaving the center tend to and the Federal Republic of Germany. Soviet re- be reflected back by the increasing magnetic field search has continued, but German and British re- at the outside, just as particles leaving the sim- search programs have stopped. Meanwhile, a ple mirror tend to be reflected back at the ends. program in Japan has begun. Major field-reversed This configuration is stable, and there is no ten- configuration experiments around the world are dency for the plasma as a whole to escape. How- listed in table 4-6. ever, despite these improvements, the minimum- B mirror cannot confine a plasma well enough "Open” Concepts to generate net fusion power. plasmas in open magnetic confinement devices The tandem mirror (figure 4-6c) improves the are confined by magnetic fields that do not close simple magnetic mirror by utilizing additional back on themselves within the device but rather mirrors to improve the plugging at each end. extend well outside the device. Since plasma par- These plugs, called end cells, are themselves mag- ticles can easily travel along magnetic field lines, netic mirrors. Rather than trapping the main some additional mechanism is required to reduce plasma, the end cells hold particles that gener- the rate at which plasma escapes out the ends ate an electric field. This electric field, in turn, of an open confinement device. keeps the plasma in the central cell from escap-

able 4.6.—Major World Field-Reversed Configurationse

Device Location Status LSX ...... United States (Spectra Technologies) Under construction FRX-C ...... United States (LANL) Operating BN, TOR ...... U.S.S.R. (Kurchatov) Operating TRX-2 ...... United States (Spectra Technologies) Operating OCT, PIACE ...... Japan (Osaka University) Operating NUCTE ...... Japan (Nihon University) Operating aListed approximately by decreasing order of size; similarly sized devices at the same institution are listed together. SOURCE Office of Technology Assessment, 1987; from information supplied by the Los Alamos National Laboratory.

64 ● Starpower: The U.S. and the International Quest for Fusion Energy

Figure 4-6.—Magnetic Mirrors

(a) Simple mirror (b) Minimum-B mirror

Plasma /

SOURCE: Lawrence Livermore National Laboratory, “Evolution of the Tandem Mirror,” Energy and Technology Review, November 1986 ing. While particle losses from the end cells are Dense Z= Pinch high, these losses can be compensated by inject- In this concept, a fiber of frozen deuterium- ing new particles. tritium fuel is suddenly vaporized and turned into The tandem mirror concept was developed plasma by passing a strong electric current through simultaneously in the United States and the So- it. This current heats the plasma while simultane- viet Union in the late 1970s. The Mirror Fusion ously generating a strong magnetic field encircling Test Facility B (MFTF-B), located at Lawrence the plasma column (figure 4-7), “pinching” it long Livermore National Laboratory in California, is enough for fusion reactions to occur. Many de- the largest mirror device in the world and the vices investigated in the earliest days of fusion largest non-tokamak magnetic confinement fu- research in the 1950s operated in a similar man- sion experiment. Budget cuts, however, forced ner, but they were abandoned because their MFTF-B to be moth balled before it could be used plasmas had severe instabilities and were una- experimentally. The Tandem Mirror Experiment ble to approach the confinement times needed Upgrade (TMX-U) at Livermore, a smaller version to generate fusion power. of MFTF-B, was terminated as well, and the TARA device at the Massachusetts Institute of Technol- The dense z-pinch differs from the 1950s pinches ogy will be shut down in 1988. At that point, in several important aspects that, as calcuIations Phaedrus at the University of Wisconsin will be and experiments have shown, improve stability. the only operational U.S. mirror machine. Mir- Crucial to the modern experiments are precisely ror research is still conducted in the Soviet Union controlled, highly capable power supplies that and Japan. Table 4-7 presents a list of major world would have been impossible to build with 195os tandem mirror facilities. technology, and the use of solid, rather than gase- —

Ch. 4.—Fusion Science and Technology ● 65

Table 4-7.—Major World Tandem Mirrorsa

Device Location Status MFTF-B ...... United States (LLNL) Moth balled TMX-U ...... United States (LLNL) Mothballed Gamma-10 . . . .Japan (Tsukuba University) Operating TARA ...... United States (MIT) To be terminated, fiscal year 1988 Phaedrus . . . . . United States (University of Wisconsin) Operating Ambal M . . . . . USSR (Novosibirsk) Under construction aListed in decreasing order of size. SOURCE: Office of Technology Assessment, 1987; from data supplied by the Lawrence Livermore National Laboratory.

Figure 4-7. —Dense Z-Pinch ● Many fusion concepts are under study because the frontrunner tokamak, while likely to be scientifically feasible, may yet be found weak in some critical area or less economically attractive than alternatives. Features being studied in alternate concepts include eased conditions for steady-state operation, reduced external magnet complexity and cost, and improved use of the magnetic field. Searching for optimum reactor configurations and developing further understanding of the fusion process mandate that the range of concepts under investigation not be prematurely narrowed. The tokamak concept is by far the most developed, and it has attained plasma conditions closest to those needed in a fusion reactor. At present and for the next several years, studies of reactor-like plasmas will be done with tokamaks because no other con- SOURCE: Office of Technology Assessment, 1987 cept has yet proven that it can reach reactor conditions. A number of other confinement OUS, fuel to initiate the discharge. However, it is concepts have features that might make much too early to tell whether this concept can them preferable to the tokamak if they are be developed successfully. If the concept can be capable of progressing to an equivalent stage developed, the device has the potential to be far of performance. It remains to be seen which smaller and far less expensive than devices based of these concepts will attain that perform- on other concepts. External magnets are not ance level, what their development will cost, needed since the plasma current supplies the en- and to what degree the tokamak concept it- tire confining field. Dense z-pinch research is tak- self will further improve. ing place in the United States at two facilities: the ● Different confinement studies complement Naval Research Laboratory and Los Alamos Na- each other. Knowledge obtained through re- tional Laboratory. search on a specific concept often can be generalized. Throughout the history of fusion research, plasma science issues originally in- Conclusions Concerning vestigated because of their relevance to a Confinement Approaches particular concept have become important to studies of other concepts as well. A number of general conclusions can be drawn ● A great deal of progress in understanding from studies of the confinement concepts that fusion plasmas and confinement concepts have evolved over the past 10 to 15 years: has been made to date. Many concepts 66 ● Starpower: The U.S. and the International Quest for Fusion Energy

studied earlier, such as the simple magnetic require study at greater levels of capability mirror, are no longer studied today because before their potential as reactor candidates they cannot compare attractively to improved can be assessed. Moreover, since this has or alternate concepts. At the same time, as largely been an empirical program, advanced in the case of the dense z-pinch, problems studies will require larger and increasingly once considered intractable may be solved more expensive facilities. Fiscal constraints with additional scientific understanding and will almost certainly require that not all of more advanced technology. the concepts be “promoted” to subsequent ● Research on all confinement concepts has stages of development. Criteria such as de- benefited from international cooperation. velopment cost, characteristics of the end Studies undertaken by different groups in product, and likelihood of success must be different countries enhance each other sig- developed for selecting which concepts are nificantly. Furthermore, advances by one to be pursued further. program have frequently stimulated addi- ● progress in fusion science depends on prog- tional progress in other programs. interna- ress in fusion technology. Time after time, tional cooperation in fusion research is dis- the exploration of new ranges of plasma be- cussed further in chapter 7. havior has been made possible by the devel- ● Not all confinement concepts can be development of new heating, fueling, and plasma oped to reactor scale. Promising concepts shaping technologies.

SCIENTIFIC PROGRESS AND REACTOR DESIGN Different Dimensions of Progress understanding of fusion technology and future societal needs improves. To form the basis of a viable fusion reactor, a confinement concept must meet two objectives. No matter how it is evaluated, reactor poten- First, it must satisfy scientific performance require- tial is a requirement that, along with scientific per- ments—temperature, density, and confinement formance, must be satisfied by at least one con- time—necessary for a plasma to produce fusion finement concept before fusion power can be power. progress towards those requirements is realized. Figure 4-8 shows two different paths by easy to measure. which a concept can develop toward commercial use. Along the “performance-driven” path, Second, a confinement concept must demon- a concept first demonstrates the ability to attain strate “reactor potential. ” Unlike scientific per- plasma parameters near those required to pro- formance, reactor potential is difficult to meas- duce fusion power; subsequently, innovations or ure. A viable reactor must be built, operated, and successive refinements show that the concept’s maintained reliably, and it must be economically, scientific capabilities can be used in a viable re- environmentally, and socially acceptable. While actor design. Alternatively, along the “concept- fusion’s acceptability in these respects depends improvement-driven” path, features that are at- on factors external to fusion technology, it also tractive in a fusion reactor—e.g., compact size, depends on the choice of confinement concept. ease of maintenance, simple construction, and reliable operation—are apparent before the sci- Each concept may have different advantages, entific performance necessary to produce fusion and, in the absence of quantitative measures, the power is demonstrated. process of i dentifying the concepts t hat offer t he most attractive reactors depends in large part on The actual development of any given confine- the innovation and technological optimism of the ment concept will fall somewhere between these reactor designer. Also, attributes of an attractive extremes. Development of the tokamak appears reactor can be identified today, but the relative to be closer to the performance-driven curve. Its importance of these attributes may change as our scientific performance, along with its use in de- Ch. 4.—Fusion Science and Technology ● 67

Figure 4-8.—Alternate Paths for Concept Development

SOURCE Adapted from Argonne National Laboratory, Technical Planning Activity: Final Report, commissioned by the U.S. Department of Energy, Office of Energy Research, AN L/FPP-87-1, January 1987, figure 1.5, p. 56. veloping plasma technology and diagnostics, has Input and output power are measured at some been the primary motivation for study to date; instant after the plasma has reached its operat- improvements to the basic tokamak concept are ing density and temperature. In experimental currently focused on improving reactor poten- plasmas that do not contain tritium and therefore tial. Other concepts are more concept-improve- do not produce significant amounts of fusion ment-driven in that their features might make power, an “equivalent Q“ is measured. It is de- them preferable to the tokamak if they can reach fined as the Q that would be produced by the reactor scale. However, the ability of other con- plasma if it were fueled equally by both deu- cepts to attain the necessary plasma conditions terium and tritium (D-T) and if it had attained the is much less certain because their experimental same plasma parameters. z databases are less developed. The numerator of the Q ratio includes all the fusion power produced by the plasma, even Scientific Progress though most of the output power (80 percent) Energy Gain “’Equivalent Q“ is either calculated from the measured plasma An important measure of scientific progress density and temperature or derived from actual measurements of towards attaining reactor-relevant conditions is deuterium-deuterium (D-D) fusion reactions. Since the ratio be- energy gain, denoted as “Q. ” Energy gain is the tween the D-T reaction rate and the D-D reaction rate under the ratio of the fusion power output that a device gen- same conditions IS believed known, a measurement of D-D reactions can be used to infer what the D-T fusion yield would be erates to the input power injected into the plasma. under the same conditions. 68 “ Starpower: The U.S. and the International Quest for Fusion Energy

immediately escapes from the plasma via ener- crates output power without auxiliary input power getic neutrons. The denominator of the ratio– from external sources. (Power to drive currents the power used to heat the plasma—greatly un- in the plasma and to cool the magnets to their derestimates the amount of power actually con- operating temperature will be required even for sumed. Losses incurred in generating heating ignited plasmas, but, as stated above, this power power and delivering it to the plasma are not in- is not included in Q.) cluded, nor is the power needed for the confin- Successfully reaching ignition—or at least suc- ing magnets, vacuum system, and other support cessfully generating a plasma that produces many systems. In present-generation experiments, the times more power than is input into it—will be power excluded from the definition of Q is as a major milestone in determining fusion’s tech- much as 35 times greater than the power ac- nological feasibility. The energy and the reaction counted for in this ratio.3 products generated in a plasma producing apprecia- Q excludes most of the power drawn by a fu- ble amounts of fusion power will significantly sion experiment because it is a scientific meas- affect the plasma’s behavior. Understanding these ure that is not intended to gauge engineering effects may be crucial to utilizing self-sustaining progress. Present experiments, needing only to fusion reactions in reactors, and these effects can- operate for short pulses, have not been designed not be studied under breakeven conditions alone. to minimize consumed power; to lessen construction cost, they use magnets that are far less effi- Breakeven cient than those likely to be used in future re- The breakeven curve in figure 4-9 shows the actors. Similarly, the inefficiencies in generating conditions under which a plasma generates as the externally applied plasma heating power are much power through fusion reactions as is in- not included because auxiliary heat is not rejected into it to maintain the reactions. Although quired once a plasma generates enough fusion reaching breakeven will be a major accomplish- power to become self-sustaining. Even so, some ment, it will not have the technical significance external power will be required in any steady- of reaching ignition. Due to the way that energy state plasma device except the stellarator to main- gain is defined, the breakeven threshold in some tain electrical currents within the plasma. respects is arbitrary, and it depends significantly Figure 4-9 shows the plasma temperatures and on the manner in which the plasma is heated. confinement parameters needed to obtain Qs of Crossing the threshold does not cause a signifi- at least 1, a condition known as “breakeven. ” cant change in plasma behavior and in no way The plasma temperatures and confinement pa- indicates that the experiment is able to power it- rameters that have been attained experimentally self. Problems that are not fully evident under by various confinement configurations are also breakeven conditions may yet be encountered shown. No device has yet reached breakeven, on the way to ignition. although tokamak experiments have clearly come The breakeven curve in figure 4-9 is calculated the closest. for plasmas that are uniformly heated. If the plasma is heated in such a way that a small frac- Ignition tion of the plasma particles become much hot- The most significant region in figure 4-9 is ig- ter than the rest, this fraction will produce a dis- nition in the top right corner. An ignited D-T proportionate amount of fusion power and the plasma not only generates net fusion power but breakeven requirements can be substantially lo- also retains enough heat to continue producing wered. For this reason, plasmas heated with neu- fusion reactions without external heat. The Q of tral beams can reach breakeven under conditions an ignited plasma is infinite, since the plasma gen- that would not be sufficient without the use of neutral beams.

Jsee specifications for the Tokamak Fusion Test Reactor at the Neutral beams are extremely hot jets of neu- Princeton Plasma Physics Laboratory, footnote 4 below. tral atoms that can penetrate the confining mag-

Ch. 4.—Fusion Science and Technology ● 69

Figure 4-9.— Plasma Parameters Achieved by Various Confinement Concepts

0.1

Confinement parameter (particle –see cm-3) KEY: S-1: Spheromak-1; Princeton Plasma Physics Laboratory, Princeton, NJ. TMX-U: Tandem Mirror Experiment Upgrade; Lawrence Livermore National Laboratory, Livermore, CA. ZT-40M: Toroidal Z-pinch, -40, Modified; Los Alamos National Laboratory, Los Alamos, NM. FRX-C: Field-Reversed Experiment C; Los Alamos National Laboratory, Los Alamos, NM. OHTE: Ohmically Heated Toroidal Experiment; GA Technologies, Inc., San Diego, CA. Gamma-IO: University of Tsukuba, Ibaraki, Japan. WVII-A: Wendelstein VII-A; Institute for Plasma Physics, Garching, Federal Republic of Germany. HEL-E: Heliotron-E; Kyoto University, Kyoto, Japan. D Ill: Doublet Ill; GA Technologies, Inc., San Diego, CA. JET: Joint European Torus; JET Joint Undertaking, Abingdon, United Kingdom. TFTR: Tokamak Fusion Test Reactor; Princeton Plasma Physics Laboratory, Princeton, NJ. ALC-C: Alcator C; Massachusetts Institute of Technology, Cambridge, MA. SOURCE Office of Technology Assessment, 1987.

netic fields to enter the plasma. Beam atoms col- significantly hotter than the original plasma par- lide with particles inside the plasma and become ticles. (Once the beams are turned off, the in- electrically charged, thereby becoming trapped jected particles cool down to the temperature of by the magnetic field. Through collisions, much the remaining plasma.) Since the fusion reaction of the energy carried by the beams is transferred rate increases very rapidly with temperature, the to the “target” plasma, heating it up. In the proc- hotter particles from the neutral beam have a ess, the beam particles themselves cool down. much higher probability of generating fusion reactions than other particles in the plasma. in this However, it will take many collisions for the manner, a beam-heated plasma can achieve beam particles to cool down to the temperature breakeven with plasma parameters up to a fac- of the target plasma. As long as the beams are tor of 10 lower than those needed for plasmas on, the most recently injected beam particles are heated by other mechanisms. However, since the 70 ● Starpower: The U.S. and the International Quest for Fusion Energy beams themselves require so much power to of the confinement concepts to date. Tokamak operate, it is not expected that beam-heated experiments have clearly made the most progress plasmas will be used in reactors. Therefore, the in terms of coming the closest to the ignition lower breakeven threshold for beam-heated region. plasmas may not translate into lower requirements for a practical reactor. TFTR, in particular, has reached the highest temperature and confinement parameters of any The Tokamak Fusion Test Reactor (TFTR) at magnetic fusion experiment. In 1986, TFTR at- Princeton Plasma Physics Laboratory was de- tained ion temperatures of 20 kiloelectron volts signed to take advantage of beam heating. It is (kev) or more than 200 million degrees C, well expected that breakeven-equivalent (breakeven over the temperature needed for breakeven or conditions in a plasma not containing tritium) will ignition. However, these high-temperature results be obtained sometime between fall 1987 and were obtained in a relatively low-density plasma spring 1988. Experiments to realize true break- having a confinement parameter of 1013 second- even using tritium are scheduled for the end of particles per cubic centimeter, which is about half 1990. These achievements will be important be- of the confinement parameter needed to reach cause, for the first time, a significant amount of breakeven at that temperature. The equivalent heat from fusion power will be produced in a Q actually attained by the plasma was 0.23. Use magnetic fusion device. Moreover, successful D-T of neutral beam heating under these conditions operation of TFTR will provide important tritium- reduces the breakeven threshold by almost a fac- handling experience necessary for future reactor tor of four; a plasma heated to 20 keV without operation. the use of neutral beams would need a confine- Nevertheless, TFTR–not being an engineering ment parameter 7.5 times higher than was at- facility–does not address most of the technologi- tained to reach equivalent breakeven. cal issues that must be resolved before a fusion In a separate experiment at a lower tempera- reactor can be built. Moreover, it will not reach ture of 1.5 keV, TFTR reached a confinement pa- ignition, and the advantage it derives from using rameter of 1.5 X 1014 second-particles per cubic neutral beams will probably not translate into a centimeter. Had this confinement been attained workable reactor. It does not incorporate ad- at a temperature of 20 keV, TFTR would have vanced physics aspects that have been identified been well above equivalent breakeven, coming since its design in the 1970s. TFTR will not—and close to meeting the equivalent ignition condi- never was intended to—have the capability to tion. However, in practice, TFTR will not be able generate electricity from the fusion power it will to attain temperature and confinement values this produce. Even on attaining breakeven, the TFTR high simultaneously. Temperature can be raised experiment as a whole—as opposed to the TFTR at the expense of confinement, and vice versa, plasma alone—will produce less than 3 percent 4 but the product of the two–which determines of the power it will consume. equivalent Q—is difficult to increase. With additional neutral beam power and other improve- State of the Art ments, TFTR may well be able to raise its equiva- Temperature and Confinement.–Figure 4-9 lent Q from 0.23 to 1 and reach equivalent shows results that have been attained by each breakeven. However, it is extremely unlikely that equivalent Qs much greater than 1 are attaina- 4TFTR is being upgraded to deliver up to 27 megawatts of neu- ble in TFTR. tral beam power to the plasma. To reach breakeven, where the fusion power generated equals the external power injected into Beta.–The beta parameter, also called the the plasma, 27 megawatts of fusion power would have to be generated in the plasma. If reaching breakeven were to require TFTR “magnetic field utilization factor, ” measures the to draw near the maximum amount of power available from its elec- efficiency with which the energy of the magnetic trical supply, it could consume close to 1,000 megawatts of elec- field is used to confine the energy of the plasma. tricity. This amount IS 37 times greater than the fusion power to be produced at breakeven. Beta is defined as the ratio of the plasma pres- Ch. 4.—Fusion Science and Technology c 71

ing that have been obtained by certain other confinement concepts (albeit to date at much poorer temperatures and confinement parameters). How- ever, physical phenomena in the plasma prevent beta values from being increased indefinitely. These phenomena, which differ from concept to concept, are not completely understood; gaining additional understanding in this area is a high priority. Low beta values can also be compensated by raising the magnetic field strength. Whereas raising beta primarily involves plasma physics issues, the issues involved in raising the magnetic field strength are primarily engineering-related: stronger magnetic fields are more difficuIt and expensive to generate and place greater stress on the magnet Photo credit: Princeton Plasma Physics Laboratory structures. At some field strength, the advantages The PBX tokamak at Princeton Plasma Physics of stronger magnetic fields will be outweighed Laboratory. by the additional expense of the magnets. Scaling.–Understanding how tokamak per- sure to the magnetic field pressures Record toka- formance can be expected to improve is crucial mak values for beta of 5 percent, in the PBX ex- to evaluating the tokamak’s potential for future periment at Princeton Plasma Physics Laboratory, reactors as well as to designing next-generation and 6 percent, in the D II I-D experiment at GA tokamak experiments. As mentioned earlier, the Technologies, have been attained. These results complete theoretical mechanism determining are especially important in that they generally tokamak scaling has yet to be understood. Ob- validate theoretical models that predict how fur- servationally, plasma confinement has been found ther improvements in beta can be obtained. to improve with increased plasma size. Empiri- In a fusion reactor, the fusion power output per cal data also show that tokamak confinement im- unit volume of the plasma would be proportional proves when plasma density is increased, but that to beta squared times the magnetic field strength this behavior holds only for ohmically heated to the fourth power. Since tokamaks have rela- plasmas. Non-ohmically heated plasmas follow tively low betas compared to many of the other what has come to be known as “L (Low) -mode” confinement concepts currently studied, improv- scaling, in which confinement degrades as in- ing the beta of tokamaks can be useful. Betas creasing amounts of external power are injected. greater than 8 percent are indicated in some sys- A few years ago, experiments on the German tem studies as being necessary for economical Axisymmetric Divertor Experiment (ASDEX) dis- performance,6 and values considerably exceed- covered a mode of tokamak behavior described by a more favorable scaling, labeled “H (High)- ~plasma pressure IS equal to plasma temperature times density and is proportional to the plasma energy per unit volume; mag- mode. ” In this mode, performance even with netic field pressure, which is proportional to the square of the mag- auxiliary heating behaved more like the original, netic field strength, is a measure of the energy stored in the magnetic field per unit volume. ohmically heated plasmas. However, H-mode Typical reactor studies indicate that the plasma in an operating scaling could be achieved only with a particuIar fusion reactor WIII have a pressure several times that of the earth’s combination of device hardware and operating atmosphere at sea level, The plasma density, however, will only conditions. Subsequently, additional work at be about 1/1 00,000 the density of’ the atmosphere at sea level That so tew par-t lcles can exert such a h lgh pressure IS a measure ot thel r other tokamaks has broadened the range of con- extreme tern peratu re about 10,000 electron volts, or more than ditions under which this more favorable behavior 100 million degrees C. 6For ~xam Pie, J, Sheffield, et a[., Cost Assewnent of.? ~eflerlc can be found. The challenge to tokamak re- Magnet/c Fus/orr Rex-tor, oak Rlcige National Laboratory, searchers is to obtain H-mode scaling in config- (3RNLKM-931 1, March 1986, p. 5. u rations and operating regimes that are also con-

72 . Starpower: The U.S. and the International Quest for Fusion Energy

many systems besides those that heat and confine the plasma. Fusion’s overall engineering feasibility will depend on supporting the fusion reaction, converting the power released into a more usable form of energy, and ensuring operation in a safe and environmentally acceptable manner. Developing and building these associated systems and integrating them into a functional whole will require a technological development effort at least as impressive as the scientific challenge of creating and understanding fusion plasmas. The following section describes the systems in a fusion reactor. Since the tokamak confinement Photo credit: Commission of the European Communities concept and the D-T reaction are the most ex- The ASDEX tokamak at the Max-Planck Institute for tensively studied, a tokamak-based reactor fueled Plasma Physics, Garching, Federal Republic of Germany. with D-T is used as an example. However, most of the systems described here would be found, in some form, in reactors based on other con- ducive to attaining reactor-like temperatures and cepts as well. densities. The overall fusion generating station (figure 4- Reactor Design 10) consists of a fusion power core, containing the systems that support and recover energy from Just as an automobile is much more than spark the fusion reaction, and the balance of plant that plugs and cylinders, a fusion reactor will contain converts this energy to electricity using equip-

Figure 4-10.—Systems in a Fusion Electric Generating Station

Rejected heat Fusion power core inside

Balance of plant -

Electric power out to grid

Ch. 4.—Fusion Science and Technology “ 73

ment similar to that found in present electricity station. It consists of the plasma chamber, the sur- generating stations. Features that might convert rounding blanket and first wall systems that re- fusion power to electricity more directly in ad- cover the fusion energy and breed tritium fuel, vanced fusion reactors are described in a subse- the magnet coils generating the necessary mag- quent section. netic fields, shields for the magnets, and the fueling, heating, and impurity control systems. Be- fore an acceptable design for a fusion power core Fusion Power Core can be developed, the behavior of fusion plasmas The fusion power core, shown schematically must be understood under all conditions that in figure 4-11, is the heart of a fusion generating might be encountered. Furthermore, significant

Figure 4-11.—Systems in the Fusion Power Core

Electromagnetic radiation

Neutrons

SOURCE. 74 . Starpower: The U.S. and the International Quest for Fusion Energy advances must be made in plasrna technologies, tions. These systems use heat provided by the fu- which confine and maintain the plasma, and nu- sion core to produce steam that drives turbines c/ear technologies, which recover heat from the and generates electricity. The steam is cooled by plasma, breed fuel, and ensure safe operation. passing through the turbines, and the remaining heat in the steam is exhausted through cooling Balance of Plant towers or similar mechanisms. Balance of plant generally describes the systems More advanced systems that convert plasma of a fusion generating station outside of the fu- energy directly into electricity also may be pos- sion power core. In the example shown in fig- sible. Fusion reactors incorporating such systems ure 4-11, the balance-of-plant resembles systems could be made more efficient than those using found in other types of electric generating sta- steam generators and turbines.

FUSION POWER CORE SYSTEMS

The Fusion Plasma sult, ohmic heating is not sufficient to reach ignition in many configurations. At the center of a fusion reactor, literally and figuratively, is the fusion plasma. A number of Neutral Beam Heating. –Energetic charged or supporting technology systems create and main- neutral particles can be used to heat fusion tain the plasma conditions required for fusion re- plasmas. However, the same magnetic fields that actions to occur. These technologies confine the prevent the plasma from escaping also prevent plasma, heat and fuel it, remove wastes and im- charged particles on the outside from easily get- purities, and, in some cases, drive electric cur- ting in. Therefore, beams of energetic neutral (un- rents within the plasma. They also recover heat, charged) particles that can cross the field lines breed fuel, and provide shielding. are usually preferred for heating the plasma. Further development of many of these plasma Radiofrequency Heating. -Electromagnetic ra- technologies is required before they will be ca- diation at specific frequencies can heat a plasma pable of producing a reactor-scale plasma. Fur- like a microwave oven heats food. Radiofrequency thermore, each of these supporting systems af- or microwave power beamed into a plasma at fects plasma behavior, and the interactions are the proper frequency is absorbed by particles in incompletely understood. progress in both plasma the plasma. These particles transfer energy to the technology and plasma science is therefore rest of the plasma through collisions. needed before reactor-scale fusion p lasmas can Compression Heating. –Increasing the confin- be created. ing magnetic fields can heat a plasma by compressing it. This technique has been used in toka- Heating mak devices and is one reason for studying the field-reversed configuration confinement ap-

Description.–Some heat loss from I a plasma proach. As stated earlier, there is hope that com- is inevitable (see box 4-A), but, with good con- pression may be sufficient to heat an FRC plasma finement, the losses can be made up by external to ignition. heating and/or by fusion self-heating. Different Fusion Self-Heating.–The products of a D-T fu- mechanisms for heating the plasma, illustrated sion reaction are a helium nucleus—an alpha in figure 4-12, are listed below. particle–and a neutron. The neutron, carrying Ohmic Heating. -Like an electric heater, a most of the reaction energy, is electrically un- plasma will heat up when an electrical current charged and escapes from the plasma without re- is passed through it. However, the hotter a acting further. The alpha particle, carrying the rest plasma gets, the better it conducts electricity and of the energy from the fusion reaction, is charged therefore the harder it is to heat further. As a re- and remains trapped within the confining mag-

Ch. 4.—Fusion Science and Technology ● 75

Photo credit: GA Technologies Inc View inside vacuum vessel of the D II I-D tokamak at GA Technologies, San Diego, California. The plasma is contained within this vessel.

netic fields. Hundreds of times hotter than the gigahertz (billions of cycles per second), are un- surrounding plasma, the alpha particle heats der study. Each frequency range involves differ- other plasma particles through collisions. ent technologies for generation and transmission. Status.– Recent system studies show that radio- Issues.—Additional research and development frequency (RF) heating offers significant advan- (R&D) in heating technologies is essential to meet tages over neutral beam heating. Consequently, the needs of future experiments and reactors. Key the U.S. neutral beam research program has been technical issues in RF heating are the develop- reduced while the RF heating program has grown. ment of sufficiently powerful sources of radiofre- Various types of RF heating, using different frequency power (tens of megawatts), particularly quencies of radiation from tens of megahertz (mil- at higher frequencies, and the development of lions of cycles per second) to over a hundred launchers or antennas to transmit this power into

the plasma, particularly at lower frequencies. Fueling Resolution of these issues will require technologi- –Any fusion reactor that operates cal development as well as improved understand- Description. in pulses exceeding a few seconds in length must ing of the interaction between radio waves and plasmas. be fueled to replace particles that escape the plasma and, to a lesser extent, those that are con- Since no ignited plasma has yet been produced, sumed by fusion reactions. Firing pellets of fro- the effects of fusion self-heating on plasma con- zen deuterium and tritium into the plasma cur- finement and other plasma properties are not rently appears to be the best approach for fueling. experimentally known. Confinement could de- Both pneumatic (compressed gas) and centrifugal grade, just as it does with other forms of auxiliary (sling) injectors have been used (figure 4-13). heating. Although self-heating can be simulated Neutral beam fueling has been used in experi- in some ways in non-ignited plasmas, its effects ments, but fueling reactors in this way would take can be fully studied only upon reaching high excessive amounts of power. energy gain or ignition. The ignition milestone, therefore, is crucial to the fusion program, and Status.–Pellets up to 4 millimeters in diameter understanding the behavior of ignited plasmas is have been fired into experimental plasmas at one of the program’s highest scientific priorities. speeds of up to 2 kilometers per second and at

Ch. 4.—Fusion Science and Technology . 77

Figure 4-12.—Plasma Heating Mechanisms

Radiofrequency heating

hydrogen atoms Magnetic deflector Hydrogen //ion Neutralizer source Neutral injection Accelerator heating

SOURCE. Oak Ridge National Laboratory

repetition rates ofs to 40 pellets per second. U.S. development of pellet fueling technology, centered at Oak Ridge National Laboratory, is well ahead of fueling technology development elsewhere in the world. By building state-of-the-art pellet injectors for use on foreign experiments, the United States is able in return to gain access to foreign experimental facilities. Issues.—Reactor-scale plasmas will be denser, hotter, and perhaps bigger than the plasmas made o date in fusion experiments; moreover, reactor pIasmas will contain energetic alpha particles. All these factors will make it much more difficult for pellets to penetrate reactor plasmas than plasmas made in present-day facilities. Penetration to the center of the plasma, most desirable from a theo- Photo credit: Princeton Plasma Physics Laboratory retical point of view, probably will be extremely Princeton Large Torus at PPPL, showing waveguides difficult in reactor plasmas. Experiments are now for the RF heating system. underway to understand how deeply a pellet

78 ● Starpower: The U.S. and the International Quest for Fusion Energy

Figure 4-13.—Centrifugal Pellet Injection

SOURCE: Oak Ridge National Laboratory must penetrate. Tokamaks, for example, appear difficult to produce, but they may disturb the to have a mechanism, not yet understood, that plasma too much; additional work needs to be transports fuel to the center of the plasma. Fuel done to determine how fuel pellets affect plasma might be brought into the center more effectively behavior, If larger pellets cannot be used, higher in some of the alternate confinement concepts injection speed will be required, which is tech- with turbulent plasmas, such as the reversed-field nologically much more difficult. Improving pres- pinch or the spheromak. ent techniques is unlikely to increase injection speeds by more than about a factor of 2. New If deeper penetration is required than can now techniques capable of producing much higher in- be attained, either larger pellets or higher injec- jection speeds are being investigated, but the tion speeds will be needed. Larger pellets are not pellets themselves may not survive injection at Ch. 4.—Fusion Science and Technology ● 79 these speeds due to fundamental limitations in “pushing” directly on electrons in the plasma or their mechanical properties.7 by selectively heating particles traveling in one direction. Experiments have confirmed the the- Current Drive ory of radiofrequency current drive and have suc- ceeded in sustaining tokamak current pulses for Description.–Several confinement concepts, several seconds. including the tokamak, require generation of an electric current inside the plasma. In most present Some other confinement concepts, such as the experiments, this current is generated by a trans- reversed-field pinch or the spheromak, can gen- former. In a transformer, varying the electric cur- erate plasma currents with small, periodic varia- rent in one coil of wire generates a magnetic field tions in the external magnetic fields. Such current- that changes with time. This field passes through drive technologies do not involve complex ex- a nearby second coil of wire—or in this case the ternal systems. conducting plasma—and generates an electric Issues.–The principal issues involving steady- current in that coil or plasma. Varying the mag- state current drive are cost and efficiency, espe- netic field is essential; a constant magnetic field cially under reactor conditions. I n particular, the cannot generate current. radiofrequency technique becomes less efficient in tokamak experiments, a coil located in the as the plasma density increases. This inefficiency “doughnut hole” in the center of the plasma could pose problems because reactors will prob- chamber serves as one coil of the transformer. ably operate at higher densities to maximize gen- Passing a steadily increasing current through this erated power. At this time, it is not known whether coil creates an increasing magnetic field, which the efficiency of continuous current drive can generates current in the plasma. When the cur- be increased to the point where it could replace rent in the first coil levels off at its maximum the pulsed transformers now used in tokamaks. value, its magnetic field becomes constant, and However, radiofrequency current drive might the current in the plasma peaks and then starts also be used to augment the puIsed transformer to decay. If the fusion plasma requires a plasma by starting up the plasma current in a period of current, its pulse length is limited by the maxi- low-density operation. Once the plasma current mum magnetic field of the first coil and the length was started, the density could be raised and the of time taken for the plasma current to decay.8 transformer used to sustain the current. The radiofrequency current drive together with the Status.–Techniques are now being studied for transformer would be able to generate longer last- generating continuous plasma currents, rather ing pulses than the transformer alone. than pulsed ones, because steady-state reactors are preferable to ones that operate i n puIses. g In- Reaction Product and Impurity Control jecting radiofrequency power or neutral beams into the plasma might be able to generate such Description .–Alpha particles, which build up steady-state currents in tokamaks. The injected as reaction products in steady-state or very long- power or beams generate currents either by pulse fusion reactors, will have to be removed so that they do not lessen the output power by 7Argon ne National Laboratory, Fusion Power Program, Techni- diluting the fuel and increasing energy loss by ra- ca/ Planning Activity: Find/ Report, commissioned by the U.S. De- diation, Devices that collect ions at the plasma partment of Energy, Office of Fusion Energy, AN L/FPP-87-l, january 1987, p. 189. edge can be used to remove alpha particles from 81n tokamaks, this decay time can be thousands of seconds. For the plasma. Alpha particles, when combined with confinement concepts with plasmas that are more resistive to elec- electrons that are also collected at the plasma tric currents, the decay time is shorter, on the order of hundreds of seconds. Operating for periods of time longer than the decay edge, form helium gas that can be harmIessly re- time requires non-transformer current drive mechanisms. leased. Unburned fuel ions also will be collected; 9 Components in pulsed systems undergo periodic stresses not these will be converted to deuterium and tritium experienced in steady-state systems. Pulsed reactors also require some form of energy storage to ellminate variations in their elec- gas, which will have to be separated from the trical output. helium and reinfected into the plasma. 80 ● Starpower: The U.S. and the International Quest for Fusion Energy

The same devices that collect ions at the plasma issues such as the conditioning and cleaning of edge help prevent impurities from entering the surfaces in contact with the plasma, the erosion plasma. Even small amounts of impurities can of these surfaces and redeposition of their mate- cool the plasma by greatly accelerating the rate rials elsewhere in the plasma chamber, the ef- at which energy is radiated away. fects of high heat loads, the development of cooling systems, and the degree and effects of tritium permeation. Status.–Two types of devices are being considered for these tasks: pumped limiters and Burn Control diverter-s. A limiter is a block of heat-resistant material that, when placed inside the reaction cham- Description. —When a fusion reactor plasma ber, defines the plasma boundary by intercept- is ignited, it provides its own heat and no longer ing particles at the plasma edge. A variant, the depends on external heating. Two opposing ten- pumped limiter, combines a limiter with a vacuum dencies make it difficult to determine how sta- pump to remove the material collected by the ble, or self-regulating, an ignited plasma will be. limiter. A divertor generates a particular magnetic An ignited plasma may be inherently unstable field configuration in which ions diffusing out of due to the strong temperature dependence of the the fusion plasma, as well as those knocked out fusion reaction rate. If, for whatever reason, a hot of the vessel walls and drifting towards the spot forms in the plasma, the fusion reaction rate plasma, are diverted away and collected by ex- there will go up. As a result, more fusion power ternal plates. will be generated in that area, heating it further and compounding the original problem. Both limiters and diverters are in direct contact with the plasma edge. Although temperatures If the plasma particles mix with sufficient speed, at the edge are far below the 100-million-degree hot spots that form will not persist long enough C temperatures found in the plasma center, these to grow. If, on the other hand, the mixing is slow, components will nevertheless get very hot. All this thermal instability might make it very diffi- the energy injected into or produced by the cult to maintain a steady reaction. Formation and plasma that is not carried away by neutrons or growth of hot spots could cause output power radiated away as electromagnetic energy is even- levels to fluctuate considerably, and in the worst tually deposited on the limiter or divertor plates case these hot spots could grow until much of by electrons and ions. Therefore, these devices the fuel present in the reaction chamber was con- must withstand high heat loads under energetic sumed. The amount of fuel would not be large— ion and neutral particle bombardment while beat most a few seconds’ worth-making this proc- ing exposed to intense neutron radiation. In a fu- ess more of an operational problem than a safety sion environment, they will become radioactive one. The reactor would have to be designed so due to neutron-induced reactions and, to a much that it could not be damaged, and its contents lesser extent, to permeation with tritium. Their not be released, by the maximum amount of reliability must be high since they will be located energy that could be produced in this way. deep within the reactor, inside the vacuum ves- Countering this possible instability is a self- sel, where maintenance will be difficult. regulating mechanism that limits the maximum issues.–A key issue for reaction product and attainable value of the beta parameter. Any in- impurity control will be the choice between stability that heated the plasma would increase pumped limiters and diverters. The devices not the plasma beta, which is proportional to tem- only have different efficiencies but have differ- perature. However, since the power generated ent effects on plasma confinement. Limiters are by a fusion reactor is proportional to beta squared, simpler, but diverters may have operational ad- a reactor would probably already be operating vantages. 10 More R&D is necessary to investigate

IOThe H.mode of tokamak operation, in which confinement prop- ters. This mode, now thought to depend on processes occurring erties are significantly improved, is seen in tokamaks with diver- at the plasma edge, may be difficult to reproduce with Iim iters. Ch. 4.—Fusion Science and Technology ● 81

at the highest value of beta consistent with good ated by fusion reactions and transfer it to other performance. Further increases in beta would de- parts of the facility to generate electricity. De- grade plasma confinement and increase energy pending on plant design and materials selection, loss. These increased losses would cool the these cooling systems also might be needed to plasma back down, counteracting the initial in- remove afterheat from the radioactive decay of stabiIity. materials in the blanket after a plant shutdown. In addition, the tritium fuel required by the re- These beta-limiting processes could maintain actor is produced, or “bred,” in the blanket. Fur- a steady reactor power level. The plasma would thermore, the blanket must support itself and any tend to operate just under the limiting beta value, other structures that are mounted on it. and, by adjusting the magnetic field or the plasma density, the power level corresponding to the The safety of the plant will be greatly influenced limiting beta value could be controlled. by the blanket breeder, coolant, and other subsystems. Since the blanket will perform multiple Status and Issues.– It is impossible, without functions, its development will require an in- creating and studying an ignited plasma, to de- tegrated R&D program. This program must have termine how a plasma will behave in the face of two primary aspects: it must develop the capa- the two opposing tendencies described above. bility to predict the behavior of blanket compo- Neither the causes of beta-limiting processes nor nents and systems under actual reactor usage, their effects on the plasma are fully understood and it must develop technologies that can pro- in general. More research is necessary before the duce fuel and recover energy in the blanket while ability of these processes to stabilize a fusion maintaining attractive economic, safety, and envi- plasma can be determined. ronmental features. The processes that control the reaction rate and Intense irradiation by neutrons produced in the burn stability of an ignited plasma are probably fusion plasma will make blanket components the most device-dependent and least understood radioactive, with the level of induced radioactivity of any aspect of burning plasma behavior. 11 Even depending on the materials with which these for tokamaks, the properties that determine sta- components are made. Tritium bred within the bility have been studied only under conditions blanket will add to the blanket’s total radioactive well short of ignition; still less is known about the inventory. As the largest repository of radioactive properties of other confinement concepts. If these materials in a fusion plant, the blanket will be the issues are indeed concept-specific, only limited 12 focus of environmental and safety concerns. information from a burning plasma experiment using one confinement concept can be used to The discussion below focuses on blankets that predict the behavior of another. would be used in fusion reactors that generate electricity. Reactors used for other purposes, The Fusion Blanket and First Wall some of which are discussed in appendix A, would have different blanket designs. The region immediately surrounding the fusion plasma in a reactor is called the blanket; the part Description of the blanket immediately facing the plasma is called the first wall. In some designs, the first wall Energy Conversion.–The first wall is heated is a separate structure; most often, however, the by radiation from the plasma as well as by energy first wall refers to the front portion of the blan- carried by particles leaking out of the plasma. ket that may contain special cooling channels. Energetic neutrons produced in the plasma penetrate the blanket, where they slow down and con- The blanket serves several functions. Cooling vert their kinetic energy into heat. coolant cir- systems in the blanket remove the heat gener- cuIating within the blanket and first wall transfers this heat to other areas of the plant, where it is

I I Argonne Nat I. na I La t)orato ry, Technic,;/ P/arming ActI\It)’: F;- na/ Report, op. cit., p. 155. I J plant safety characterlst ICS are d ISCU JSed tu rther I n ch. J 82 . Starpower: The U.S.. and the International Quest for Fusion Energy

used to generate electricity. The coolant also pre- vents blanket and first wall components from overheating during reactor operation; depending on plant design, coolant also may be needed to prevent overheating after plant shutdown, whether scheduled or emergency. Depending on the level of radioactivity within the blanket and coolant, secondary heat exchangers like those now used in nuclear fission plants may be required to isolate the coolant. Fusion neutrons slow down by colliding with the nuclei of blanket materials, transferring energy to the blanket in the process. Additional heat is also generated in reactions that occur when the neutrons are captured by materials in the blanket. Depending on their energy, the neutrons travel up to several centimeters between collisions. Collisions change the neutrons’ directions, and a blanket thickness of from one-half meter to one meter is enough to capture most of the neutron energy. Tritium Breeding.–Through reactions with fusion neutrons, the nuclei in the blanket can be changed into other nuclei that are either stable or radioactive. In particular, if a fusion neutron is captured by a lithium nucleus, it will induce a reaction that produces tritium (see box 4-B).13 Therefore, the presence of lithium in the blanket is necessary for tritium breeding. The number of tritium nuclei produced in the fusion blanket per tritium nucleus consumed in the fusion plasma, called the breeding ratio, must be at least 1 for the reactor to be self-sufficient in tritium supply. Accounting for losses and im- reactive and may pose safety problems i n fusion perfections in the blanket, as well as uncertain- reactors. Liquid lithium’s reactivity can be les- ties in the data used to calculate tritium breed- sened by alloying it with molten lead, but the ing rates, this ratio probably should be in the addition of lead substantially increases the pro- range of 1.1 to 1.2. duction of undesired radioactive materials in the blanket. Lithium can be contained in the blanket in either solid or liquid form. Lithium metal has a low Liquid metal coolants can be avoided by sep- melting point (186 o C) and excellent heat trans- arating the function of cooling the blanket from fer properties, making it attractive as a coolant that of breeding tritium. A non-lithium-containing in addition to its use in breeding tritium. How- fluid can be used as the coolant, and solid lith- ever, in its pure form, liquid lithium can be highly ium-containing compounds can be used to produce tritium. However, solid lithium compounds 1 JLithium is a reactive metal that does not occur in its pure form contain other elements, such as oxygen and alu- in nature. However, chemical compounds containing lithium are found in many minerals and in the waters of many mineral springs. minum, that would capture some of the fusion Fuel resources for fusion are discussed in ch. 5. neutrons and lower the breeding ratio. To com- Ch. 4.—Fusion Science and Technology ● 83

pensate for the lost neutrons, substances called Other fusion neutrons will penetrate the blanket neutron rnultipliers can be added to the blanket. to make reactor structures outside the blanket

Neutron multipliers convert one very fast fusion radioactive. Since the degree of radioactivity gen- neutron to two or more slower neutrons by erated within the reactor structure strongly de- means of a nuclear reaction. pends on the reactor’s composition, development and use of /ow-activation materials that do Recovering the tritium from solid breeder ma- not generate long-lived radioactive products terials is more difficult than from liquid breeders. under neutron bombardment will greatly lessen When tritium is bred in a liquid coolant, the cool- induced radioactivity, ant carries the tritium directly outside the blanket where it can be extracted. Tritium produced Due to radiation damage, blanket and first wall in solid lithium-containing compounds, on the components in a fusion reactor wil I require peri- other hand, must first diffuse out of those com- odic replacement. After their removal, the old pounds before it can be collected and flushed components will constitute a source of radio- out of the blanket by a circulating stream of active waste. ’ 5 helium gas. Impact on Fusion Reactor Design .–Although Blanket Structure.—The heat loads, neutron the blanket and first wall components themselves fluxes, and radiation levels found in the blanket may not represent a large fraction of the cost of place stringent requirements on the materials a fusion reactor, blanket design has a substan- with which the blanket is made. Conditions are tial influence on total reactor cost. The blanket most severe at the first wall, which is bombarded thickness (along with that of the shield, described by neutron and electromagnetic radiation from below) determines the size and cost of the mag- the plasma, by neutral particles, and by plasma nets, which are substantially more expensive than electrons and ions that escape confinement. First the blanket. The blanket coolant temperature de- wall issues are similar to many of the issues asso- termines the overall efficiency with which the ciated with limiters and diverters (discussed pre- plant converts fusion power into electricity, di- viously in the section on “The Fusion Plasma, ” rectly affecting the cost of electricity. The selec- under the heading “Reaction Products and im- tion of materials in the blanket determines the purity Control”), which undergo even higher heat amount of long-term radioactive waste and the and particle fluxes than the first wall. amount of heat produced by radioactive decay in the blanket after plant shutdown; both the Neutron irradiation introduces two major prob- waste and the heat affect the reactor’s environ- lems in the blanket materials. First, irradiation can mental and safety aspects. Finally, the ability of lead to brittleness, swelling, and deformation of the blanket materials to withstand heat loads and the reactor structural materials. During the serv- neutron irradiation levels determines the amount ice lives of first wall and blanket components, of fusion power that can be generated in a plant each atom in those components will be displaced of a given physical size, which has a significant several hundred times by collisions with fusion effect on reactor size and cost and on its behavior neutrons. The amount of radiation damage that during accidents. the blanket materials can withstand determines component lifetimes and also places an upper Status and Issues limit on reactor power for a blanket of a given size. A wide variety of designs have been proposed for the blanket and first wall. However, since the Second, neutron irradiation makes the blanket radioactive. Not all the neutrons penetrating the 1 sAccord ! ng to Argonne National Laboratory, Technical P/.lnn/nL~ blanket will be captured in lithium to breed Acti\ity: F/na/ Repor?, op. cit., p. 283, the amount ot long-l{~ed tritium, Some will be absorbed by other blanket (more than 5 years) radioactive waste depends primarily on the materials, making those materials radioactive. amounts of copper, molybcien u m, nitrogen, niobium, and nickel used In the blanket. Radioacti\lty levels, radioactive wastes from I J Beryl I I u m ~ ncj lead are common Iy used I n rea~to r stud I es Js fusion reactors, and Iow-activation materials are discussed tu rther neutron mu Itlpliers, In ch. 5. 84 . Starpower: The U.S. and the International Quest for Fusion Energy fusion research program has concentrated to date for high radiation areas inside the reactor. Since primarily on plasma science issues, relatively lit- a typical effect of radiation damage on insulators tle experimental work has been done on blan- is to increase electrical conductivity, developing ket design or fusion nuclear technologies in gen- materials that will remain insulators under high eral. As the program moves from establishing radiation fluxes is a challenging task. scientific feasibility to demonstrating engineering Special Materials.–Other materials require- feasibility, engineering issues will become much ments for a fusion reactor may include special more important. materials to coat plasma-facing surfaces to mini- Tritium Self-Sufficiency .-Engineering designs mize their effect on the plasma, coatings or clad- must be developed to produce tritium at a rate dings used to form barriers to contain tritium, and equal to the rate of consumption in the plasma advanced superconducting magnet materials (de- plus an additional margin, The extra tritium, 10 scribed in the section on magnets, below). Many to 20 percent of the amount consumed in the of the specific requirements for these materials plasma, is needed to compensate for losses due have not yet been determined. to radioactive decay and to provide the initial in- Compatibility.–Certain combinations of ma- ventory to start up new reactors. Improvements terials, each suitable for a particular task, may in in calculating neutron flow through the reactor combination prove unacceptable in a reactor de- structure and in collecting additional basic nu- sign. For example, liquid lithium reacts violently clear data such as reaction rates are necessary with water, so a liquid lithium-cooled blanket de- to develop adequate engineering designs. Exper- sign would probably prohibit use of water as an imental verification of the calculation methods additional coolant. and data is also required to demonstrate tritium self-sufficiency. Tritium Permeation and Recovery.–Once produced inside the blanket, tritium must be recov- Structural Materials.–Structural materials in ered and removed. However, tritium will perme- the first wall and deeper in the blanket must be ate many materials that are continuously exposed developed that can withstand neutron-induced to it. Its interactions with blanket materials un- effects such as swelling, brittleness, and defor- der the conditions inside a fusion reactor will mation. Stainless steel alloys already have been have to be understood. In particular, tritium may identified that appear to show adequate perform- be difficult to collect from solid breeder materials. ance under neutron fluxes at the low end of those expected in a reactor. However, these materials Liquid Metal Flow.—Liquid metal coolants in produce more radioactive products than may be a fusion reactor will be subject to strong magnetic desirable for commercial reactors. Developing fields created both by the plasma and by exter- low-activation materials that also have acceptable nal magnets. Liquid metals are conductors of physical properties under irradiation remains a electricity; when electrical conductors move significant challenge. The task will require further through magnetic fields, voltages and currents are basic research in materials science as well as generated.16 The currents induced in the cool- progress in materials technology. ant, in turn, are subject to forces from the magnetic field that oppose the motion of the cool- Non-Structural Blanket Materials.–The tritium- ant, increasing coolant pressure and adding to breeding properties of various lithium-containing the power required for pumping. materials must be studied and compared. The choice between solid and liquid breeder materials, in particular, will greatly affect overall blan- The Shield ket design. in addition to lithium, other materi- Description and Status als may be required in the blanket such as neutron multipliers and moderators (which slow Since many neutrons will penetrate all the way down neutrons to make them more easily ab- through the blanket during fusion reactor oper- sorbed in the blanket). Insulators, or materials that do not conduct electricity, also maybe required IGThis process IS the basis of electrical generators. Ch. 4.—Fusion Science and Technology ● 85 ation, a shield may be required between the blan- The most important choice concerning design ket and the magnet coils.17 The shield may be of the magnets is whether they will be made of composed of materials such as steel and water, superconducting materials or of conventional will probably contain a circulating coolant, and conductors such as copper. Copper is an excel- would have a thickness from tens of centimeters lent conductor of electricity but nevertheless has to over a meter. The shield would provide extra sufficient resistance to electric currents that a protection to the magnets and could reflect es- great deal of power is wasted as heat when the caping neutrons back into the blanket to improve magnet is running. This heat must be removed the efficiency of tritium breeding. Additional by cooling systems. Superconducting coils lose shielding wouId probably surround the entire re- all resistance to electricity when cooled suffi- actor core, perhaps in the form of thick walls for ciently; below a temperature called the critical the enclosing building. temperature, their magnetic fields can be sustained without any additional power. However, Most existing fusion experiments have not been power is required to establish the fields initially, designed to use tritium and are incapable of gen- and a small amount of refrigeration power is re- erating significant amounts of fusion power. Con- quired to keep superconducting magnets at their sequently, shielding has generally not been an operating temperature. No heat is generated in- important issue for the research program. It has, side a superconducting magnet, but heat that however, been a factor in the design of devices leaks in from the outside must be removed. such as TFTR and the Joint European Torus that are intended to use tritium. As future machines Although recent discoveries could revolution- are designed that will generate appreciable amounts ize the field (see “issues” section below), all su- of fusion power, shielding will become more im- perconducting materials that have so far been portant. used in large magnets have critical temperatures within about 20° K of absolute zero. The only Issues substance that does not freeze solid at these temperatures is helium, and the only way to cool su- The intensity of the incident neutron radiation; perconducting magnets to these temperatures is the size, shape, and effectiveness of the shield; to circulate liquid helium through them. Use of and the permissible levels of neutron irradiation liquid helium makes superconducting magnets penetrating the shield must all be determined to more complicated and expensive to build than evaluate shielding requirements. As improved copper magnets; superconducting magnets also magnet materials are developed that are less sen- require thicker shields. However, superconduct- sitive to neutron radiation, shielding requirements ing magnets require much less electricity to run, for plant components will lessen. However, pro- substantially lowering their operating costs. tection of plant personnel alone will require substantial shielding. Conceptual design studies typically have shown The Magnets that the operational savings from using superconducting magnets in commercial fusion reactors Description would more than compensate for their higher ini- The external confining magnetic fields in a fu- tial cost. However, there may be exceptions, sion reactor are generated by large electric cur- especially for confinement concepts with higher rents flowing through magnet coils surrounding beta values that are able to confine fusion plasmas the plasma. These magnets must withstand tremen- at lower magnetic field strengths. At lower field dous mechanical forces, strengths, copper magnets, which do not require as much shielding as superconducting magnets, can be made to fit more closely around the .. —-—-—. . plasma chamber. The resultant reduction in size I Plf th magnets are superconducting, the shield will be requl red. e of the magnet/shield combination might reduce If they are made of copper, the shield may not be necessary. How- ever, without a shield, the coils would require periodic replace- its cost enough to outweigh the operational in- ment. See the following section on magnets. efficiencies of copper magnets. 86 . Starpower: The U.S. and the International Quest for Fusion Energy

Whereas the magnets in future fusion reactors worked very well and have exceeded their origi- will operate for long pulses, if not continuously, nal design specifications. 20 magnets in present-day fusion experimental facilities generally operate only for several seconds Issues at a time. For pulses this short, the cost of elec- Recent discovery of new superconducting ma- tricity is less of a factor in determining magnet terials with critical temperatures far above those design, making the simpler construction of cop- of previously known materials, and possibly with per magnets preferable in most cases. A notable the capability to reach very high magnetic field exception is the MFTF-B device at Lawrence Liv- strengths, will have a profound impact on a great ermore National Laboratory, which was built with many fields, including fusion. Materials have been superconducting magnets because copper coils identified with critical temperatures higher than would have been prohibitively expensive to oper- the 77 Kelvin (–196° C) threshold that would ate even for 30-second puIses. permit use of liquid nitrogen as a refrigerant. Liq- uid nitrogen is cheaper and easier to handle than Status liquid helium, and its use could reduce the cost The first fusion device built with superconduct- and complexity of superconducting magnets. ing magnets was the Soviet T-7 tokamak, com- However, the discovery of these “high-temper- pleted 7 years before any Western fusion device ature’ using superconducting magnets. The Soviets are superconductors does not necessarily mean that they can soon be utilized in fusion ap- now building T-1 5, a much larger superconduct- plications. Little is known about the physical ing tokamak. Difficulties with the T-1 5 magnets processes underlying superconductivity in these have been among the reasons that the project’s materials, and they present great engineering completion has been delayed for several years; challenges. They are difficult to fabricate into however, these difficulties apparently have been magnet coils, and they may not be able to with- resolved. The Tore Supra tokamak being built in stand the forces exerted in fusion magnets. Al- France will also use superconducting magnets though their current-carrying capability is improv- and will probably exceed the parameters of T- 15.18 In the United States, MFTF-B was completed ing, they may not be able to carry high enough currents under high magnetic fields to be useful in 1986; its superconducting magnets have been in large-scale magnets. Moreover, their response successfuIly tested at their operating conditions. to neutron irradiation is not known. If these ma- Overall, DOE considers U.S. magnet develop- terials are highly susceptible to radiation damage, ment to be comparable to that in Europe and Ja- their use in fusion magnets could be difficult. pan and ahead of that in the Soviet Union.19 Conversely, if they proved more resistant to ra- Generally, magnet development has been asso- diation effects than previous superconducting ciated with individual fusion confinement exper- materials, thinner shields and correspondingly iments rather than with facilities dedicated specifi- smaller magnets could be used. cally to magnet development. A major exception Further research is required to see whether the is the Large Coil Task, an international program new superconducting materials can be used in to build and test superconducting magnets. Mag- practical applications. The great economic advan- nets developed through the Large Coil Task have tage that they would have in numerous applications ensures that much of this research will be 161 nformation on Soviet tokamak development IS from an oral undertaken independently of the fusion program. presentation on “Assessment of Soviet Magnetic Fusion Research” However, fusion does have particular require- by Ronald C. Davidson, Director of the Plasma Fusion Center, Mas- sachusetts Institute of Technology, to the Magnetic Fusion Advi- ments for large, high-field magnets that may not sory Committee, Princeton, Nj, May 19, 1987. otherwise be investigated. l~lnternational comparisons are from a presentation by R.J. Dowl- ing, Director of the Division of Development and Technology, Of- fice of Fusion Energy, U.S. Department of Energy, to the Energy Research Advisory Board, Sub-Panel on Magnetic Fusion, Wash- ington, DC, May 29, 1986. zOThe Large Coi I Task is discussed further in ch. 7.

Ch. 4.—Fusion Science and Technology ● 87

Photo credit: Lawrence LIvermore National Labora/ory 375-ton superconducting magnet being moved to the east end cell of MFTF-8 for installation. This magnet's location within MFTF-8 is shown at top.

72-078 0 - 87 . 3

88 . Starpower: The U.S. and the International Quest for Fusion Energy

tritium in a fusion reactor once it has been produced and separated. The task of extracting tritium from a blanket under reactor conditions while at the same time generating electric power with high efficiency has yet to be done.

Status To acquire experience with tritium handling for fusion applications, DOE has built and is operating the Tritium Systems Test Assembly (TSTA) at Los Alamos National Laboratory. A prototype of the tritium processing and handling facilities needed for a full-scale fusion reactor, TSTA includes plant safety equipment such as a room atmosphere detritiation system. TSTA operators have developed system maintenance procedures that minimize or eliminate tritium release. This system, however, does not duplicate the production or extraction of tritium from a fusion blanket.

Issues Specific issues involved with tritium processing include monitoring, accountability, and safety. Being radioactive, tritium cannot be allowed to Issues for superconducting fusion magnet ma- diffuse out of the reactor structure. if tritium col- terials include further development and investi- lects on inaccessible surfaces within the reactor, gation of the new high-temperature materials. If it cannot be completely recovered, and it will these new materials prove unacceptable for fu- make those surfaces radioactive. Developing trit- sion, improvements in the strength, workability, ium processing systems will require additional re- and maximum current capacity of the previously search in measuring basic tritium properties such known superconductors will be important. Issues as diffusivity, volubility, and oxidation chemistry. for copper magnets include fully exploiting cop- Safety needs include developing and maintain- per’s strength and developing joints (needed to ing the capability to contain and recover tritium assemble and maintain the magnet) that can carry from air and from water coolants (if any) in the large electric currents. event of tritium contamination.

Fuel Processing Remote Maintenance Description Due to their inventory of radioactive tritium Tritium fuel contained in the exhaust from the and the activation of their structural components, plasma, or generated in the reactor blanket, must the interior of all subsequent fusion experiments be extracted, purified, and supplied back to the that burn D-T will become too radioactive for fueling systems for injection into the plasma. Con- hands-on maintenance. Therefore, remote main- siderable experience has been developed in han- tenance is a key issue not only for future power dling tritium, particularly within the nuclear weap- reactors, but also for near-term D-T experiments. ons program, making tritium technology more Nearly all aspects of the research program, from highly developed than many of the other nuclear design of experiments to operation and mainte- technologies required for fusion. However, this nance to decommissioning, will be affected by experience is applicable primarily to handling the the need for remote maintenance.

Ch. 4.–Fusion Science and Technology “ 89

Photo credit Oak Ridge National Laboratory

The Swiss superconducting magnet coil being installed in the International Fusion Superconducting Magnet Test Facility (Large Coil Task) at Oak Ridge National Laboratory.

The fusion program at present is relying on tenance requirements for fusion facilities will in- activities outside the fusion community for gen- clude transporters able to move heavy loads (over eral development of remote maintenance equip- 100 tons) with precision alignment; manipulators ment. Much work in remote manipulation and made of nonmagnetic material that can operate remote maintenance has been done, but some under high vacuum conditions; and rapid and applications are likely to be unique to fusion and precise remote cutting, welding, and leak detec- will require special development. Remote main- tion equipment. The first challenge in this field

90 “ Starpower: The U.S. and the International Quest for Fusion Energy

Photo credit: Los Alamos National Laboratory The Tritium Systems Test Assembly at Los Alamos National Laboratory will be identification of the remote maintenance quently, needs for test facilities and reactors must requirements for near-term facilities and the de- be identified and assessed. velopment of any necessary equipment. Subse-

ADVANCED FUEL AND ENERGY CONVERSION CONCEPTS

Even though the fusion power core systems de- Advanced Fuels scribed in the previous section have not yet been developed, researchers already are designing re- The fusion power core described in the previ- actors using more advanced concepts. Improve- ous section uses D-T fuel because it is by far the ments described below are not mere refinements most reactive of all potential fusion fuels. This of the systems already described; they are qualita- reactivity can be increased still further by align- tively new features that may be much more ating the internal spins of the deuterium and tritium tractive. In general, these improvements involve nuclei, a technique known as spin polarization. use of either advanced fuels or advanced meth- If the spins can be aligned initially, the magnetic ods of converting fusion energy into useful forms. field of the fusion reactor will tend to keep them Ch. 4.—Fusion Science and Technology ● 91

in alignment. Therefore, research is ongoing at ● They might permit the use of more efficient Princeton Plasma Physics Laboratory to develop methods to generate electricity from fusion intense sources of spin-polarized fuel. energy. I n advanced fuel fusion reactions, more energy is released i n the form of ener- The principal disadvantage of D-T fuel is that getic charged particles, such as protons or the D-T reaction produces energetic neutrons that alpha particles, than is the case in the D-T cause radiation damage and induce radioactiv- reaction. Therefore, these advanced fuels ity in reactor structures. Moreover, reactors using may be amenable to various techniques that D-T must breed their own tritium, substantially generate electricity directly from the fusion adding to reactor complexity and radioactivity plasma or from plasma-generated radiation levels. For these reasons, the possibility of using without having to first convert the energy other fuels in fusion reactors is being investigated. into heat. (See the following section on “Ad- Fuels other than D-T require higher tempera- vanced Energy Conversion.”) tures and Lawson confinement parameters to reach ignition and higher beta values to perform Table 4-8 presents five fusion fuel cycles, in- economically. Achieving these parameters will re- cluding the “baseline” D-T cycle and four pos- quire stronger magnetic fields, higher plasma cur- sibilities for advanced fuel cycles. Of the advanced 3 rents, and substantial improvements in other cycles, the D- He cycle is currently drawing the plasma technologies beyond those needed to most attention within the fusion community. The reach ignition with D-T fuel—a task that in itself primary reaction produces no neutrons, and neu- has not yet been accomplished. However, re- trons resulting from corollary D-D reactions can actions that use advanced fuels would have a be minimized by using a mixture consisting mostly 21 number of advantages: of 3He or by using spin-polarization. c They wouId require little to no tritium, re- ZI Deuterium, being relatively scarce i n a 3He -rich mixture, would be much more likely to react with a 3He nucleus than with another ducing or eliminating the need for the blan- deuterium nucleus, making D-D reactions relatively rare. However, ket to breed tritium and permitting a much one consequence of this mode ot operation, in addition to mini- wider range of blanket designs. Tritium in- mizing neutron generation, wou Id be the lessening of output power since most of the 3He nuclei would be unable to find D nuclel with ventories would be smaller and the conse- which to react. Increasing the ratio of D to ‘He to more nearly equal quent radioactivity levels would be lower. proportions, theretore, would increase both the output power and ● They would generate fewer and lower energy the neutron generation. Spin polarization suppresses the D-D reaction rate because, un- neutrons, alleviating radiation damage and like the D-T reaction, two deuterium nuclel whose spins are allgned minimizing radioactive wastes. are Jess likely to react with each other,

Table 4-8.—Fusion Fuel Cyclesa 92 ● Starpower: The U.S. and the International Quest for Fusion Energy

However, the D-3He reaction is much more dif- into electricity, with the remainder discharged as ficult to start than the D-T reaction. The minimum waste heat. This efficiency, roughly the same as temperature required to ignite D-3He is several that of fossil fuel and nuclear fission generating times higher than that needed for D-T; the mini- stations, is determined primarily by the process mum confinement parameter is about 10 times of generating electricity from the energy in the higher. Given that the requirements for igniting steam. Efficiency could be raised if advanced, D-T have not yet been experimentally achieved, high temperature materials in the blanket and first attaining conditions sufficient to ignite D-3He is wall of a fusion reactor permitted higher coolant considerably farther off. On top of its technologi- temperatures to be used. 3 cal requirements, H e is scarce. It is an isotope If the intermediate step of heating steam could of helium with one fewer neutron than natural be bypassed, a higher percentage of the energy helium (4He), and it occurs on earth only as the released in fusion reactions couId be converted end-product of tritium decay. The only way to into electricity. Several techniques to integrate collect 3He is to make tritium and wait for it to generation of electricity directly into the fusion decay or to breed 3He as the product of another power core have been conceived. One of these, advanced fuel fusion reaction, the D-D reaction. applicable to D-T reactors as well as to advanced Due to the scarcity of 3He, the D-3He reaction fuel reactors, would convert energy carried off has been considered primarily an academic curi- by escaping charged particles directly to electri- osity until recently. city by collecting the particles on plates. This Today, a resurgence of excitement about 3He technique is most applicable to open confine- comes with the discovery that it is found in sub- ment concepts, in which charged particles can stantial amounts in the uppermost layers of soil be allowed to escape along magnetic field lines. on the moon. Analysis of moon rocks brought Other techniques, which can work with closed back by the Apollo missions shows that 3He, confinement concepts, require plasma temper- which is constantly emitted by the sun and car- atures significantly higher than the 10- to 15- ried by the solar wind, is deposited and retained kiloelectron-volt D-T ignition temperatures. Very in the lunar surface. In principle, a rocket with hot plasmas radiate more energy away in the form the cargo volume of the space shuttle could carry of microwave radiation than cooler plasmas do,23 back enough liquid 3He to generate all the elec- and it appears that this radiation could be cap- tricity now used in the United States in one year. tured at the first wall or in the blanket and con- Of course, the technology to recover 3He from verted directly into electricity. These “direct con- the moon would not be available for decades, version” techniques would be better suited to and the energy and capital investment required advanced fuels, which not only burn at higher to mine, refine, liquefy, and transport the 3He temperatures than D-T but also produce most of have yet to be evaluated.22 their energy in the form of energetic charged particles. Unlike neutrons, which escape from the Advanced Energy Conversion plasma without heating it, charged particles are retained within the plasma. The D-T reaction, in Despite the very high-level technology in the fusion core, a baseline fusion reactor would gen- which only 20 percent of the energy is given to erate electricity in much the same way that pres- charged particles, is less suitable for techniques ent-day fossil fuel and nuclear fission powerplants that recover energy directly from the plasma. do. Heat produced in the reactor would be used Several direct conversion techniques that may to boil water into steam, which would pass through convert well over 35 percent of the fusion energy turbines to drive generators. Through this proc- to electricity have been identified. Until they can ess, about 35 to 40 percent of the energy probe tested experimentally under conditions simi- duced in the fusion reaction would be converted lar to those in an advanced fusion reactor, they ———— must be considered speculative. Nevertheless, ~~Use of lunar ‘He is discussed in “Lunar Source ot ‘He for Com- they provide a tantalizing goal. mercial Fusion Power, ” by L.J. Wittenberg, J.F, Santarius, and G.L Kulclnski, Fus/on Technology 10(2): 167, 1986. J ‘See Item 2 In box 4-A, ‘ ‘Plasma Energy Lo\s Mec hanisnl~ ‘‘ Ch. 4.—Fusion Science and Technology ● 93

RESEARCH PROGRESS AND FUTURE DIRECTIONS

In 35 years of fusion research, the technologi- uct provides a rough measure of how well these cal requirements for designing a fusion reactor three requirements have been simultaneously have become clearer, and considerable progress achieved. has been made towards meeting them. Improved The next figure, 4-1 4(b), plots the temperature understanding, based on both experiments and alone and compares it to the minimum temper- increased computational ability, is providing ature below which neither breakeven nor igni- much of the predictive capability needed to de- tion can occur no matter how high the density sign, and eventually to optimize, future plasma and confinement time. The TFTR point shows experiments and fusion reactors. temperatures well into the reactor regime and far Major advances in plasma research have been above that needed for ignition. However, the fact made possible by progress in tokamak plasma that the corresponding TFTR point in figure 4- technologies: 14(a) is below the ignition threshold indicates that high temperature is not sufficient; the product of . By the 1960s, experiments demonstrated the density and confinement time must also be high crucial importance of attaining high vacuum for ignition. and low impurity levels in the plasma to achieve high densities, temperatures, and Figure 4-1 4(c) shows progress in the parame- confinement times. ter beta, the ratio of plasma pressure to magnetic ● In the mid-197os, neutral beam technology field pressure. Note that devices that have achieved was first used to heat plasmas to tempera- high values on one of the three plots often have tures several times higher than those previ- not been the ones that have gotten the highest ously attained. High-performance, high-field values in others. Future devices will have to copper magnets were used to obtain high achieve high values in all areas simultaneously. Lawson confinement parameters in compact tokamak plasmas. The Technical Planning Activity ● The development in the late 1970s of pellet injectors to fuel plasma discharges led to fur- The technological issues to be resolved betore ther advances in plasma density and confine- fusion’s potential as a power producer can be ment. Development of the poloidal divertor assessed have been examined in detail in the at about the same time led to the discovery Technical Planning Activity (TPA), an analysis of the “H-mode,” a mode of tokamak be- commissioned by DOE’s Office of Fusion Energy havior that was not subject to degraded con- and coordinated by Argonne National Labora- finement when auxiliary heating was used. tory.24 Over 50 scientists and engineers from the ● I n the early 1980s, advances in high-power fusion community identified and analyzed the radiofrequency technology gave experimenters tasks and milestones that constitute the research new tools to modify the temperature, cur- needed to reach the goal of the DOE fusion pro- rent, and density distributions within the gram: the establishment of the “scientific and plasma. Much of this new capability has yet technological base required to carry out an assess- to be exploited. ment of the economic and environmental aspects of fusion energy. ”25 According to DOE’s assign- These accomplishments have contributed to ment to TPA, the assessment of fusion wouId be the steady progress in plasma parameters plot- culminated by the construction and operation of ted in figure 4-14. Figure 4-14(a) shows the prod- “one or more integrated fusion faciIities . . . in uct of the temperature, density, and confinement the post 2000 period. ”26 time that has been achieved simultaneously in various experiments over the last 20 years. Since 24 Argon “e N~tl~nc~ I L~bratc)ry, ~6Thf7;cd/ P/JfJfllf7~ Acfll 1~)”” ‘/- nc7/ Report, op. cit. all three of these parameters must be high simul- 251 bid., “Technical Pl~nnlng Acti\ @ Mlsslon Statement, ” p. 348 taneously for the product to be high, this prod- ‘blblci. 94 “ Starpower: The U.S. and the International Quest for Fusion Energy

Figure 4-14.-Progress in Tokamak Parameters

A) B) 20 6 10

5 5

0.5 2

0.2

0.1 1965 1970 1975 1980 1985 1990 1965 1970 1975 1980 1985 1990 1970 1975 1980 1985 1990

Year

The nature of an integrated fusion facility is not properties of burning plasmas, fusion materials, specified by either DOE or TPA. The TPA report and fusion nuclear technology .18 For each of describes it only as “the beginning of the com- these issues, TPA set technical goals and deter- mercialization phase of fusion” that could “per- mined requirements for facilities that could reach haps” take the form of a demonstration power these goals. reactor. 27 The decision to proceed with an integrated facility is scheduled in the TPA report Magnetic Confinement Systems in the year 2005. The key issue in confinement systems is the development of confinement concepts that would Key Technical Issues and Facilities be suitable for commercial fusion reactors. Prog- DOE defines four “key technical issues” that ress here will require that a series of facilities be must be resolved: magnetic confinement systems, built for whichever concepts are judged worthy of further development. A preliminary experi- zTlbid., p. 26. On p. 11 of the TPA report, table S.2 provides “rep- ment that investigates basic characteristics of a resentative goals” for an integrated fusion facility (IFF) and for a new concept can be done for a few million dol- commercial power reactor. Comparing the two sets of goals shows that the IFF falls well short of commercial performance. h would lars or less. An experiment that looks promising only produce from one-sixth to one-third the heat generated by can be followed up by a larger “proof-of-con- a commercial-scale reactor, and it would have considerably lower availability and shorter lifetime than a commercial plant. The IFF described by these parameters, therefore, could not be considered w .s. @partrnent of Energy, Office of Energy Research, Mag- to be a “demonstration” power reactor. netic Fusion Program P/an, DOE/ER-0214, February 1985, p. 6. Ch. 4.—Fusion Science and Technology ● 95

cept” experiment, costing up to tens of millions follow up on the PBX-M and D II I-D results dis- of dollars; such a device would explore the scal- cussed in the earlier sections “Advanced Toka- ing properties of the concept and determine mak, ” p. 59, and “Beta,” p. 70), steady-state whether it offers the potential for extrapolation tokamak operation, and high-magnetic-field ap- to a reactor. proaches to tokamak confinement.31

If the results are promising, a “proof-of-prin- Properties of Burning Plasmas ciple” experiment would then be required to provide confidence that the concept could be scaled Some of the most critical scientific issues yet up to reactor-level conditions. The JET, TFTR, and to be resolved in the fusion program involve the JT-60 tokamaks are in this category. They are not behavior of ignited, or burning, plasmas. These themselves reactor-level devices, but they will en- issues include the effects of self-heating on con- able decisions to be made about whether to pro- finement and the effects of energetic alpha parti- ceed to the final stage of concept development: cles on plasma stability, burn control, and fueling. demonstration of reactor-level plasma conditions, Effects such as these, which existing experiments including fueling, burn control, ash removal, and cannot yet address, can profoundly influence fu- other functions necessary for reactor operation. sion’s feasibility. TFTR may be able to provide No reactor-level devices have yet been built for some information about the effects of alpha par- any concept, including the tokamak. ticle generation if it attains near-breakeven conditions in D-T operation. However, TFTR does Cost is very difficult to estimate for a future not have the capability to reach ignition and proof-of-principle or reactor-level device. The therefore will not be able to resolve burning TPA report estimates costs ranging from 100 mii- plasma issues definitively. The European JET de- Iion to several hundred million dollars or more.29 vice should also have the capability to reach and The costs of the existing JET, TFTR, and JT-60 de- perhaps exceed breakeven, but it too will not be vices range between $600 million and $950 mil- able to resolve many of the burning plasma lion dollars,30 but these devices perform many issues. functions in addition to proof-of-principle for the tokamak concept. There is no reason to think that According to TPA, two different tasks are re- proof-of-principle devices for other confinement quired to study burning plasma issues fully. One concepts would be as expensive. A reactor-scale is a short-pulse ignition demonstration to create device for a particular concept would have more a self-sustaining fusion reaction. The second is stringent technical requirements than its proof- a long-burn demonstration to maintain a self-sus- of-principle device and presumably would be taining fusion reaction long enough to study ef- more expensive. However, the cost of a reactor- fects such as the evolution of the plasma under Ievel device depends on whether it would serve steady-state burn and the buildup of reaction other functions such as the long-pulse burn, nu- products. These two tasks could be done in sep- clear technology demonstration, or system in- arate facilities or in the same facility. tegration functions discussed below. For fiscal year 1988, DOE has requested funds In addition to generic device requirements for to start building a Compact Ignition Tokamak selected alternate confinement concepts, TPA (CIT) to study short-pulse ignition issues (figure also set a requirement for additional tokamaks 4-15). This device, to be located immediately ad- to investigate features such as shaped plasmas (to jacent to TFTR at Princeton Plasma Physics Lab- oratory, is anticipated to cost about $360 million 29 Argonne National Laboratory, Technical P/arming Activ;tY: Fi- (including diagnostic equipment and associated nal Report, op. cit., table S. 12, p. 44 and table S. 16, p. 48. R&D) and will take advantage of existing equip- JOU .s, Congress, House Committee on Science and Technology, ment at the site. Operation is scheduled to be- Task Force on Science Policy, Science Policy Study Background Report No. 4: World Inventory of “Big Science” Research lnstru- rnents and Facilities, Serial DD, prepared by the Congressional Re- search Service, Library of Congress, 99th Cong., 2d sess., Decem- 31 Argonne National Laboratory, Technical P/arming Act;v;~y: Fi- ber 1986, pp. 111, 121, and 127. na/ Report, op. cit., p. 79.

96 . Starpower: The U.S. and the International Quest for Fusion Energy

Figure Preliminary Design

SHIELD

SOURCE: Princeton Plasma Physics Laboratory, 1987. gin in 1993, and annual operating cost is esti- back as 1977, proposals were made for compact, mated at about $75 million. According to a review high-magnetic-field tokamak devices using high- by a panel of the Magnetic Fusion Advisory Com- performance copper magnets; this is the approach mittee (M FAC)32, CIT will be able to study most that was selected for CIT. Other proposals, which of the effects that generation of alpha particles were ultimately not adopted, called for long-pulse might have in a fusion plasma. tokamaks using superconducting magnets and costing well over over $1 billion. The CIT design Ever since TFTR was designed in the mid- 1970s, is intended to focus on scientific aspects of the the design for a successor device has been a topic fusion process, and it will not necessarily form of active interest in the fusion community. As far the engineering basis for future fusion reactors:

Committee is a committee ClT’s copper magnets consume amounts of elec- of scientists and engineers from academia, national labora- tricity that would be prohibitive for commercial tories, and industry that advises DOE on technical matters purposes, they cannot operate for longer than a fusion research. An (Panel XIV, chaired by Dale few seconds at a time without overheating, and Meade of Princeton Plasma Physics Laboratory) reviewed plans for in the Report on Assessment Phenomena their compact size does not provide enough Feb. 10, 1986. The re- room for a blanket to recover fusion energy or port was reviewed by the full in Advisory breed tritium. But CIT will have the ability to re- Committee on Compact Experiments (Charge XIV), submitted to Dr. Alvin Director, Off Ice of Energy Re- solve critical physics uncertainties sooner and at search, Department Energy, Washington, DC, February 1986. lower cost than an experiment having more of Ch. 4.—Fusion Science and Technology ● 97

the engineering features that a reactor wouId refer in energy and effects from fusion-generated quire. Moreover, although specifics of the CIT de- neutrons; tests of materials in fission reactors have sign may not be applicable to future reactors, the to be carefully arranged in order to provide overall approach of high-field, high-performance meaningful data on fusion neutron effects. magnets in fact may be relevant if such magnets Eventually, a high-intensity source of 14-million- can be made with superconducting technology. electron-volt (14-MeV) neutrons will be required CIT is being designed through a national effort to evaluate the lifetime potential of most materi- with wide-based technical support, and the proj- als. To accelerate the effects of aging, the test fa- ect has been endorsed by MFAC as a “cost-ef- cility must generate neutron irradiation levels sig- fective means for resolving the technical issues nificantly higher than those expected in a reactor. of ignited tokamak plasmas.”33 MFAC determined Such levels could be provided by a device such that the “existing tokamak data base is adequate, as a driven fusion reactor, which would gener- with credible extrapolation, to proceed with the ate fusion neutrons but consume more power design of the ClT,” and that by fiscal year 1988 than it generated. Such a device would be com- “we shouId have acquired sufficient information pletely impractical as an energy source, but could from present large machines to support proceed- bean effective method of generating high fusion ing with the construction of the CIT.”34 MFAC neutron intensity over a small volume (1 O to also stated that CIT “should be part of a balanced 1,000 cubic centimeters). overall fusion program, “ implying that it should TPA estimates that a materials irradiation test not drain funds away from “other essential ele- facility would cost from $150 million to $250 mil- ments . . . in the DOE Magnetic Fusion Program lion and would take about 4 years to build. Ma- Plan.”35 terials testing would also require several addi- Long-term burn issues, which cannot be ad- tional facilities each costing $10 million or less. dressed by CIT, will require another device in the future. Even if constructed solely to study physics Fusion Nuclear Technology issues, such a device would probably cost at least Fusion nuclear technologies are those involved $1 billion. If other functions such as nuclear tech- with the recovery of energy from the fusion re- nology testing were incorporated, the cost would action and the breeding and recovery of tritium be even higher. needed to replace the tritium consumed in the reaction. Most of the nuclear technology func- Fusion Materials tions of a fusion reactor are incorporated in the According to TPA, “the ultimate economics first wall, blanket, and shield. and acceptability of fusion energy, as with most The first wall/blanket test program is currently other energy sources, will depend to a large ex- at a very early stage. However, the characteris- tent on the limitations of materials for the vari- tics of the required experiments have been de- ous components.”36 Addressing the specific ma- fined in the FINESSE study .37 A number of exper- terial issues identified earlier in the chapter iments, each costing about $5 million, will be requires faciIities for testing and evaluating can- important for guiding the future of the program. didate materials. Some of this testing can be done Several larger experiments will be needed to fol- by exposing materials to neutrons in fission re- low upon the earlier ones; each of these will cost actors. Fission-generated neutrons, however, dif- up to tens of millions of dollars to build and $1 million or more a year to operate .38 33Magnefic Fusion Advisory Committee Report on compact ignition Experiments (Charge X/V), letter from MFAC chair Fred L. j~he FINESSE study IS a 3-year study done to r DOE Ink o I \ I ng Rlbe to Dr. Alvin Trlvelpiece, Director, Office of Energy Research, organizations and scientists from the U n ited States, ELI rope a nci Department of Energy, Feb. 24, 1986. Japan. The study produced many pub]lcatlons; one example IS ‘A ]~1 bid, Study of the Issues and Experiments (or Fusion Nuclear Technol- 3jlbid. ogy,” by M. A. Abdou, et al., Fwon Technology 8, November 1985. 16 Argonne N~tlona [ Laboratory, Techrr/ca/ ~/.3flfl;~g Act/~;ty: FI- IBArgonne Nationa I Laboratory, Technic a/ f’/.? nngng Ac~l~’lty. FI - rra/ Report, op. cit., p, 259, na/ Reporf, op. cit., table 4.13, pp. 234-236. 98 ● Starpower: The U.S. and the International Quest for Fusion Energy

After individual facilities enable blanket con- If a nuclear-technology-only device is built in- cepts and components to be designed and the stead of an ETR, an additional device would be number of options to be reduced, a large-scale required specifically to study long-term burn. This nuclear technology demonstration facility will be additional experiment would probably cost more required to integrate these components and test than $1 billion. Further expense would come later them under fusion reactor conditions. Such a when the tested nuclear technology systems were large-scale device must not only produce enough scaled to reactor-level and integrated with a fusion power to provide a realistic environment reactor-sized plasma. Thus, the cost of an ETR for nuclear technology testing, but it must also cannot be compared only to the cost of a nuclear incorporate development and construction of the technology device plus a long-term burn device. individual nuclear technology systems themselves. Although DOE recognizes the need for an ETR If this device is also intended to address the or equivalent, it has no plans to build one. The physics issues associated with long-term fusion Japanese and European programs each have burns, it will become still more complex and ex- plans to design such a device independently, but pensive. neither has yet committed to its construction. The One possibility, identified by the FINESSE study Soviet and the U.S. fusion programs, on the other and reviewed and adopted by TPA, is building hand, appear to prefer international collabora- a nuclear technology demonstration facility that tion on such a facility. The U.S. Government has does not simultaneously serve as the long-burn proposed to the other major fusion programs that physics test facility. A device built solely to study conceptual design of an international engineer- nuclear technologies would need a source of ing test reactor, called the International Ther- fusion-generated 14-MeV neutrons, but this source monuclear Experimental Reactor (ITER), be jointly would not need to be an ignited plasma. Such undertaken. The U.S. proposal does not extend a device could test scaled-down versions of nu- to multinational construction of such a device. clear technology components, provided that However, at the conclusion of the conceptual de- these results could be applied with confidence sign effort, the parties could decide whether they to reactor-sized versions. TPA estimated that such wanted to proceed with construction, either in- a nuclear-technology-only device would cost dependently or jointly. Possible avenues of fu- about $1 billion and would take 5 to 6 years to ture international collaboration in fusion research build. TPA did not estimate operating costs for are discussed in chapter 7. this device. TPA identified as a second possibility an engi- Resource Requirements neering test reactor (ETR) that would include both Schedule long-term burn physics and nuclear technology studies. Such a device would require an ignited TPA identified six major decision points that de- or near-ignited plasma, making it big enough to termine the course and schedule of future fusion accommodate full-size nuclear technology com- research, leading up to the overall assessment of ponents. Both the more stringent physics require- fusion’s potential. In figure 4-16, each decision ments and the need for full-scale nuclear tech- is pegged to a key technical issue and to a year. nology components would make an ETR much more expensive than a nuclear-technology-onIy The ratio of annual operating expense to capital expense for TFTR facility. TPA estimated the cost to build an ETR is about 15 percent, and that projected for CIT is about the same if the value of existing facilities at Princeton Plasma Physics Lab- at about $3 billion. It did not estimate operating oratory is included in ClT’s capital cost. Applying this 15 percent costs but said that the experience with TFTR ratio to an engineering test reactor would predict annual operat- would suggest $150 million annually.39 ing expenses of close to $500 million. However, fusion scientists argue that there is no reason to believe the ratio of operating expense to capital expense to be the WIt is not clear how this estimate of $150 million is obtained; it same for an ETR as it is for significantly smaller devices. They agree is not computed merely by assuming the annual operating expense that the more a device costs to build, the more it will cost to oper- of a device to be a specific fraction of its capital cost. Were the ate. However, they maintain that there is no reason to expect cap- estimate made in this manner, it would be considerably higher. ital and operating costs to increase at the same rate,

Ch. 4.—Fusion Science and Technology “ 99

Figure 4-16.-Top Level Decision Points in the Magnetic Fusion Program

SOURCE: Argonne National Laboratory, Technical Planning Activity: Final Report, commissioned by the U.S. Department of Energy, Office of Fusion Energy, ANL/FPP-87-1, January 1987, figure S.8, p. 23.

TPA did not examine all the possible scenarios assured of success. Rather, it shows that an ex- resulting from different timings and outcomes for haustive process of technical review has not un- these decisions but instead adopted a “reference covered any inconsistencies. scenario” believed to reflect current DOE planning. The years in figure 4-16 are taken from the cost reference scenario, which is shown in greater detail in figure 4-17. TPA estimates that the worldwide research required between 1987 and 2005 under the refer- In the reference scenario, the decision to pro- ence scenario will cost in the range of $20 bil- ceed with CIT as the short-term burn experiment lion. This cost does not include an integrated is made in 1987. By about 1990, the decision is fusion facility, demonstration reactor, or any made to combine nuclear technology studies and other facility constructed after the assessment of long-term burn physics issues in a single engineer- fusion in 2005. Total operating cost worldwide ing test reactor, possibly ITER. At about the same is judged to be relatively constant at about $800 time, decisions are made concerning the nature million annually, and total yearly funding for fu- of a materials testing facility and the selection of sion research increases to about $1.5 billion in confinement concepts to be tested at the proof- the mid-1990s when construction cost is added. of-principle scale. By 1997, certain alternate con- The total construction budget is estimated at finement concepts successfully showing proof- about $6 billion, half of which is required for an of-principle are selected for reactor-scale dem- engineering test reactor. onstration, and the overall assessment of fusion is targeted for 2005. TPA does not conclude that TPA acknowledges that the ground rules used the reference scenario is fastest, cheapest, or most for cost projection could have been applied more

January 1987, figure S.1O, p. 27. uniformly, that no iterative review of the cost esti- estimated total cost is higher than an actual man- mates was undertaken, and that no effort was ager would spend when faced with fiscal con- made to estimate the resources required for alter- straints. Similarly, these critics complain that any nate research scenarios. Nevertheless, the report study done by experts from a single field has an states that the information gathered is sufficient inherent bias towards overestimating that field’s to present “a broad view of the resources re- research requirements. Researchers in a field are quired for a full assessment of the commercial presumed to have an interest in maintaining or potential of fusion.”40 increasing their field’s funding, these critics argue, and the researchers would not have any in- Some critics of TPA’s cost estimates argue that, centive to prepare a study underestimating the since TPA was not charged with designing, man- cost of research if such a study might be used as aging, and executing an actual research strategy— justification for cutting the field’s research budget. indeed, TPA was forbidden from performing such programmatic planning, which is strictly DOE’s Other critics, however, feel that any bias in domain–the total cost represents a sum of “wish TPA’s estimated total is likely to be in the direc- lists” rather than a realistic budget. According to tion of underestimating the total rather than in- these critics, without the requirement to conduct flating it. Since each technical aspect of the study the politically difficult task of eliminating research was analyzed by experts in the field, some de- that, although useful, may not be necessary, the gree of technical optimism is probably inherent at each stage; unanticipated difficulties would Laboratory, drive the cost of the research program above Report, op. cit., p. 28. TPA’s estimates. Moreover, these critics suggest, Ch. 4.—Fusion Science and Technology ● 101

it would not be in the collective interest of the Characteristics and prospects of fusion as a com- fusion community to estimate a higher total cost mercial energy source are discussed in chapter 5. than necessary, since continued support of the fusion program depends on perceptions that its Findings benefits are worth its cost. Overestimating the to- Estimates of the annual worldwide funding re- tal cost could threaten the program’s support. quired to evaluate fusion’s potential early in the The process by which TPA estimated the to- next century are several times today’s annual U.S. tal cost of future fusion research involved a wide fusion research budget. The estimated annual degree of fusion community participation, and worldwide funding is, however, on the order of OTA can find no evidence that the estimate is the amount now spent each year by all the world’s flawed. However, OTA also recognizes that while major fusion programs put together. The fund- the researchers in any technical field are the ing estimates suggest three possibilities to U.S. most qualified to estimate costs of experiments policy makers for continuing the U.S. fusion re- in that field, they are also the beneficiaries of search program: support given to the field. Therefore, their esti- 1. With funding levels several times their pres- mates may be influenced by non-technical fac- ent level and with a significant measure of tors, although it is not clear whether the esti- technical success, the U.S. fusion program mate would be too high or too low as a result. can decide on its own whether or not to begin the demonstration and commercializa- Summary tion of fusion power in the early part of the next century. Probability of Success 2. If the major world fusion programs can col- It seems likely that at the conclusion of the re- laborate and plan their research efforts to search program, fusion’s technological feasibil- complement each other and eliminate dupli- ity—the ability to use fusion power to generate cation, and if the effort has a significant electricity—can be shown. The fusion program measure of technical success, a collective has made steady progress over the last 35 years assessment to proceed with fusion’s devel- on the key technical issues. It is still possible that opment could be made early in the 21st cen- fusion’s scientific feasibility will be impossible to tury. In this case, only modest increases in demonstrate, due to surprises in the behavior of funding would be required for each of the a plasma that generates substantial amounts of world’s fusion programs, with the exact fusion power. However, successfully attaining ig- amount of the increases depending on how nition in CIT will resolve most of the scientific un- well the programs were able to avoid dupli- certainties. cation of research. 3. If major international collaboration is not at- Most of the subsequent scientific and engineer- tained, and if the U.S. fusion budget is not ing challenges in designing and building a reactor increased to the point where the necessary have been identified. Once scientific feasibility research can be carried out domestically, the is established, a concerted and well-funded re- United States cannot assess fusion’s poten- search effort should be able to develop a reactor tial until later in the next century. that produces fusion power. However, it cannot yet be determined whether or not such a These possibilities form the basis of the policy fusion reactor will be commercially attractive. options discussed in greater detail in chapter 8, Chapter 5

Fusion as an Energy Program CONTENTS

Page Characteristics of Fusion Electric Generating Stations...... 105 Risk and Severity of Accident ...... 106 Occupational Safety ...... 108 Environmental Effects ...... 109 Nuclear Proliferation Potential ...... 112 Resource Supplies ...... 113 cost...... ● * * *, . . * ***..*... 6.**.....*...*.*...... 113 The Supply of and Demand for Fusion Power ...... 116 The Availability of Fusion Power ...... 116 The Desirabitity of Fusion Power...... 117 Comparisons of Long-Term Electricity Generating Technologies.— ...... 119 Fusion’s Energy Context ...... :...... *O . 123 Conclusions ...... $...... 127 Characteristics of Fusion Reactors ...... 127 Timetable for Fusion Power ...... 127

Figure No. Page 5-1. Post-Shutdown Radioactivity Levels ...... **...... 110

5-2. Post-Shutdown Afterheat Level s ...... ● ...... 111 5-3. Projections of Global Primary Energy Consumption to 2050...... 126

Table No. Page 5-1. Principal Locations of Potential Hazardous Agents in D-T Fusion Reactors ...... 109 5-2. Utility Requirements Summary ...... ● ✎ ✎ ✎ ✎ ✎ ✎ ...... 118 5-3. Comparison of Prospective Long-Range Electricity Supply Options ...... 124 Chapter 5 Fusion as an Energy Program

The primary long-term goal of U.S. fusion re- teristics of such a fusion reactor and on the char- search is to develop a fusion reactor that is an acteristics of other energy technologies with attractive source of electricity. ’ The overall role which fusion will compete. It is too early to evalu- that fusion might play in the future energy sup- ate either of these characteristics: fusion’s com- ply of the United States depends on the charac- mercial prospects are not yet known and neither are the prospects of developments i n other technologies. However, preliminary analyses can be performed on the basis of fusion system studies ] Fusion a I so may be \a I uable I n a n u m her cd non-electric appl I- catlons, descrl bed i n ap~). A. conducted to date.

CHARACTERISTICS OF FUSION ELECTRIC GENERATING STATIONS

Pre-conceptual designs and feasibility studies tential for making fusion reactors attractive and for fusion generating stations were developed as competitive. Their value to the fusion program long ago as 1954.2 However, it was not until the notwithstanding, system studies should not be early 1970s that studies began to simultaneously considered definitive assessments of future fusion address the plasma physics, structural materials, reactors. Given that the scientific and technologi- operating characteristics, economics, and envi- cal base for fusion has not yet been established, ronmental implications of fusion reactors.3 Dur- fusion system studies are inherently based on in- ing the late 1970s and early 1980s, comprehen- complete information, and the values calculated sive system studies and comparative models were for reactor parameters such as capital cost and developed to evaluate the interdependence of fu- cost-of-electricity must be considered highIy un- sion reactor performance and various scientific certain. As a result of the technical progress made and technological parameters. in fusion research, system studies today describe reactors that are very different from those envi- These studies represent a mix of technological sioned 30 years ago. It is likely that the fusion re- optimism and conservatism. They optimistically actor that eventually enters the marketplace will assume that the research and development (R&D) make today’s designs appear just as dated. effort mapped out in chapter 4 of this assessment will be successfully completed and that it will permit a fusion reactor to be designed and built. The discussion that follows identifies generic At the same time, studies are inherently conserv- features of future fusion reactors as well as fac- ative in that they cannot account for as-yet- tors that depend on particular design choices. The unforeseen developments and innovations i n fu- focus is on reactors that produce electricity from sion and competing technologies. fusion alone, called pure fusion reactors, as distinguished from fusion reactors that draw part of The studies have been especially valuable in their energy from fission or that are used to make identifying improvements in fusion physics or fissionable fuel.4 Much of the discussion draws technology that appear to have the greatest po- on comparisons of fusion technology to present- 2L. Spitzer, Jr., et al., Problems of the Stellarator as a Usefu/ Power generation light-water reactor fission technology, Source, NYO 6047 (Princeton, NJ: Princeton University, 1954), the closest analog to fusion for which significant ‘The evol ut Ion of fusion reactor stud Ies 15 d i scussed I n FujIorJ Re- actor Desgn: On the RoJd to Comrnercl.]/iz~ tlon, by G. L Ku ICI n- operational data exists. Fusion and fission plants skl, Fusion Engineering Program, NUC Iear En~lneerlng Department, Unwerslty of Wlsconsln, LJWFDM-5.29, Nlachson, \Vl, May 31, 1983, p. 3.

105 106 ● Starpower: The U.S. and the International Quest for Fusion Energy

are comparable because both are nuclear tech- With appropriate materials choices, afterheat nologies suited for central-station power gener- from fusion reactors should be much less ation, and because they share some of the same than from fission reactors. environmental and safety concerns. However, potential accidents that could occur in fu- the further that a technology is extrapolated be- sion reactors should be less serious than yond present experience, the less certain any of those that could take place in fission reactors. its features become. As a resuIt, all characteriza- With suitable materials choices, the radio- tions of future systems—including the ones in this active inventory of a fusion reactor should chapter—should be treated with extreme caution. be considerably less hazardous than that of a fission reactor. Fusion reactors would not Risk and Severity of Accident contain biologically active fission products such as strontium and iodine. Moreover, the The D-T fusion process has several advantages radioactive materials in a fusion reactor over fission that should make it easier to assure would generally be less likely to be released the safety of a fusion reactor than of a fission re- in an accident than wouId those in a fission actor. This statement does not imply that exist- reactor, since they would largely be bound ing fission reactors are unsafe, or that fission tech- as metallic structural elements. The only nology will not continue to develop and improve. volatile or biologically active radioactive However, assuring public safety with fusion tech- component in a fusion reactor would be the nology should be easier for the following reasons: active tritium inventory; gaseous and volatile radioactive products in a fission reactor ● Fusion reactors cannot sustain runaway re- would be present in amounts orders of mag- actions. Fuel will be continuously injected, nitude greater. and the amount contained inside the reactor vessel at any given time would only oper- recent study of fusion’s environmental, safety, ate the reactor for a short period (probably and economic attributes quantitatively compares seconds or less). A fission reactor, on the the safety of fusion and fission designs. s This other hand, contains several years of fuel in study, referred to here as the ESECOM report, its core—a far greater amount of stored energy sorts various fission and fusion reactor designs potentially available for release. Moreover, into four categories according to the means by the conditions necessary to sustain a fusion which prompt off-site fatalities are prevented in reaction are difficult to maintain; any signif- the event of an accident. Some of the designs icant system malfunction would stop the re- studied depend on active safety systems to pre- action. vent off-site fatalities. These reactors can be safe, ● Fusion reactors should require simpler post- but demonstrating their safety involves certifying shutdown or emergency cooling systems that the safety systems will work as expected dur- than fission reactors, if such systems are ing all conceivable accidents. In other designs, needed at all. Due to the decay of radioactive materials in the reactor, both fusion Jjohn Holdren, et al., Exp/oring the Cornpetiti~7e Pofentia/ ofMa~- and fission reactors will continue to gener- netic Fusion Energy: The Interaction ot’fconomics With Safety and ate heat at a small fraction of the full power Environmental Characteristics, excerpts from the Report of the Sen- ior Committee on Economic, Safety, and Environmental Aspects rate after they have been shut down. I n a of Magnetic Fusion Energy (ESECOM). Interim results from this study fission reactor, this decay heat, or afterheat, were presented to the Magnetic Fusion Advisory Committee in is largely due to fission byproducts that ac- Princeton, NJ, on May 19, 1987; the full report should be published as a Lawrence Livermore National Laboratory report in Septem- cumulate in the spent fuel rods. In a fusion ber 1987. This study will be cited hereinafter as the ESECOM report. reactor, afterheat results mostly from radio- ESECOM analyzed and compared the environmental, safety, and activity induced in the reactor structural ma- economic aspects of eight pure fusion reactor designs, two fission/fusion hybrids, and four types of fission reactor. Of the pure fusion terials, and the afterheat level is highly de- reactors, six were tokamaks and two were reversed-tield pinches; pendent on the choice of those materials. both the hybrid reactors were tokamak-based. Ch. 5.—Fusion as an Energy Program ● 107

nents such as relief valves and pump seals— and the safety of these systems is much easier to in conjunction with the failure of any active demonstrate. 6 systems—could be tolerated without risking off-site fatalities. However, ensuring safety The levels of safety assurance derived by at this level requires assuming the integrity ESECOM, ordered by increasing ease of demon- of key systems such as coolant loops, as well strability, are: as maintaining the large-scale physical integ- ● Level 4: Active Protection. This level of pro- rity of the overall structure. It would have tection depends on the proper operation of to be proven that passive design features active safety systems to ensure safety.7 It is alone could keep these critical components extremely difficult to certify that such systems or systems from being damaged under credi- will indeed work as expected in case of ac- ble accident scenarios. cident. These systems must be designed to Level 2: Large-Scale Passive Protection. A respond to particular contingencies, and large-scale passively protected reactor would deciding which accident scenarios should be be able to prevent the release of dangerous covered is not easy. Furthermore, as the amounts of hazardous materials as long as 1986 Chernobyl accident in the Soviet Union certain large-scale structures remained intact. showed, active safety systems can be discon- Such a system would not rely on active safety nected. At this level of protection, it is im- systems and would be able to withstand any possible to eliminate the risk of operator combination of small-scale component or error. system failures. Demonstrating the safety of ● Level 3: Small-Scale Passive Protection. At such a reactor wouId only require showing this level, safety does not depend on active that no credible accident could destroy the safety systems. Moreover, failure of compo- large-scale geometry of the device. Level 1: Inherent Safety. A reactor with this bThe analysis in this study computes ‘‘worst-case” radiation ex- degree of safety assurance could be shown posures to members of the public by calculating the maximum radiation dose deliverable to an individual at the worst possible loca- to be incapable of causing an immediate, off- tion at the plant boundary, under weather conditions that keep site fatality in the event of any conceivable the radiation from dispersing. Effects that would serve to mitigate failure, including total system reconfiguration the delivered dose, such as buildings, rain, or fallout, were not in- (e.g., it would remain safe even if the entire cluded (except that the effect of buildings on the wind pattern was included). Absence of prompt fatalities corresponds to limiting the reactor were somehow crumpled up into a ‘‘worst-case” dose to under 200 reins, an amount of radiation ex- ball). This level of protection is assured by posure generally accepted to be the minimum capable of causing the properties of the reactor materials in one a prompt fatality in the absence of medical treatment. This radiation dose is about 2,000 times the total dosage typically received of two ways: either the radioactive inventory in one year due to cosmic rays and other naturally occurring sources must be so small that, if totally released, it of radiation. In addition to prompt radiation dose, the study also considered could not constitute a lethal dose to the pub- the long-term dose from ground contamination due to an accident. lic, or the inventory must consist of materi- However, these long-term dosages were not used to define the cat- als that could not be melted, converted into egories of safety assurance. Long-term effects of radiation release are more difficult to determine than prompt effects because the volatile oxides, or otherwise dispersed by the effects of long-term, low-level exposure to radiation are highly con- sudden release (in an explosion, fire, or troversial. Estimates of the cancer fatalities resulting from a given power surge) of all the plant’s stored energy. long-term, low-level exposure vary by more than a factor of 10.

7U rider the ESECOM analysis, any system such as an emergency cooling system that would have to be activated or powered at the According to the ESECOM report, attributes time of an accident, or any system that would have to be actively turned off, is considered an active system. A containment build- of the fusion process show that fusion reactors ing is considered an active system under this definition since pene- should be able to achieve greater degrees of trations such as airlocks, ventilation systems, and plumbing are man- safety assurance than fission reactors. Of the aged by active systems. Therefore, designs relying significantly on containment buildings to prevent escape of radiation could not eight fusion designs that ESECOM evaluated, one achieve a rating higher than Level 4. was a Level 1 system, three were Level 2, one 108 ● Starpower: The U.S. and the International Quest for Fusion Energy

was Level 3, and three were Level 4. Design report even the complete release of the active changes were identified for several of the Level tritium inventory of current reactor designs un- 3 or 4 fusion systems that could raise them to der adverse meteorological conditions would not Levels 2 or 3, respectively. ESECOM found that produce any prompt fatalities off-site.9 There is present-generation commercial light-water fission much greater freedom to choose appropriate ma- reactors are Level 4 systems, and that two “in- terials that minimize safety hazards in fusion re- herently safe” fission reactor designs now under actors than in fission reactors. Therefore, a higher investigation should be capable of reaching Level degree of safety assurance should be attainable 3 on this scale. with fusion. Different fusion designs varied significantly in Occupational Safety terms of the maximum radiation dose that could be delivered to the public in an accident. Designs Most of the occupational hazards a worker using low-activation materials, which do not gen- might encounter at a fusion reactor site are al- erate long-lived radioactive byproducts under ready familiar from other occupations. Table 5-1 neutron irradiation, and designs operating on ad- shows the locations of potential hazards during vanced fuel cycles were calculated to have a the operation and maintenance of a D-T fusion higher degree of safety assurance than the “refer- reactor. ence” design, an updated version of a tokamak Of the potential hazards listed, the least is reactor study originally published in 1980.8 How- known about the effects of magnetic fields. There ever, materials selections and design choices are is no reason to suppose that the steady or slowly also possible that yield fusion reactors that require varying magnetic fields associated with fusion reactive safety systems. actors could cause adverse health effects. How- ESECOM concluded that Level 2 fusion reactors ever, little is known definitively about the bio- should be possible to design, and that Level 1 logical effects of such fields; after many years of designs–although more difficult due to limited research, the technical literature is “extensive and materials choices—should also be possible. None often contradictory. ” 10 The U.S. Department of of the fission designs ESECOM analyzed could at- Energy (DOE) established interim occupational tain these levels of safety assurance. Although fis- magnetic field exposure guidelines on an ad hoc sion designs are being developed that appear to basis in 1979, although the committee that de- have greater degrees of safety assurance than ex- veloped these guidelines expressed “strong con- isting fission reactors, fusion appears to have cerns about the lack of data upon which one can 11 some fundamental advantages. Many of the po- construct appropriate exposure criteria,” tentially dangerous substances present in fission 9joh n Hold ren, et al., ESECOM Report, op cit. Larger “inactive” reactors are either fuels or fission byproducts that tritium supplies would be stored in the plant in addition to the ac- are inherent to the fission reaction. The products tive working inventory, but these could be divided up and extremely well protected. of the fusion reaction, on the other hand, are not 10J, B, cannon (ed .), Background Information and Technical Ba- in themselves hazardous. Tritium fuel does pose sis for Assessment of Environmental Implications of Magnetic Fu- a potential hazard, but according to the ESECOM sion Energy, DOE/ER-01 70, prepared by the Oak Ridge National Laboratory for the U.S. Department of Energy, Office of Fusion Energy, Division of Development and Technology, August 1983, BCharles C. Baker, et al., STARFIRE—A Commercial Tokamak p. 6-2. Power P/an( Study, AN L/FPP-80-l, Argonne National Laboratory, This document, hereinafter referred to as Background /format- 1980. The STARFIRE study, conducted by a team of 70 research- ion, served as the principal reference for a generic Environmental ers, is one of the most comprehensive fusion reactor design studies Impact Statement that was prepared for the magnetic fusion pro- completed to date. It presents a conceptual design of a full fusion gram. The generic statement, although completed, has not been powerplant, including descriptions of the tokamak reactor as well reviewed and approved by DOE. DOE has chosen not to file a as all the associated subsystems in the remainder of the facility. generic impact statement for the program as a whole but rather The STARFIRE study has been extensively drawn upon by, and to prepare specific statements for individual fusion facilities as provides a base of comparison for, many subsequent analyses ot needed. fusion reactors and system designs. The ESECOM report chose the I I Letter from Dr. Edward Alpen, Director of the Dormer Labora- STARFIRE design, updated with lower activation materials and a tory, Unwerslty of California at Berkeley, and Chairman of the com- more recent blanket design, as its ‘‘point-of-departure’ reference mittee established to set interim magnetic field exposure standards, case. to Dr. Kenneth Baker, U.S. Department of Energy, July 23, 1979. Ch. 5.—Fusion as an Energy Program w 109

Table 5-1 .—Principal Locations of Potential Hazardous Agents in D-T Fusion Reactors

Locations of possible exposure Locations of possible exposure Hazard during operation during maintenance

● Radiation from tritium...... ● Tritium recovery systems Reactor hall and structure ● Coolant loops ● Blanket processing ● Fuel recycling

● Radiation from activation products. . . . ● Coolant loops Reactor hall and structure ● Blanket processing ● Steam generator

● Radiation from neutrons ...... ● Not present in accessible areas Not present

Non-radioactive toxic materials ...... ● Possibly in auxiliary reactor systems ● Chemical processing ● Radiofrequency (RF) fields ...... ● Near power sources Not present unless RF components ● Along waveguides are being tested Magnetic fields...... Environment of reactor hall ● Not present unless magnets are being tested aHazards are only listed for areas where personnel will be permitted, personnel will not be permitted in the reactor hall during reactor operation, so activation products and neutron radiation present there are not considered occupational hazards in this table. SOURCE Adapted from J B. Cannon (ed), Backrground Information and Technical Basis for Assessment of Environmental Implications of Magnetic fusion Energy, DOE/ER-0170, prepared by Oak Ridge National Laboratory for the U.S. Department of Energy, Office of Fusion Energy, Division of Development and Technol- ogy, August 1983, table 6.1, P 6-2

These standards are still being used on a trial Environmental Effects basis; although researchers analyzing this issue have flagged uncertainties that call for further re- Radioactive Waste search, they have still not found many well-docu- The main environmental problem with fusion mented studies that show detrimental biological reactors is expected to be radioactive waste. Al- effects of static (non-varying) or slowly varying though the reaction products of the D-T fusion magnetic fields such as those to be found in fu- reaction are not radioactive, the fusion reactor sion reactors. The National Committee on Radi- itself—particularly the first wall, blanket, shield, ation Protection and Measurement has estab- and coils—will be. The first wall will be the most lished a subcommittee on Biological Effects of severely affected; the cumulative effects of radi- Magnetic Fields to recommend limits on magnetic ation damage will require that the first wall be field exposure; this subcommittee is in its final replaced every 5 to 10 years and disposed of as stages of document preparation prior to submis- radioactive waste. sion to the full committee. ’ 2 The type and amount of radioactive waste gen- Significant exposure to magnetic fields in or erated by a fusion reactor is highly dependent near a fusion reactor probably would be limited on the choice of materials. With appropriate ma- to plant workers because magnetic fields extend- terials, fusion reactors can avoid producing the ing beyond the site boundary are not expected long-lived, intense, and biologically active wastes to be stronger than the earth’s field. The interim inherently produced by fission reactors. Accord- standards established by DOE were for occupa- ing to the ESECOM report, although fusion wastes tional exposure only, and the committee that de- may have greater volume than fission wastes, they veloped them stated that it was “not prepared will be of shorter half-life and intensity and should to offer an exposure criteria for general popula- be orders of magnitude less hazardous. ” The 13 tion exposure." wastes from fusion reactors operating with ad-

I ZI nformation provided to OTA staff by Dr. Donald ROSS, Acting Director, Occupational Safety and Health Division, Office of Oper- 14ESECOM measured racjioactive waste hazard by calcu Iating the ational Safety, U ,S. Department of Energy, Apr. 22, 1987; and by dosages that future “intruders” could acquire by excavating or farm- Dr. Dennis Mahlum, chairman ot’ the National Committee on Ra- ing a radioactive waste site hundreds of years from now. Radio- dlatlon ProtectIon and Measurement Scientific Committee 67 on active waste produced by the fusion designs ESECOM studied were Biological Effects of Magnetic Fields, Apr. 28, 1987. orders of magnitude less hazardous than those produced by tls- 13 Letter from A I pen to Baker, note 1 1 above. sion designs by this measure.

110 . Starpower: The U.S. and the International Quest for Fusion Energy

vanced, non-tritium-based fuel cycles would be Figure 5-1 .—Post-Shutdown Radioactivity Levels even less radioactive than those from D-T fusion for Fission Breeder Reactor, Reference STARFIRE Fusion Reactor, and Low-Activation Fusion reactors. Reactor Design ESECOM’s estimates of radioactive waste hazards also indicate that fusion designs differ among themselves by several orders of magnitude. The study found that advanced “low- 10’ activation” fusion designs could be tens to hundreds of times better than the fusion reference 10° design, and that other designs could be hundreds or thousands of times worse if the wrong materials are chosen. ESECOM concluded that with proper materials selection, radioactive waste from all of the fusion designs could qualify as low-level waste under existing Nuclear Regulatory Com- mission regulations.15 Figure 5-1 shows the dependence of fusion reactor radioactivity levels on materials selection. Figure 5-2 shows the corresponding dependence for afterheat produced by radioactive decay. For the top curve in each figure, the reactor first wall and blanket are assumed to be made out of a type of steel. The lower curve, having radioactivity and afterheat levels thousands to millions of times lower, assumes that low-activation materials are used in the blanket and first wall.16 These figures represent the potential of low- activation materials to reduce radioactive wastes but do not necessarily address the feasibility of using these materials. The source for figures 5- I and 5-2 was a preliminary conceptual design study that attempted to design credible replacements using low-activation ceramic materials for all reactor structures in the high neutron flux zone of the STARFIRE reactor (footnote 8, above). Engi- neering feasibility of these materials was considered, and at an initial level of analysis the designs were found to be achievable. However, using

al., induced radioactivity intrinsic to the low-activation materials themselves is extremely small; the majority of the radioactiv- ceramics for these components poses engineer- ity shown by the “low-activation” curve more than one day after shutdown is due to iron impurities. According to Cannon, Back- ing issues quite different from those encountered ground op. cit., p. 3-41, realizing impurity levels as with the metals typically used in engineering ap- low as those assumed in this figure is a “difficult and expensive plications today. Substantial development of ma- task at the present time, and may or may not be achievable at the time rity structural materials are required terials and fabrication techniques would be re- in a fusion reactor economy. ” quired to use ceramics in a fusion reactor.

Ch. 5.—Fusion as an Energy Program ● 111

Figure 5-2.— Post-Shutdown Afterheat Levels diation.17 Two types of radioactive substances for Fission Breeder Reactor, Reference STARFIRE may be emitted by fusion reactors: activation Fusion Reactor, and Low-Activation Fusion Reactor Design products, which are substances made radioactive by neutron irradiation, and tritium, which is produced in the reactor blanket and used as fuel. Activation products would be released either through liquid waste processing systems or plant ventilation systems; most of the tritium releases would be to the atmosphere.

Activation products released by fusion reactors should be no more hazardous than those routinely released by fission reactors. Tritium discharges from fusion reactors, in terms of radioactivity levels, would be much larger than activation product emissions. However, since tritium differs significantly from activation products in the type of radiation emitted and the method of absorption in the body, the total radiation dosages due to tritium releases would not be correspondingly large.

Very preliminary estimates of tritium emissions from fusion reactors are on the order of 5,000 to 10,000 curies per year from a 1,000-megawatt plant.18 Most of these emissions would occur during major system maintenance, and they might be removable by an atmospheric detritiation system before release to the environment. Tritium releases of this amount are well within the range of routine tritium releases from some existing DOE facilities. By comparison, tritium emissions from an equivalently sized pressurized-water fission reactor—the predominant type of commercial nuclear fission reactor—would be about

background radiation is due primarily cosmic and to radioactive elements contained rocks and soils. In the United States, the dosages due to these sources vary by factors of 2 to 4 depending on location; the typical contributions of the two sources are comparable. Medical X-rays and provide, on average, a radiation dosage about equal to the natural background. A sub- Routine Radioactive Emissions stantially smaller contribution comes from the sum of other manmade sources such as atmospheric nuclear weapons tests, occupa- The total estimated radiation dosages attrib- tional radiation exposure, nuclear powerplant emissions, and con- utable to routine releases from fusion reactors sumer products. of a substance is the amount needed to would be a very small fraction of the radiation have 3.7 X radioactive disintegrations per second. Ten thou- dose due to naturally occurring background ra- sand curies have a mass of about one gram. —

112 ● Starpower: The U.S. and the International Quest for Fusion Energy

1,400 curies per year.19 It is estimated that the tion risk.zl However, if the blanket of a pure fu- total dose to the population within 80 kilometers sion reactor were appropriately modified, fission- (50 miles) of a routinely operating fusion reactor able fuel could be bred there. To ensure that should be less than 0.01 percent of the dose from fissionable materials were not surreptitiously natural background sources .20 produced, changes to the reactor blanket would have to be prevented. The difficulty of detecting such changes would depend on the design of the Routine Nonradioactive Emissions reactor; it is plausible that reactor designs could be developed that would make undesirable modifi- The energy generated in a fusion reactor that cations easy (or difficult) to monitor.22 is not converted into electricity would be discharged as heat, primarily into the atmosphere. In this respect, a fusion reactor would resemble Proliferation concerns are not unique to fusion fossil fuel and nuclear fission generating stations. reactors; fission reactors also pose this risk. De- Like a fission plant, but unlike a plant that burns pending on the fuel cycle used, the proliferation fossil fuels, a fusion plant would not emit com- potential of fission can be much greater than that bustion products such as carbon dioxide into the of a pure fusion reactor. After being irradiated atmosphere. Since carbon dioxide emissions may in the core of a fission reactor, uranium fuel will potentially affect world climate, this aspect of fu- be converted into plutonium, which can be ex- sion (and fission) technology could prove to be tracted from the uranium and other byproducts very advantageous. Carbon dioxide emissions are by chemical reprocessing, Alternatively, pluto- discussed later in this chapter under “Compari- nium can be produced in breeder reactors (pure sons of Long-Term Electricity Generating Tech- fission or fission/fusion hybrid) designed explicitly nologies. ” for plutonium production. If either reprocessing or breeder reactors become used on a wide scale, Nuclear Proliferation Potential it is possible that material usable for nuclear weapons could be produced and extracted dur- A fusion reactor’s ability to breed fissionable ing the production, processing, and transporta- materials such as uranium or plutonium could tion of fissionable fuel.23 possibly increase the risk of nuclear weapons proliferation. A pure fusion reactor would not contain fissionable materials usable in nuclear weapons, and it would be impossible to produce such materials by manipulating the reactor’s normal fuel cycle. Therefore, normal operation of ZI Pure fusion reactors do contain tritium, which could be used a pure fusion reactor poses negligible prolifera- in thermonuclear weapons such as the hydrogen bomb. However, such weapons cannot be built by parties who do not already possess fission weapons, and possession of tritium will not provide any assistance to a party that is trying to develop fission weapons. 22A fission/fusion hybrid reactor would incorporate a blanket de- lgFusion reactor radioactive discharge and radiation dosage esti- signed specifically to breed (and/or utilize) fissionable fuel. Prolifer- mates are from Cannon, Background /nforrnation, op. cit., chs. 4 ation concerns for hybrids are therefore considerably more seri- and 8, particularly tables 4.19, 8.8, and 8.9. Pressurized water re- ous than those for pure fusion reactors. actor emissions are from Nuclear Regulatory Commission, Ca/cu- zjThe Plutonium procfuced in a fission reactor consists Of a m iX- Iation of Releases of Radioactive Materials in Gaseous and Liquid ture of different isotopes whose relative proportions depend on how Eff/uents From Pressurized Water Reactors, NUREG-0017, Rev. 1, long the original uranium is irradiated. Any mixture of plutonium 1985, p. 2-70. isotopes can be used to make a nuclear explosive, but weapons ZODOSageS estin-rated from tritium releases assume that all the designers prefer to minimize the percentage of the heavier isotopes tritium is in the form of tritium oxide, or tritiated water. Tritiated that are produced when the fuel is irradiated for longer periods water is water in which one or both of the hydrogen atoms are of time. Therefore, short fueling cycles are preferable—but not replaced by tritium atoms, and it is absorbed by and discharged required—for producing plutonium usable in nuclear weapons. from the human body like ordinary water. These dosages repre- Since plutonium can be produced in this manner in existing tis- sent conservative upper bounds, and are tens of thousands of times sion reactors, the International Atomic Energy Agency operates a higher than the dosages that would result if the tritium were re- safeguards program to assure that production and diversion of fis- leased in the form of tritium gas. Tritium gas is not readily absorbed sionable fuel would be detected, minimizing the possibility of covert by the body. production of nuclear weapons. Ch. 5.—Fusion as an Energy Program “ 113

Resource Supplies The study compared these estimates to non- fusion demand projections, based on U.S. Bureau Much of fusion’s allure stems from the essen- of Mines estimates, which were extrapolated over tially unlimited supply of fuel. D-T fusion reactors a time span comparable to that assumed for the will require two elements—deuterium and lithium fusion estimates. The study also compared de- –for fueling. Deuterium will be used as fuel mand estimates to estimated world supplies. directly in the reaction chamber and lithium will be used in the blanket to breed tritium fuel. Ad- The study did not find any materials for which vanced fuel cycles discussed in chapter 4 that do total fusion demands exceeded non-fusion de- not use tritium wouId not require lithium. mands. Therefore, in those cases for which total It appears that domestic supplies of fusion demand appeared to exceed available supply fuel will not constrain the development and use when projected over many decades, overall scar- of fusion power. Deuterium contained in water city would not be due solely to fusion. There is readily extractable, with each gallon of water wouId be ample motivation other than fusion for having the energy equivalent of 300 gallons of either identifying substitutes or finding new sources gasoline. This supply offers billions of years’ worth of Supply. 26 of energy at present consumption rates. Similarly, domestic lithium supplies probably offer thou- At this stage of fusion reactor design, substitutes sands of years’ worth of fuel with vastly greater can be found for any of the materials that might quantities of lithium contained in the oceans. Al- be in short supply. However, replacing several though recovering lithium from seawater is not materials simultaneously, such as all those that currently economical, it could be in the future; wouId be in short supply if foreign sources were fuel costs are such a small part of the cost of fu- not available, would be much more difficult than sion power that lithium could become many finding substitutes for any one material. If re- times more expensive without substantially affect- source constraints affect fusion reactors, they ing the cost of fusion electricity. According to a will concern materials for reactor construction study of fuel resources for fusion, it appears “un- rather than fuel supply. likely that an absolute shortage of lithium could constrain the prospects of D-T fusion in any time cost of practical interest.”24 Estimating the costs of fusion reactors that can- Preliminary studies of the materials required to not yet be designed in detail is difficult. The task build fusion reactors also do not foresee any im- is considerably complicated by the fact that eco- portant materials constraints, although the pre- nomic projections, more than many other fea- liminary nature of fusion reactor designs makes tures discussed so far, depend critically on pa- firm conclusions impossible. In 1983, Oak Ridge rameters that can be little more than guessed at National Laboratory conducted a study that estimated a “per reactor” materials demand from to be supplied by generating stations averaging 1 gigawatt each and a set of fusion reactor design studies completed having an average lifetime of 40 years, an average of in the 1970s. These estimates were converted into 1,500+-40= 37.5 plants would have to be replaced per year. The annual fusion demands by assuming that in the study assumed that all replacements would eventually be made with fusion reactors. long run, close to 40 fusion reactors would be zGlbid, table 9.24, p. 9-36. Although fusion materials demand did built per year.25 not constitute the majority of the total (fusion plus non-fusion) demand for any of the materials studied, fusion requirements con- stituted between 10 and 50 percent of the total demand for fwe 24w. Hafele, j. F. Hold ren, and G. L. Kulcinski, ‘‘The Problem of materials: beryllium, lithium, helium, tungsten, and vanadium. All Fuel Resources, ” Fusion and Fast Breeder Reactors (Laxenburg, Aus- of these except tungsten were found to be in ample supply. tria: International Institute for Applied Systems Analysis, 1977), p. 32, Fusion demands were calculated from an ensemble of 10 dJffer- 2jCannon, Background /nformat)on, op. cit., ch. 9. The study as- ent reactor designs. Such an ensemble represented a diversity of sumed a worldwide installed electric generating capacity of 1,500 reactor concepts, and using the ensemble kept the analysis from gigawatts, or about 2.4 times the 1986 U.S. installed capacity [given being too dependent on a single design. Any individual reactor de- by the North American Electrlc Reliability Council, “ 1986 Electri- sign, however, may have materials requirements significantly differ- city Supply and Demand, ” figure 8, p. 25]. Assuming this capacity ent from the ensemble average. today. Many non-technical factors such as inter- seismic qualification, redundancy and di- est rates, construction time, and the licensing and versity; regulatory process will have a profound and un- ● the costs of waste disposal and decommis- predictable impact on ultimate cost. sioning; and ● the life expectancies and failure modes of Fusion will be a capital-intensive technology. plant components, which depend on the Existing system studies show that most of the cost combined effects of neutron irradiation, of electricity will come from building the power- magnetic fields, high temperatures, and cor- plant. Costs for the deuterium and lithium re- rosion. quired to fuel fusion reactors will be a negligible fraction of the total cost. More significant as an Existing information on the costs of fusion ex- effective “fuel” cost will be the expense of peri- perimental facilities does not necessarily provide odically replacing the blanket components as much guidance for estimating the future costs they exceed their service lifetimes. Even includ- of commercial reactors. No experiment to date ing these replacements, however, total opera- comes close to integrating the various systems tional and maintenance expense is projected to that would be required in an operating reactor. constitute less than half of the total cost of fusion- Many individuals argue that the proposed costs 27 generated electricity. of future experimental facilities—an engineering In analyzing how the costs of fusion electricity test reactor, for example, which will cost at least depend on various physics and technology pa- $1 billion and very possibly several times that rameters, system designers can determine impor- much—do not bode well for inexpensive power- tant cost drivers and identify high-payoff areas for plants. However, experimental facilities and com- further research. Because of overall uncertainties, mercial devices have very different missions and however, the actual costs estimated in system design constraints. studies are less dependable than their variation as design assumptions are changed. A National A number of factors would tend to make com- Research Council report on fission/fusion hybrid mercial facilities less expensive than experimental reactors 28 identifies many sources of uncertainty devices that produce comparable amounts of in present cost estimates, including: power. Experiments are necessarily based on incomplete knowledge—otherwise there would be ● incomplete design information; no need for them—and their designs must be con- ● limited understanding of the required fusion servative to ensure that their objectives can be technologies, methods of fabrication, mate- fulfilled. Experiments must be flexible; they must rials, and support systems, including in par- have the ability to operate under a wide range ticular incomplete knowledge of the effects of conditions, since the operating parameters that of high-energy neutron irradiation; will be of most interest for future commercial re- ● complex requirements for tritium recovery actors are not yet known. They must be exten- and handling, and the need for remote han- sively instrumented with diagnostic equipment, dling and storage of large, radioactive com- since their primary objective would be to proponents; duce information, not electricity. The result of this ● the degree of containment facility that will information and the experience with the technol- be required for the reactor and for associ- ogy acquired through the research program should ated tritium handling systems; make it possible to reduce the cost of subsequent ● the approach taken towards licensing, in- facilities, including commercial ones. cluding the need for in-service inspection, On the other hand, a different set of factors

27 would tend to increase the cost of commercial J. Sheffield, et al,, Cost Assessment of a Generic Magnetic Fu- sion Reactor, Oak Ridge National Laboratory, ORNL/TM-931 1, facilities over that of their experimental counter- March 1986, table 1.2, p. 7. parts. Expenses may be incurred in ensuring long 28NatiOnal Re5earch council, ~u[/oO& (or ~he Fusjort Hybrid and life, reliability, ease of maintenance, and ease of Tritiurn-Breedirtg Fusion Reactors (Washington, DC: National Acad- emy Press, 1987), p. 90. operation, qualities that are crucial for commer- Ch. 5.—Fusion as an Energy Program ● 115

cial facilities but that may not be so important assurance standards. Components and systems for experimental devices. Many of the design fea- built to meet these “nuclear-grade” standards are tures and requirements introduced in the proc- considerably more expensive than similar com- ess of licensing, optimizing, and commercializ- ponents in less critical applications. Since the ing fusion reactors will also tend to add to the safety of reactor designs with higher levels of expense of commercial facilities. It is therefore safety assurance would not be as dependent on very difficuIt to draw conclusions about reactor particular components or systems, fewer “nu- cost from existing experience or from the cost of clear-grade” components would be required. The proposed experiments. ESECOM report estimated that up to 30 percent of the “overnight” construction costs (e. g., the ESECOM has conducted the most extensive total cost if construction could be completed in- analysis to date comparing costs of various fusion stantaneously, not including interest charges or designs to one another and to fission reactors. inflation) could be avoided if nuclear-grade con- In the ESECOM report, construction cost estimates struction were not required. Such a decrease in varied by about a factor of 2 among the fusion construction cost would lower the cost of elec- designs, and the pure fission costs were similar tricity by about 25 percent. This savings is over- to or below the low fusion estimates. “Cost-of- estimated in that no fusion system is likely to be electricity’ estimates varied over a somewhat able to avoid nuclear-grade construction entirely; smalIer range, and the fission designs again were tritium-handling systems, for example, will always at the low end. have the potential to release some radioactivity The lowest operating cost of any of the reactors in the event of sufficient component failures. examined by ESECOM was for the “best experi- Nevertheless, the ability to relax construction ence” light-water reactor, representing the lowest standards through higher levels of safety assur- cost fission reactors now operating. The highest ance could lead to cost savings. operating cost of all designs was for the “median Possibly mitigating these cost savings is the experience’ light-water reactor, representing a price of achieving increased safety assurance in cross-section of present light-water reactor experi- the first place. In the ESECOM report, the costs ence. Estimated operating costs for all the fusion of the pure fusion designs (before any savings due designs fell in between these cases. Construction to safety assurance were taken into account) cost (as opposed to operating cost) estimates var- tended to be higher for those designs with higher ied similarly, with some of the pure fusion de- levels of safety assurance. The net effect of safety sign construction costs exceeding that of the “me- assurance on reactor cost, therefore, depends on dian experience” light-water reactor. whether savings can outweigh the price of addi- One feature of fusion reactor design that could tional design constraints. significantly affect economics is its level of safety Future technological developments could also assurance. The easier it is to demonstrate the decrease the cost of fusion power. For example, safety of a fusion reactor, the easier that reactor the recent discovery of new superconducting ma- will be to license and site. in particular, if the terials that do not require liquid helium temper- licensing process does not depend on complex atures could affect fusion design and economics and controversial calculations concerning the if these materials can be used in fusion magnets. performance of active safety systems, it might pro- Cheaper magnets, by themselves, will not dra- ceed more quickly and with greater consensus. matically alter the price of a fusion reactor. Even If in turn the construction process were sped up, if the magnets in the STARFIRE design were free, considerable cost savings could result. the total capital cost would only be reduced by Higher degrees of safety assurance could also about 12 percent .29 However, if new magnet ca- have a more direct effect in reducing construc- pabilities in turn make possible the use of sign if- tion cost. Because safe operation of commercial nuclear reactors today depends on active safety ‘9J. Sheffield, et al,, Cost Assessment ofa Generic Magrtetlc Fu- systems, those systems must meet exacting quality sion Reactor, op. cit., tables A,4. 1 and A.4.2, pp. 84-85, 116 . Starpower: The U.S. and the International Quest for Fusion Energy

icantly different designs—e.g., the use of substan- that of a D-T reactor since the advanced reactor tially higher magnetic fields, which could ease technology would be considerably more chal- the requirements on other systems or permit the lenging. On the other hand, if an advanced re- use of advanced fuels—then significantly differ- actor were able to generate electricity directly, ent economic estimates might result. JO without the use of steam generators and turbines, it might be able to bypass some of the balance- If reactors running on advanced fuel cycles of-plant costs. were developed that had substantially lower levels of neutron irradiation, blanket components Given all the uncertainties, OTA finds that the would not have to be changed as often, reduc- economic evidence to date concerning fusion’s ing operating costs, However, in the case of the cost-effectiveness is inconclusive. No factors yet D-3He cycle, the costs of the actual fuel would identified in the fusion research program conclu- no longer be negligible due to the expense of sively demonstrate that fusion will be either much generating or recovering 3He, which is not found more or much less expensive than possible com- in nature. Capital cost for the fusion core of a re- petitors, including nuclear fission. Fusion appears actor using advanced fuels might be higher than to have the potential to be economically competitive, but making reliable cost comparisons will lopossible appl icatic3ns of high field superconducting magnets to require additional technical research and a bet- fusion reactor design are discussed in Tokarnak Reactor Concepts ter understanding of non-technical factors, such Using High Temperature, High Field Superconductors, by D.R. Cohn, et al., Massachusetts Institute of Technology Plasma Fusion as ease of licensing and construction, that can Center, PFC/RR-87-5, Apr. 14, 1987. have a profound influence on the bottom line.

THE SUPPLY OF AND DEMAND FOR FUSION POWER

The factors that influence how successfully fu- geted toward enabling a decision on fusion’s sion technology will serve as a source of energy overall potential to be made by 2005. Accord- include how well fusion’s characteristics meet the ing to TPA, if the decision is made to proceed requirements of potential customers and how with fusion at that time, an “Integrated Fusion well fusion compares to alternate electricity-gen- Facility” (IFF) based on “commercially relevant erating technologies. How well fusion will meet fusion technology” could be built that would the needs of its users, primarily electric utilities, mark the “beginning of the commercialization depends in turn both on when it can become phase of fusion.”32 TPA did not specify the na- commercially available and on what its users ture of the IFF. It could be a demonstration or want. These issues are discussed first below. Next prototype reactor, although the IFF parameters is a brief summary of competing energy supply TPA presented in an example show it to be well technologies that provides some context for fu- short of commercial performance (see ch. 4, foot- sion power. Finally, the implications of estimates note 28). Thus, the technical steps that might fol- of future electricity demand are analyzed. low the research phase, in terms of the necessary facilities that would lead to a prototype The Availability of Fusion Power commercial fusion reactor, have not yet been determined. Financial resources permitting, the research program outlined by the Technical Planning Ac- The institutional process by which any dem- tivity (TPA)31 and described in chapter 4 is tar- onstration fusion reactor might be built and operated is also highly uncertain. Under present Fed- llThe TeChniCal plarln~ng Activity was a fusion communitywide effort to identify the technical issues, tasks, and milestones that char- ment of Energy, Office of Energy Research, AN L/FPP-87- 1, Janu- acterize the remaining fusion research effort. Its primary output was ary 1987. The Technical Planning Activity is described in the sec- Technical Planning Activity: Final Repofl, prepared by the Argonne tion of ch. 4 titled “The Technical Planning Activity. ” National Laboratory, Fusion Power Program, for the U.S. Depart- lzTechnica/ planning Activity: Final Report, op. c!t., PP. ~ and 26. Ch. 5.—Fusion as an Energy Program ● 117

eral policy, building and operating a demonstration existing electrical generating capacity will not be reactor is the responsibility of the private sector, replaced overnight. If early fusion plants can be which has certainly proven capable of demon- built and operated without undue delays or sur- strating major new technologies in the past. How- prises, they may begin to develop a satisfactory ever, involving the private sector in an effort of track record that will stimulate further construc- this scale may not be straightforward. According tion; if early plants show unfavorable operating to one utility executive: experience, commercialization will be delayed. At any rate, it will take decades from their first . . . there is a certain level of concern for the successful demonstration for fusion reactors to enormous gap in perception that exists between industry and government concerning private sec- generate a considerable fraction of the Nation’s tor commercialization. It may be unrealistic to as- electricity. Even under the most favorable cir- sume that once a scientific and related technol- cumstances it does not appear likely that fusion ogy data base is established in the program, the will be able to satisfy a significant fraction of stage will be set for private sector commerciali- the Nation’s electricity demand before the mid- zation of attractive fusion energy sources.33 dle of the 21st century. Unless the Federal Government becomes responsible for owning and operating fusion gen- The Desirability of Fusion Power erating stations—a change whose ramifications Ultimately, fusion’s commercial potential will would extend far beyond fusion’s development— be determined by its ability to meet societal needs some mechanism for easing the transition from more effectively than its alternatives. This deter- government to private responsibility will be re- mination will be made by the eventual purchasers 34 quired. of fusion technology, most likely electric utilities. The timing of the commercialization process However, given the long-term nature of the fu- is difficult to predict for both technical and in- sion program, it is difficult to predict what char- stitutional reasons. Conceivably, if the research acteristics will be important to future customers. program provides the information necessary to The best that can be done is to identify those at- design and build a reactor prototype, such a de- tributes that are important to utilities today, rec- vice couId be started early in the next century. ognizing that utilities and their requirements may After several years of construction and several evolve with time. more years of qualification and operation, a base Certainly one of the most important factors will of operating experience could be acquired that be the capital cost of fusion plants and the cost wouId be sufficient for the design and construc- of fusion-generated electricity. Although fusion tion of subsequent reactors. If the regulatory and may be economically competitive with other licensing processes proceeded concurrently, ven- energy technologies, it is not likely to be substan- dors could begin to consider the manufacture tially less expensive. Nevertheless, without a and sale, and utilities could consider the pur- demonstrable economic advantage, it might be chase, of commercial fusion reactors midway difficult to convince potential purchasers to risk through the first half of the next century. substantial investments in what wouId be an un- The subsequent penetration of fusion reactors known and unproven technology. into the energy market wouId take time because Even if fusion cannot beat its competitors eco- ~jKenneth L. Matson, Vice President, PSE&G [Public Service Elec- nomically, it still may be judged preferable on tric & Gas Co.] Research Corp., Newark, NJ; quoted in “Panel Dis- environmental, safety, and resource security cussion on Industry and Utility Perspectives on Future Directions grounds. If the potential of fusion technology in in Fusion Energy Development, ” Journa/ of Fusion Energy, vol. 5, No. 2, June 1986, pp. 144-145. This issue of the Journa/ of FusiorI these areas is achieved, and if these attributes are Energy presents an edited transcript of a symposium sponsored by important enough to compensate for an eco- Fusion Power Associates titled “The Search for Attractive Fusion nomic penalty, explicit policy decisions could be Concepts. ” jqFor more discussion of the role of the private sector in fUsiOn’s made to promote fusion through legislation or development, see the section in ch. 6 on “Private Industry. ” regulation. Barring such direct intervention, how- 118 ● Starpower: The U.S. and the International Quest for Fusion Energy

ever, the primary determinant of fusion’s market some areas can be noted. For example, success- penetration probably will be cost. fully designing fusion reactors with high levels of safety assurance could satisfy plant safety require- In addition to purely economic factors, a num- 35 ments, lessen financial liability , and improve ber of additional factors–most of them indirectly plant licensability. In addition, if fusion reactors influencing the cost of energy—are also impor- could be convincingly demonstrated to be safe, tant to present utilities. The Electric Power Re- siting flexibility might be increased; reactors could search Institute (EPRI) surveyed a number of elec- be located close to population centers on sites tric utilities in 1981 to determine how important that would not be considered for fission reactors. factors other than the cost of energy would be to their acceptance of fusion. The results of the potential advantages for fusion reactors also survey are shown in table 5-2. emerge with respect to other utility requirements. Due to its virtually limitless fuel supply, fusion EPRI found that utilities identified four factors should be able to satisfy the fuel availability cri- as “vital” and ten as “very important” for future teria. Moreover, it appears that the waste han- fusion reactors. Although it is too early to evalu- dling and disposal should be better addressed by ate how well fusion will be able to satisfy these fusion than by fission. requirements, the potential of the technology i n A number of uncertainties remain for other factors of importance to utilities. At present, there Table 5-2.—Utility Requirements Summary is virtually no industrial base for fusion, although (in addition to cost of energy) existing fission, aerospace, and materials indus- Requirement Weighting tries all have capabilities relevant to fusion’s A. Utility planning and finance needs. Developing fusion’s industrial base is es- 1. Plant capital cost ., Vital sential if the commercialization process is to suc- 2. Plant O&Ma and fuel cost Important 3. Outage rates Very important ceed. Moreover, due to uncertainties in eco- 4. Plant life Important nomic studies, how well fusion will be able to 5. Plant construction time Very important minimize plant capital cost cannot yet be deter- 6. Financial liability ,.. Vital 7. Unit rating ~ ~ Moderately important mined. In addition to affecting the cost of energy B. Safety, siting, and licensing through life-cycle capital amortization, large cap- 1, Plant safety Vital ital expenditures can complicate corporate finan- 2. Flexibility of siting ~ ~ Very important 3. Waste handling and disposal .Very important cial management in areas such as debt-to-equity 4. Decommissioning ., Important ratios and capital flexibility. It is clear that fusion 5. Licensability. Vital reactors will be capital-intensive, but at this stage 6. Weapons proliferation Important C. Utility operations of development their costs cannot be accurately 1. Plant operating requirements Very important determined. 2. Plant maintenance requirements Very important 3. Electrical performance . Very important Hardware availability, which measures the 4. Capability for load change Moderately important cost, scarcity, and supply dependability of ma- 5. Part load efficiency . . Moderately important 6. Minimum load . . . Moderately important terials required for plant construction, cannot be 7. Startup power requirements Important determined at this stage of design. Factors such D. Manufacturing and resources as outage rates, plant construction times, plant 1, Hardware materials availability Very Important 2. Industrial base. . . . . Very Important operating requirements, plant maintenance re- 3. Fuel and fertile material availability Very important quirements, and electrical performance, also Order of significance viewed as very important by utilities, probably 1. Vital cannot be evaluated until fusion reactors are well 2. Very important 3. Important into the commercialization process. Experience 4. Moderately important No factors were judged ‘‘slightly important’; factors judged ‘‘unimportant’ have been deleted from the list. ) aOperations and maintenance JJFinancial Ilability measures the maximum potential flnanClal losses due to death, injury, property damage, loss of revenue, and SOURCE Electric Power Research Institute Utility Requirements for Fusion EPRI AP-2254 February 1982 table 2-1 p 2-3 other costs in the event of an accident. Ch. 5.—Fusion as an Energy Program ● 119

with construction, operation, and maintenance pared to its alternatives. Therefore, improved effi- of the reactors will be necessary to fully under- ciency of energy use is not specifically discussed stand these aspects of fusion technology. here as a generating technology.

A factor that is interesting due to its relatively Fossil Fuel Technologies low weighting is unit rating, or the electrical capacity of a particular generating station. In the Coal.–Coal is the most abundant energy source early 1970s, fusion reactor conceptual designs in the United States and is currently used to gen- had electrical outputs considerably higher than erate over half of the Nation’s electricity .38 Ac- those of existing generating stations. Subsequent cording to the Energy Research Advisory Board: designs have lowered electrical capacities to Coal supply for the 1985-2020 period does not 1,000 megawatts of electricity or less, more in line seem to require any special attention at this time with existing stations; some recent studies have . . . It has been the conventional wisdom that the even considered fusion plants generating as lit- U.S. coal resource base is of such magnitude that tle as 300 megawatts of electricity, although at it can be safely relied upon to supply any demand a higher projected cost of electricity.36 Now that for the foreseeable future. This would be true fusion reactor designs are sized within the range even if nuclear generation does not grow and if of utility experience—together with the relative a major demand for coal-based synthetics should 39 unimportance of this parameter —fusion reactors arise, should have little trouble meeting unit rating re- Many coal technologies are highly developed quirements. and well understood, and they are economically attractive. Proven domestic reserves of coal are Comparisons of Long-Term Electricity adequate to maintain present rates of use for sev- Generating Technologies eral hundred years. However, there are serious environmental impacts associated with or antic- This section summarizes the long-range poten- ipated from the combustion of coal. Mitigating tial of various electricity generating technologies these adverse environmental impacts increases in the 21st century and discusses possible prob- the cost of coal combustion and may reduce the lems associated with their use and/or further de- efficiency of conversion to electricity. Further- velopment. A detailed examination of the char- more, coal combustion inherently produces car- acteristics of these energy technologies, however, bon dioxide gas, which may affect world climate is beyond the scope of this report .1’ and make the use of coal undesirable. The role of demand modification, such as con- The main near-term problem associated with servation and improvement in the efficiency of the use of coal appears to be emissions of com- energy use, is critical in determining future energy bustion byproducts such as sulfur and nitrogen requirements. However, as shown in the follow- oxides and particulate. These emissions are a ing section on “Fusion’s Energy Context, ” the major contributing factor to acid deposition, also level of electricity demand does not strongly af- called “acid rain. ” Air pollution from coal and fect the relative demand for fusion power com- other fossil fuel combustion can harm natural

jBln 1985, coal generated 1,401 billion of the 2,469 billion Jbone study presenting cost of electricity as a fu nCtiOn Of electri- kilowatt-hours of electricity generated in the United States, accord- cal output is J. Sheffield, et al., Cost Assessment ofa Generic Mag- ing to Annua/ Energy Review 1985, published by the U.S. Depart- netic Fusion Reactor, op. cit., figure 4.17, p. 48. ment of Energy, Energy Information Administration, DOE/EIA- Jzselected OTA studies that have examined other energy tech- 0384(85), table 81, p. 185. nologies i n more detail include New .E/ectric Power Technologies: jqEnergy Research Advisory Board, “Appendix D: Coal Research Problems and Prospects i’or the 1990s, OTA-E-246 (Washington, and Development, ” by Eric H. Reichl, Cuide/ines for DOf Long DC: U.S. Government Printing Office, July 1985); Nuc/ear Power Term Civilian Research and Development, vol. VI( Report of ERAB in an Age of Uncertainty, OTA-E-216 (Washington, DC: U.S. Gov- Supply Subpanel, Long-Range Energy Research and Development ernment Printing Office, February 1984); and /ndustria/ and Com- Strategy Study, A Report of the Energy Research Advisory Board rnercia/ Cogeneration, OTA-E-192 (Springfield, VA: National Tech- to the U.S. Department of Energy, DOE/S-9944, December 1985, nical Information Service, February 1983). p. 65. 120 ● Starpower: The U.S. and the International Quest for Fusion Energy

ecosystems, damage economically important ma- as well.43 Near-term electricity generating tech- terials, impair visibility, and may affect human nologies are discussed in a separate OTA assess- health.@ ment .44

The near-term environmental problems asso- Carbon Dioxide Buildup.–Carbon dioxide

ciated with coal and fossil fuel combustion, (C02) is formed as a byproduct of the combus- though serious, can be controlled. The release tion of fossil fuels–coal, oil, and gas. in the past

of combustion byproducts can be mitigated by several decades, the amount of CO2 in the atmos- using cleaner fuels, attaining more complete com- phere has increased about 10 percent, largely as bustion, or cleaning (“scrubbing”) the combus- a result of fossil fuel combustion. Atmospheric tion exhaust. Several technologies to reduce un- carbon dioxide gas can trap some of the heat radi- desirable combustion byproducts are currently ated from the earth instead of allowing it to es- 41 available, and more are being developed. Such cape into space. Therefore, the buildup of C02 pollution abatement systems make coal-fired is associated with a global warming effect, some- electricity somewhat more expensive, but they times called the “greenhouse effect. ” do not eliminate coal as a major source of future Increased use of fossil fuels is only one poten- electricity supply. With the exception of carbon tial contributor to global warming. Other gases dioxide buildup, discussed below, issues con- released into the atmosphere, such as methane, cerning the environmental acceptability of coal nitrous oxide, and chlorofluorocarbons, have combustion are resolvable by burning cleaner similar heat-retaining properties and may, in ag- fuels or by using “clean coal” technologies. gregate, contribute as much as C02 to global Oil and Gas.–Oil and gas today generate sub- warming. Moreover, the connection between fos- stantially less electricity in the United States than sil fuel use and global warming is influenced by coal.42 The domestic resource bases for oil and factors such as the production and use of CO, gas are considerably smaller than coal’s, and for by green plants, its absorption by the oceans, and this reason oil and gas technologies are not gen- vegetative decomposition. Global warming is po- erally included in discussions of long-range elec- tentially a very serious problem, and the con- tricity supply over the periods in which fusion sensus within the scientific community studying may make a major contribution. the issue is that such a warming appears inevitable if emission of C0 and other “greenhouse In the nearer term, however, these fuels—par- 2 gases” continues to increase. However, there is ticularly gas—may have an increasing role in elec- no certainty to date about the timing and mag- tricity generation and may very well form part of nitude of the effect, nor about what its climatic the mix of generating technologies at the time that implications might be. fusion reactors are first introduced. Advanced gas

turbines now under development may be highly The use of fossil fuels will always produce CO2;

efficient sources of electricity emitting far less there is no way to eliminate C02 as a product combustion byproducts than current coal plants. of the combustion process. As noted above, how- Furthermore, such turbines would produce only ever, different fossil fuels and combustion tech-

about one-third as much carbon dioxide per kilo- nologies produce different amounts of CO2 per watt-hour as a coal generation plant, reducing unit of generated energy. Techniques to capture

(but not eliminating) carbon dioxide emissions the C02 from fossil fuel combustion emissions have been proposed, but they are generally considered to be impractical for either economic or

40u .s. Congres5, Office of Technology Assessment, Ac;d Rain and technological reasons. Neither is there a practi-

Transpotied Air Pollutants: Implications for Public Policy, OTA-O- cal way to recover C02 and other greenhouse 204 (Washington, DC: U.S. Government Printing Office, June 1984), pp. 9-13.

41 Ibid., Appendix A.z: “control Technologies for Reducing SUI - qJPa~ of the reduction IS due to the higher etficlency Of these fur and Nitrogen Oxide Emissions, ” p, 152. turbines; part is due to the lower carbon content of the fuel. AZTotal use of oil and gas, however, including uses other than AANew E/ectric power Technologies: Problems and Prospect> for electricity generation, is greater than that of coal. the 1990s, op. cit., chs. 4 and 5. Ch. 5.—Fusion as an Energy Program ● 121

gases that are already in the atmosphere. The only percent of U.S. electricity supply,45 and nuclear way to reduce CO2 emissions from fossil fuel power is likely to remain the second largest combustion is to curtail the combustion of fossil source of domestic electricity generation (after fuels. coal) into the 21st century. Nuclear fission may become a more important source of electricity Limiting the use of fossil fuels will not be easy. if CO or other environmental problems require The simplest way, up to a point, would be to in- 2 constraint of coal combustion. The main impedi- crease the efficiency of energy use, lessening the ments to increased use of nuclear fission appear growth of energy demand. Displacing fossil fuel to be its unfavorable economics and concern usage with other energy technologies will be about health and safety. I n the long run, many more difficult. Coal will continue to be a major decades from now, fuel constraints may affect the source of electricity for the early 21st century, and potential of nuclear fission unless more efficient deemphasizing its use would foreclose a substan- technology, fuel reprocessing, or fuel breeding tial resource base. Oil and gas currently gener- is instituted. ate more C02 annually than coal due to their heavier use; much of their use is in decentralized Public Acceptance.–The long-term feasibility applications such as transportation and space of nuclear fission technologies will require reso- heating where they will be difficult and expen- lution of health and safety concerns. Nuclear sive to replace. power is currently the target of widespread opposition for several reasons. Members of the public Without government intervention, technologies feel that mechanisms to dispose of radioactive developed to reduce fossil fuel usage must be wastes are inadequate to prevent the uItimate re- economically preferable to succeed. Because lease of dangerous radioactive effluents. More- CO buildup would be a global problem, fossil 2 over, there is concern about the safety of nuclear fuel combustion would have to be reduced on reactors, particularly in the aftermath of the Three a global scale. It is not clear that developing na- Mile Island (U. S.) and Chernobyl (U. S. S. R.) actions would be willing or able to shift from fossil cidents. The potential for mechanical failure and fuels to other energy sources if doing so would operator error casts doubt on the integrity of re- impose serious economic hardship. Furthermore, actor safety systems. those regions of the world that might benefit from Economics.–The economics of nuclear power CO2-induced climatic change would have no incentive to reduce CO2 emissions unless they were are currently uncertain for several reasons, not otherwise compensated. all of which are related to characteristics of the technology. The technology is complex and de- Possible global warming due to carbon dioxide mands strict quality control; nuclear plant con- buildup is a complex problem with a number of struction requires longer lead times and greater contributing causes. It provides an incentive to capital investment than coal plants. Changing reg- develop new technologies that can substitute for ulations, inadequate management at some plants, or otherwise curtail the use of fossil fuels. How- and time-consuming litigation add to its cost. The ever, the degree to which these new technologies combination of these factors with the soaring in- reduce fossil fuel use will depend heavily on their terest rates of the late 1970s resulted in costs economic advantages, and any reductions they much higher than expected. Although some contribute to fossil fuel use will occur gradually. plants–even in recent years–have been built on schedule and within budget, the more common Nuclear Fission Technologies experience has been so traumatic that utilities will Nuclear fission currently appears to be the main continue to be extremely cautious about under- alternative to the widespread future use of coal. taking new nuclear construction. Furthermore, The technology is well developed and relatively large-scale plants–the only type available at well understood, and it is supported by a sub- present for nuclear fission–are unattractive in the stantial research and development infrastructure. In 1985, 95 nuclear powerplants produced 16 122 . Starpower: The U.S. and the lnternational Quest for Fusion Energy

situation of uncertain demand growth that utili- function. 46 Research and development are also ties now face. Smaller scale, modular plants that focusing on making modular reactor systems, track load growth more flexibly are preferred in which could be constructed with shorter lead- these circumstances. times and less financial risk to the utilities, and on developing systems that use fuel more effi- Fuel.–The light-water reactor technology cur- ciently. rently used in fission reactors is capable of extracting only a small fraction of the energy po- The nuclear industry appears to have the potentially available from uranium fuel rods. In the tential to develop a superior advanced reactor, “once-through” fuel cycle currently in use, the and a number of designs for such powerplants fuel rods are withdrawn from the reactor and exist. However, it is less certain that public con- stored or disposed of once they become unusable. fidence in the nuclear industry will improve sig- With greatly expanded use of fission reactors of nificantly, particularly in the near term. Without this type, the demand for uranium would increase restoring public confidence, the long-term nu- and the supply of inexpensive uranium would clear option may be unattainable. eventually be depleted. At some point, the price of uranium would rise high enough to make light- Renewable Energy Technologies water reactor technology economically prohibi- In addition to coal-fired and nuclear fission tive, although current projections indicate that powerplants, there are several renewable energy such a point is not likely to be reached before technologies. Two well-developed renewable the middle of the next century. Advanced con- technologies currently contribute significantly to vertor reactors, which extract much more energy world energy supply: hydroelectric power and from the uranium fuel, are being developed and conventional biomass (wood), although only the could extend uranium supply still further. former is used significantly to generate electricity, If the price of uranium rises too high for even Several other technologies, such as wind, uncon- advanced convertor reactors to be economical ventional biofuels, solar photovoltaics, geother- on a once-through fuel cycle, other fuel cycles mal, solar thermal, and ocean energy, may offer may be possible. These fuel cycles are sufficient significant contributions during the 21st century.47 to give fission technology a very long-term re- Renewable energy sources are attractive be- source base. However, since these cycles involve cause many of them do not require construction the production, separation, and transportation of of large facilities for optimal economic operation fissionable fuel, they could increase the risk of and because their fuel supplies are continually nuclear proliferation over that of a once-through replenished. Other attractive features of some, fission economy. (See the discussion of “Nuclear but not all, of these technologies, according to Proliferation Potential” earlier in this chapter). an OTA report, “include fewer siting and regu- Research and Development.– It does not ap- latory barriers, reduced environmental impact, pear that nuclear fission technology is unusable and increased fuel flexibility and diversity.”48 or necessarily uneconomical. Extensive research is currently directed at developing advanced fission reactors that will be more acceptable to the qbsuch designs have been called “inherently safe. ’ However, in- public and more attractive to utilities; the intent herent safety in this sense differs from the usage adopted by the of this research is to demonstrate that future nu- ESECOM report and discussed earlier in this chapter in the section clear fission reactors with very different charac- on “Risk and Severity of Accident” under “Characteristics of Fu- sion Electric Generating Station s.” The ESECOM report found that teristics than current plants can be a viable source passively safe fission reactors–although having greater safety as- of electricity. in particular, the nuclear industry surance than existing nuclear plants—would not attain the highest is attempting to develop passively safe reactors levels of safety assurance, including the level ESECOM labeled “inherent safety. ” that could not release large amounts of radioac- 47 Energy Research Advisory Board, “Appendix D,” op. cit., P. 11. tivity due to operator error or mechanical mal- daNew Electric Power Technologies, Op. cit., P. 19. Ch. 5.—Fusion as an Energy Program ● 123

Problems associated with renewable energy Second, it appears possible to design fusion resources, however, may limit their role as major actors that will not depend on active safety sys- sources of electricity. Few of the technologies are tems to prevent serious accidents; such reactors currently economically competitive in other than could have a higher degree of safety assurance highly specialized applications. Many renewable than fission reactors. Finally, high levels of safety resources are only available intermittently, and assurance, environmental advantages, and inde- their availability depends on factors like the pendence from geographical constraints could weather and the time of day. Moreover, the avail- make siting a nuclear fusion powerplant consider- ability of renewable technologies depends on ably easier than siting a plant based on another geography and climate. The average amount of energy technology. avaiIable solar energy varies significantly across The ultimate feasibility of nuclear fusion will the United States, largely as a result of differing not be known until the technology is developed weather conditions. Wind energy is most effec- and can be compared with the other energy op- tively recovered in California and Hawaii. Finally, tions that exist at that time. At this point, it is only most renewable energy sources are diffuse, re- possible to make projections based on the char- quiring central-station powerplants to occupy acteristics of the technology and the research nec- more land than those using technologies such as essary to overcome problems identified to date. coal and fission. On the other hand, the diffuse nature of renewable also makes them well-suited Table 5-3 compares various future electricity for decentralized applications, which may offset supply options, based on extrapolations of cur- the need for large centralized facilities. rent technologies. On this basis, magnetic fusion has the potential to be a very attractive energy In general, both technical and economic im- source. Obviously, unanticipated developments provements are needed to make renewable in any of the technologies described in this ta- energy technologies competitive i n the 21st cen- ble could significantly alter their future role. tury. Research is being conducted on a wide variety of approaches for harnessing these energy sources, and significant improvements are likely. Fusion’s Energy Context Nevertheless, it is not expected that renewable The anticipated need for energy over the period technologies will eliminate the need for central- in which fusion wouId undergo commercializa- station generating technologies such as coal and tion will influence the urgency of fusion research nuclear fission. and the pace of its entry into the energy supply marketplace. OTA convened a workshop in No- Nuclear Fusion Technology vember 1986 to examine the factors that would Unlike the other supply options, nuclear fusion determine demand for electricity in general and is still in a pre-development stage. Much of the fusion in particular. Several points became clear 49 technology required for generating electricity during the discussion: from magnetic fusion has not been demonstrated, ● The overall size and composition of elec- and the commercial potential of fusion cannot tricity demand, by itself, should neither re- yet be determined. quire nor eliminate fusion as a supply op- Nuclear fusion appears to have attractive fea- tion. Economics and acceptability, rather tures. First, it could have significant environ- than total demand, will determine the mix mental advantages with respect to other central- of energy technologies. If fusion technology station generating technologies. The fusion proc- is preferable to its alternatives, it will be used ess does not produce CO2, nor—with appropriate choice of materials—does it appear that radio- AqFusion Energy Context Workshop, Office of “[ethnology Assess- active waste will be as high-level or as biologically ment, Washington, DC, Nov. 20, 1986. A list of participants is given hazardous as waste produced by nuclear fission. at the front of this report. 124 ● Starpower: The U.S. and the International Quest for Fusion Energy

Table 5-3.—Comparison of Prospective Long-Range Electricity Supply Options

Energy source Advantages Disadvantages and research needs Coal ● Plentiful ● Near-term environmental implications require de- Technology exists today velopment of “clean coal technologies” or fuel sub- Safe stitutions that may increase the cost of energy ● CO2 buildup may make increased dependence on fossil fuels undesirable Oil and gas ● Technology exists today ● Questionable long-term resource base ● ● Fewer combustion byproducts emitted than Does not avoid CO2 emission coal ● Less CO2 emitted per unit energy than coal Fission ● Plentiful ● Unfavorable economics and safety concerns suggest ● No emission of CO2 development of advanced reactor designs that are ● No emission of combustion byproducts smaller and passively safe ● Technology exists today ● Nuclear waste disposal not yet resolved ● Public confidence must be improved and may or may not result from technical improvements Renewable “ Unlimited fuel supply ● Uncertain economics and technical problems require ● No net CO2 emission more R&D ● Technologically simple ● Intermittence and diffuseness may make renewable ● Modular design inadequate substitute for central-station power generation in arbitrary locations Fusion Unlimited fuel supply ● Significant R&D effort required to establish technical Potential for higher degree of safety assur- feasibility ance than fission ● Environmental and safety potential highly dependent ● No CO2 production or combustion on design, especially on materials choice byproduct emission ● Economic potential unknown ● Substantially less hazardous nuclear waste than fission” SOURCE” Office of Technology Assessment, 1987.

to replace retired generating capacity even ● Given that technologies such as coal com- if overall demand is low. If fusion proves in- bustion and nuclear fission are already ferior to its competitors, it may not be used commercialized, fusion will have to prove even at very high demand levels. Fuel sup- better-not only comparable—before it can plies for both coal and nuclear fission are start to displace them. The criteria on which adequate to meet high levels of demand for fusion will be judged include economic, at least a few hundred years without fusion. safety and environmental issues as well as However, late in the next century, fission resource security. Advantages in one area may require the use of breeder reactors. may, but will not necessarily, compensate Should fusion technology prove favorable, for shortcomings in another. rapid growth in demand would facilitate its ● Potential problems with the major technol- introduction because the opportunities for ogies currently viewed as supplying electri- new powerplant construction would be city in the future provide incentives to de- greater. Nevertheless, demand alone cannot velop alternate energy technologies and/or turn an unattractive technology into an at- substantially improve the efficiency of en- tractive one. ergy use. Considerable expansion of coal use ● It is unlikely that any one technology will may prove undesirable due to the “green- take over the electricity supply market, bar- house effect”; safety or proliferation con- ring major difficulties with the others. At cerns may similarly impair expansion of the present, a number of supply technologies nuclear fission option. Over the long run, fu- have roughly equivalent marginal costs of sion could provide a substitute for these production, and all participate in the supply technologies. The urgency for developing fu- mix. sion, therefore, depends on assumptions of Ch. 5.—Fusion as an Energy Program ● 125

the likelihood that existing energy technol- sense. They are inherently simplified, and even ogies will prove undesirable in the future. if they accurately reflect the behavior of the sys- ● There is little to be gained and a great deal tem they represent, the input data they act on to be lost if fusion is prematurely intro- are in many cases highly uncertain. duced without attaining its potential eco- A recent review of a number of world energy nomic, environmental, and safety capabil- models discusses their respective methodologies ities. Even in a situation where problems and compares some of their results, finding that with other energy technologies urgently call there is more than an order of magnitude varia- for development of an alternative source of tion in their respective estimates for energy de- supply, that alternative must be preferable mand in the year 2050 (figure 5-3).50 The variation in order to be accepted. It would be unwise resuIts largely from differing input assumptions, to emphasize one fusion feature—economics as is shown by the fact that, for several of the or safety or environmental advantages—over models, a number of different projections are the others before we know which aspect will plotted based on different assumptions or differ- be most important for fusion’s eventual ent sets of input data. Nevertheless, unless it is acceptance. known which assumptions are correct, even a ● New energy technologies take a long time model known to be valid cannot produce valid to develop and gain wide use. It currently predictions. appears that it will be many decades before fusion will be able to supply a significant frac- The relative contributions of different forms of tion of U.S. electricity even under optimis- energy supply are no better determined than the tic assumptions concerning its technological total energy demands calculated by these models. development. The costs of different supply technologies cannot be known over the periods of interest and With respect to global energy demand, in par- must be assumed. The mix of supply technologies ticular, as a motivation for fusion, workshop par- computed by these models therefore depends ticipants discussed various estimates of future primarily on the corresponding input assump- energy demand. Models attempting to chart the tions. Furthermore, a detailed sensitivity analy- evolution of global energy demand over many sis using one global energy model shows that decades have been developed in the last few overall energy consumption figures appear to be years. Because the time periods of interest are much more sensitive to parameters relating to much too long for projections of recent experi- demand–e.g., relative rates of economic devel- ence to be valid, these models must instead simu- opment and productivity growth-than to param- late the future world economy and use of energy. 5 eters describing supply technologies and costs. 1 These models start with a number of assumptions concerning world economic and population This finding further reinforces the conclusion growth; the relationship between economic that predictions of future energy use provide lit- growth, technological development, and energy tle information about the demand for any par- use; and the resource bases and costs of various ticular supply technology. The urgency for de- energy technologies. The models calculate the veloping fusion technology, therefore, depends evolution of those parameters assumed to be de- on one’s assumptions as to the likelihood that terminants of energy use and then determine existing sources of energy supply cannot be desired outputs such as the supply and price of counted on in the future. Little justification can various types of energy. be provided from demand estimates alone.

These models are most useful for parametric SoBill Keepin, “Review of Global Energy and Carbon DIo\Kle l+)- analysis: What might be the consequences of jections, ” Annua/ Review of Energy, Jack Hollander, I+art m Brooks, some set of actions? Which parameters appear and David Stern llght (eds. ), vol. 11 (Palo Alto, CA: Annual Rejleih< to be the most sensitive determinants of future Inc., 1986), p. 357. 5 I j .M. Rei I!y, j .A. Ed mods, R. H. Gardner, and A. L. B ren ken, ‘‘~’ n- demand? The models are, however, much less certalnty Analysis ot the I EA/ORAU CO1 Emlsslons Model ‘‘ Energ}f able to project future behavior in any absolute )ourna/, vol. 8, No. 3, July 1987, pp. 1-30. 126 ● Starpower: The U.S. and the /international Quest for Fusion Energy

Figure 5-3.—Projections of Global Primary Energy Consumption to 2050

Edmonds 85 (z 95th) NY (high). • • Edmonds 84 (high) 55

o :!:.. 40 c:: o ~ E 35 ::J IJ:l c:: 8 30 >- e> Q) tfi 25 ~ to .§ 20 a. C:;j .c o 15 B

I~U 2UUU 2020 2040

Year '~T: IIA;:'A: International Institute for Applied Systems Analysis, Energy in a Finite World: A Global Systems Analysis (Cambridge, MA: Ballinger, 1981). _OVtns: Lovins, A.B., Lovins, LH., Krause, F., and Bach, W., Least Cost Energy: Solving the CO. Problem (Andover, MA: Brick House, 1982). rvt:v ..vorld Energy Conference, Energy 2O(J()-2020: World Prospects gnd Regions Stresses, J.R Frisch (ed.), World Energy Con· ference Conservation Commission (London: Graham & Trot· 'TIan, 1983). ~ T: Nordhaus, W.O., and Yohe, G., "Future Paths of Energy and :;arbon Dioxide Emissions, Changing Climate (Washington, JC: National Academy of Sciences, 1983). 1111 tL: ~ose, D.J., Miller, M.M., and Agnew, C., Global Energy Futures ind CO,-Induced Climate Change, MITEL 83'()15 (Cambridge, \4A: MIT Energy Laboratory, 1983). J.S. Environmental Protection Agency, Warning: Can We ')elaya Greenhouse Warming? S. Seidel and D. Keyes (eds.) Washington, DC: U.S. Environmental Protection Agency, 1983). :dmonds, J., and Reilly, J., "Global Energy and CO. to the fear 2050," Energy Journal 4(3):21-27, 1983. :dmonds 84: Edmonds, J., Reilly, J., Trabalka, J.R, and Reichle, D.E., An Analysis of Possible Future Atmospheric Retention of Fos· sll Fuel CO" Report No. DOElORI21400-1 (Washington, DC: U.S. Department of Energy, 1984). :dmonds 85: Edmonds, J., Reilly, J., Gardner, R, and Brenkert, A., Uncer tainty In Carbon Emissions, 1975-2075, Report of the Carbon Dioxide Emissions Project (Oak Ridge, TN: Institute for Energy AnalySis. 1985). 20ldemberg: Goldemberg. J., Johansson, T.B., Reddy, A.K.N., and Williams, RH., "An End-Use Oriented Global Energy Strategy," Annual levlew of Energy, Jack Hollander, Harvey Brooks, and David iternlight (eds.), vol. 10 (Palo Alto, CA: Annual Reviews Inc., 985), pp. 613·88.

iQURGE: Bill Keepin, "Review of Global Energy and Carbon Dioxide Projections," Annual Review of Energy, vol. 11, 1986, figure 2, p. 364. Data points are keyed to different models analyzed in that paper. Ch. 5.—Fusion as an Energy Program ● 127

CONCLUSIONS

Characteristics of Fusion Reactors opment. Existing studies tend to show the cost of electricity from present fusion designs would Fusion reactors appear to have the potential, be somewhat more expensive than that of exist- using only passive systems, to assure safe opera- ing energy supplies. However, these studies can- tion and shutdown in the event of accident, mal- not be considered definitive for a number of rea- function, or operator error. If this potential for sons. First, any comparisons between prospective a high degree of safety assurance is realized, a technologies and existing ones are highly uncer- fusion reactor would be easier to certify as safe tain, considering the disparate levels of develop- than a reactor that depends on active safety sys- ment. Second, fusion’s costs are difficult to estimate tems, such as today’s fission reactors. Moreover, because substantial research and development fusion reactors do not appear likely to pose new remains to be done. Technical features that may types of occupational hazards. lead to decreased fusion costs are being explored, With proper choice of materials, the environ- and the ultimate success of these features is un- mental characteristics of fusion reactors would certain. Alternatively, technical problems that likely be preferable to other energy technologies. drive up the cost maybe encountered. More sig- Unlike fossil fuel combustion, fusion does not nificantly, fusion’s economics will be profoundly produce carbon dioxide that could contribute to affected by non-technical factors— e.g., the ease overall global warming. Fusion reactors will pro- and length of the construction and licensing proc- duce radioactive waste, but these wastes should esses—whose impact on fusion costs is not well be less radioactive, less hazardous, and easier to understood at present. Finally, the costs for fu- dispose of than those from nuclear fission re- sion’s potential competitors are uncertain. actors. However, fusion reactor designs can differ by orders of magnitude in the amount of radioactive waste to be generated. In principle, waste Timetable for Fusion Power generation can be greatly minimized by the use Considering the remaining technical research of materials that would not generate long-lived to be done and the time period needed for the radioactive isotopes inside a fusion reactor; such commercialization process to result in substan- materials must still be developed and tested. Rou- tial market penetration, it does not appear likely tine radioactive emissions from fusion reactors that fusion will be able to satisfy a significant frac- are expected to be insignificant. tion of the Nation’s electricity demand before the One of the most attractive features of fusion middle of the 21st century. The degree to which is its essentially unlimited fuel supply. Sufficient fusion is indeed able to penetrate the energy mar- deuterium is available and recoverable at low ket depends on how effectively it meets the needs cost from water to provide energy for billions of of its customers in comparison with other energy years at present rates of use. The lithium needed technologies. Although the needs of 21st century to breed tritium in D-T reactors is not as plenti- utilities cannot be predicted with confidence, a ful as deuterium, but it is nevertheless present in number of features desirable to utilities today can sufficient quantity that supply of adequately priced be identified. Economic competitiveness is cer- fuel is very unlikely to constrain the prospects of tainly one of the most important; other crucially D-T fusion over any time of conceivable inter- important attributes are plant capital cost, safety, est. Pending detailed fusion reactor designs, other licensability, and maximum financial liability in resource requirements are harder to estimate; case of accident. Developing fusion reactors with however, there is no reason to believe that other high degrees of safety assurance would make fu- resource requirements will constrain fusion’s de- sion attractive in many of these respects. velopment. Competitors with fusion have the potential to Projections of the economics of fusion reactors supply most or all of the electricity required by are inconclusive at this stage of fusion’s devel- the United States in the first half of the next cen- 128 ● Starpower: The U.S. and the International Quest for Fusion Energy

tury; the overall size of future electricity demand suppliers of electricity that could make fusion the should neither require nor eliminate fusion as a technology of choice. The degree to which fu- supply option. However, there are potentially sion will replace its competitors is impossible to fundamental problems involving the alternate predict today. Chapter 6

Fusion as a Research Program .

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,...., ● *,*... ● o 147 Chapter 6 Fusion as a Research Program

The ultimate objective of fusion research is to A complete analysis of the fusion energy program produce a commercially viable energy source. must include the immediate, indirect benefits and Yet, because the research program is exploring costs of the ongoing research effort, in addition new realms of science and technology, it also pro- to its progress in reaching its long-term goal. vides a weal h of near-term, non-energy benefits.

NEAR-TERM BENEFITS

Fusion research has provided four major near- and fluid dynamics. Today, plasma physics goes term, non-energy benefits. It has been a driving beyond fusion research. Since most known mat- force behind the development of plasma physics. ter in the universe is in the plasma state, plasma It educates plasma physicists who contribute to physics is central to our understanding of nature fusion and other fields. It produces technologies and to the fields of space science and astrophysics. with valuable applications elsewhere, and it has Theories and techniques developed in plasma put the United States in a strong position in the physics are providing fundamental new insights world scientific community. into classical physics and are opening up new areas of research.

Development of Plasma Physics The field of plasma physics has grown rapidly The development of the field of plasma physics since the 1950s. When the American Physical So- ciety formed the Division of Plasma Physics in was driven by the needs of scientists working on 1958, for example, the division had less than 200 controlled thermonuclear fusion and space science and exploration. In the case of fusion energy, members. Today, the Division of Plasma Physics is one of the society’s biggest groups, with almost The simultaneous achievement of high temper- 3,400 members. The careers of most of these atures, densities, and confinement times [needed members originated in magnetic fusion-related for a plasma to generate fusion power] required work. In addition, over 40 American universities significant improvements in forming and under- now have major graduate programs in plasma standing plasmas confined by magnetic fields or physics and/or fusion technology. Graduate level by inertial techniques.l plasma physics courses are also taught in applied Thus, research conducted on the prospects of fu- mathematics and in electrical, nuclear, aeronau- sion energy necessitated concurrent advances in tical, mechanical, and chemical engineering de- the area of plasma physics, and, in fact: partments.

The international effort to achieve controlled As shown in figure 6-1, the Department of thermonuclear fusion has been the primary stimu- Energy (DOE) has played a major role in plasma lus to the development of laboratory plasma physics research, funding over three-quarters of 2 physics. federally sponsored plasma physics research in The field of plasma physics has synthesized fiscal year (FY) 1984. Virtually all DOE support many areas of physics previously considered dis- was directed at fusion applications; 72 percent tinct disciplines: mechanics, electromagnetism, of DOE’s funding was dedicated to the magnetic thermodynamics, kinetic theory, atomic physics, fusion program, 26 percent funded the inertial confinement fusion program, and only 2 percent ($3 million, in 1984 dollars) was directed at gen- 1 National Research Council, Physics Through the 1990s: F%srnas and F/uids (Washington, DC: National Academy Press, 1986), p. 5. eral plasma physics. Outside of the fusion ap- ~lbid. plications, Federal funding for plasma physics

131 132 ● Starpower: The U.S. and the International Quest for Fusion Energy

Figure 6-l.— Federal Funding of Plasma Physics Although DOE supports the education of most in 1984 of the Nation’s plasma physics graduates, the de- NOAA (0.2°/0) partment does not have the resources to employ many of these people. A large fraction of the Na- tion’s plasma physicists are engaged in defense- related work;5 plasma physicists also work in universities, private industry, and the National Aeronautics and Space Administration (NASA) space science program. Education in plasma physics and fusion research enables these scientists to “make major contributions to defense applications, space and astrophysical plasma physics, materials science, applied mathematics,

computer science, and other fields."6

Advancing Science and Technology

Many high-technology R&D programs produce secondary benefits or “spin -offs.” Spin-offs are not unique to particular fields of research, since extending the frontiers of practically any technology can lead to external applications. Although spin-offs may benefit society, they are unanticipated results of research and should not be viewed research is very limited. A National Research as a rationale for continuing or modifying high- Council report concluded that “support for basic technology research programs. Spin-offs may not plasma physics research has practically vanished be efficient mechanisms of developing new or in the United States, ” with only the National Sci- useful technologies, compared to programs dedi- ence Foundation providing funds “clearly for this cated specifically to those purposes. Moreover, purpose.” 3 applications of new technologies are often drawn from several fields and may not be attributable Educating Plasma Physicists to any particular one.

Educating plasma physicists, as well as other Over the years, fusion research has contributed scientists and engineers, is one of the most widely to a variety of spin-offs in other fields. While the acknowledged benefits of the fusion program. program cannot claim sole credit, each of the in- Over the last decade, DOE’s magnetic fusion novations listed below has at least one key ele- 7 program has supported the education of almost ment that came from the fusion program. all of the plasma physicists trained in the United ‘Energy Research Advisory Board, Review of the National Re- 4 States. This achievement is due largely to DOE’s search Council Report: Physics Through the 1990s, prepared by commitment to maintaining university fusion pro- the Physics Review Board for the U.S. Department of Energy, Feb- ruary 1987, p. 44. grams during a period when budget reductions ‘Ronald C. Davidson, “Overview of Magnetic Fusion Advisory have forced other agencies to curtail their fund- Committee Findings and Recommendations, ” presentation to ing of plasma physics research. In addition, DOE Energy Research Advisory Board Fusion Panel, Washington, DC, June 25, 1986. provides 37 fusion fellowships annually to qual- This list is drawn from three reports: U.S. Department of Energy, ified doctoral students. Office of Energy Research, Technology Spin-offs From the Magnet\c Fusion Energy Program, DOE/ER-01 32, May 1982; U.S. Department of Energy, Office of Fusion Energy, Technology Spinoffs From the Jlbid., p. 97. Magnetic Fusion Energy Program, DOE/ER-01 32-1, February 1984; 4John F. Clarke, Director, DOE Office of Fusion Energy, P/asrna and U.S. Department of Energy, Office of Energy Research, The Physics Within DOE and the Academy Report-Physics Through Fusion Connection, DOE/ER-0250, October 1985. For more infor- the 1990s, Department of Energy, Office of Fusion Energy, July 1986, mation about the role of these technologies and others in magnetic p. 5. fusion research, see ch. 4. Ch. 6.—Fusion as a Research Program . 133

Contributions to Industry magnetic fusion program in the development of neutral beams and accelerators for free electron Certain phenomena associated with fusion re- lasers have been instrumental to the development search have proven particularly applicable to the of directed-energy weapons necessary for SDI ap- development of electronic systems and industrial plications. manufacturing processes. Plasma etching is an important process in the semiconductor industry. Fusion research has provided information Contributions to Basic Science necessary to characterize and understand the Plasma physics is by now considered one of process more completely and also has contrib- the core areas of physics research. Advances uted plasma diagnostics that can be used to mon- made in the fusion program in the understand- itor the etching process. ing of plasma phenomena have been used by Microwave electronics is another fusion con- NASA, the Department of Defense (DoD), and tribution that has both civilian and military ap- others. Moreover, the fusion program has sup- plications. Microwave tubes and plasmas share ported basic atomic physics research for more certain physical principles of operation, and ad- than two decades in order to develop detailed vances in the understanding of basic plasma knowledge of fundamental atomic and molecu- physics have contributed to improvements in lar processes influencing plasma behavior. microwave technology. The fusion program has Magnetic fusion research requires computa- also fostered development of the microwave in- tional methods and facilities that are not avail- dustry through its requirements for high-frequency, able in other disciplines. Thus, the magnetic fu- high-power microwave sources, such as the gy- sion program leads the way in the acquisition and rotron. Typical applications of microwave tech- use of state-of-the-art computers. The Magnetic nology include high-power radar stations, tele- Fusion Energy Computing Center’s (MFECC) sys- vision broadcasting, satellite communications, tem of Cray computers and the satellite network and microwave ovens. system installed for these computers are impor- Plasma physics phenomena studied in the fu- tant advances in computer technology. In addi- sion program also have significant applications tion, the fusion program has developed advanced i n the plasma coating and surface modification computational methods in order to model and of industrial materials. Plasma coating is impor- analyze plasma behavior. tant to the manufacturing industry because it may Finally, fusion research has contributed to the enable materials to better resist wear and corro- development of plasma diagnostic technologies sion. Finally, fusion experimental facilities use so- that have commercial, scientific, and defense ap- phisticated power-handling technologies; electric plications. The demands of fusion research on utilities are interested in the near-term applica- diagnostic instrumentation are extremely exact- tions of these technologies. ing. Not only are plasmas very complex phenomena, but measurements of their characteris- Contributions to National Defense tics must be made from the outside of the plasma Although magnetic fusion research has no di- so as not to affect it. Therefore, considerable de- rect application to military uses, the fusion pro- velopment of sophisticated instrumentation has gram has contributed to the national defense. The been required throughout the history of fusion most valuable contributions are in the background research. plasma physics research conducted by the fusion program and the education of scientists that later Stature are hired by defense programs. in addition, many scientific ideas and technological developments The stature of the United States abroad bene- being investigated under the Strategic Defense fits from conducting high-technology research. Initiative (SDI) grew out of research in the fusion The United States has been at the forefront of fu- program. For example, contributions made by the sion R&D since the program was initiated in the

134 ● Starpower: The U.S. and the International Quest for Fusion Energy

1950s. Maintaining a first-rate fusion program has grams to the United States, and has enhanced the placed the United States in a strong bargaining reputation of the United States in scientific and position when arranging international projects, technical programs other than magnetic fusion. has attracted top scientists from other fusion pro-

NEAR-TERM COSTS Magnetic Fusion Funding Comparing Fusion to Other Government R&D The fusion program utilizes both financial and The Federal budget for R&D has grown stead- personnel resources. This section analyzes the ily during the 1980s, in real terms. The bulk of monetary cost of fusion research by providing a this growth has been driven by increases in de- sense of context for fusion expenditures. Fusion fense R&D spending, which almost doubled be- expenditures are compared to other government tween 1982 and 1987. Non-defense R&D has also R&D programs and to energy R&D programs in grown, though only 15 percent over the same particular. period (see figure 6-2).

Figure 6-2.-Defense and Civilian Federal R&D Expenditures (in current dollars)

1982 1983 1984 1985 1986 1987 1988 (estimate) (request) Year

■ Defense ❑ Civilian Ch. 6.—Fusion as a Research Program ● 135

Figure 6-3.–Major Components in Federally high energy physics and nuclear physics pro- Funded R&D in Fiscal Year 1987 grams. DOE conducts most Federal energy R&D; the Nuclear Regulatory Commission and the Envi- ronmental Protection Agency also conduct limited energy research.

Those Federal R&D programs with budget authority estimated at over $200 million in FY 1987 are listed in table 6-1.8 The intent of this table is to provide a context for the fusion program by depicting its relative funding commitment. The table is not intended to compare the magnetic fusion program to other programs, because the programs listed are not directly comparable. Some are near-term efforts; others—like fusion— are very long-term. Some, also like magnetic fusion, are focused on a single primary application; others, like the cancer research conducted by NIH, encompass a wide range of smaller subprograms. The balance between research and development varies considerably as well. DoD’s large research, development, and testing programs include a small amount of research and a great deal of development and testing, whereas NSF’s programs, for example, are almost entirely pure research. As the table shows, the largest Federal R&D programs are defense-related. Magnetic fusion is DOE’s fifth largest R&D program, following weapons R&D and testing, naval reactor development, high energy physics, and basic energy sciences. Although table 6-1 provides a sense of scale between magnetic fusion research and other Fed- eral R&D programs, it cannot be used to compare the programs themselves or the decisions by which these programs are funded. The criteria by which funding decisions are made in different agencies and departments are not consistent, and the degree of competition for funds between programs–either within a specific office or between offices, agencies, or departments—is dif- The next largest identifiable blocks of Federal ficult to measure. The budgets of different pro- R&D funding, each of approximately equal size, grams are prepared separately within the executive are space, health, energy, and general science branch and considered separately in Congress. research. Space activities are conducted by NASA. Most health-related research is conducted by the 8A distinction is made between Budget Authority and Budget Out- Department of Health and Human Services, lay. Budget authority denotes how much a program could spend. through the National Institutes of Health (NIH). In some cases, however, actual budget outlays (what the program did spend) will differ from the budget authority. A program may Most general science research is carried out by spend less than its budget authority, or more if it has accrued saw the National Science Foundation (NSF) and DOE’s ings from previous years. 136 . Starpower: The U.S. and the International Quest for Fusion Energy

Figure 6=4.—Historical Component Funding Levels of Federal R&D Programs (in currant dollars)

Energy Space Health

Overall comparisons of one program to another Comparing Fusion to Energy R&D are typically made only at the highest levels of aggregation, if at all. Since 1980, significant shifts in the emphasis of DOE appropriations have occurred. The de- In addition, this table does not represent a com- partment has focused more heavily than it did plete picture of all research undertaken by the previously on atomic energy defense activities U.S. economy. It only measures Federal invest- and less heavily on activities conducted by civil- ments, and in many programs there is substantial ian programs, while overall DOE appropriations private sector involvement. Total private sector have decreased. Thus, civilian programs have investment in R&D activities for 1987 is estimated competed for a smaller piece of a shrinking pie, at $60 billion, about the same as Federal R&D resulting in serious financial pressure on civilian investment for that year. g energy R&D. This shrinkage is in large part due

gNational Science Foundation, Division of Science Resources to the Reagan Administration policy that devel- Studies, Science and Technology Data Book 1987 (Washington, opment of near-term technology for civilian ap- DC: National Science Foundation, 1986), NSF-86-31 1, figure 1, p. 3. plications is better left to the private sector. Ch. 6.—Fusion as a Research Program ● 137

Table 6-1 .—Federally Funded R&D Programs With Budget Authority Over $200 Million in Fiscal Year 1987

Fiscal year 1987 Fiscal year 1987 Research and development budget estimatea Research and development budget estimatea program name ‘ (millions) program name (millions) Department of Defense ...... $ 38,374.5 Department of Health and Human Army ...... ($ 4,754.6) Services ...... $ 6,709,8 Navy ...... ($ 9,381.9) Alcohol, Drug Abuse and Mental Air Force ...... ($ 15,416.8) Health Administration ...... ($ 569.4) Defense agencies ...... ($ 7,185.5) General Mental Health ...... [$ 307.5] Strategic Defense Initiative...... [$ 3,743.4] National Institutes of Health ...... ($ 5,853.2) b Defense Advanced Research Cancer ...... [$ 1,371 .5] Projects Agency ...... [$ 785.2] Heart, Lung, and Blood ...... [$ 891 .2] Office, Secretary of Defense...... [$ 569.1] Allergy and Infectious Diseases. . . [$ 535.6] Defense Nuclear Agency ...... [$ 306.0] Diabetes, Digestive and Kidney Diseases ...... [$ 488.2] Neurological and Communicative National Aeronautic and Space Diseases and Stroke ...... [$ 476.5] Administration ...... $ 3,127.7 Child Health and Human Space Station ...... ($ 420.0) Development ...... [$ 352.5] Space Transportation Capability Eye ...... [$ 211 .1] Development ...... ($ 495.5) Environmental Health Sciences . . . [$ 200.4] Space Science and Applications . . . . $ 1,552.6) National Science Foundation ...... 1,520.3 Physics and Astronomy ...... 552.8] $ Mathematical and Physical Planetary Exploration ., ...... [$ 358.4] Sciences. , ...... 463.4) Environmental Observations . . . ., . 320.9] ($ [$ Biological, Behavioral, and Social Aeronautics and Space Sciences ...... ($ 257.7) Technology ...... ($ 592.0) Geosciences ...... 284.6) Aeronautical research and ($ technology ...... [$ 376.0] Department of Agriculture...... 1,027.5 Agricultural Research Service ...... (: 523.3) Cooperative State Research Service . ($ 300,3) Department of Energy ...... $ 5,561.1 Department of Interior ...... 362.2 Energy Supply R&D ...... ($ 1,498.6) Geological Survey...... (: 208.6) Basic Energy Sciences ...... [$ 470.6] Department of Transportation ...... $ 285.2 Magnetic Fusion ...... [$ 345.3] Department of Commerce ...... 401.6 Nuclear Energy ...... [$ 325.9] $ National Oceanic and Atmospheric General Science and Research . . . . . ($ 716.8) Administration ...... 287.5) High Energy Physics ...... [$ 499.7] ($ Nuclear Physics ...... [$ 217.1] Environmental Protection Agency . . . . . $ 343.4 Atomic Energy Defense Activities . . . ($ 2,785.7) Veterans Administration ...... $ 225.3 Weapons R&D and Testing ...... [$ 1,882.2] Agency for International Naval Reactors Development . . . . . [$ 563.8] Development ...... $ 224.2 aValues denoted with "( )" comprise programs included within the preceding department total. and values denoted with “[ ]“ comprise subprograms included within the preceding program total Only departments, programs, and subprograms with an annual budget over $200 million are listed; therefore, the listed program and subprogram budgets may not total the preceding departmental or program budget bTotal program budget given for the National Institutes of Health Includes an overall reduction of $67.1 million, which has not been allocated among individual Institute subprogram budgets in these figures SOURCE American Association for the Advancement of Science, Intersociety Working Group, AAAS Report Xll: Research and Development FY 1988 (Washington, DC American Association for the Advancement of Science, 1987)

Though magnetic fusion has fared better than Unlike short-term energy development, the many other energy programs, its budget has long-term, high-risk nature of the fusion energy fallen significantly in recent years. From a peak program satisfies the criteria of the Reagan Ad- of $659.7 million in FY 1977 (in 1986 dollars), ministration’s science and technology policy. funding for the fusion program has declined by Long-term, research-oriented programs like fu- over half, to a level of $319.1 million in FY 1987 sion have been able to maintain Federal budget- (in 1986 dollars) .10 Figure 6-5 illustrates the recent ary support because, although there is a poten- budgets of DOE’s larger energy R&D programs. tially high payoff, there is currently little incentive —..— — -—.. I t)gud~et \ alues and I nflatlon i nd Ices were pro~lded by J. Ronald of Energy, Off Ice of Energy Research, letter to the Office of Tech- Young, Director of the Ot’t’lce ot Management, U.S. Department nology Assessment, Aug. 15, 1986. 138 . Starpower: The U.S. and the International Quest for Fusion Energy

Figure 6-5.—Annual Appropriations of DOE Civilian R&D Programs (in current dollars)

3.2 I

0.6

0.4

0.2 0

for industrial involvement. Even if the risks were The most expensive fusion projects to date are not high, the benefits are so far off that their the Tokamak Fusion Test Reactor (TFTR) and the present value is not sufficient to interest private Mirror Fusion Test Facility (MFTF-B), which are investors today. Virtually all fusion research is an order of magnitude more expensive than other funded by the Federal Government. DOE’s pro- confinement experiments. In part, TFTR and grams in nuclear energy, fossil fuels, conserva- MFTF-B were more expensive than other exper- tion, and renewable energy, on the other hand, iments because they required development of an have lost much of their Federal support because extensive supporting infrastructure as well as con- it is believed that industry financing is appropri- struction of the actual device. In addition, these ate in these cases. facilities are more advanced and much larger than the experiments constructed on alternative Costs of Fusion Facilities concepts. Table 6-2 lists the total construction costs of The next facility the U.S. fusion program plans some representative fusion program experiments.11 to construct, the Compact Ignition Tokamak

I I For information about the technical details of many of these (ClT), has an estimated cost of $360 million. It projects, see ch. 4. is proposed to be built at Princeton Plasma Physics Ch. 6.—Fusion as a Research Program ● 139

Table 6-2.—Cost of Representative Fusion Experiments

Construction cost Experiment Location Type (millions of 1987 dollars) Tokamak Facility Test Reactor...... PPPL Tokamak $562 Mirror Fusion Test Facility-B ...... LLNL Tandem Mirror $330 Doublet Ill ...... GA Tokamak $ 56a Doublet III-D (Upgrade) ...... GA Tokamak $ 36a International Fusion Superconducting Magnet Test Facility . . .ORNL Magnet Testb $ 36C Poloidal Divertor Experiment , ...... PPPL Tokamak $54 Princeton Large Torus ...... PPPL Tokamak $43 Tritium Systems Test Assembly ...... LANL Tritium Testb $26 Tandem Mirror Experiment ...... LLNL Tandem Mirror $ 24 Tandem Mirror Experiment Upgrade ...... LLNL Tandem Mirror $23 Texas Experimental Tokamak ...... UT Tokamak $ 21 Advanced Toroidal Facility ...... ORNL Stellarator $ 21 TARA ...... , ..MIT Tandem Mirror $ 19 ZT-40 ...... LANL Reversed-Field Pinch $17 Alcator C ...... MIT Tokamak $ 15 Rotating Target Neutron Source ...... LLNL Materials Testb $11 Impurity Studies Experiment-B ...... ORNL Tokamak $5 Field Reversed Experiment-C ...... LANL Field-Reversed $3 Configuration Phaedrus ...... UW Tandem Mirror $ 1.8 Macrotor...... UCLA Tokamak $ 1.5 IMS ...... UW Stellarator $ 1.4 Tokapole ...... UW Tokamak $ 0.6 KEY PPPL—Princeton Plasma Physics Laboratory, Princeton, New Jersey LLNL—Lawrence Livermore National Laboratory, Livermore, California ORNL—Oak Ridge National Laboratory, Oak Ridge, Tennessee GA—GA Technologies, Inc. San Diego, California LANL—Los Alamos National Laboratory, Los Alamos, New Mexico UT—University of Texas, Austin, Texas MlT—Massachusetts Institute of Technology, Cambridge, Massachusetts UW—University of Wisconsin, Madison, Wisconsin UCLA—University of California, Los Angeles, California aValues shown for the combined Doublet III facility and upgrade do not Include an additional $54 million (in current dollars) of hardware provided by the government of Japan or $36 million (in 1987 dollars) for a neutral beam addition bThese facilities are fusion technology facilities; all others on the table are confinement physics experiments. CThe cost of this facility does not include the cost of the six magnet coils that are being tested there. It is estimated that the magnet coils cost between $12 million and $15 million each (in current dollars) SOURCE US Department of Energy, Office of Fusion Energy, 1987

Laboratory, where it can take advantage of the Magnetic Fusion Personnel Iab’s existing infrastructure. With initial construc- The fusion program currently supports approx- tion funds requested in the FY 1988 DOE bud- imately 850 scientists (almost all Ph.D.s), 700 get, CIT will be the largest fusion project under- 12 taken in recent years. engineers, and 770 technicians. These researchers work primarily at the national laboratories and Looking beyond CIT, the U.S. fusion program in the university and college fusion programs. Be- sees a next-generation engineering test reactor cause the size of the labor pool responds to shifts as necessary during the 1990s. Funding for this in the demand for labor, and because the long- device, which is projected to cost well overabil- term value of having a person work on one pro- Iion dollars, has not been requested by or appropriated to DOE. A recent DOE proposal to un- I ZThOrna5 G. Finn, u. S. Ckpa rtment of Energy, Office Of Fu SiO n dertake international conceptual design and Energy, letter to the Office of Technology Assessment, Mar. 12, supporting R&D is currently being considered. 1987. The number of technicians represents only full-time staff asso- lf successful international construction and oper- ciated with experiments; shop people and administrative staff are not included. Figures for scientists and engineers include u n ive r- ation of the device couId follow the design phase sity professors and post-doctoral appointments; graduate student of the project (see ch. 7). employees are not included. 140 ● Starpower: The U.S. and the International Quest for Fusion Energy

gram as opposed to any other is difficult to meas- out Ph.D.s, and the staffs of smaller fusion re- ure, it is hard to quantify the implications of search centers, have also declined substantially. dedicating scientific and engineering manpower A recent study for the National Academy of Sci- to the fusion program. The value of the fusion ences predicts that if recent funding trends con- program for training plasma physicists, however, tinue, the fusion program could lose 345 Ph.D.s cannot be denied. The fusion program trains far between 1985 and 1991. Most fusion research- more people than it employs, and these people ers who have left the fusion program have found make valuable contributions in a variety of fields work easily in other research programs within other than fusion. DOE and DoD. Many former fusion researchers are working on SDI. As the mobility of fusion re- According to DOE, since 1983 the number of searchers shows, these individuals have skills that Ph.D. staff positions at the major national fusion are in demand in many areas. research centers has declined by almost 20 percent. Personnel levels among individuals with-

PARTICIPATION IN MAGNETIC FUSION RESEARCH

DOE’s Office of Fusion Energy (OFE) funds re- involvement of the national laboratories in the search conducted by three different groups: na- research program will remain important at least tional laboratories, colleges and universities, and until the technology is transferred to the private private industry. Each of these groups has differ- sector for commercialization. The four major fu- ent characteristics, and each plays a unique role sion laboratories are described below, in decreas- in the fusion program. ing order of their share of the FY 1987 fusion budget. Department of Energy National Laboratories Princeton Plasma Physics Laboratory The Princeton Plasma Physics Laboratory (PPPL), DOE’s national laboratories play an important located in Princeton, New Jersey, is one of the role both in the fusion program and in the de- fusion program’s oldest and most important fa- partment’s general energy R&D. Figure 6-6 depicts cilities. It is located on Princeton University’s DOE’s distribution of laboratory funding among James Forrestal Campus, and, in FY 1987, PPPL various subject areas. A list of DOE’s major na- is estimated to receive the largest share of DOE’s tional laboratories, showing the extent of their magnetic fusion budget of any single institution fusion participation, is shown in table 6-3. (27 percent).14 PPPL is a program-dedicated lab- National laboratories are generally government- oratory, which means that virtually all of its re- owned, contractor-operated facilities. Most of search involves magnetic fusion. The bulk of them were created during or shortly after World PPPL’s budget is used to operate TFTR, the largest War II to conduct research in nuclear weapons U.S. tokamak experiment. TFTR is one of two and nuclear power development. Four DOE na- operational experiments in the world designed tional laboratories have major research programs to burn D-T fusion fuel, the other being the Euro- in magnetic fusion. It is estimated that these lab- pean Community’s Joint European Torus.15 In oratories will conduct over 70 percent of the mag- addition to TFTR, PPPL operates other smaller netic fusion R&D effort in FY 1987. According to tokamak experiments. DOE, the laboratories “are a unique tool that the United States has available to carry on the kind of large science that is required to address certain problems in fusion. ” It is expected that the laBased on U.S. Depaflment of Energy, FY 1988 Congression Bud- get Estimates for Lab/Plant, January 1987.

13john F, Clarke, Director, DOE Off Ice of Fusion Energy, ‘ ‘plan- Is prl nceton plasma physics Laboratory, A n Overview. Princeton ning for the Future, ’ /ourna/ of Fuwon Energy, vol. 4, nos. 2/3, June P/asrna Physics Laboratory, April 1985, p. 5. For more information 1985, p, 202. on TFTR and other experiments, see ch. 4. Ch. 6.—Fusion as a Research Program c 141

Figure 6-6.—Major DOE Civilian R&D Funding at DOE’s magnetic fusion energy budget.16 LLNL has National Laboratories in Fiscal Year 1987 concentrated on tandem-mirror systems, and most of the experimental facilities at the laboratory have explored the capabilities of this confinement scheme.17 The major magnetic fusion facility at LLNL is MFTF-B, a project that was moth balled in 1986, due to budget cuts, just weeks after construction was completed; MFTF- B has never operated. In addition to MFTF-B, there is another significant tandem-mirror facility at LLNL—the Tandem Mirror Experiment Up- grade (TMX-U), which has also been terminated. LLNL is now installing a small tokamak experiment and has been given responsibility for the design of the next-generation engineering test reactor. LLNL also operates the Magnetic Fusion Energy Computing Center for DOE. Moreover, LLNL conducts the largest component of the Na- tion’s inertial confinement fusion research programs (see app. B). Lawrence Livermore National Laboratory In FY 1987, it is estimated that Lawrence Liver- IGBased on U.S. Department of Energy, FY 1988 congressional Budget Estimates, op. cit. more National Laboratory (LLNL), located in 1 TFor technical information on the tandem m i rror configuration, Livermore, California, will receive 15 percent of see ch. 4.

Table 6.3.—DOE’S Major National Laboratories

Magnetic Laboratory Location fusion research Ames Laboratory ...... Ames, IA None Argonne National Laboratory...... Argonne, IL Minor Bettis Atomic Power Laboratory ...... West Mifflin, PA None Brookhaven National Laboratory...... Upton, NY None Fermi National Accelerator Laboratory ...... Batavia, IL None Hanford Engineering Development Laboratory...... Richland, WA Minor Idaho National Engineering Laboratory ...... Idaho Falls, ID Minor Knolls Atomic Power Laboratory ...... Schenectady, NY None Lawrence Berkeley Laboratory ...... Berkeley, CA Minor Lawrence Livermore National Laboratory ...... Livermore, CA Major Los Alamos National Laboratory...... LOS Alamos, NM Major Mound Laboratory ...... Miamisburg, OH None Nevada Test Site ...... Mercury, NV None Oak Ridge National Laboratory ...... Oak Ridge, TN Major Pacific Northwest Laboratory ...... Richland, WA Minor Paducah Gaseous Diffusion Plant ...... Paducah, KY None Pinellas Plant ...... St. Petersburg, None Portsmouth Gaseous Diffusion Plant...... Piketon, OH None Princeton Plasma Physics Laboratory ...... Princeton, NJ Major Rocky Flats Plant ...... Golden, CO None Sandia National Laboratory ...... Albuquerque, NM Minor Savannah River Plant ...... Aiken, SC None Stanford Linear Accelerator Laboratory ...... Stanford, CA None KEY: None - No magnetic fusion funding. Minor - Fusion funding is less than $10 million in fiscal year 1987. Major - Fusion funding is more than $10 million in fiscal year 1987. SOURCE: Office of Technology Assessment, 1987.

Oak Ridge National Laboratory ment programs. In addition, ORNL is the host for the Fusion Engineering Design Center, which sup- Oak Ridge National Laboratory (ORNL), located ports both reactor and next-generation device in Oak Ridge, Tennessee, conducts research studies throughout the program. It is estimated across the full range of magnetic fusion program that ORNL will receive about 15 percent of the activities and is actively involved with national magnetic fusion energy program’s budget in FY and international cooperation in virtually every 1987.19 area. The Advanced Toroidal Facility (ATF), when complete, will be ORNL’s main experiment in Los Alamos National Laboratory toroidal confinement. It is anticipated that ATF, a stellarator, will make important contributions Los Alamos National Laboratory (LANL) is lo- to the improvement of toroidal systems by in- cated in Los Alamos, New Mexico, and it contrib- creasing the understanding of fundamental con- utes to DOE’s fusion energy program in several finement physics.18 Contributing to this under- ways. LAN L has focused on alternative concepts. standing are other ORNL programs in theory, These concepts, not as far developed as the toka- diagnostics, and atomic physics The ORNL tech- mak or mirror, are studied in several experiments nology program is fusion’s largest, and it includes at Los Alamos that are smaller and therefore less plasma heating and fueling, superconducting expensive than the large tokamak and mirror ma- magnets, materials, and environmental assess- — — ..-. description the confine- of Energy, 1988 concept. mates, op. cit.

Ch. 6.—Fusion as a Research Program “ 143

Photo credit: Oak Ridge National Laboratory

Assembly of The Advanced Toroidal Facility at Oak Ridge National Laboratory. chines. 20 In addition, LANL conducts research in Universities and Colleges fusion technology and materials, studies reactor systems, and operates the Tritium Systems Test Role in the Research Program Assembly (TSTA)—a prototype of the tritium- Universities and colleges contribute to many handling apparatus necessary to fuel a D-T fusion areas of energy research, including magnetic fu- reactor. In FY 1987, LANL will receive about 7 sion. The role of these programs in fusion R&D percent of the magnetic fusion energy program’s activities differs significantly from the role of the budget .21 national laboratories. Universities and colleges provide education and training and have been t. h. 4 tech n information o n a Iterative CO historically a major source of innovative ideas as ment concepts. Congressional Budget well as scientific and technical advances. These mates, op. cit. programs could not replace the national labora- s w s Q En rg

m m N ry

b d m Am g h 0 b 0 hp g m d p h h d pm h h gh d k m k p g p m d h d d b p h h w b d C h d om h mp h p m pm p g d h d opm b h o How d g d g 0 h 0 g dd p g m h m d q d mp rt p g m h m d mp b h h b m Ch. 6.—Fusion as a Research Program c 145

cepts. Overall, the Magnetic Fusion Advisory University and college fusion programs also edu- Committee (MFAC) Panel V found: cate the young researchers in the field. The contributions from university-based exper- table 6-4 lists the university and college fusion imental programs over the past decade have been programs. It is estimated that these programs col- significant, obviously cost-effective and have had Iectively will receive over 14 percent of the mag- a major impact on the development of fusion netic fusion budget in FY 1987 directly from DOE. energy in general, and the large-scale or “main- In addition, university and college fusion pro- Iine” experiments at the national laboratories in grams could receive another 2 to 3 percent of particular. 22

zzMagnetic Fusion Advisory Committee Panel V, Princi~a/ Find- the Fusion Program, July 1983, p. 18. The Magnetic Fusion Advi- ings and Recommendations of the Magnetic Fusion Advisory Com- sory Committee is a committee of fusion scientists and engineers mittee Subpanel Evaluating the Long-Term Role of (Universities in that provide technical advice to DOE’s Office of Fusion Energy.

Table 6-4.—Universities and Colleges Conducting Fusion Research in Fiscal Years 1983 and 1986 (in 1986 dollars)

Fiscal year 1983 Fiscal year 1986 University or college budget authority budget authority --- - . . . . Massachusetts Institute of Technology ...... $26.6 million $24.6 million University of Texas ...... $ 6.9 million $ 5.4 million University of California—Los Angeles ...... $ 4.1 million $ 6.2 million University of Wisconsin ...... , $ 4.1 million $ 4.8 million University of Maryland ...... $ 1.9 million $ 983,000 New York University ...... $ 1.3 million $ 1.1 million Columbia University ...... $ 1.1 million $ 1.2 million University of Washington ...... $ 776,000 $ 708,000 Cornell University ...... $ 760,000 $ 535,000 University of California—Berkeley ...... $ 618,000 $ 438,000 Johns Hopkins University ...... $ 483,000 $ 340,000 University of California—Irvine...... $ 481,000 $ 147,000 Rensselaer Polytechnic Institute ...... $ 353,000 $ 392,000 California Institute of Technology ...... $ 351,000 $ 503,000 Georgia Institute of Technology...... $ 271,000 $ 115,000 Pennsylvania State University...... $ 263,000 $ 97,000 University of California—Santa Barbara ...... $ 241,000 University of Illinois ...... $ 226,000 $ 335,000 Auburn University ...... $ 212,000 $ 372,000 University of Missouri ...... $ 201,000 $ 239,000 University of California—San Diego ...... $ 175,000 $ 240,000 Yale University...... $ 123,000 $ 50,000 University of Arizona ...... $ 115,000 $ 13,000 College of William and Mary...... $ 95,000 $ 18,000 University of Connecticut ...... $ 90,000 $ 80,000 Western Ontario University ...... $ 78,000 — University of Michigan ...... $ 66,000 Wesleyan University ...... $ 63,000 $ 50,000 Stanford University ...... $ 60,000 $ 13,000 University of lowa ...... $ 30,000 — University of Virginia ...... $ 30,000 — State University of New York—Buffalo ...... $ 24,000 Dartmouth College ...... $ 14,000 $ 60,000 University of Colorado ...... — $ 60,000 North Carolina State University ...... — Stevens Institute of Technology...... — $ 15,000 Syracuse University ...... — $ 101,000 University of New York City ...... — $ 25,000 Total university and college budget ...... $52,322,000 $49,301,000 (33 programs) (30 programs) SOURCE: Fiscal year 1983 budgets from Magnetic Fusion Advisory Committee Panel V, Principal Findings and Recommenda- tions of the MFAC Subpanel Evaluating the Long-Term Role of Universities in the Fusion Program, July 1983, p. 9 Fiscal year 1986 budgets provided by DOE’s Office of Fusion Energy, FY 1988 Congressional Budget Contractor Summary, Jan 16, 1987 146 ● Starpower: The U.S. and the International Quest for Fusion Energy

the fusion budget indirectly through subcontracts case, continued tight budgets and the loss of uni- from the national laboratories. The programs con- versity programs reduces the ability of the fusion ducted by the universities in fusion are diverse, program to attract and educate new researchers. varying in funding level and research area. Over In response to the funding cuts and the nar- 80 percent of the university programs received rowing of the fusion program’s scope, UFA has less than $1 million each from DOE in FY 1986. recommended that “approximately 3 to 5 per- Recent budget cuts have seriously affected uni- cent additional funding should be added back versity and college fusion programs, which have into the fusion budget to support innovative and suffered larger percentage budget reductions than new ideas.”25 According to UFA, one of the most the fusion program as a whole. University fund- urgent uses of this money would be to provide ing was $49.3 million in FY 1986, is estimated at seed money to innovative research proposed by $44.7 million in FY 1987, and is requested to be universities, national laboratories, and private in- $41.7 million in FY 1988, in current dollars. The dustry. UFA contends that this funding would last two figures represent percentage decreases help preserve some of the small university proof 9 and 7 percent, respectively.23 The cor- grams endangered by budget cuts, as well as cre- responding decreases for the overall fusion bud- ate the atmosphere of excitement necessary to get ($361.5 million in FY 1986, an estimated attract top students to the field. This idea has been $341.4 million in FY 1987, and a requested endorsed by other members of the fusion com- $345.6 million in FY 1988, in current dollars) are munity. 6 percent and – 1 percent. Given recent budgets, university and college For university and college fusion programs, fusion programs are concerned about the future DOE is the only source of financial support. NSF, direction of DOE’s fusion program. In particular, the other likely Federal support agency, does not representatives of UFA worry that the role of uni- fund fusion research because it is considered ap- versity fusion programs may be difficult to pre- plied, as opposed to basic, research and because serve if the Federal fusion program becomes it is believed to be DOE’s area. Thus, given re- more dependent on international cooperative cent budget cuts, two-thirds of the university and projects. The international activities of college college programs have either reduced or elimi- and university fusion programs are generally nated their programs since 1983. Seven colleges small-scale, and it is not clear how these activi- have eliminated their fusion programs, while five ties could fit in a collaborative engineering test new programs have been added. It is anticipated reactor effort. by University Fusion Associates (UFA), an informal grouping of individual fusion researchers University and College Activities from universities and colleges, that if current Universities and colleges have made contribu- funding trends continue, as many as half of the tions to fusion research in a variety of areas. In colleges and universities will eliminate their fu- tokamak development, university fusion pro- sion research programs between 1986 and 1989.24 grams have worked on radiofrequency heating DOE has stated that it intends to maintain the and current drive, boundary physics, high beta university fusion budget at a constant level (cor- stability, and transport of heat and particles in fu- rected for inflation) and does not foresee any sion plasmas.26 The largest university tokamak ex- need for additional programs to drop out. In any periments are MIT’s Alcator project, the Texas Experimental Tokamak (TEXT) experiment at the z~lf the Massachusetts Institute of Technology (MIT), the largest university fusion program, is not included, the university fusion bud- University of Texas, and Macrotor at the Univer- get decreases in FY 1987 and FY 1988 are 7 and 2 percent, respec- sity of California at Los Angeles (UCLA). tively. ~qGeorge H. Mi Icy, testimony on Fisca/ Year 1987 DeParOnefrt of Energy Authorization (Magnetic Fusion Energy), Hearings before the Subcommittee on Energy Research and Production, House Sci- *sIbid., p. 100. ence and Technology Committee, 99th Cong., 2d sess., vol. 5, Feb. *b For more information on the tech n ica I aspects Of these cent ri 26, 1986, p. 103. butions, see ch. 4. Ch. 6.—Fusion as a Research Program ● 147

Programs at the University of Arizona, Auburn University, University of California at Santa Bar- bara, UCLA, Georgia Institute of Technology, University of Illinois, MIT, University of Michi- gan, Rensselaer Polytechnic Institute, University of Washington, and University of Wisconsin focus on reactor systems, materials, surface effects, and superconducting magnets.

Private Industry

Role in the Research Program

Private industry can take a variety of different roles in fusion research, depending on its level of interest and the stage of development. The most useful roles fall into three main categories.27 These categories, along with the principal functions performed in each category, are listed in table 6-5. Photo credit: Plasma Fusion Center, MIT Industry as Advisor.–The advisory role of pri- The Alcator C tokamak at the Massachusetts Institute of Technology. vate industry is filled frequently by corporate executives who are asked to help assess various stages of program development. The principal In addition to tokamak research, a small group benefit of the advisory role is the development of universities is exploring the mirror confinement of appropriate program goals. As a support serv- concept. The TARA facility at MIT and Phaedrus ices contractor, industry assigns individuals or at the University of Wisconsin are the major smalI groups to work i n direct support of a man- university mirror experiments and, since the ager at DOE or at a national laboratory. Private moth balling of the mirror machines at LLNL, have industry also provides members of its technical become the only U.S. mirror experiments. Sup- staffs to serve on technical committees, such as port for university mirror programs has decreased, however. In fact, in the budget for FY 1987, DOE 27 Argonne National Laboratory, Fusion pOw’er program, T~chnl- proposed elimination of funding for these univer- ca/ F%nning Acti\ ;ty: FirIa/ Report, commissioned by the U.S. De- sity-based mirror projects. Congress has made ad- partment of Energy, Office of Fusion Energy, AN L/FPP-87- 1, 1987 pp. 340-343. ditional funds available to keep both operational throughout FY 1987, and it appears that Phaedrus will remain operational throughout FY 1988 as Table 6-5.—lndustrial Roles and Functions welI.

Several universities also study other confine- Roles Functions ment concepts for fusion reactors, including the Advisor ...... Support services contractor Advisory committee stellarator, compact toroid, and reversed-field Direct participant . . . Materials supplier pinch. Work in these concepts is conducted at Component supplier and the University of California at Irvine, UCLA, Cor- manufacturer nell University, University of Maryland, Pennsyl- Subsystems contractor Prime contractor, project manager vania State University, University of Illinois, Facilities operator University of Washington, and University of Wis- Customer consin. Sponsor ...... Research and development SOURCE: Argonne National Laboratory, Fusion Power Program, Technical Finally, several university programs are explor- Planning Activity: Final report, commissioned by the U S. Department of Energy, Office of Fusion Energy, ANL/FPP-87-1, 1987, table 7-4, p ing technology development and atomic physics. 340 748 c Starpower: The U.S. and the International Quest for Fusion Energy

the Magnetic Fusion Advisory Committee (MFAC) cases of direct participation. Industry represent- or the Energy Research Advisory Board (ERAB). atives serve on the Energy Research Advisory Through advisory arrangements, DOE gains in- Board and the Magnetic Fusion Advisory Com- dustry’s expertise and skills, and industry gains mittee, both of which advise DOE on the fusion knowledge, contacts, and income. However, program. Other industrial participation is facili- there is no commitment in this type of advisory tated through sub-contracts from national labora- relationship that the advice will be used by DOE tories. or the national laboratories. Only one private company, GA Technologies of San Diego, California, participates significantly Industry as Direct Participant. -To become in fusion research. GA Technologies is a private major participants in the fusion program, indus- firm that conducts fusion research under Federal try executives must understand near-term pro- contract. In this sense, GA has been compared gram objectives and be willing and able to con- to a national laboratory in the field of fusion re- tribute to the achievement of these objectives. search. The company became involved in fusion Industry’s direct participation will be particularly research during the 1950s, when the energy ap- important during the engineering phase of the re- plications of fusion were thought to be closer. search program, when information and expertise Because GA Technologies (then called General must be transferred to industry from the national Atomic Corp.) was able to assemble a high-quality laboratories and universities. team of fusion scientists and engineers, the Fed- eral Government has funded the bulk of its fu- As a direct participant, industry can serve a sion research since 1967, when GA lost its pri- variety of functions. It can supply off-the-shelf mary source of private fusion support. In FY 1987, components, as well as design and manufacture GA Technologies received 10 percent of DOE’s components made to customer-supplied speci- fusion budget. fications. One form of direct participation, which industry sees as most valuable, allows the cus- The fusion program at GA Technologies con- tomer (e.g., DOE, a national laboratory, or even- sists primarily of tokamak confinement research; tually an electric utility) to define a project and GA operates the Doublet II I-D (D III-D) tokamak, to assign responsibility for the task to a company. which is the second largest tokamak in the United Industry can also act as a prime contractor or States. 28 D II I-D is also the largest U.S. interna- project manager; in this case, industry is directly tional project. Japan and the United States, responsible to a customer for defined aspects of through GA Technologies, have jointly financed management, engineering, fabrication, and instal- and operated the D II I-D facility since 1979.29 lation of a product, such as a fusion device or In addition, GA Technologies and Phillips Pe- power reactor. troleum Co. invested over $30 million in invent- Industry as Sponsor.—The most extensive ing, fabricating, developing, and operating the level of industrial involvement will be the spon- Ohmically Heated Toroidal Experiment (OHTE) sorship of private R&D activities. Sponsorship in- at GA. OHTE is the only major fusion experiment cludes the contribution of direct funds, labor, or constructed and operated largely with private both. As a sponsor, industry finances its own re- funds. OHTE was completed in 1982 and oper- search program independently, whereas as a di- ated until 1985. In 1985, GA and Phillips re- rect participant industry’s activities are largely quested financial support from DOE for further financed by the Federal Government. Sponsor- development of the concept. However, DOE ing privately funded R&D requires confidence in would not fund this additional work, initiating a the eventual profitability of the technology. comparable program at LAN L instead. Without

Current Industrial Activities Z8The Tokamak Fusion Test Reactor (TFTR) at Pri fK@On pbSma Physics Laboratory is about twice as large as D III-D. To date, industrial involvement in fusion re- zgFor more information on the international cooperation aSpeCtS search primarily has been advisory, with limited of GA’s D II I-D experiment, see ch. 7, pp. 162-163.

Ch. 6.—Fusion as a Research Program s 149

are not conducting fusion research either, because of the large investment required and the difficulty of convincing regulatory agencies to al- low research costs to be transferred to ratepayers.

An MFAC panel on industrial participation in fusion noted that:

. . . fusion commercialization is sufficiently far in the future and fusion technology sufficiently specialized so that significant cost sharing [between the Federal Government and the private sector] should not be expected. The government and its national laboratories are the immediate customers and should pay the full cost of received products and services. Jl The position of industry, at least until commercialization is closer, appears to be a subordinate role supporting the national laboratories and universities.

The role of industry in the U.S. fusion program Photo credit: GA Technologies is completely different from its role in the Japa- OHTE fusion device at GA Technologies, San Diego, nese program, where mechanisms for technol- California. ogy transfer from government to industry have been institutionalized. In Japan, the Japan Atomic Energy Research Institute (JAERI) and various na- Federal financial support, OHTE was discon- tional laboratories and universities conducting fu- tinued. In mid-1986, DOE agreed to provide GA sion research contract with industry to do all the with a grant to operate OHTE, and the experi- design, research, and development that is nec- ment was restarted. Recently, DOE decided not essary. As in the United States, the financial con- to renew GA’s operating grant for OHTE after FY tribution of Japanese industry to fusion research 1987; it is anticipated that the experiment will be is small. However, its role is critical; according permanently mothballed. to one JAERl official, the Japanese Government’s role is limited to “resolving what type of machine At this stage in the research program, other pri- is needed and designing it, ” and even this task 32 vate companies have found no compelling rea- is “shared” with industry. Thus, Toshiba, Hitachi, son to sponsor fusion research. Even GA Tech- and Mitsubishi are intimately involved in fusion nologies’ involvement would be severely limited research. were it not for extensive Federal funding. Nei- In the United States, in contrast, fusion is pri- ther are electric utilities currently conducting fu- marily a government research program. The na- sion research. By 1986, the Electric Power Re- tional laboratories maintain large engineering search Institute (EPRI), a utility-funded research staffs and have strong manufacturing capabilities. organization, had phased out what had been a $4 million per year program. According to the former EPRI fusion manager, EPRI is unwilling to Fusion Advisory Committee Panel VI Report on spend money on fusion because the energy ap- Participation in Fusion Energy Development, May 1984, 30 5-2 to 5-3, plications are so long-range. Individual utilities official, quoted in H. national in Magnetic Fusion Energy: The Industrial Robert Scott, “Industry and Perspectives on Future Role. A Strategy for Industry Participation in an International Engi- Directions in Fusion Energy Development, ” neering Test Reactor Project, prepared for the U.S. Department of Energy, vol. 5, No. 2, June 1986, p. 138. Energy, Office of Fusion Energy, August p. 15. 150 “ Starpower: The U.S. and the International Quest for Fusion Energy

DOE has only a limited role at present for involv- maintain that it is too early in the program to en- ing industry in fusion research; industrial partici- courage substantial industrial participation. They pation is typically ad hoc. Due to the budget cuts predict that as demonstration and commerciali- in recent years, the role of industry has been zation approach, industry will naturally become additionally limited, both because of the few ma- more interested in the applications of fusion tech- jor new projects undertaken and because con- nology, hopefully to the point where they are stricted budgets have made the national labora- willing to invest money to explore the technol- tories reluctant to subcontract to industry. The ogy’s potential. These individuals believe that role of industry in the U.S. fusion program is not limiting industry’s participation in the near-term institutionalized. will not preclude its eventual role in demonstration or commercialization; they believe prema- Establishing an Industrial Base ture industrial involvement could be detrimental. for Fusion Others argue that it is essential to involve in- Under current administration policy, the pri- dustry in the research effort before the demon- vate sector will be responsible for the demonstra- stration stage. The proponents of early industrial tion and commercialization of fusion technology. involvement stress that technology transfer shouId As discussed in chapter 5, it is important to estab- occur from the national laboratories and univer- lish an industrial capacity on which the private sities to private industry at all stages of the re- sector can base its development efforts. An MFAC search program, and that such transfer cannot be panel on industrial participation in fusion re- effective without active industrial participation. search concluded that: The willingness of industry to invest in the technology should not be used as a criteria for de- . . . if a utility is to invest capital to build a fusion termining the appropriate degree of involvement, prototype or power plant, it must have confidence in its suppliers. This confidence can be these people argue, because industry needs in- established only if the suppliers have been qual- formation and expertise to accurately assess the ified through active participation in the fusion value of the technology. program and have a record of furnishing quality According to these individuals, early involve- goods and services.33 ment of industry and utilities ensures that the Currently, there is controversy over how to pre- technology developed will be marketable by ven- pare the industrial base. In particular, there is ex- dors and attractive to its eventual users. Technol- tensive disagreement over the timing of indus- ogy transfer will take time; if this transfer is not trial participation in the research program prior started until after completion of the research pro- to the demonstration and commercialization gram, fusion’s overall development could be de- stages. layed. In addition, proponents of this position cite a variety of near-term benefits of industrial par- For the research phase of fusion development, ticipation, including increasing support for the fu- many fusion scientists contend that industry sion program, facilitating spin-offs from fusion to should be an advisor or low-level direct partici- other technologies, and transferring skills ac- pant supporting national laboratories and univer- quired by industries involved in fusion to other sities. Given the current budget situation and the areas of high-technology such as aerospace and nature of the research to be completed before defense. demonstration and commercialization, these individuals believe that there are not enough op- The impact of various levels of industrial par- portunities appropriate for industry to develop ticipation in the research program on the success- and maintain a standing capability in fusion. ful commercialization of fusion technology can- Moreover, since the private sector is reluctant to not be determined now. Since the mechanisms invest its own funds, proponents of this position for transferring responsibility for fusion’s development from the Federal Government to the pri- JsMagnetic Fusion Adviso~ Committee panel Vll, op. cit., pp. 2-4. vate sector are not yet known, the impact of early Ch. 6.—Fusion as a Research Program ● 151

industrial participation on the pace and effective- commercialize fusion technology. If the indus- ness of this transfer is unclear. However, even trial base is insufficient, it will not only be diffi- without linking near-term industrial participation cult for industry to construct and operate a dem- in research to the success of future development, onstration reactor, but the customers (probably a well-established industrial base must be in place electric utilities) will be reluctant to purchase fu- before the private sector can demonstrate and sion reactors.

SUMMARY AND CONCLUSIONS

Fusion research has provided a number of near- over, many researchers have left fusion. Budget term benefits such as development of plasma cuts have also interfered with the attainment of physics, education of trained researchers, con- the program’s near-term goals. In particular, the tribution to “spin-off” technologies, and support ability of the fusion program to attract new re- of the scientific stature of the United States. How- searchers to its university programs and to train ever, fusion’s contributions to these areas does them has suffered. Constrained budgets also limit not imply that devoting the same resources to the participation of industry in fusion research. other fields of study would not produce equiva- In addition, the United States is no longer the un- lent benefits. Therefore, while near-term bene- disputed leader in fusion research; the Japanese fits do provide additional justification for conduct- and European fusion programs have caught up ing research, it is hard to use them to justify one with—and may have even surpassed—the U.S. field of study over another. effort.

Virtually all of the money spent on fusion re- OTA has not evaluated whether Federal fusion search in the United States comes from the Fed- research funds are being spent in the most effec- eral Government. The fusion program is DOE’s tive and efficient manner. Neither has it evalu- fifth largest research program, and in recent years ated the appropriate priority to be given to fu- the program has been relatively well-funded com- sion research as compared to other research pared to DOE’s other energy R&D programs. programs. Comparisons among R&D programs Nevertheless, the budget for magnetic fusion are difficuIt to make and are typically not made R&D has fallen by about a factor of 2 since 1977 explicitly during the budgetary process. There- (in constant dollars). These budget decreases fore, comparative funding levels do not neces- have severely constrained program activities. sarily provide an indication of relative priority. Funding limitations have affected the activities The appropriate funding level given to fusion re- of all three major groups that conduct fusion research depends on the motivations and goals of search: national laboratories, universities and col- the program. It also depends on where the leges, and private industry. Few new construc- money will come from—whether from cutting tion projects have been initiated in recent years, other programs or from additional sources of and research in some areas (particularly mirror revenue—and the impacts of these funding choices fusion) has been curtailed or eliminated. More- reach far beyond the program itself. Chapter 7

Fusion as an International Program 'CONTENTS

Page Inttoduction ...... 155 Why Cooperation Is Attractive ...... •...... 155 Forms of Cooperation • . . . • ...... : ...... 156 Major International Agreements .. , ...... 158 Multi lateral Activities ...... • ...... , .... , 158 ,8ilateral, Activities ...... ,....,...... 161 EvaluatIOn of Collaboration ... .-, .....•..... , .. ,...... , .... 164 8!enefits~ and Risks " • • • . . . • . • . . . . , . . . . . • ...... 164

:.<;lbstaCres • • • •':.; ;:. ; • :. 1;' !! • ,~ • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • , • • • • • • 166 ,:~;:-" flalement ApproacMs ...... 170 ~arison of International Fusion Programs ... , ...•...... , ... 174 , QiJfrafative :Comparisons , ...... , ...... 174 Quantitative Comparisons ...... , ...... , .... , ...... 174 Potential Partners ., .. "...... •...... , ...... ,...... , 179 The Unked States ...... , ..... ,., ..... , ... , .. ,., ...... ,', .. 179 The European Community ...... 180 The Soviet Union .....••...... 180 japan .•...... ' ~ •...... 161 ProsPects for International Cooperation ...... 182 U.S. Plans for Futu re Cooperation ...... , ...... , 182 Analysis of U.S. Proposal for ITER ...... •..•...... 185 Summary and Conclusions ..•••...... , ...... 185 Fllure. Figure No. . Page "·1; Emphases of Major Programs on Confinement Concepts, 1986 ...... 175 7.:.2. Emphases of Major Programs on Technology Development, 1986 ...... 175 1·3. Cornparison of International fusion, Budgets ...... 176 i .... ~ ~Compartson of intemational Equivalent Person-Years ...... 177 7-5. C()fhparison of International Fusion Budgets by Percentage of Gross National Product ...... • ...... 178 Tabl •• Tlble No. Page 7·1. C9rnparison of Type of Cooperation and Level of Agreement ...... 157 '.2. Principal International Fusion Activities •...... 158 7~3. Applicability of Existing Projects to Future fusion Collaboration ...... 173 7-4. Pro8ram Goals of Major fusion Programs ...... 174 Chapter 7 Fusion as an International Program

INTRODUCTION

Many nations of the world have cooperated on Fusion Research Is Expensive magnetic fusion research for almost 30 years. The high cost of fusion research is a practical Since U.S. magnetic fusion research was declas- incentive for nations to cooperate. The next-gen- sified in 1958, the major international programs eration engineering test reactor, for example, is have engaged in regular information and person- expected to cost well over $1 billion and possi- nel exchanges, meetings, joint planning efforts, bly several times that much, requiring a substan- and jointly conducted experiments. ’ tial increase in U.S. annual fusion budgets if it The leaders of the U.S. fusion community con- were to be built domestically. It is not clear tinue to support international cooperation, as whether or not the governments of any of the ma- does the U.S. Department of Energy (DOE). In jor fusion powers would be willing to construct the past, the United States cooperated interna- such an expensive experiment alone. Given the tionally on a variety of exchanges that have pro- expense and considering the similarity in next- duced useful information without seriously jeop- step program goals, the major fusion programs ardizing the autonomy of the domestic fusion have agreed in principle that the world does not program. In recent years, in response to budget- need four engineering test reactors of the same ary constraints and the technical and scientific kind. Limited funding can be allocated more effi- benefits of cooperation, DOE has begun coop- ciently if nations are willing to collaborate on one erating more intensively i n fusion, and the major major experimental facility. fusion programs have become more interdependent, For the future, DOE proposes undertak- Fusion Programs Are ing cooperative projects that will require the at Comparable Levels participating fusion programs to become signif- The comparable levels of progress among the icantly interdependent; indeed, DOE now sees major fusion programs make higher levels of co- more intensive international collaboration as a operation attractive, particularly over the next financial necessity. decade. While there are differences in emphasis and achievement, the programs have com- Why Cooperation Is Attractive parable scientific and technical capabilities and recognize the need for similar next-generation ex- Without exception, all of the major fusion pro- periments. Cooperative projects are easier to im- grams participate in international activities and look favorably on more intensive future activi- plement in complementary programs because the benefits can be distributed equitably and because ties. There are several reasons for this widespread 2 all participants stand to gain from their partners’ interest. expertise.

‘Major fusion programs are currently active in the United States, Fusion Can Advance More Effectively Japan, the European Community (EC), and the Soviet Union. Pri- mary contributors to the European Community’s fusion program International collaboration in fusion research are the Federal Republic of Germany, France, Italy, and the United is attractive because it provides a forum for sci- Kingdom, although other member nations are also involved. ZThe reasons that follow were based i n part on a discussion of entists and engineers to interact. If the major pro- Incentives to collaborate found in: Energy Research Advisory Board, grams can coordinate their activities, the intel- International Co//~? boration in the U.S. DOE’s Research and De- Iectual resources available to address pressing ve/oprrrent Programs, report to the U.S. Department of Energy, pre- issues in fusion research and development (R&D) pared by the ERAB International Research and Development Panel, D(lE/S-0047, December 1985, p, 11, can increase dramatically.

155 — — .

156 . Starpower: The U.S. and the International Quest for Fusion Energy

Forms of Cooperation retical team. Assignments are one of the most effective ways to transfer expertise. International cooperative efforts range from ● simply exchanging information in international Joint Planning. Joint planning includes activi- meetings through the joint construction and oper- ties to identify areas for future cooperative re- ation of experimental devices to complete in- search, to provide a forum for coordinating ex- tegration of research efforts.3 Various types of perimental and theoretical programs on large cooperation entail different levels of program in- experimental devices, and to avoid unneces- tegration, information transfer, and trust. The po- sary duplication of effort while still ensuring tential risks and benefits of the programs vary cor- verification of important experimental or theo- respondingly. retical results. ● It is necessary to make a distinction between Joint Research. Through joint research, ma- the terms “cooperation” and “collaboration. ” jor facilities are made available for research This report will adopt the usage of a recent Na- projects of other programs. The facility is fi- tional Research Council report on cooperation nanced and constructed primarily by the host in fusion research.4 Throughout this OTA assess- program, with other participating programs ei- ment, “cooperation” will refer to all activities in- ther providing a percentage of construction volving nations, or individuals from different na- and operation costs or contributing equipment. tions, working together. “Collaboration,” a more In exchange for their contributions, participat- intensive type of cooperation, will describe activ- ing programs are granted access to the ma- ities involving a substantial degree of program in- chine and experimental data. Frequently, con- tegration, funding commitment, and joint man- tributions of the participants enable an existing agement. machine to be upgraded; in some cases these contributions are essential to the construction Types of Cooperation and Collaboration of the machine in the first place. Activities involving joint research are becoming increas- ● Information Exchange. Information exchange ingly common. is the most common form of international co- ● operation. Information on achievements and Joint Construction and Operation. Joint con- advances, as well as technical approaches and struction and operation of major experiments experimental data, is exchanged through sev- and facilities are the most intensive forms of eral channels, including meetings, conferences, international cooperation; this form of coop- symposia, workshops, and publication in tech- eration is referred to as collaboration. Partici- nical journals. pating programs agree to pool their resources and construct a commonly owned and oper- ● Personnel Exchange. Personnel exchanges– ated facility. There is no “host” program in this visits and assignments—also are widely used. case; the facility is operated by a management During a typical visit, research scientists tour team comprised of representatives from each one or more of the host program’s facilities for program. 1 or 2 weeks. Assignments are extended stays in which the guest participant actually works Plans for future U.S. participation in interna- on an experiment and contributes to the host tional fusion activities include collaborative proj- program’s research effort. For the duration of ects in addition to the other levels of coopera- the assignment, the guest participant is a full- tion. The largest scale example of a collaborative fledged member of the experimental or theo- project under discussion today would be a jointly constructed and operated engineering test reactor. The current proposal for this experiment, 3 A discussion of proposals for tutu re cooperation and collaboration now under consideration can be found later in this chapter called the International Thermonuclear Experi- under “Prospects for International Cooperation. ” mental Reactor (ITER), involves only conceptual ‘National Research Council, Cooperation and Competition on the Path to Fusion Energy (Washington, DC: National Academy design and supporting R&D for the project. If this Press, 1984), p. 5. phase of the project is arranged and proves work- Ch. 7.—Fusion as an International Program . 157

able, more extensive collaboration on construc- risk that the signing head of state, or a suc- tion and operation could be considered. ceeding one, would disavow the agreement is small. If successfully negotiated, ITER probably will ● Ministerial-level Agreement. A ministerial be the world’s largest, most expensive, and most agreement is arranged between ministries of visible cooperative project. Therefore, this chap- the participating governments, and it is less ter primarily focuses on it. The full scope of DOE’s formal than either a treaty or a heads-of-state plans for future cooperative activity includes a agreement. It requires less review and ap- variety of additional, lesser facilities in areas such proval than the more formal agreements and as materials research and technology develop- is affected more directly by changes in bud- ment. DOE plans to investigate more intensive getary constraints and political objectives. forms of cooperation–including joint research, However, it still carries the full weight of the planning, and possibly even joint construction government. In the United States, ministerial- and operation of facilities—on these other proj- Ievel agreements in fusion research are ne- ects as well. The U.S. plans for future coopera- gotiated with participation of the Depart- tion are analyzed in this chapter under “Prospects ments of Energy and State. for International Cooperation.” ● Informal Arrangement. An informal arrangement can be undertaken between govern- Types of Agreements ments, laboratories, and individuals. It can Different levels of international agreements provide an excellent means of transferring could be used to facilitate cooperation. These information among scientists, but it does not agreements can range from formal treaties down provide a basis for programmatic or interna- to informal workshops and publications: tional planning. This arrangement is typically instituted on an ad hoc basis, in response to ● Treaty. A treaty between governments is the particular needs and objectives of the par- most binding and formal agreement that can ticipants. be established. Ratification signifies commitment to the substance of the agreement; D ifferent types of agreements are appropriate obligations incurred under a treaty can be for the various forms of cooperation that occur abrogated, but such action is not taken lightly in fusion and in other areas (see table 7-1). or often. However, a treaty is the most diffi- Most cooperative efforts occur u rider a general cult type of agreement to implement. There arrangement called an umbrella agreement. An is a greater risk of negotiations breaking down during the development of a treaty, and more issues must be resolved in order Table 7-1.—Comparison of Type of Cooperation for a treaty to be ratified. Moreover, the ratifi- and Level of Agreement cation process for a treaty is time-consuming; Type of cooperation Level of agreement a treaty may be obsolete by the time it is fi- Information exchange ...... Informal Arrangement nally ratified. In the United States, a treaty Ministerial Agreement must be signed by the President and ratified Heads-of-State Agreement by a two-thirds majority of the Senate. Personnel exchange ...... Informal arrangement Ministerial Agreement ● Heads-of-State Agreement. A heads-of-state Heads-of-State Agreement agreement is less formal than a treaty but is Joint planning ...... Ministerial Agreement considered binding by most governments. Heads-of-State Agreement Such an agreement carries the full weight of Joint research ...... Ministerial Agreement the government in power, and abrogation Heads-of-State Agreement by a signatory head of state would bean un- Joint construction and usual, though not impossible, act. When the operation ...... Ministerial Agreement Heads-of-State Agreement subject of the agreement has a strong base Treaty of support among many different groups, the SOURCE Office of Technology Assessment, 1987 158 ● Starpower: The U.S. and the International Quest for Fusion Energy

umbrella agreement usually is established as part ogy, sets up joint planning and negotiation efforts, of a ministerial agreement before any specific co- and provides a forum for exploring the potential operative agreement is instituted. It defines the of future cooperation on medium- and long-term principles of cooperation and provides a frame- projects. An umbrella agreement is not a final work for developing future cooperative agree- agreement. It is not intended to address the sub- ments. It is undertaken when governments are stantive issues involved in decisions to undertake interested in cooperation and want to formalize specific cooperative projects. It is a useful device, the intent to cooperate. An umbrella agreement however, for defining areas of potential cooper- typically states that the participating governments ation and for creating a framework for negotiat- support cooperation and are ready to begin ne- ing future agreements. gotiating specific cooperative projects.

Frequently, an umbrella agreement authorizes transfer of preliminary information and technol-

MAJOR INTERNATIONAL AGREEMENTS

Under current arrangements, the United States Multilateral Activities participates in cooperative fusion activities at all levels except that of joint construction and oper- International Atomic Energy Agency ation. To date, only one international fusion project has been collaborative in this sense: the joint The International Atomic Energy Agency (IAEA) European Torus project of the European Com- has been one of the most important facilitators munity (EC). Table 7-2 summarizes the principal of fusion cooperation. The IAEA is an independ- existing international fusion arrangements; the ent intergovernmental organization within the organizations and agreements mentioned in the United Nations system, and its mission is to pro- table are described below. mote and ensure the peaceful use of atomic

Table 7-2.—Principal International Fusion Activities

Type of cooperation Representative project Agreement Information exchange. . . . . Large Tokamak Agreement IEA Nuclear Fusion journal IAEA Conferences IAEA Personnel exchange ...... Large Tokamak Agreement IEA 50 transfers each way U.S.-Japan Bilateral Six transfers each way U.S.-USSR Bilateral To be determined U.S.-EC Bilateral Joint research ...... ASDEX Upgrade IEA Large Coil Task IEA Doublet III-D Upgrade U.S.-Japan Bilateral Tore Supra U.S.-EC Bilateral Joint planning ...... INTOR IAEA Large Tokamak Agreement IEA Joint Institute for Fusion Theory U.S.-Japan Bilateral To be determined U.S.-EC Bilateral Joint construction and operation ...... Joint European Torus European Community SOURCE: Office of Technology Assessment, 1987. Ch. 7.—Fusion as an International Program “ 159

energy. The headquarters of the IAEA are located Test Facility at Oak Ridge National Laboratory in in Vienna, Austria. All countries currently doing Tennessee at a cost of about $40 million. This fa- fusion research are members of the IAEA. It has cility is designed to test superconducting magnet facilitated two different types of cooperative activ- coils. s It holds six large coils, one each con- ity: information exchanges and joint planning structed by the European Atomic Energy Com- efforts. munity, the Japan Atomic Energy Research Insti- tute, and the Swiss Institute for Nuclear Research Major informational activities conducted by the and three constructed by U.S. manufacturers.6 IAEA in the area of fusion research include host- Each coil cost between $12 million and $15 mil- ing biennial meetings and arranging topical meet- lion to construct. international involvement in the ings and workshops on areas of special interest LCT has distributed the costs of the project among or concern. In addition, the IAEA publishes a several nations, and it has also enabled different technical journal, Nuclear Fusion, in which fu- types of coils to be tested in a common facility, sion researchers can share their findings. allowing direct comparison. Moreover, the LCT The IAEA also facilitates a joint planning activ- is the major instance in the fusion area that in- ity, called the International Tokamak Reactor (l N- volved industry in international cooperation. TOR) design study. INTOR began in 1978, and Several other cooperative projects also occur it involves the European Community, Japan, the under IEA auspices. The European Community Soviet Union, and the United States. The goal of and the United States participate in joint plan- INTOR is to define concepts and designs for a ning on next-generation stellarator experiments conceivable next-generation fusion experiment. to coordinate their research efforts. It appears that It is a forum where Western fusion scientists have Japan will soon be joining this project. Through regular contact with their Soviet counterparts. Na- the IEA, the United States and the European Com- tional teams work on parallel tasks and meet two munity are also conducting joint research on the or three times a year for several weeks to com- Axisymmetric Divertor Experiment (ASDEX) and pare results and plan future work. Most analysts its upgrade (ASDEX-U). These facilities are located agree that INTOR discussions have successfully at the Institute for Plasma Physics at Garching, identified critical issues in both physics and tech- Federal Republic of Germany, and U.S. partici- nology. pation in this research has made it unnecessary for the United States to construct similar facilities. International Energy Agency The IEA provides no funding for any of these The International Energy Agency (IEA) was cre- projects, only an umbrella framework and minor ated by 21 Western oil-importing nations in 1974 secretariat functions. in response to the OPEC oil embargo. IEA’s main The most recent IEA agreement, signed in Jan- task is to plan for crisis response to future oil em- uary 1986, provides for cooperation among the bargoes. In addition, the IEA also promotes in- three large operational tokamak experiments (jT- ternational cooperation in research and devel- 60 in Japan, the joint European Torus (JET) in the opment of energy technologies that have the European Community, and the Tokamak Fusion potential to decrease the West’s dependence on Test Reactor (TFTR) in the United States). Under oil imports, The European Community, Japan, this agreement, the three programs conduct per- and the United States participate in IEA’s coop- sonnel and information exchanges for tokamak erative projects. Magnetic fusion research is one experiments. An executive committee, consist- of many areas IEA promotes, largely by facilitating of two members from each fusion program, ing joint research efforts. The IEA is headquar- tered in Paris, France. 5For a discussion of the role of superconducting magnets in a fLJ - In 1977, the Large Coil Task (LCT) was orga- sion reactor, see the section of ch. 4 titled “The Magnets” under nized u rider the auspices of the I EA. As part of “Fusion Power Core Systems. ” the LCT, the U.S. fusion program constructed the W .S. Department of Energy, Office of Energy Research, ,14agnefrc Fusion Energy Research: A Summary of Accomp/ishmerrts, DOE/ER- International Fusion Superconducting Magnet 0297, December 1986, p. 19.

160 . Starpower: The U.S. and the International Quest for Fusion Energy

Photo credit: Oak Ridge National Laboratory

The International Fusion Superconducting Magnet Test Facility at Oak Ridge National Laboratory, containing the six superconducting magnets.

will meet at least once a year to coordinate re- following a political wrangle of 21/2 years over search. The agreement is in effect from 1986 to project location. 1991. This agreement has the potential to evolve The JET experiment is located adjacent to the into joint planning and program coordination. Culham Laboratory, in Abingdon, United King- dom. The land on which JET is constructed is tem- Joint European Torus porarily leased from the United Kingdom; at the The joint European Torus is Europe’s most im- completion of the project the land will be returned. portant experimental fusion facility and the world’s Construction of JET began in 1977, and the facil- largest tokamak. JET is a joint undertaking of the ity began operating in 1983; current plans call member nations of the European Community; it for JET to operate until about 1992.7 has been designed, constructed, and operated by the EC. The JET Working Group was created of design phase and the political negotiations concerning JET, see Denis A European Experiment: to explore the project in 1971; the device was Launching of Project (Bristol, U. K.: Adam Ltd., approved by the EC Council of Ministers in 1978, 1981 ).

Ch. 7.—Fusion as an International Program ● 161

The EC pays 80 percent of the costs of JET through the contributions of member nations. in addition to their contributions through the EC, the national programs also contribute directly to the project. Direct national contributions represent 10 percent of the costs. The final 10 percent is a site premium paid by the United Kingdom. This premium offsets the financial benefits that the host country receives from the project. In the last 5-year budget plan, approved in 1985, funding for the overall EC fusion program for 1985- 89 was set at 690 million European Currency Units (worth at that time about $766 million). Of this amount, roughly half will go to JET.

The JET model has been effective and efficient. Through cooperating on the project, national programs have saved money, have had access to a world-class experiment, and have advanced the state of European scientific research.

Bilateral Activities United States-Japan Bilateral Agreement In 1979, a ministerial-level agreement was signed committing the United States and Japan to cooperate on general energy research and, more

Photo credit: JET Joint Undertaking specifically, to develop commercial fusion power for the 21st century. Within the framework of this The Joint European Torus, located in Abingdon, United Kingdom. umbrella agreement, the United States and Japan have negotiated several specific cooperative agreements. The U.S.-Japan cooperation is the Legally, JET is an independent international en- most extensive international cooperation in fu- tity; it is not a national project. The JET adminis- sion research in which the United States partici- trative structure is multinational. The project is pates. Information and personnel exchanges, managed by a project director on site, but all im- joint research activities, and joint planning activ- portant strategic decisions must be presented to ities all occur within the context of the umbrella and approved by the JET Council, which is com- agreement. prised of two members from each participating About 50 formal personnel exchanges occur nation, one of which is a scientist. When the each way annually between the United States and project is completed, the administrative structure Japan. 8 There are also a few (usually under 10) will be dismantled. personnel exchanges arranged yearly on an ad JET is staffed by two distinct and roughly equal- hoc basis; these informal exchanges enable the ized groups: the multinational staff supported by partners to accommodate unique program needs. the EC and a local staff supported by the United Kingdom Atomic Energy Agency. Provisions have been made for staff to return to their national fu- ‘Michael Roberts, rector I Programs, U sion programs after completion of their appoint- Energy, Fusion Energy, letter to the ments at JET. Technology Aug. 1986.

162 ● Starpower: The U.S. and the International Quest for Fusion Energy

Photo credit: GA Technologies, Inc. D II I-D fusion device at GA Technologies, San Diego, California, showing neutral beam injection systems.

Under the umbrella agreement, a specific agree- The United States hosts the Doublet project, ment to conduct a major joint research project which is located at GA Technologies’ laboratory was also signed in 1979. Through this agreement, in California. Since 1979 the project has had joint Japanese involvement in the upgrade of the U.S. funding and a joint management team. Between Doublet Ill (D Ill) tokamak was formalized.9 The 1979 and 1984, the United States contributed Japanese and the Americans shared machine time $104 million and the Japanese contributed $62 on the experiment equally, and both have had million to finance an upgrade in the D Ill facility access to all data generated in the experiments (after the upgrade the name was changed to D III- run on the machine. D). In 1983, the agreement was extended until 1988, and additional upgrades were undertaken for which the United States is contributing $37.8 “U.S. of Energy, Magnetic fusion Energy Research, op. cit., p. 20. million and Japan $8.5 million. Currently, discus- Ch. 7.—Fusion as an International Program ● 163

sions are underway to extend cooperation until in each direction. These exchanges are limited 1992. 10 by the United States to fusion science issues, such as experiments and theory, with no regular in- The Doublet cooperation has provided both teraction on technology development .12 Most of parties with access to a state-of-the-art tokamak the personnel exchanges are visits; some are as- for much less than the cost of independently con- signments, however, which have given Soviet sci- structing and operating the experiment. In fact, entists an opportunity to work with U.S. scien- it is unlikely that the D Ill upgrades would have tists on research projects, and vice versa, been possible without Japanese funding contributions. In addition, Japanese and U.S. scientists The U.S.-U.S.S.R. bilateral agreement is vulner- both have made valuable technical contributions able to the political situation between the two to the experiment that have improved the scien- countries. For example, no exchanges occurred tific quality of the project. during 1980 or 1981, the years following the So- viet invasion of Afghanistan. However, since the Within the context of the U.S.-Japan umbrella 1985 U.S.-U.S.S.R. summit meeting in Geneva, agreement, the countries also have undertaken bilateral activity between the nations has progressed joint planning activities. The United States and to a point where collaboration with the Soviet Japan have created a joint Institute for Fusion Union on the conceptual design and supporting Theory (JlFT) and designated two theory centers, R&D of a major fusion experiment is being con- one at the University of Texas at Austin and the sidered. 13 other at Hiroshima University in Hiroshima, Japan. Each fusion center has continued to operate in- United States= European Community dependently, and a coordinating committee has Bilateral Agreement been created to oversee and guide cooperative activities. The United States and the European Commu- nity have cooperated extensively for more than United States-U.S.S.R. 30 years without a formal bilateral agreement. Bilateral Agreement Until recently, most cooperation involving the EC and its member states was conducted indirectly The Soviet Union has cooperated extensively through the I EA. While this cooperation was re- with the United States and has made substantial warding, many tasks were not easy to arrange contributions to the U.S. fusion program (see the under the existing arrangements. history of tokamak development in ch. 3). The United States and the Soviet Union have had a A ministerial agreement was signed between formal agreement to cooperate in fusion research the United States and the EC in December 1986. since 1958. In 1973, this agreement was strength- Because the agreement was signed so recently, ened, under the Nixon-Brezhnev Accord, to ex- details for all of the activities that will occur within tend and broaden cooperation in fusion research. its framework have not yet been formalized. Ar- Most of the detailed information that the U.S. fu- rangements have been made for joint research sion program has about the Soviet program comes at the JET facility in the United Kingdom and at from the U.S.-Soviet exchange activities.11 the Tore Supra facility in France. The agreement will provide an annual forum for management Under the terms of the Nixon-Brezhnev Ac- discussions about bilateral cooperation issues and cord, 12 personnel exchanges occur between the will establish a legal basis that can simplify the United States and the Soviet Union annually, six exchange of hardware and the initiation of some cooperative endeavors. It also will increase the ——. .— mobility of European scientists; within the EC, a 10Test;mony of Dr. David Oversket, Senior Vice President at GA formal agreement helps facilitate personnel ex- Technologies, Inc., before the House Science, Space, and Tech- nology Committee, Energy Research and Production Subcommit- changes. tee on the Fiscal Year 1988 Magnetic Fusion Energy Budget, Feb. 24, 1987, p. 4. I Zlbid., app. A.

11 u .s, Depa~rnent of Energy, Office of Fusion Energy, ~Va/Ua- 1 IThe Geneva summit meeting and the SU bseq uent proposal for tion of Benefits of Cooperation on Magnetic Fusion Energy Between a major fusion collaboration involving the Soviet Union are dis- the United States and the Soviet Union for the period 1983 to 1985, cussed on p. 184. November 1985. .

164 . Starpower: The U.S. and the International Quest for Fusion Energy

EVALUATION OF COLLABORATION

Benefits and Risks The full extent of the cost savings is unclear, however. As the National Research Council re- Knowledge Sharing port pointed out, because cooperation requires All forms of international cooperation involve extensive negotiation and more formal manage- information transfer. Throughout the history of ment structures, the total administrative costs of fusion research, access to information–including constructing and operating a cooperative project technical know-how, experimental data, and new are higher than if the same project were con- theoretical ideas—has enabled fusion scientists structed independently.15 Moreover, there are to learn from each other. Innovative ideas and additional costs if the facility is not sited in the a wider variety of approaches to projects are United States, such as lost domestic contracts, more likely to arise in an international versus a employment, and support facilities.16 Although purely domestic program .14 Researchers can com- these added costs temper the financial benefits pare their experimental results with those of other of international cooperation, it is expected that programs, making it possible to verify results, the contribution of any one partner will be less identify anomalous data, and distinguish experi- than the cost of that partner proceeding inde- mental results based on fundamental character- pendently with an identical project. istics from results based on special features or flaws in a particular experimental device. Thus, Risk Sharing scientific progress can occur more rapidly through International cooperation on major experi - cooperation. mental facilities can mitigate the risk of project On the other hand, some observers feel that failure by spreading the financial and program- extensive knowledge sharing between national matic costs over all participants. Constructing and fusion programs should be discouraged in the in- operating large experimental facilities is expen- terests of national security and national competi- sive; the cost of failure, both monetarily and on tiveness. These individuals believe that the ad- a program’s morale and future plans, can be high. vantages of information transfer, in terms of Through sharing knowledge between major fu- improved scientific research, do not outweigh the sion programs, there is a greater probability of disadvantages of participating in extensive coop- scientific or technical success, In addition, the for- erative projects. mal agreements required to negotiate an international project and the political implications of Cost Sharing abandoning such an undertaking may serve to stabilize national commitments to the project. One advantage of international cooperation is that it potentially can save significant amounts of On the other hand, some scientists feel that the money. Information and personnel exchanges absence of competition and duplication among enable independent programs to learn, at low cost, about the research activities of other pro- I JNationa[ Research Counci 1, Cooperation c?nd competition, op. grams. joint planning activities enable fusion pro- cit., p. 31. Actual statistics are difficult to collect; however, one su r- grams to coordinate activities to avoid duplica- vey of technical personnel involved in the I NTOR workshop indi- tion of effort and to conduct mutually beneficial cated that constructing INTOR as an international project would increase total costs by about 70 percent, staffing requirements by research. Most dramatically, joint research and 15 percent, and require 2 years longer to complete. It is not clear joint construction and operation of projects dis- that these projections are generally applicable; cooperative contribute the costs of major experimental facilities, struction of JET probably did not inflate costs this much. However, no matter to what degree, collaboration will tend to increase con- while still providing the experimental results to struction times and project costs.

all participants. IGTesti mony of Dr. Walter A. McDougall, Associate ?rOfeSSOr of History at the University of California–Berkeley, Science Po/icy lqsee U.S. Departrnerrt ot Energy, Office of Energy Research, /fJ- Study Vo/ume 7: /nternationa/ Cooperation in Science, Hearing be- ternational Program Activities in Magnetic Fusion Energy, DOE/ER- fore the Task Force on Science Policy of the Committee on Sci- 0258, March 1986, p. 5; or National Research Council, Coopera- ence and Technology, House of Representatives, 99th Cong., 1st tion and Competition, op. cit., p. 19. sess., June 18-20 and 27, 1985, p. 70. Ch. 7.—Fusion as an International Program ● 165

experimental facilities may increase technical risk able in the case of U.S.-Soviet cooperation, and and that extensive cooperation may increase the that more intensive cooperation with the Soviets risk of abandonment before project completion. should be pursued. Some members of the fusion community point Some people consider these non-technical dip- out that coordinating research to the point of lomatic benefits a positive feature of large-scale jointIy constructing a single international facility, cooperative projects. Others, however, fear that as opposed to comparable national facilities, the diplomatic implications of collaboration could would eliminate the potential for validating ex- result in the subordination of technical objectives perimental results through comparisons between to non-technical goals, which would be undesira- different machines of similar size and purpose. ble. Moreover, some observers fear that interna- With more than one machine, a number of differ- tional projects should be viewed cautiously be- ent scientific and technical approaches could be cause broken cooperative agreements could explored, and experimental results among ma- complicate international relations. If a nation chines could be compared. In addition, some feel abandoned its commitment in the course of a co- that the absence of competition among facilities operative undertaking, there could be important will lead to more conservatism in design and political consequences. The fear of these conse- operation, which can limit progress. Finally, all quences might even cause reluctance to ter- participants must fulfill their financial and person- minate a technically undesirable project. nel obligations if the project is to succeed, especially with larger, more complex projects that ex- Domestic Implications tend over several years. The entire project can be jeopardized if even one nation abrogates the In addition to its technical benefits, many agreement, and cancellation can have implications proponents of cooperation support it as a method far broader than just one abandoned project.17 of preserving the U.S. fusion program. These individuals are concerned, at least in part, that cur- Diplomatic and Political Implications rent budgets are insufficient to maintain a viable domestic fusion effort. At current funding levels A large cooperative experiment will clearly and as currently structured, the U.S. fusion pro- have significant diplomatic and political implica- gram cannot construct and operate essential ex- tions. Many proponents of international cooper- perimental facilities on its own without dramatic ation believe the diplomatic and political conse- curtailment of other necessary aspects of the fu- quences can be positive. The commitment to sion effort. Collaboration proponents therefore cooperate on an experimental fusion device is see intensive international cooperation as criti- not trivial; a commitment represents confidence cal for a challenging, growing U.S. research pro- in the reliability of the other participants and faith gram. This point is made in the National Research that they can work together to the benefit of all Council report: involved. Through the negotiating process, differences between partners can be reconciled and a For the United States at this time, large-scale commitment to a common goal can be affirmed. international collaboration is preferable to a mainly domestic program which wouId have to In addition, the diplomatic value of a decision command substantial additional resources for the to cooperate could be used to further U.S. ob- competitive pursuit of fusion energy development jectives and improve U.S. relations in areas other- or run the risk of forfeiture of equality with other 18 wise unrelated to fusion, For example, an agree- world programs. ment to cooperate on magnetic fusion could be Increased international cooperation in fusion reached as part of a larger non-technical diplo- energy research can also stabilize the commit- matic initiative. Some observers argue that such ment of the U..S Government to the magnetic fu- diplomatic benefits have been particularly valu- sion program.19 Moreover, international projects

I TNationa] Research COU ncil, Cooperation and Competition, op. ‘81 bid., p. 11. cit., p. 23. ‘g Ibid., p. 22. 166 . Starpower: The U.S. and the International Quest for Fusion Energy

often have more visibility than domestic under- ation projects. Some analysts are also concerned takings and therefore can better mobilize public that cooperation in fusion could jeopardize U.S. support. competitiveness in international markets. However, incentives for future collaboration on National Security .–Some of the technologies big fusion projects must be traded off against a developed for use in fusion experiments–e.g., variety of other domestic concerns. Some mem- high-power neutral beams, high-power micro- bers of the fusion community, for example, worry wave technology, and plasma diagnostics—can, that the United States might link the continued with varying degrees of modification, have mili- viability of its fusion program to international tary applications. Various individuals and govern- activities that it cannot adequately influence. *0 ment agencies contend that the Soviet Union will Others are concerned that U.S. policy makers be able to utilize technology transferred through might sacrifice the Nation’s domestic fusion pro- more extensive fusion cooperation for military ap- gram in order to promote international cooper- plications. According to Richard Perle, former As- ation,21 particularly if domestic budgets were not sistant Secretary of Defense for International increased sufficiently to cover the additional cost Security Policy, “Soviet officials and agents have of an expensive cooperative project. In addition, successfully exploited the openness of the U.S. some individuals are concerned that undesirable and European scientific communities to gather changes in the direction of fusion research might militarily useful technical information.”23 Oppo- be made to facilitate increased cooperation. Fi- nents of extensive cooperation with the Soviets nally, there is concern that the participation of contend that it wouId be difficult, if not impossi- domestic universities and industry in fusion re- ble, to control the transfer of militarily sensitive search could be limited if the program empha- technology in an experimental facility such as sizes international cooperation. ITER. In particular, opponents contend that long- term association with Western scientists will provide disproportionate benefits to the Soviets. Op- Obstacles22 ponents say that through the ITER project, Soviet A number of potential obstacles must be ad- scientists will be able to acquire Western know- dressed through negotiation before the United how, technology, and experience in leading-edge States can participate in large-scale cooperative technologies. projects in fusion research. Supporters of cooperation do not claim that military applications of fusion-related technol- Technology Transfer ogies are irrelevant, but they believe that many Transferring high technology to our partners of the concerns raised by opponents are over- could be the most serious political obstacle to stated. When examined in detail, proponents ar- more intensive international cooperation. Many gue, most of the objections disappear, and those critics worry that militarily significant technology that remain can be addressed on a case-by-case could be transferred, either directly or indirectly, basis. As the Director of the Office of Energy Re- to the Soviet Union through fusion cooperation, search at DOE has stated: especially through joint construction and oper- It is my opinion . . . that a device of the sort we are talking about could be built and that the nec- — ——— essary computer activities associated with it could ,?ol bld , be carried out in a manner that did not involve 21 Ibid., p. 23. any violation to COCOM regulations.24 zzThe information in this section is based on a workshop on issues in International Cooperation held by the Office of Technol- ogy Assessment, Washington, DC, on Oct. 14, 1986 (list of panelists zjRichard perle, Assistant Secretary of Defense for I nternatlona I presented in front of this report); on reports done under contract Security Policy, “Technology Security, National Security, and U.S. to OTA by specialists in Japan, Europe, and the Soviet Union; on Competitiveness, ” /ssues in Science and Technology, fall 1986, vol. discussions and interviews conducted with members of the fusion [II, No. 1, p. 112. community; and on the National Research Counci I report Coop- ~aTestlmony of AIvin W. Trivelpiece, Director Of the office of eration and Competition, op. cit. Energy Research, U.S. Department of Energy, Fisc~?/ Year /987’ De- Ch. 7.—Fusion as an International Program ● 167

Proponents point out that, generally, fusion Over the years, the Soviet Union has made val- technologies are not directly applicable to mili- uable contributions to fusion research, and its tary needs; those technologies that do have de- participation in a major project would improve fense applications must undergo substantial modifi- the quality of the undertaking. cation and redesign before reaching military Undoubtedly, measures taken to resolve tech- significance. For example, although many of the nology transfer concerns will constrain the free technologies currently being investigated in the flow of information and technology between the Strategic Defense Initiative were first developed partners in collaboration. Such constraints may for or used by the magnetic or inertial fusion pro- pose an obstacle to collaboration in their own grams, U.S. scientists are nevertheless spending right: it is possible that after compromises have billions of dollars to apply these technologies to been made to satisfy technology transfer con- weapons systems. Applying fusion technologies cerns, the proposed collaborative project might to military uses may require as much indigenous not satisfy the needs of the parties in the activ- technical capability as developing the technol- ity, including the U.S. fusion community. If, for ogies in the first place. example, it was decided that the use of old tech- Furthermore, supporters of U.S.-Soviet fusion nology would avoid the risk of transferring state- collaboration argue that those technologies pos- of-the-art technology, the overall capabilities of ing true risks can be identified through careful the device could be reduced, and as a result the review procedures and that problems can be han- project could become less attractive. dled on a case-by-case basis. If, for example, a The national security debate is not easily re- particular component poses a significant technol- solved, and it involves underlying motivations ogy transfer risk, the Soviets couId be asked to and assumptions concerning the U.S.-Soviet rela- provide it, its use could be restricted, or the ex- tionship that go far beyond the details of any spe- periment could be redesigned to eliminate it. cific technical exchange. Given the depth of the Proponents of increased cooperation insist that debate within the U.S. Government, it appears there are significant benefits to the United States that the United States will not be able to partici- from collaborating with the Soviet Union that pate in a major joint undertaking with the Soviet must be weighed against the risks. Magnetic fu- Union until these issues are settled. Many ob- sion research is not classified; information about servers contend that resolving the national secu- experiments, techniques, and methodologies are rity questions ultimately will require a presiden- available in international publications. Moreover, tial decision. as the Associate Director of Confinement at Oak U.S. Competitiveness.–Many analysts are con- Ridge National Laboratory noted: cerned about the competitiveness of American Everything in the world is not done here. In industry in international markets, and some are many areas we are not ahead . . . We got the fact hesitant, in particular, about the long-term im- that you could make a gyrotron [a high-power plications of intensive cooperation with the Jap- microwave generator] from the Russians. All sorts anese and the Europeans i n fusion.26 At present, of things came out of the Russian program .25 U.S. industry is only minimally involved in the —.— .—— fusion program. If no provisions are made to partment of Energy Authorization: Magnetic Fusion Energy, Hear- directly involve U.S. industry in future collabora- ings before the Subcommittee on Energy Research and Production, tive projects such as ITER, some observers fear Committee on Science and Technology, House of Representatives, 99th Cong., 2d sess., Feb. 25-26, 1986, p. 24. that U.S. industry could fall farther behind Japa- COCOM IS the acronym of the Coordinating Committee, an in- nese industry—particularly since Japanese indus- formal, voluntary, cooperative alliance through which the United try is more directly involved in fusion research.27 States and its allies seek to control the export of strategic goods and technology to the Eastern bloc, It is an intergovernmental com - jGThe General Accounting Office documents th IS concern in Its m ittee, and 15 nations participate i n it—the NATO countries (ex- report The Impact ot International Cooperation in DOE’s Magnetic cept for Iceland and Spain) and Japan. Members of COCOM have Confinement Fusion Program, report to the Honorable Fortney H. agreed to restrict export of certain specified items to Communist Stark, Jr., House of Representatives, GAO/RCED-84-74, February cou ntrles for strategic reasons. 1984, pp. 13-14.

25Mark Crawford, “Soviet-U.S. Fusion Pact Divides Administra- jTFor a more detai led d Iscussion of i nd ustria I participation I n the tion, ” Science, May 23, 1986, p. 926, quoting John Shefflelci, Asso- U.S. fusion program, see the section in ch. 6 titled “Prl\ate in- ciate Director of Conti nement at Oak Ridge National Laboratory. dustry. ”

72-678 () - 87 _ 5 168 ● Starpower: The U.S. and the International Quest for Fusion Energy

DOE does not consider U.S. competitiveness located within the other’s borders. In addition, issues to pose a serious obstacle to increased co- with both the Western Europeans and the Japa- operation in fusion. As DOE points out, magnetic nese sensitive about superpower dominance, fusion is currently in a pre-competitive stage. Be- they too might be reluctant to site the project in cause there are few commercial applications of either the United States or the Soviet Union. the technology, there are no substantial risks from Even after the competition is narrowed down sharing the technology internationally, Accord- to one nation or region, internal competition for ing to DOE, there appears to be little risk that the the site will be intense. In the case of the JET United States would sacrifice its future competi- project, for example, the siting negotiations took tive position through near-term cooperative en- over 21/2 years to resolve and almost caused the deavors. abandonment of the project.29 The siting deci- Technical Differences sion for ITER probably will be even more difficult, since it will be a larger facility and more na- Successful cooperation on a major device like tions will be involved. Collaboration on ITER ITER requires that the partners agree on a com- requires that the project have value to all partici- mon set of goals and objectives, that their fusion pants, including those that do not host it. programs beat comparable levels, and that they be moving in compatible directions. Differences U.S. Commitment between the long-term objectives of the partners’ Another difficulty for U.S. participation in a ma- fusion programs or research plans must be ac- jor international joint undertaking is the degree commodated or resolved. of commitment by the U.S. Government to the At present, all the major world fusion programs fusion program. The U.S. fusion program has agree on the need for an experiment such as ITER faced decreasing budgets, in real terms, for 9 of and welcome it as an opportunity for more in- the last 10 years, and, given this recent history, tensive cooperation. However, given the differ- international partners could reasonably question ences in detailed technical objectives among the U.S. commitment to the development of fusion programs, designing an experiment that satisfies energy, Moreover, many nations already believe each program’s goals simultaneously will involve that cooperating with the United States is risky. a great deal of negotiation and compromise. A recent Energy Research Advisory Board panel on DOE’s international research and develop- Project Location ment activities concluded:

Siting major projects, whether domestically or . . . the Department [of Energy] has a poor repu- internationally, is traditionally time-consuming tation abroad for long-term commitment to inter- and politically sensitive. According to the Na- national collaborative programs. This poor repu- tional Research Council, selecting a project site tation will make it extremely difficult for DOE to is a “frequent sticking point in large international attract foreign countries into significant new part- 28 nerships . . . the responsibility lies with DOE to projects.” Intense competition for the site of a improve its own image abroad.30 major international fusion project can be expected, since such a facility will be beneficial to local in- The United States needs to establish a strong and stitutions, may provide some advantage to local stable commitment to its domestic fusion pro- industry, and will carry a great deal of prestige. gram as well as to international projects in order to win the confidence of potential partners. Most analysts believe it is unlikely that the facility will be located in either the United States or the Soviet Union. It is not expected that either nation would participate if the project were zgDenis Wlllson, A European Experiment: The Launching of the JET Project, op. cit. JoEnergy Research Advisory Board, International Collaboration 28National Research council, cOOpHdtbJ dfld cO~pe~ifiO~, op. in the U.S. Department of Energy’s Research and Development Pro- cit., p. 57. grams, op. cit., p. 2. Ch. 7.—Fusion as an International Program . 169

Equitable Allocation of Benefits processes are quite different. Whereas the Japa- nese budget process is very incremental, with ma- Negotiating an agreement in which the bene- jor changes in program funding levels being un- fits of the project are distributed equitably in re- usual, in the United States the budget cycle is less lation to the investment of the participants will stable and less predictable. Funding choices are be complex. Among the benefits are the distri- reevaluated annually in the United States, and bution of available staff positions, the amount of changes in priorities are common. Thus, there is design and equipment fabrication work to be some concern that the United States might make done by contractors, and the access or rights to a commitment to begin a long-term project and information and technical know-how generated then change its mind. by the project. Benefits associated with hosting the site of the experiment also must be accounted It has been suggested that the United States for, a task that has frequently resulted in requir- adopt a multi-year budget cycle or take major in- ing the host to contribute more to the project’s ternational projects “off-budget.” While such ac- costs. I n the JET project, for example, the United tions certainly would reduce the budgetary ob- Kingdom contributes 10 percent of project costs stacles to cooperation, the chance of such a as a site premium, over and above its contribu- change is slim, because the ramifications of such tion as a participant. a decision wouId extend far beyond any particular project. Different Currencies and Economic Systems.– It Administration is generally considered easier if international proj- For cooperation to be successful, it will be nec- ect management minimizes currency transfers be- essary to resolve a variety of administrative issues tween nations. Different budget cycles, fluctuat- faced in all cooperative programs. ing exchange rates, and different economic systems —particularly with regard to the Soviet Union— Different Institutional Frameworks.–Each na- make limiting the exchange of currency an attrac- tional agency involved in negotiations operates tive goal. Therefore, having participants contrib- under different ruIes and procedures. In addition, ute components and services is preferable to the negotiating agencies generally have varying having them contribute funds to a central man- degrees of autonomy, flexibility, and decision- agement agency that contracts for construction making power. of necessary components. Decentralization of the U.S. Government.— Different Legal Systems.–Nations also have The decentralized character of the U.S. Govern- different legal systems that can complicate nego- ment poses a challenge to developing major in- tiations. Defining legal ownership of the experi- ternational agreements. Each executive branch mental facility and of the information generated agency has different concerns, making it difficult there is a critical facet of a workable agreement. for the U.S. Government to reach the consensus needed to “speak with one voice. ” Therefore, Personnel Needs.–The staff of a joint under- negotiators will have to ensure either that there taking will include participants from all programs is widespread commitment to the project within involved in the project, and administrative ar- the U.S. Government or that the project has sup- rangements will have to accommodate their needs, port at levels of government high enough to as- Currently, relationships between staff and their sure such a commitment. respective governments differ over such issues as the ability to sign contracts, intellectual property Different Budget Cycles.–Agreements will rights, and compensation. have to reconcile differences in national budget- setting procedures in order to finance a major Staff for the project would come to a central cooperative undertaking. The European Commu- location from many countries and would in most nity, for example, has a multi-year budget cycle, cases bring their families. They wouId expect, whereas both the United States and Japan have without undue difficuIty, to find housing with ac- annual budget cycles. Even these annual budget cess to shopping facilities and other amenities. 170 c Starpower: The U.S. and the International Quest for Fusion Energy

In particular, they would want an international, The management structures of the existing co- rather than national, educational system for their operative projects examined below offer some children. Moreover, most staff will return to their insight into how—or how not—to organize fusion home fusion programs after completion of their collaboration. Since each project’s goals are dif- assignments at the joint facility, and they will need ferent, it is unlikely that any of these existing ar- to be assured that their positions at home will re- rangements will be applicable as is for future fu- main available to them. sion collaboration. Each project weighs its goals and requirements independently, and, through Management Approaches negotiation, unique trade-offs among competing goals are made. Studying the organizational struc- If the conceptual design phase of the ITER proj- tures of existing international projects, however, ect is successful, it could be followed by a deci- can be useful in exploring future projects such sion to jointly construct and operate a major fusion as ITER. experiment. The prospects for such an activity are being investigated by the major fusion pro- International Tokamak Workshop (INTOR)31 grams. Any agreement to undertake such a project would be complex, and a variety of manage- Conducted under IAEA auspices, the INTOR ment and organizational issues could arise in design study for a next-generation fusion experiment has features that may be useful for future project negotiation and implementation. This sec- collaborative projects. INTOR has successfully en- tion explores the applicability of management abled the international fusion programs to co- structures developed for existing international operatively develop a design for and explore the projects, both in fusion and in other areas, to the technical characteristics of a next-generation ma- potential collaborative fusion endeavor. chine. Moreover, the INTOR process was devel- The organizational structure of a large-scale in- oped without causing concerns about national ternational project such as ITER depends on its security and is the most extensive cooperative fu- overall goals and objectives, which will be de- sion activity involving the Soviet Union. Since termined through negotiation. The main require- INTOR is strictly a design effort, however, it pro- ment for the organizational structure is that it de- vides no guidance for the construction and oper- fine each participants’ degree of control over the ation of future fusion collaborative experiments. project by establishing such things as the project’s technical and political decisionmaking proce- Joint European Torus (JET)32 dures, the allocation of contributions and bene- The JET management structure is another ap- fits among the partners, the degree of autonomy proach for major collaborative projects. The JET between the collaborative project and the sup- facility was designed and built by multinational porting domestic fusion programs, the arrange- teams, is financed by the EC and the participat- ments for staff and contractors, and the routine ing national fusion programs, and is managed by operation and long-range planning of the en- a multinational council. The project has been suc- terprise. cessful, and the EC currently is exploring the pos- The degree of control that any participant ex- sibility of using the same approach to manage a erts over the direction of the project can vary sig- next-generation experiment (the Next European nificantly, from minor technical influence to over- Torus or NET). sight of the entire project. Generally, however, Though the JET approach has proven success- the amount of control a partner exercises is pro- ful for European fusion collaboration, it is not portional to the amount of financial support it directly applicable as a model for ITER. First, the provides. In the case of ITER, it appears likely that financial support will be fairly evenly divided among partners; thus, project control probably JIThe I NTOR project is discussed in more detail on p. 159 will be shared by the partners. Jzsee pp. 160-161 for a detailed description of JET. Ch. 7. —Fusion as an /international Program s 171

JET agreement was negotiated within the exist- This approach might resolve technology trans- ing umbrella structure of the European Commu- fer concerns, but it could also introduce consid- nity in which most of the administrative obsta- erable difficulties into project management. Since cles to international collaboration were already a primary goal of collaborating on a next-gen- resolved. Negotiating a major fusion cooperation eration fusion experiment would be to make ex- that included parties outside of the EC would be perimental techniques and results available to all significantly more complex because there is no the cooperating parties, the independent devel- previously negotiated legal framework. opment approach probably would not be acceptable in ITER. In addition, it would be difficuIt to In addition, the JET approach was not designed divide a major fusion project into isolated mod- to provide a mechanism for limiting the transfer ules connected at interfaces; ITER probably will of potentially sensitive technologies. Within the be a complex and interrelated assemblage of sys- JET framework, all participants have access to the tems and components. Moreover, coordinating information and technology used or developed a project in which data and access were restricted in the project. Finally, the JET structure operates would require an extremely effective manage- through the cash contributions of participating ment team. programs to its central management agency. Hard currency transfers among the participants Another problem with applying the LCT model in an ITER-type project would be more difficult to a future collaboration like ITER is control of to arrange. the project. In the LCT, the United States contributed most of the financial support and as- Large Coil Task (LCT)33 sumed principal technical control. For ITER, on the other hand, it appears unlikely that any part- The Large Coil Task is a superconducting mag- ner will assume the responsibility of becoming net testing project that has been conducted un- project leader and shouldering most of the cost. der the auspices of the IEA. The United States has Thus, the management design of the LCT will not taken the lead on the project, financing construc- be applicable to ITER. tion of the magnet testing facility and three of the six test magnets. The facility was designed jointly, Doublet Ill Project (D III)34 and three magnets were designed, constructed, and financed by foreign participants in the Doublet Ill is the most extensive cooperative project. All information and non-proprietary tech- fusion project in which the United States cur- nology used in construction of the test magnets rently is involved. The United States is the host and all data generated through the experiment country for the Doublet project, and the Japa- are available to participating programs. nese have contributed over one-third of the funds necessary to support the project i n recent years. Although the LCT was not designed to preclude This direct contribution of currency distinguishes information and technology transfer, its structure the Doublet cooperation from other fusion activ- could be slightly modified and used if limiting ities in which the United States participates. The such transfer was an objective. If a given task project is jointly managed by a team of U.S. and were broken down into distinct components, Japanese scientists; machine time and experi- each subtask could be assigned to a partner who mental results are shared equally between the would be responsible both financially and tech- two nations. Doublet’s management structure has nically for its contribution. Provided that the “in- distributed control of the project and financial dependent development” met technical speci- responsibility effectively among the Japanese and fications, each partner’s contribution could be American participants. integrated into the overall machine, minimizing exchange of information. Several factors, however, may complicate the use of the Doublet approach for more intensive

~~FOr mo~e detai led cj Iscussion of Doublet-1 I I D project, ~ee PP ~lThe Large Coil Task IS described in more detail on p. 159. 162-163. 172 c Starpower: The U.S. and the International Quest for Fusion Energy

future undertakings. The scope of the project, Yet CERN, like JET, does not provide a com- though extensive by U.S. standards, is quite lim- plete model for a future ITER. First, CERN relies ited when compared with the scale of potential on cash contributions, which may not be appro- future projects such as ITER. Only two nations priate for ITER. Second, CERN does not have are involved, and the amount of currency trans- mechanisms in place for protecting sensitive tech- ferred is small compared to the projected cost nologies. Third, some more formalized system of of ITER. Also, the original D I I I facility was an in- “national rights, ” at least with respect to imme- dependent U.S. project, and the Japanese did not diate economic return and longer term research become involved until the upgrades were under- and development return, may be necessary to al- taken. Thus, the Doublet project did not have to locate the benefits of ITER among diverse econ- address facility design and construction issues omies that are not already as interdependent as from the beginning, as a completely collabora- the individual European Community economies tive project would. are.

European Laboratory for Space Station Nuclear Research (CERN)35 The space station, a proposed multi-billion dol- CERN was established in 1954 by several West- lar orbiting facility, is the only attempt by the ern European nations. Its objective was to ad- United States to cooperate internationally on a vance knowledge in high energy physics, and it scale financially comparable to future fusion has provided a framework for extensive cooper- plans. Under U.S. proposals for space station col- ation in the design and construction of large-scale laboration, the United States would take the lead experimental facilities. It has enabled the Euro- on the project and invite participation of others, pean nations to conduct physics research on a particularly Japan, Canada, and the European scale that would have been impossible for any Space Agency. Currency exchanges would be of them acting independently. minimal. Each of the programs would contribute its own hardware to the station, and these con- CERN is coordinated by a council consisting tributions would be joined together at carefully of two representatives—one administrative and defined interfaces. Each program would retain es- one technical—from each participating nation. sential control over development of its own hard- Participants make cash contributions to CERN ware, but the United States would bear overall based on a percentage of each nation’s gross na- responsibility for program direction and coordi- tional product (GNP). No nation can contribute nation, for overaIl systems engineering and in- more than 25 percent of CERN’s costs annually. tegration, and for development and implementa- There are no “national rights” within the CERN tion of overall safety requirements. This approach structure. Participating nations are not guaran- is intended to ensure compatibility and cooper- teed particular positions for their representatives, ation without transferring technology that the specified shares of CERN’s procurements, or pri- partners may wish to protect. ority for projects within CERN. Some aspects of the space station project could Many features of the CERN management struc- provide a model for large-scale fusion collabo- ture could be attractive in future fusion coopera- ration. In particular, the space station may develop tion. For example, the practice of making decisions a workable mechanism for limiting the undesira- based on merit, not national rights or privileges, ble transfer of technology among the participants. is considered by many analysts to be responsi- In addition, it is likely that administrative aspects ble for CERN’s excellent technical record. In addi- of the agreement might have relevance to future tion, involving both technical and administrative joint undertakings in fusion. Both the space sta- people in decisionmaking has resulted in informed, tion and a future fusion collaboration such as ITER comprehensive decisions. would have to address issues such as ownership

~SThiS dlcusslon based on pp. 92-93 of the National Research of equipment, intellectual property rights, dispute Council report, Cooperation and Competition, op. cit. settlement, liability, selection and assignment of Ch. 7.—Fusion as an International Program ● 173

personnel, and establishment and maintenance subordinate role in a fusion collaboration if another of safety standards. If the space station can re- nation were to assume leadership of the project. solve these issues successfully, it could provide Fusion projects also have to address siting issues, a model for ITER. which the space station avoids because it is not located on national territory. Finally, the space In many ways, however, it is difficult to apply station project does not include the Soviet Union, the space station approach to future fusion col- and thereby avoids the additional security and laborations. The space station is designed to be diplomatic concerns introduced by Soviet par- modular, with participants contributing independ- ticipation. ently developed components. As noted earlier, the independent development approach would Summary of Potential Management probably be unacceptable and unworkable for Approaches ITER. In addition, the United States is taking the lead on the space station, dividing tasks and It is unlikely that any existing cooperative shouldering much of the cost. It is not clear that project will provide a model management struc- such an approach in a major fusion collabora- ture for a major international effort such as tion would be acceptable to either the United ITER. The strengths and weaknesses of existing States or other participants. Moreover, it is not projects, with respect to large-scale fusion col- certain that the United States would accept a laboration, are summarized in table 7-3.

Table 7-3.—Applicability of Existing Projects to Future Fusion Collaboration

Project Strengths Weaknesses

INTOR ...... Proven approach to project design phase ● Poorly suited for construction and operation ● Most extensive fusion collaboration involving the Soviet Union

JET ...... ● Successful design, construction, and ● Negotiated within preexisting cooperative operation of world-class facility framework ● Might not address technology transfer issues adequately

● LCT ...... ● Successful joint research project United States was lead agency and bore ● Could provide for control of technology majority of costs transfer ● “Independent development” approach might be unworkable for ITER ● Might not ensure technical equality of participants, depending on distribution of tasks

D Ill ...... ● Successful management structure ● United States was lead agency and bore majority of costs ● Small-scale project when compared with ITER ● Joint project dealt only with upgrade of previously constructed experiment ● Involves hard currency transfer CERN ...... c Successful design, construction, and ● Involves hard currency transfer operation of world-class high-energy ● Might not address technology transfer issues physics program adequately ● Not bound by “national rights” system ● Lack of “national rights” system may limit equitable allocation of project benefits

Space Station ...... ● Successful conclusion of negotiations will ● Negotiations have not been finalized show that large-scale, multi-year, and ● Independent developments approach might multi-billion dollar collaborations can be be unworkable for ITER established by the United States Does not address siting issues Provides no experience with Soviet participation SOURCE: Off Ice of Technology Assessment, 1987 174 ● Starpower: The U.S. and the International Quest for Fusion Energy

COMPARISON OF INTERNATIONAL FUSION PROGRAMS

Comparing levels of effort among the interna- Figure 7-1 compares the programs’ research tional fusion programs is complex. Qualitative and development emphases on confinement con- measures show that the programs are similar in cepts, and figure 7-2 compares their technology direction and achievement, but these measures development efforts.36 Variations among programs are subjective. Quantitative measures are more are influenced by differing program concentra- objective, but they may be distorted. Moreover, tion, funding levels, technological capabilities, different techniques give different results. and program history.

Qualitative Comparisons Quantitative Comparisons

Qualitative comparisons show that the four ma- There are a variety of ways to compare quan- jor fusion programs are comparable in levels of titatively the levels of effort among the U. S., EC, effort and accomplishment and in their near-term and Japanese fusion programs, but each way has research objectives, although the stated long-term flaws. (Data for the Soviet Union is not included goals and rationales for the programs differ (see in this discussion; it is difficult to obtain reliable table 7-4). Three of the programs operate toka- information on the size of the Soviet program, mak experiments of similar capability and com- its funding level, and the number of people it em- plexity, and the fourth (the Soviet Union) is in ploys.) Figure 7-3 compares DOE’s estimates of the process of building a large tokamak of some- the annual fusion budgets of the three programs what similar capability; each program also studies converted into dollars. According to this figure, alternative confinement concepts. All of the pro- the United States has had the highest level of ef- grams recognize the need for a next-generation fort in fusion research. However, this conclusion experiment during the mid-1990s to advance fu- is dependent on the exchange rates used in the sion technology and science. currency conversion. The relative magnitude of the U.S. effort is due in part to the extraordinary strength of the dollar in the mid-1980s with re- Table 7-4.—Program Goals of the spect to European and Japanese currencies. To Major Fusion Programs the extent that goods and services purchased with Program fusion research funds are not traded on interna- Goal Rationale tional markets, fluctuations in exchange rates dis- Us. tort the calculations of relative expenditures. Sud- Demonstrate science and Determine potential as an den shifts in the value of the dollar have dramatic technology base for energy option fusion power effects on dollar-based comparisons of the fusion EC budgets, but do not represent actual changes in Prototype construction Develop energy option fusion work effort. Promote industrial capability To correct for distortions from fluctuating ex- Strengthen political unity change rates, DOE has used another method to Japan 37 Demonstration plant Develop energy option compare fusion programs. In this method, the Fulfill national project }bThe discussion I n this and the following paragraph is based on U.S.S.R. Fusion hybrid systema Support fission program documentation by Dr. Stephen 0, Dean, President of Fusion Power Maintain international Associates and author of figures 7-1 and 7-2. His insights represent activity a view commonly held by the fusion community regarding the rela- aFusion hybrids are discussed in app. A. tive levels of effort among the major fusion programs. The technical characteristics of the confinement concepts are explained in SOURCE Michael Roberts, Director of International Programs, U.S. Department of Energy, Office of Fusion Energy, briefing on “lnternatlonal Discus. ch. 4. sions on Engineering Test Reactor, ” before the ETR Workshop, Rock- JTjohn Willis, U.S. Department of Energy, Office of Fusion Energy, vine, MD, July 16, 1966 Oc. 9, 1986, personal communication to OTA.

Ch. 7.—Fusion as an International Program ● 175

Figure 7-1.— Emphases of Major Programs on Confinement Concepts, 1986

JAPAN

USSR

Figure 7.2.–Emphases of Major Programs on Technology Development, 1986

SOURCE Fusion Power Associates.

fusion budget of each program is divided by the This figure does not literally represent the num- average annual manufacturing wages prevailing ber of people employed by the respective fusion in the country or region, with both values meas- programs, but rather represents an arbitrary means ured in local currency. The resulting value is a of comparing relative levels of effort. Expenditures measure of the level of effort of each program on construction and operation of facilities are in units of “equivalent person-y ears.” Compari- converted, along with actual personnel costs, into sons are shown in figure 7-4. “person-years” of effort. The validity of this meas-

176 ● Starpower: The U.S. and the International Quest for Fusion Energy

Figure 7-3.—Comparison of International Fusion Budgets (in current dollars)

1980 1981 1982 1983 1984 1985 1986

Year

■ United States ❑ European Community ❑ Japan SOURCE: U.S. Department of Energy, Office of Fusion Energy, 1986,

ure depends on how well the quoted manufac- “equivalent person-years."38 Unless the majority turing wage rates reflect the wages relevant to the of the costs incurred by the Japanese and U..S. fusion program, on how similar the productivity fusion programs actually rose by the same amount of labor is between programs, and on how simi- as the wage rate, the conversion to “equivalent lar the relative values of capital and labor expend- person-years” overestimates the decline in these itures are among the three programs. fusion efforts.

Figure 7-4 shows that by this measure, both the Japanese and the U.S. levels of effort dropped programs, the average industrial wage slightly from 1980 to 1986. In both programs, the 1980 to 1986 rose 38 percent in the United States, rose 76 percent fusion budget rose in real dollars. However, in- in Japan, and fell 6 percent in the European Community. Over the same period, the fusion budget rose only 4.6 percent in the United creases in the average industrial wage rate over States, rose 24 percent in Japan, and rose 97 percent in the Euro- the same period resulted in a substantial drop in pean Community, in real dollars.

Ch. 7.—Fusion as an International Program . 177

Figure 7-4.—Comparison of International Equivalent Person-Years 32

0 1980 1981 1982 1983 1984 1985 1986

Year

Japan

OTA used a third method of comparison to compared to the rest of the economy of each construct figure 7-5, which illustrates the fusion party. It does not present a comparison of abso- budgets as a percentage of each program’s GNP. lute levels of effort, but might be taken to indi- Under this method, the fusion budgets, as reported cate some measure of the commitment of each by DOE, are divided by the national GNP.39 Al- nation to its fusion program. Of course, many ex- though all values are converted to dollars, inac- ternal factors that strongly influence each nation’s curacies in the conversion process should not af- spending priorities cannot be shown in this fig- fect the final result since both GNP values and ure. For example, this figure does not show the fusion budgets were adjusted. This approach, great asymmetry in defense expenditures of the which shows that the Japanese devote the great- various nations. est proportion of their resources to fusion, meas- An additional problem confounds all of the ures the relative level of effort of fusion research quantitative methods: the calculations are based

European Community was calculated by adding on program budgets that are not directly com- the GNPs the member parable. Budget figures provided by the Japanese

178 ● Starpower: The U.S. and the International Quest for Fusion Energy

0.004

0.002

0 1980 1981

■ United States ■ European Community SOURCE: Office of Technology Assessment, 1987

Government, for example, do not include per- spend), and these values can be substantially sonnel costs. In the figures shown here, these different. costs were estimated by DOE for the Japanese Obviously, quantitative level-of-effort compar- program and added to the Japanese figures. In isons based on budget levels may not be relia- the EC and the United States, distinctions must ble. Each method of analysis discussed here sug- be made between budget authority (how much gests different results, and no conclusions can be the program was authorized to spend) and bud- drawn. get outlay (how much the program actually did Ch. 7.—Fusion as an /international Program . 179

POTENTIAL PARTNERS

Since DOE is investigating the possibility of in- cial resources necessary to construct experiments creased levels of collaboration, an analysis of the of this scale by itself. Another incentive is DOE’s goals and incentives of the potential collabora- belief that a well-developed scientific and tech- tive partners is important. nological base for fusion will be easier to establish if the major fusion programs share informa- The United States tion and expertise. Program Goals At this point, the U.S. fusion program is considering the possibility of collaborating on ITER The stated goal of the U.S. fusion program is with any or all of the major fusion programs. Of to establish the scientific and technological base the major programs, the United States has coop- necessary to evaluate the potential for fusion erated most extensively with Japan. Formal ties energy by early in the 21st century. In 1988, de- between the United States and the European sign and construction of the next major facility, Community are more recent, but the EC fusion the Compact Ignition Tokamak (CIT), may begin, program is highly advanced and would be an at- if approved by Congress. The United States rec- tractive partner. The U.S. fusion community also ognizes the need to have an engineering test re- highly values input from its Soviet counterpart, actor by the mid-1990s to study technical issues which has made significant contributions to past related to reactor design and operation, but, due cooperative projects and which continues to to funding limitations, DOE would like to con- make technological advances. However, the pol- struct such a reactor in collaboration with one itics of the U.S.-Soviet relationship are more vola- or more other fusion programs. In the concep- tile than those between the United States and Ja- tual design and supporting R&D proposal cur- pan or the EC. This difference will make major rently being negotiated, this project is called the collaboration with the Soviet Union the most dif- International Thermonuclear Experimental Re- ficult to arrange. actor (ITER). The U.S. fusion program does not Nevertheless, Soviet participation in a multi- currently have plans to construct an engineering lateral fusion project has been supported at the test reactor independently. Beyond a collabora- highest levels of both governments. At the Geneva tive engineering test reactor, the U.S. program has no plans to construct a demonstration re- Summit of 1985, President Reagan and General 40 Secretary Gorbachev “advocated the widest actor. practicable development of international collabo- Views on Collaboration ration” in fusion research .4’ The United States explicitly made this arrangement conditional The United States is extremely interested in fu- upon allied participation, and a strictly bilateral ture international collaboration, particularly on collaboration between the two countries on ITER construction and operation of ITER. A primary would be very unlikely. incentive is financial; at present, the domestic fusion program is not able to command the finan-

q~see the Section Ot ch, 4 titled ‘‘Research Progress and Future Directions” for a more detailed cliscussion of the U.S. research plans ~1 From statement at the Reaga n-Gorbache\ Sum m It, November and facility needs. 1985. 180 ● Starpower: The U.S. and the international Quest for Fusion Energy

The European Community42 Japanese fusion programs, but contact with them has been less frequent. Program Goals Even without international collaboration, the The member countries of the European Com- European Community’s program has established munity are making a long-term investment in fu- political support and momentum through JET. sion for its possible value as a major new energy The EC has a clear strategy for future fusion resource that could contribute to Western Europe’s search, in which NET plays a vital role, and it ap- future energy security. Collaboration within the pears committed to carrying this program out. EC has been extremely successful; it has been a Nevertheless, the European Community is will- source of pride. ing to investigate prospects for a large-scale col- The joint European Torus (JET) is the EC’s most laboration with the other major fusion programs. important experimental fusion facility and the At the same time, the EC plans to continue work- world’s largest tokamak.43 Planning has begun for ing independently on NET unless and until the a second facility—the Next European Torus (NET) ITER effort offers convincing guarantees of suc- —which, like ITER, is intended to confirm the sci- cess. The EC might not wish to participate in a entific feasibiIity of fusion and address the ques- major project that is not located in Europe. tion of engineering feasibility. The current sched- 44 ule for NET calls for a detailed design decision The Soviet Union in 1989 or 1990 and a decision on construction Program Goals in 1993. A third facility envisioned by the EC is a prototype fusion power reactor to demonstrate The Soviet Union has an active fusion research the economic feasibility of fusion. The timetable program, which is supported by a strong com- for this prototype depends on the success of JET mitment to nuclear power for geographical and and NET. Construction is projected to begin be- fuel cycle reasons.45 The breeder reactor is the tween 2010 and 2020. primary focus of the Soviet atomic energy program for the 199os, and the fusion reactor is the Views on Collaboration focus of the next century. The Soviet Union is also investigating the potential of fission-fusion The European Community is interested in in- hybrid reactors for its thermal and breeder reactor ternational collaboration for a variety of reasons. program .46 In recent years, the EC has confronted tight budgets and competing demands for funding, The Soviet Union is currently constructing a which increase the attractiveness of working with major tokamak experiment, T-15, which is simi- partners outside of Europe. Like other nations, lar in objective and capability to the large toka- the EC recognizes the substantial benefits of cost maks currently being operated in the United savings and knowledge and risk sharing. More- States, EC, and Japan. Completion of T-15 was over, through the JET project, the EC has had positive first-hand experience with the scientific, 441 nformation on the Soviet Union’s fusion program was provided technical, and management aspects of collabo- to OTA by Dr. Paul Josephson, “The History and Politics of Energy ration. In addition, the EC fusion effort has co- Technology: Controlled Thermonuclear Synthesis Research in the operative relationships with the other programs, USSR. ” Josephson has studied Soviet science and technology policy issues at the Massachusetts Institute of Technology’s Program principally the United States for which it has con- in Science, Technology, and Society. siderable respect. It also respects the Soviet and dsseventy percent of Soviet energy consumption and POPU Iatlon is located in the European part of the country, but 90 percent of the fuel resources are located in Siberia and Soviet Central Asia. The cost of transporting the energy thousands of miles from east qzThi5 discussion is based in part on information provided by an to west, either in its primary form or as electricity, is high. There- OTA contractor, Professor Wilfrid Kohl, in a report titled “The Po- fore, the government is pursuing the rapid commercialization of litical Aspects of Fusion Research in Europe.” Kohl IS director of nuclear energy near the western population centers. the International Energy Program at the Johns Hopkins University aGFission-fusion hybrid reactors use the neutrons generated in fu- School of Advanced International Studies. sion reactions to produce fissionable fuel. For more information, JJThe j ET project is de5cribed I n cfeta i I i n ‘‘Mu ki Iaterat Activities. see app. A. Ch. 7.—Fusion as an International Program ● 181

originally scheduled for 1982, but the project has this century a terrestrial sun . . . thermonuclear been delayed repeatedly due to engineering energy. We note with satisfaction that it was problems and is now expected to operate in agreed in Geneva to carry on with that important work.49 1988. The Soviets are considering construction of a device called the Operational Test Reactor In addition to incentives to collaborate, there (OTR) to succeed T-1 5.47 This device is believed are also obstacles from the Soviet perspective. to be analogous to the next-generation devices These include pressures within the U.S.S.R. to planned in other major national programs, ex- avoid technological reliance on the West and cept that it is also intended to verify how effec- shortages of hard currency with which to partici- tively fusion can be used to breed fuel for fission pate. Another obstacle is any unforeseen deteri- reactors. oration of the U.S.-U.S.S.R. relationship due to political developments unrelated to fusion; in Views on Collaboration 1980, for example, the Soviet invasion of Af- The Soviet Union has regularly made proposals ghanistan interrupted cooperative fusion work that had been relatively stable until then. to enhance international cooperation in fusion. The INTOR project was initially proposed by the It appears that the Soviets would be comforta- Soviets, as was the genesis of the current proposal ble collaborating with any of the major fusion for an international next-generation experiment. programs on ITER, judging from the positive So- The Soviet Union has made major contributions viet evaluation of INTOR. However, as yet nei- to past international projects and has clearly ther the Japanese nor the Europeans have sought found the activities rewarding. to build a machine with the Soviets.50 Because of the Soviet Union’s relatively long-term involve- It appears that budgetary constraints are put- ment with the United States in bilateral scien- ting pressure on the Soviet fusion program. While tific agreements, the role of these scientific ex- it is difficult to provide actual data on the size changes in the pursuit of improving relations, of the Soviet fusion budget, a review of Soviet the present international outlook of Soviet leaders journals indicates that plasma physicists currently toward technology, and Soviet respect for Amer- are more circumspect in their predictions for fu- ican science and technology, the Soviets appear sion power than they used to be, and that they interested and willing to collaborate with the are fighting to retain their fusion budgets in the face of intense pressure from other energy re- United States. search programs such as breeder reactors.48 Japan51 There is high-level political support for collaboration in fusion, and General Secretary Gorbachev Program Goals has stressed repeatedly its importance. He raised Many Japanese see fusion as the ultimate so- the issue with President Reagan at the Geneva lution to Japan’s energy problems. Japan is more Summit in 1985 and again in a speech before the dependent on imported energy than any other Supreme Soviet in 1986. On the latter occasion, major economic power, and the Japanese are he said: concerned about how precarious this depen- On the initiative of the U. S. S. R., work involv- dence makes their economy. Nuclear energy has ing scientists from different countries has begun on the tokamak thermonuclear reactor project

[lNTOR], which opens up an opportunity to rad- 49M S. GOrbac hev, as cited I n Kadomtw\, ‘‘ Toka ma k, SOL let ically resolve the energy problem. According to L/fe, August 1986, p. 13. scientists, it is possible to create as early as within 50Mark Crawford, “Researchers’ Dreams Turn to Paper In U.S - USSR Fusion Plan, ” Science, vol. 234, Nov. 7, 1986, p. 667 5)Thls section IS ba~ed In part on a report completed for OTA ~7MlCha~l RO&rlS, U, S. Department of Energy, (] ftlce Of Fusion by Dr. Leonard Lynn, “Politlcal Aspects of Fusion Research In ja- Ener~y, brlet’lng on ‘‘International Dlscus\ions on ETR, ” Rock\ llle, pan, ” Lynn IS a proiessor who analyzes Japanese science and tech- MD, jU]Y 16, 1986. nology pollcy I n the Department oi Social and Decision Sciences 48P, Josephson, “H I$tory and Politics, ” op. cIt,, pp. 16-19. at Ca rnegle-Mel Ion U n[verslty. 182 ● Starpower: The U.S. and the International Quest for Fusion Energy

helped the Japanese decrease their dependence Although the Japanese are interested in col- on oil, and Japanese policy makers favor the con- laborating on fusion research, there maybe some tinued use and development of nuclear power. obstacles to such collaboration. The Japanese Japan’s general long-range energy policy calls for confront a major debt burden that has grown rap- an increased reliance on conventional nuclear idly in the last few years and that has increased energy over the next 25 years. It is anticipated government pressure to cut spending.52 In addi- that this policy will be followed by a reliance on tion, the Japanese might be unwilling to partici- fast breeder reactors around 2010 and a transi- pate if the experiment is not sited in Japan. tion to fusion energy about 30 years later. The Japanese are willing to explore the possi- The largest experimental fusion facility in Ja- bility of multilateral collaboration on ITER, how- pan is JT-60. Japanese scientists have begun con- ever, and they are currently participating i n dis- ceptual design studies for a next-generation toka- cussions of the project with the United States, the mak, the Fusion Experimental Reactor (FER), European Community, and the Soviet Union. Of which is intended to succeed JT-60. FER, which the three, Japan appears most interested in col- could be built in the late 1990s, would resemble laborating with the United States. In addition to NET or ITER and probably would be designed to extensive cooperative experience with the United achieve ignition and demonstrate the technical States, the Japanese also have a bilateral arrange- feasibility of the nuclear fusion reactor. ment with the EC that involves meetings of experts and information exchange.53 However, the Views on Collaboration Japanese and European programs currently are less familiar with each other than either is with International collaboration is attractive to the the United States. The Japanese have the least Japanese for many of the same reasons that it is experience cooperating with the Soviet Union. attractive to other countries. The Japanese, like others, feel that the financial and human resources Jzlbid,, ~p, 46.47: public debt climbed from 2.2 trllllon Yen In 1976 required to construct a next-generation fusion de- (13 percent ot’ GNP) to 130 trillion yen in 1985 (42 percent of GNP), vice may be too great a burden to bear alone. In 1986, the cost of servicing this debt accounted for more thdn Moreover, the Japanese have both contributed 20 percent of government expenditures. This compares to 14 percent of government expenditures going to service the U.S. national and received valuable technical information from debt in 1985. past fusion cooperative projects. 5Jlbid., pp. 42-43.

PROSPECTS FOR INTERNATIONAL COOPERATION U.S. Plans for Future Cooperation International collaboration in fusion research and development has become a key factor in DOE is interested in the prospects for more ex- DOE’S program planning. tensive international cooperation on future magnetic fusion experiments. In fact, a recent DOE Possible Areas for International report on international activities in magnetic fu- Cooperation sion states: There are several possible areas of cooperation The objectives of U.S. international collabora- delineated in DOE’s report.55 These areas are tion are to share the many high priority tasks, to linked to the four key technical issues in the DOE reduce the total costs associated with the required Magnetic Fusion Program Plan (see the section major facilities and to combine intellectual forces 54 in ch. 4 titled “Key Technical Issues and Facil- in pursuit of the most essential problems. ities” under “Research Progress and Future Direc-

J~U .s, Depaflnlent of Energy, Office of Fusion Energy, /nte~na - fiorra/ Program Activities In Magnetic FusIorr Energy, op. cit., p. 1. ~Jl bid., Attachment 3, pp. 1-5.

tions”). In confinement systems, DOE states that Considerations of the International possible initiatives include gaining long-term ac- Thermonuclear Experimental Reactor cess to the JET experimental programs and pos- To date, DOE’s proposal to design ITER collabora- sibly those at JT-60, developing a coordinated tively has drawn the most attention among the program to develop the reversed-field pinch con- many cooperative efforts outlined in DOE’s report. cept, and using selected foreign facilities to con- Within the framework of the Versailles and Geneva tinue development of superconducting magnets. summits, DOE has been involved in negotiations in burning plasmas, the United States would seek with the other major fusion programs to develop foreign participation in the planning and opera- the conceptual design and supporting R&D for tion of CIT. In nuclear technology for fusion sys- ITER. The proposal does not currently extend to tems, DOE is investigating proposals to extend joint construction and operation of the experi- the current cooperative activity in technology re- mental faciIity. At the conclusion of the concep- search and development and to coordinate ef- tual design effort, the parties would be free to forts in development of tritium handling technol- build such a device, either alone or collectively. ogy. In fusion materials, DOE further proposes to coordinate research with the other major The Versailles Economic Summit.—Several na- programs. tions participate each year in an economic sum- 184 ● Starpower: The U.S. and the International Quest for Fusion Energy

mit meeting.56 These nations began considering Switzerland, followed up on this point. At the the implications of technology for economic conclusion of the meeting, President Reagan and growth and employment at the urging of French General Secretary Gorbachev issued a joint state- President Mitterand in 1982 when the meeting ment supporting fusion collaboration to the “widest was held in Versailles, France, and a process for degree practicable.” The statement did not rec- considering specific ideas on this topic was estab- ommend a specific proposal or approach. lished. The prospect of international cooperation Current Status of the ITER Project.–No for- in magnetic fusion was one of 18 ideas specifi- mal agreement has been reached on the ITER cally investigated. Cooperative efforts in fusion project. Recently, the United States proposed that research have been discussed since then, and a the potential partners begin a 3-year joint plan- great deal of effort has gone into developing plans ning activity to do conceptual design and sup- for a workable joint undertaking.57 porting R&D for the device. Areas of collabora- Under the framework established at the Ver- tion would include defining the scope of the sailles summit, the Fusion Working Group was project, developing a conceptual design for the created in 1983. The Fusion Working Group is device, and coordinating the research needed to involved in early joint planning efforts and dis- support the design effort. cussions aimed at identifying necessary major fa- Representatives from the United States, Japan, cilities. in 1985, the Fusion Working Group cre- the European Community, and the Soviet Union ated the Technical Working Party to consider met in March 1987, in Vienna, Austria, to discuss technical and research-related issues in interna- the conceptual design phase of such a project. tional fusion projects. In late 1985, the Techni- This meeting, held under IAEA auspices, marked cal Working Party endorsed the U.S. plan to con- the first time that all four parties met to discuss struct CIT. collaboration on ITER. The meeting produced In 1986, the Fusion Working Group reached general agreement on the nature of the project a consensus on the desirability of future collabora- “and the necessary steps to formalize it. The IAEA tive activities. Participants issued a joint statement stated at the end of the meeting: that an engineering test reactor (now called ITER) The Parties were favorably disposed to the pro- is a common midterm goal for the fusion proposal for joint conduct of conceptual design and grams of the United States, Japan, and the Euro- supporting R&D for an international thermonu- 58 pean Community. clear experimental reactor. The Parties reached The Geneva Summit.–Fusion cooperation was an understanding that the proposal was a sound basis for further discussion. The four Parties will also discussed by the United States and the So- each identify their representative to a group of viet Union at the Geneva summit in November experts to make proposals for a common set of 1985. Prior to the summit, in an October 1985 detailed technical objectives for the conceptual meeting between French president Mitterand and design and to prepare the basis for further con- Soviet General Secretary Gorbachev, Gorbachev sideration by the Parties .59 had expressed interest in pursuing international collaboration on a large next-generation fusion In some ways, the arrangement proposed by experiment. The Geneva summit between Presi- the United States resembles the International Tokamak Reactor (lNTOR) study. The proposal dent Reagan and Gorbachev, held in Geneva, is more extensive, however, than INTOR. First, ITER deliverables would have a defined sched- Sbparticipants ar the united States, Canada, the Federal f@ub- e ule, whereas the INTOR schedule is indefinite. Iic of Germany, France, Italy, Japan, and the United Kingdom. The Second, the ITER project would receive higher European Community as a whole is also represented. SzMlchael Roberts, Director of International Programs, U.S. De- level attention than INTOR. Third, under the ITER partment of Energy, Office of Fusion Energy, briefing on “international Programs in Fusion, ” presented to ERAB Fusion Panel, Wash- ington, DC, May 29, 1986. WSU mmlt Working Group on Controlled Thermonuclear Fusion, WI nternational Atom ic Energy Agency, as quoted i n hecutive Summary Conclusions, Schloss Ringberg, Jan. 17, 1986. Newsletter, Fusion Power Associates, April 1987, p. 4. Ch. 7.—Fusion as an International Program . 185

project, there would be full-time design teams The proposal is based on the INTOR model, working in each program; the INTOR design which provides an example of successful, if lim- teams are part-time. Finally, the ITER project, united, cooperation on project design. Like INTOR, like INTOR, would include cooperation on sup- in which the Soviet Union participates without porting R&D. threatening U.S. national security, this proposal does not raise technology transfer concerns be- DOE has proposed that there be a full-time cause it will include only common design, not group of managing directors to coordinate the common technology development. planning effort. According to DOE, this phase of the activity could utilize the International Atomic The current proposal does not address the Energy Agency as an umbrella organization to fa- problems that would be encountered in jointly cilitate the project. For simplicity, the coordinat- constructing and operating ITER. These obsta- ing site could be located at the IAEA headquar- cles will still arise when and if the decision is ters in Vienna, Austria. No other site agreements made to build and operate the device. The cur- would be necessary at this stage because all other rent proposal does provide a mechanism whereby work would be undertaken within the national the conceptual design and supporting R&D can programs. be completed, enabling informed decisions about proceeding with collaboration to be made at a The total cost of the 3-year conceptual design later date. phase of ITER is estimated to be between $150 million and $200 million, which includes its sup- Completing the conceptual design phase of porting R&D. The U.S. cost of the undertaking ITER may help resolve some of the obstacles to is projected at between $15 million and $20 mil- subsequent collaboration. For example, the con- lion annually. This annual budget represents ceptual designs developed over the next 3 years about a tripling of the amount the United States may enable concerns about technology transfer currently spends on design studies. to be analyzed specifically and their implications for national security to be resolved definitively. DOE anticipates that the conceptual design Furthermore, issues such as siting the facility or phase of the ITER project will occur between determining a technically acceptable project de- 1988 and 1990. At the completion of this phase, sign may be settled, either through the initial interested parties would be in a position to be- phase of the project or through concurrent dis- gin negotiations on whether or not to jointly con- cussions and negotiations. At the completion of struct and operate the device. Any party could the design phase, the major fusion programs withdraw at this point, decide to construct and should be better situated to develop detailed operate the experiment independently, or choose plans for further collaboration. to pursue the effort collaboratively. The current ITER proposal begins conserva- Analysis of U.S. Proposal for ITER tively, utilizing an already well-established cooperative arrangement. Participants will be able to The U.S. Government’s recent proposal marks work on the project without making a firm com- the first step toward a collaborative ITER. No mitment to future involvement in joint construc- agreement has been reached; the details of the tion and operation. Perhaps most importantly, proposal will be modified during negotiations U.S. Government agencies will have more time with other fusion programs. Therefore, it is im- and additional information with which to estab- possible to assess the proposal completely. lish clear policy guidelines.

SUMMARY AND CONCLUSIONS

Magnetic fusion has a long history of interna- costs, risk, and knowledge; they value the oppor- tional cooperation. For the future, the major fu- tunity to achieve collectively what no program sion programs recognize the benefits of sharing could afford to achieve alone. Any or all of the ——

186 “ Starpower: The U.S. and the International Quest for Fusion Energy

major world fusion programs would be techni- The proposal has far to go. Although successful cally attractive collaborative partners for the completion of the conceptual design and sup- United States. Higher levels of cooperation have porting R&D will be important for addressing the drawbacks, however. Cooperation may actually issues related to construction and operation, the increase the total cost and risk associated with design process alone will not resolve these issues. fusion projects, and the benefits of knowledge In the United States, at the moment, the most sig- sharing may be cut short if technology threaten- nificant issue on joint construction and operation ing national security or national competitiveness is the possible transfer of militarily relevant tech- is transferred to the partners. nology. Agencies within the U.S. Government disagree about the severity of this problem, and There are many successful examples of coop- the dispute must be settled internally before a ma- eration in fusion research and other scientific jor collaboration can proceed. areas. JET, for example, is a collaborative undertaking in which the major European fusion pro- project location is another critical issue. Just as grams have jointly constructed and operated a siting was a major problem for JET, it is likely that world-class tokamak facility. CERN, a major non- a decision on ITER location will not come eas- fusion project, is an example of the European na- ily. What does seem clear is that it is unlikely that tions pooling their resources and developing a either the United States or the Soviet Union will state-of-the-art high-energy physics program. be chosen as the site for ITER. Ultimately, reaching an agreement to jointly While future cooperation can build on the solid construct and operate an international experi- foundation of the past, collaborative projects such ment will require high-level government support. as ITER will have to resolve many new issues. Col- A clear presidential decision to support the under- laboration on this scale involving countries out- taking will be required. Even that, by itself, is inside Europe is unprecedented. Negotiating and sufficient to guarantee the viability of a project approving the necessary international agreements involving all branches of the U.S. Government will be possible only if the parties involved are and extending over several Presidential Admin- committed both to the collaborative project and istrations. Moreover, the national programs will to their domestic programs. International collabo- have to formalize their support in an agreement ration cannot substitute for a domestic fusion pro- that will establish confidence in the management gram. If the domestic program is sacrificed to sup- and operation of the project. port an international project, the rationale for collaboration will be lost and the ability to conduct DOE considers international collaboration on the project successfully will be compromised. ITER and other projects essential to the progress of the U.S. fusion program. If more extensive co- The U.S. Government’s current ITER proposal operation proves impossible or unacceptable, appears to be a workable first step toward a ma- DOE’s program plans must be reevaluated: ei- jor experimental facility. The proposal minimizes ther the U.S. program will need more funding or the risks in the project’s early stages by decoupling its schedule will have to be slowed down and design from construction and operation. revised. Chapter 8

Future Paths for the Magnetic Fusion Program CONTENTS

Page Key Issues Affecting the of Fusion Research ...... 189 The Independent Path ...... 191 Description...... 191 Motivations and Assumptions ...... 191 The Collaborative Path . .“...... 193 Description...... 193 Motivations and Assumptions ...... 193 The Limited Path...... 194 Description...... 194 Motivations and Assumptions ...... 195 The Mothballed path ...... 196

Description...... ● ...... 196

Motivations and Assumptions . . ● ...... 196 Chapter 8 Future Paths for the Magnetic Fusion Program

The likelihood that fusion will be developed as Union) at an unprecedented level of collabo- a future energy supply option is affected—although ration. This path is termed ‘‘Collaboratii’e. not completely determined—by policy choices 3. In the absence of major collaboration, a flat made today. A decision to accelerate fusion re- or declining funding profile wouId force sig- search does not ensure that fusion’s potential will nificant changes to be made in the program’s be successfully realized, any more than a deci- overall goals, including a recognition that fusion to terminate the current research program sion’s commercialization would be delayed implies that fusion will never be developed. from current projections. This path is called Nevertheless, near-term decisions clearly influ- “Limited,” indicating that progress in some ence the pace of fusion’s development. The critical areas wouId be impossible without sooner we wish to evaluate fusion as an energy additional resources. supply technology, the more important our near- 4. Shutting down the fusion program would term decisions become. Over the next several foreclose the possibility of developing fusion decades, the fusion research program can evolve as an energy supply option unless and until along any of four largely distinct paths: research were resumed. On this “Moth- balled” path, progress towards fusion in the 1. With substantial funding increases, the U.S. United States would halt. Work would prob- fusion program can complete its currently ably continue abroad, although possibly at mapped-out research plan independently. a reduced pace; resumption of research in This plan is intended to permit decisions the United States would be possible but dif- concerning fusion’s commercialization to be ficult. made early in the next century. This approach is called the “Independent” path. Current Department of Energy long-range 2. At only moderate increases in U.S. funding plans for the fusion program are aimed at the levels, the same results might be attainable– “Collaborative” path. If recent funding declines although possibly somewhat delayed—if the continue, however, or if the United States does United States can work with some or all of not successfully arrange its participation in ma- the world’s other major fusion programs jor collaborative activities, the U.S. fusion pro- (Western Europe, Japan, and the Soviet gram will evolve along the “Limited” path.

KEY ISSUES AFFECTING THE EVOLUTION OF FUSION RESEARCH

The four paths are differentiated by the degree is needed; 3) the advantages and risks of large- of commitment and the level of funding provided scale international collaboration; 4) the implica- by the U.S. Government for fusion research. Path tions of requirements for expensive research fa- characteristics and the choices between them are cilities; and 5) the value of the “auxiliary bene- determined by several factors, including: 1 ) the fits” associated with fusion research such as likelihood of technical and commercial success scientific understanding, education, and techno- in developing fusion technology; 2) the perceived logical development. Another factor, the poten- urgency with which a new supply of electricity tial for surprise inherent in any new technology,

189 190 . Starpower: The U.S. and the International Quest for Fusion Energy

may also be an important aspect of one’s choice replace coal and/or fission, affect one’s per- of research approach; however, such a factor is ception of the urgency of fusion research and not amenable to analysis. development. None of the research paths presented in Discussions earlier in this report have addressed this chapter call for a crash program to de- many of these factors, which are summarized velop fusion. It is very difficult to formulate below: a credible scenario of major, irreversible ● Likelihood of Success: In evaluating the like- electricity shortages in the early 21st century lihood of program success, technical success that would require fusion’s development on must be differentiated from commercial suc- a schedule faster than that discussed in chap- cess. According to chapter 4, the risk of tech- ter 4. nical failure appears small, particularly if ● Advantages and Risks of Large-Scale Inter- operation of the Compact Ignition Tokamak national Collaboration: It appears possible (CIT) does not uncover serious problems.1 that large-scale international collaboration If CIT operates as anticipated, it seems likely could enable the United States to make prog- that a fusion device capable of producing ress towards assessing fusion’s potential at electricity can be developed. a substantially lower cost than would be re- However, the risk of commercial failure— quired for the United States to proceed in- the development of a technology that does dependently. Chapter 7 discussed the advan- not interest potential users—is much harder tages and risks of large-scale international to evaluate. The commercial attractiveness collaboration in future fusion projects. Differ- of fusion energy will depend not only on its ent evaluations of the costs and benefits of cost, but also on conditions unrelated to fu- large-scale collaboration, which were pre- sion technology that cannot be estimated at sented in chapter 7, affect one’s willingness present. Different opinions as to the likeli- to consider undertaking the next stages of hood of successful commercialization and fusion research collaboratively. In addition, the attractiveness of fusion over other elec- different assessments of the obstacles to in- tricity alternatives affect the priority given to ternational collaboration may affect one’s will- fusion research. ingness to negotiate a collaborative agreement. ● Perceived Urgency: Chapter 5 concluded ● Implications of the Need for Expensive Re- that estimates of future electricity demand search Facilities: Chapter 4 identified several neither require nor eliminate fusion as a pos- major research facilities that may be required sible energy source. It appears that electri- to evaluate fusion’s potential. The total world- city technologies other than fusion—principally wide cost of these facilities has been esti- coal and nuclear fission—should be capable mated at $6 billion, with a next-generation of supplying ample power at reasonable engineering test reactor alone expected to prices through at least the middle of the next cost well over $1 billion. As long as multi- century. However, uncertainties as to the billion-dollar facilities are necessary to as- continued acceptability of fossil fuels and nu- sess fusion’s potential, development of fu- clear fission provide incentives to explore the sion power cannot proceed without strong potential of improved energy efficiency and financial support at the highest levels of to develop alternative energy sources. Differ- government. The private sector will not be ent estimates of the future attractiveness of willing to finance fusion research until fu- coal and nuclear fission, and different judg- sion’s potential is clearer. ments of the ability of various alternatives to The need for major facilities, along with the need to conduct a diverse array of supporting research, means that the fusion research program will not make progress towards ICIT is described in the section of ch. 4 titled “Key Technical Issues and Facilities. ” evaluating fusion’s energy potential if its funding is too low. With insufficient fund- Ch. 8.—Future Paths for the Magnetic Fusion Program ● 191

ing, the program must either delay complete servers might oppose fusion’s development evaluation of fusion’s potential or await tech- because of this inherent potential for unan- nological developments (which may never ticipated consequences; others would eagerly be realized) that lower the cost of the re- support exploration of the technology pri- search remaining to be done. marily because of the new possibiIities it may ● Near-Term Benefits: Chapter 6 discussed offer. Since unforeseen capabiIities or con- near-term benefits of fusion research such sequences are by definition impossible to as increasing scientific understanding, edu- predict, this report cannot and does not ad- cating and training skilled technical person- dress them. nel, and developing technologies with economic and defense applications. Different values assigned to these benefits, and differ- The possible advantages and disadvantages of ent estimates of the benefits that would have each of the four paths outlined at the beginning been derived had the resources spent on fu- of this chapter are described below, along with sion been allocated elsewhere, lead to differ- the assumptions that would lead to each’s selec- ent levels of emphasis on fusion research. tion. The discussions of the paths are interdepen- ● Potential for Surprise: In many respects, fu- dent; in many cases, the advantages of selecting sion technology will be unlike any existing one approach also describe the disadvantages of technology, and it may open up capabilities selecting another. The paths are discussed in gen- and applications that cannot be foreseen eral terms, and the detailed structure of the fu- today. Like other qualitatively new technol- sion research program is not specified under any ogies, fusion’s most significant impacts may of them. Extensive additional study would be re- be totally different than those that were ex- quired to determine the best way to implement pected prior to its introduction. Some ob- each path.

THE INDEPENDENT PATH Description is similar to the one specified (but not funded) in the 1980 Magnetic Fusion Energy Engineering The goal of the Independent path would be to Act.2 aggressively establish the scientific and technological base necessary to evaluate fusion’s poten- Motivations and Assumptions tial and to decide by the early 21st century whether to proceed with a demonstration reactor. All the Choice of this path would be motivated by the facilities required to establish this base would be assumption that evaluating fusion’s potential early funded and operated domestically under this ap- in the next century is an important national goal. proach. The exact funding necessary for this path The probability of success and the need for de- cannot be determined without detailed additional veloping fusion would both be assumed high examination, but considerably more support enough to justify considerably increasing the cur- would be required than is currently available to rent U.S. investment in fusion research. the fusion program. On average, between $500 The benefits of conducting fusion research million and $1 billion per year probably would without depending on the participation of other be required over the next 20 years, with peak an- countries would be assumed to outweigh the cost nual funding possibly exceeding $1 billion. Wide- savings and other possible advantages of large- spread international cooperation might continue, scale international collaboration. Although the but it would fall well short of the shared decisionmaking and funding that would characterize the ~Tht\ act IS described In the section ot ch. 3 titled “The 1980$: Collaborative approach. The Independent path Le\ elln~ Ot’t’ “ 192 . Starpower: The U.S. and the International Quest for Fusion Energy

near-term domestic benefits of fusion research ternally acquired information or technical ex- probably also would be highly valued, the pros- pertise. pects of developing a viable energy technology International Stature. –Through this research would be the primary motivation for selecting this approach, the United States would be able to path. demonstrate its technological capability and bol- ster its international stature. In addition to the po- Advantages tential economic returns, being in a position of Control Over Research and Development.– world leadership could give the United States sig- Under this approach, the United States would be nificant leverage in future cooperative projects fully self-sufficient in acquiring the information and couId make the United States a more desira- needed to assess fusion’s potential. Decisions ble cooperative partner. made in other countries or difficulties in large- scale international collaboration would not affect Disadvantages the U.S. ability to evaluate fusion’s potential on Cost.–The principal disadvantage of this re- a time scale of its own choosing. Under this ap- search approach is its cost, which is considera- proach, the United States could attempt to re- bly higher than that of any other approach. Fusion gain a position of world leadership in fusion re- is not guaranteed to succeed, and the investment search, rather than accept the technological in fusion research may not “pay off” with an at- parity required for true collaboration and inter- tractive energy technology. In this case, the in- dependence. vestment in fusion research might be considered If the United States were to go on to make a wasted. Benefits of the fusion program such as positive assessment of fusion’s potential, and if scientific return, training of personnel, techno- the U.S. technological capability in the field were logical development, and international stature– unmatched by other international fusion programs, hard as they are to measure–are unlikely to the United States would have the advantage of justify the full cost of independently developing leading the development and commercialization fusion technology. of fusion technology. Potential Overemphasis.–A sense of urgency Energy Supply. —If the United States were to and direction is necessary in order for the fusion make a positive evaluation of fusion’s potential program to command the resources it would re- as a result of pursuing this approach and were quire under the Independent path. However, the then able to develop and commercialize fusion risks of program failure are increased if an exag- technology, a new, potentially attractive source gerated sense of urgency pushes the research ef- of energy would become available. Even if fusion fort faster than it can responsibly proceed and were not viewed as preferable to other energy prematurely forces key decisions. A balance must technologies, investment in the technology might be struck between proceeding with determina- still be justified since fusion would be available tion and direction, which is necessary, and rush- as a hedge against unforeseen or underestimated ing into a “crash program, ” which can be coun- difficulties with other energy sources. terproductive.

Manpower, Infrastructure, and Technology A more subtIe risk could arise if fusion were Development.–Conducting fusion research in- emphasized at the expense of improving the ex- dependently could have significant domestic ben- isting sources of energy supply, increasing the effi- efits, in terms of training personnel, acquiring a ciency of energy use, or developing other energy domestic fusion infrastructure, and developing supply alternatives. if U.S. long-term energy re- associated technologies. Since more funds devoted search concentrates heavily on fusion, the impli- to the fusion effort would be spent domestically cations of technical or commercial failure could than under any of the other research approaches, be serious. Therefore, if concern over energy sup- these domestic benefits would be realized to a ply motivates more intense fusion research, it greater extent under this approach. Moreover, should also motivate energy research in non- the United States would not be dependent on ex- fusion areas. Ch. 8.—Future Paths for the Magnetic Fusion Program c 193

THE COLLABORATIVE PATH

Description proach to justify conducting all the necessary research domestically. Choice of the ColIaborative Ideally, the Collaborative path would accom- approach assumes that the parties involved wiII plish the same technical tasks as the independ- be able to develop a program whose cost and ent path on a similar time scale. However, the schedule is acceptable to all, that major experi- Collaborative path would use the combined re- mental facilities can be collaboratively built and sources of the world’s major fusion programs, operated, and that equitable allocation of re- making it possible for the individual contribution search tasks and results can be arranged. of any one program to be smaller than wouId be needed to perform the same tasks alone. Advantages

With large-scale international collaboration, the Cost-Sharing.–The principal benefit of the U.S. fusion program would require only modest Collaborative path is the cost-effective utilization increases in funding above current levels to evalu- of the resources avaiIable to the major fusion pro- ate fusion’s feasibiIity early i n the 21st century. grams worldwide. Total funding now spent an- Annual funding on the order of $400 million to nually on fusion research throughout the world $500 million probably would be necessary over is comparable, or greater than, the amount needed the next 20 years, with the total being highly de- per year to evaluate fusion’s potential by the early pendent on the degree of cost-sharing attainable 21st century. If the major fusion programs can through collaboration. minimize duplication of effort, reaching that evaluation should not require substantial budgetary in- Motivations and Assumptions creases in any of the major programs. Whereas pursuit of the Independent path requires dou- Choice of this approach, like the Independent bling or tripling annual U.S. fusion budgets, the approach, is based on the assumption that evalu- Collaborative path may only require funding in- ating fusion’s potential in the early 21st century creases of 20 to 50 percent above current levels. is an important national goal. The assumed probability of success and the perceived need for fu- Energy Supply.– If successfully implemented, sion power wouId be high, as they would be un- the Collaborative approach would permit the der the Independent path. The major difference United States and the other major fusion pro- between this path and the Independent path is grams to evaluate fusion’s potential by the early that under this approach the benefits of large- 21st century. The timing of this evaluation is scale international collaboration would be assumed similar—although possibly somewhat delayed— to outweigh the disadvantages. The United States from that in the Independent path. However, the wouId consider self-determination in fusion ei- results of a Collaborative research effort would ther impossible or not worth the price. be more effectively shared among the major fusion programs. Activities under the Collaborative path could Improving the Technical Base.—Fusion re- take the form of joint construction and operation search may proceed more effectively if the re- of major facilities, in which several nations’ fu- search efforts of the major programs are integrated sion programs would be simultaneously involved. to a greater degree. All of the major programs Activities could also take the form of allocating have technical capabilities and skilled personnel various research tasks to particular programs. If that can contribute to the research and develop- such an allocation were done, all programs would ment effort. In addition, effective planning among eventually need to obtain data (which is rather the major fusion research programs can ensure easily shared) and expertise or “know-how” that more research approaches are investigated. (which is harder to transfer) from the program that If through such efforts, research efforts can be had done a particular piece of research. r mutualIy supportive rather than duplicative, this The near-term benefits of fusion research would widened technological base will benefit fusion not be judged important enough u rider this ap- research worldwide. 194 ● Starpower: The U.S. and the International Quest for Fusion Energy

Foreign Policy Benefits.–The United States the United States would either have to make may wish to participate in a large-scale collabora- more resources available for fusion research, tive project for diplomatic reasons as well as tech- changing to the Independent path, or extend the nical ones. Since there appear to be significant schedule for fusion development as discussed in technical and financial benefits to the United the Limited path (below). States from successful collaboration in fusion, Cost.–Although the cost of this approach is diplomatic motivations would not appear to be substantially less than that of proceeding inde- in opposition to programmatic ones. pendently, increases in U.S. annual fusion funding are nevertheless required to carry out this ap- Disadvantages proach. If fusion research does not lead to an Shared Control and Loss of Flexibility.–Under attractive energy source, this investment might the Collaborative approach, the United States be considered wasted. would sacrifice some control over the research Adverse Impact on Domestic Development.– program. International collaboration on the scale The Collaborative approach is motivated in part necessary for this approach will require com- by pressures to share costs and lessen research promise by all partners. In particular, some ma- expenditures. However, if international collabo- jor experimental facilities, such as the interna- ration is supported at the expense of maintain- tional Experimental Thermonuclear Reactor, ing a healthy domestic program, both the col- wouId probably not be sited in the United States. laborative projects and the domestic program This approach could be less flexible than the could be damaged. A viable domestic program others, since decisions—which would be made is required to contribute to and be attractive for multilaterally—would be difficult to modify. future collaboration. Moreover, depending on how time-consuming the negotiation process is, the Collaborative path The Collaborative approach may create tension could take longer than the Independent path to between undertaking domestic activities, on the develop fusion. one hand, and participating in joint research with foreign programs, on the other. Incentives to min- Obstacles to Large-Scale Collaboration.–If the imize costs and avoid duplication will have to be potential obstacles to large-scale collaboration de- balanced against developing and maintaining scribed in chapter 7 prove insurmountable, the sufficient domestic expertise to contribute to and Collaborative approach would fail. In this case, assimilate the results of collaborative projects.

THE LIMITED PATH

Description Because there are so many different motivations for pursuing this approach, no single plan, Under the Limited path, fusion research would strategy, or estimated funding level can ade- continue but would not be supported at the level quately describe it. Clearly, the funding level necessary to evaluate fusion’s potential domes- would be less than that needed for the independ- tically in the early 21st century. The schedule for ent path and more than that for the Moth balled developing fusion under this approach therefore path (below). It probably would be less than that would be delayed compared with the independ- needed for the Collaborative path, although even ent or the Collaborative approaches. With the a funding profile sufficient for the Collaborative Limited path, funding levels would not be suffi- path would result in the Limited path if collabora- cient to support a healthy base program simul- tion were found to be undesirable or unworkable. taneously with the construction of major facilities required’ to make progress in critical research The Limited approach would attempt to retain areas. a base program in fusion research at universities Ch. 8.—Future Paths for the Magnetic Fusion Program ● 195

and national laboratories. The program would be It would be cheaper–and therefore politically limited to scientific research, however, with fund- easier—to fund a Limited path program than the ing levels and/or program intent not enabling it higher cost Independent or Collaborative ap- to advance to engineering development and proaches. demonstration. With the Limited path, fusion’s Flexibility.–In some ways, research with the scientific feasibility probably could be deter- Limited path may be more flexible than with ei- mined. It is unlikely, however, that engineering ther the Independent or Collaborative paths. Early feasibility could be determined domestically, and design selections for large and expensive research commercial feasibility would be impossible to facilities that would tend to lock in a given line evaluate without increased financial support. of research emphasis would be avoided. Delay- ing these investments could make it possible to Motivations and Assumptions build them either at substantially lower cost or with a higher probability of commercial success. With the Limited path, pursuit of fusion would not be a high national priority. Many different as- Risk Avoidance.–Under this approach, the sumptions could result in a lower priority for fu- United States could let the rest of the world shoul- sion research and lead to selection of the Limited der the expense and take the risk of determin- path. The Limited path also might be pursued as ing fusion’s feasibility. The United States would a “second choice” if either the Independent or retain a base program in fusion research to pre- the Collaborative approaches could not be sus- serve the expertise needed to evaluate and even- tained. tually reproduce work done abroad. The United States, of course, would start out with a competi- Assumptions that might lead to selection of the tive disadvantage in this case and might or might Limited approach include the judgment that fu- not be able to catch up. However, it would also sion’s promise or urgency was not high enough be able to evaluate whether or not the technol- to justify the Independent approach but too high ogy was attractive without the substantial invest- to warrant shutting the research program down ments required to pursue the Independent or Col- entirely. Moreover, either the prospects or the laborative paths. The United States would be free rewards of international collaboration could be to attempt to develop an improved technology judged too low to pursue the Collaborative ap- at some later time. proach.

Perhaps the construction of large experimental Disadvantages facilities would not be seen as warranted unless or until further technological development—in or Delaying Energy Supply .–The fundamental outside of the fusion program—brought down disadvantage of the Limited path is that it delays costs. Alternatively, it might be decided that while the evaluation of fusion. At our current level of the near-term benefits of fusion research justified understanding, experimental devices that are in- maintaining a limited program, the energy ben- herently large and expensive are required to re- efits did not justify a more extensive research ef- solve key uncertainties in the development of fu- fort. Delaying development of fusion’s energy po- sion power. Unless these facilities are funded, tential need not necessarily reduce the scientific, progress cannot be made and fusion’s potential educational, and technological benefits of fusion cannot be determined or developed, research. Technical developments may ultimately decrease the cost or eliminate the need for expen- Advantages sive experiments. However, it is not likely that Cost.–The major benefit of the Limited path such developments will occur quickly enough for is that the United States could maintain a limited the Limited approach to make fusion power avail- research capability while still retaining the abil- able on the same schedule as the Independent ity to accelerate fusion research at a later time. or Collaborative approaches. Moreover, signifi- 196 ● Starpower: The U.S. and the International Quest for Fusion Energy

cant developments may be less likely to occur if the program were perceived as having an un- or be recognized in the absence of a more am- certain future, In this event, a valuable source of bitious research program. new ideas and innovation would be lost. Loss of Direction and Scope.—If the fusion re- Loss of Momentum and International Stature.– search program is not targeted towards an evalu- With the Limited path, the fusion program could ation of fusion’s prospects as an energy source, lose its momentum. Unless other countries also it might become more of a basic science/plasma limited their programs, the United States would physics research program than an energy pro- fall behind. If other countries successfully com- gram. Without the direction provided by a rela- mercialized fusion technology, the United States tively near-term goal—evaluating fusion’s engi- could be at a competitive disadvantage, at least neering feasibility—the program’s subsequent initially. evolution might lead it away from those issues However, U.S. decisions and foreign decisions that must be resolved to develop fusion reactors. are not independent. Given that fusion research This drift would not only delay the development budgets are set in all the major fusion programs of fusion power but might also make its eventual through a political process that balances fusion development less likely. against other priorities, U.S. action to lower the Damage to Fusion Infrastructure.–Lim ited priority of fusion research might weaken the po- Federal funding of fusion research could adversely sitions of fusion researchers in other programs. affect many participants in the fusion research Foreign fusion programs might reduce their re- program. Industrial participation would be the search efforts. However, the other world fusion most severely constrained; steady and predicta- programs are clearly developing fusion for broader ble funding is required for industry to develop reasons than simply keeping up with the United and maintain the capability to participate in fu- States, and none of them are likely to eliminate sion research. Depending on the funding level, their programs. national laboratories and universities might also Difficulty in Collaboration.– If foreign fusion have to cut back on fusion work. programs pursue research more aggressively than Moreover, the field of fusion research in gen- the United States, the United States may no eral and university programs in particular might longer be seen as a desirable collaborative not be able to attract the most talented students partner.

THE MOTHBALLED PATH

Description energy supply technologies, to see whether the decision to stop funding fusion research should With the Moth balled path, the magnetic fusion be reviewed. research program would shut down. To capital- ize on the research investment to date, this path In practice, however, monitoring might be dif- would ideally be implemented in a manner that ficult. Competing funding priorities, too, might preserved the existing state of knowledge in the make it hard to acquire the resources needed to field and eased the transition of people and fa- reevaluate a canceled program. ciIities from fusion to other areas. To keep open the option of restarting the fusion program in the Motivations and Assumptions future, some resources would be desirable (either provided directly or through other programs) Choosing the mothballed approach implies that to permit periodic reevaluation of fusion. Tech- development of fusion–even as a hedge–does nical developments in other fields would have not merit appreciable investment now or in the to be monitored, along with progress in alternate near future. Proponents of this approach might Ch. 8.—Future Paths for the Magnetic Fusion Program ● 197

consider the current state of fusion technology to other programs; the associated benefits of fu- analogous to that of computer technology in the sion research such as personnel training, scien- 19th century: although many of the fundamen- tific research, and technological development tal concepts were known, a century of techno- would not continue in their current form, Al- logical progress in widely disparate fields was though scientific data and technological accom- required before computers of any practical sig- plishments would not be lost, the “know-how” nificance could be built. of individual researchers would be. Decades would be required from whenever a decision were Technological pessimism is not likely to be the made to resume the program until the earliest deciding factor in stopping the fusion program, time that it could lead to a usable product. Dis- since the operation of ClT—if successful—should mantling the existing technological base and per- confirm the scientific feasibility of fusion. instead, sonnel pool does not irrevocably eliminate fusion the decision to cancel the program probably as an option, but significant costs (in both time wouId be motivated by the belief that fusion re- and resources) would be required to rebuild fu- search will not result in a commercially, socially, sion research capability. or environmentally attractive source of energy, or that finding out how useful fusion could be Mitigating this disadvantage somewhat is the is too expensive. The near-term benefits of con- breadth of plasma physics as a research discipline. ducting fusion research would not be assumed Since plasma physics is intrinsic to many appli- to justify the program, and the expected payoff cations outside of fusion, plasma physics research of fusion would be considered too low to make and application would certainly persist through cost-sharing with other countries attractive. non-fusion-program sources, even if fusion research were discontinued. Although the areas of Advantages plasma physics most relevant to fusion would suffer, general plasma physics research could pro- Saving Money .–The major advantage of this vide a core of expertise if a program restart were approach would be avoiding the costs of future required. fusion research. Inhibiting Technical Development.–Without Disadvantages an extensive base of technical personnel trained in and sensitive to problems relevant to fusion, Unavailability of Possible Energy Supply.– discoveries that might make fusion easier to The major risk of this approach is that fusion’s achieve could go unrecognized. potential as an energy source would not be realized. ShouId future circumstances make reeval- Elimination of International Stature in Fusion.– uating fusion desirable, restarting the program if it is not conducting domestic fusion research, wouId be expensive, difficuIt, and time-con- the United States will be unable to collaborate suming. with other countries or benefit from the results of research done abroad. If fusion technology Destruction of Fusion Infrastructure.–With were developed successfully abroad, it could take the Moth balled path, the people and facilities that many years for the United States to reproduce currently carry out fusion research would switch the technology. Appendixes Appendix A Non-Electric Applications of Fusion1

The baseline D-T fusion reactor discussed in chap- Tritium Production ters 4 and 5 produces energetic neutrons as its immediate output. In an electric generating station, the One application of a fusion-reactor neutron source would be production of tritium beyond that needed energy of these neutrons would be recovered as heat 3 and used to generate electricity. Other possible ap- to fuel the fusion reactor. As discussed in chapter 4, tritium self-sufficiency is a key issue for a fusion elec- plications of D-T fusion technology might use the neu- tric power reactor;4 it is especially difficuIt to design trons themselves to produce fission or fusion fuels or to induce nuclear reactions that change one isotope a power-producing reactor capable of producing substantial amounts of excess tritium. However, tritium or material into another. Applications of fusion as a production can be enhanced at the expense of elec- neutron source and other non-electric applications of fusion energy are discussed below. tricity generation. Tritium has several industrial, medical, and military applications; its largest user is the nuclear weapons Fusion as a Neutron Source program. Tritium is radioactive, with 5.5 percent of the tritium stockpile decaying each year. Therefore, Each D-T reaction in the plasma produces one neu- the tritium supply for nuclear weapons requires con- tron, which is needed to breed tritium to replace that stant replenishment even if no additional weapons are used in the reaction. However, additional neutrons built. Four fission reactors are operated for the De- can be generated by neutron multipliers i n the reactor partment of Energy (DOE) in Savannah River, South blanket.2 These “excess neutrons” are available to Carolina, to produce tritium for nuclear weapons. make up for losses as well as for other purposes, such These reactors are currently about 35 years old, and as the production of materials in the reactor blanket. they will soon need replacement. Therefore, fusion reactors could be used as neutron A recent National Research Council study found that sources in addition to sources of electricity. although fusion reactors have promising features for If it produced a sufficiently valuable product, a fu- breeding tritium, fusion technology is not yet suffi- sion neutron source would not need to generate net ciently advanced to expand or replace the Savannah electric power to be cost-effective. In practice, how- River facilities.5 The engineering development and ever, few if any such products exist; system studies testing needed to create reliable fusion tritium-breeders show that a fusion reactor serving as a neutron source cannot be completed by the time decisions must be will probably also need to produce electric power to made concerning the Savannah River reactors. Never- be economically viable. (A possible exception, tritium theless, the study also concluded that fusion has po- production, is discussed below.) tential for producing tritium, and that DOE should Fusion-reactor neutron sources could have signifi- “undertake a program that analyzes and periodically cant advantages over fission reactors, the major ex- reassesses the concept, including design studies, existing large-scale sources of neutrons. A suitably de- perimentation, and evaluation, as fusion development signed fusion reactor would generate only about 6 proceeds.” one-sixth the heat of a fission reactor with the same Fusion technology could be applied to tritium pro- neutron output. Furthermore, the energy of the fusion duction without necessarily altering the technical neutrons is several times higher than the energy of fis- course of the civilian magnetic fusion research pro- sion neutrons, thus permitting applications that are not gram. However, if use of fusion technology for tritium possible with fission. production were to precede its commercial application as a civilian electricity generating technology, the fusion research program nevertheless could be pro-

‘Tntlum-produc i ng fusion breeders are dlscuiw>d I n N atI{Jn,I I Rt,w,l r{ h Council, Committee on Fusion Hybrid Reactors out/ooA for thf, Fuworr }{L brd and Trltlurn-Breeding Fusion Reactors (Washington D( N,l:l~)nal ,Ac ,IC{- T Much ot the material In this appendix is drawn from K. R, Schultz, B,A, emy Press, 1987), pp. 94-110. See the following wctlon ot t h I\ al~~wndlx for Engholm R F Bourque, ET Cheng, M j, Schatfert dnd C. P,C, L%’ong, The detlnltlons and discussion ot’ (usIon hybrid reactors, Fusion ApplIc atwrrs and Market El .jluatlon - “FAME’ ’-. Study, bv GA Tech- ‘See the section “The Fusion Blanket and Flr~t \\’all’ In c h .I nologies, In{ San Diego, CA, 1986 This study was done under contract 5Natlona I Research L-ou ncl 1, Out/ooA for (Iw Fuwon H},hrd ,]ncf Tritlurm to the Department of Energy’s (Iflce of Fusion Energy Breeding Fusion Reactor,, op clt , p 16. 2Neutron multipliers are discussed In ch 4, box 4-B 61bld

201 202 ● Starpower: The U.S. and the International Quest for Fusion Energy

foundly affected. On one hand, the nuclear weapons brid would not need to achieve as high a level of per- program would shoulder some of the development formance as the core of a pure fusion power reactor costs and would provide a near-term motivation for in terms of parameters such as energy gain. g supporting fusion research. Furthermore, associating In combining the fusion process with fission, a hy- fusion R&D with the nuclear weapons program would brid reactor could also combine their liabilities. Since ensure it a higher national priority. hybrid reactors involve the production and/or use of On the other hand, associating fusion power with fissionable fuels, their environmental, safety, and the nuclear weapons program could also become a proliferation concerns are more serious than those of severe liability in terms of public acceptance. More- pure fusion reactors; many of the environmental and over, since the technical requirements for breeding safety concerns of nuclear fission, both perceived and tritium and producing electricity are different, features actual, could be transferred to the hybrid. Further- of the tritium-breeder design would not necessarily more, a complete evaluation of the fuel-producing hy- be applicable in an electric power reactor. The institu- brid must include the client fission reactors. If the in- tional experience gained in developing, building, and centive for pursuing fusion research is to provide an operating a military tritium-breeder may be even less energy alternative that is environmentally or socially transferable to a civilian power reactor than the tech- preferable to nuclear fission, then combining fusion nical experience because, at present, regulatory mech- with fission in a fission/fusion hybrid reactor might anisms for the two are so different.7 For all of these not accomplish that goal. reasons, adopting the technological or institutional The economic justification for hybrid reactors is framework from a military tritium-breeder to the ci- weak at present because the price of uranium fuel is vilian fusion program could seriously compromise the so low. According to the National Research Council future acceptability of fusion power. hybrid study, uranium prices must rise by a factor of between 6 and 20 for a fission/fusion hybrid to be eco- Fissionable Fuel Production or Use nomically attractive.l ” The study concluded that accelerated use of fission reactors in the United States, In a fission/fusion hybrid reactor, excess fusion neu- coupled with policy decisions requiring U.S. reactors trons are used to breed fissionable fuel or to induce to be fueled with domestic uranium supplies, could fission reactions within the fusion reactor blanket. increase the domestic price of uranium by a factor of There are, correspondingly, two different types of fis- 10 by the year 2020. However, a more likely rate of sion/fusion hybrid: one that uses fission reactions in fission growth would cause prices to reach this level its blanket to multiply the energy generated in the fu- sometime between 2020 and 2045, and relaxing the sion core, and one that suppresses blanket fission re- constraint on domestic supply would delay such a actions to generate fissionable fuel for use i n pure fis- price increase for an additional 30 years. Therefore, sion reactors. The former type, the “power-only” the NRC study concluded that fission/fusion hybrids hybrid, does not produce fissionable fuel. The latter, will probably not be economically justified in terms or “fission-suppressed” hybrid, does not produce of increased uranium price before the middle of the much of its own power from fission reactions; instead, next century. it transforms “fertile” materials that are not readily fis- Several additional factors besides the price of ura- sionable into fissionable fuels such as uranium or nium affect the economic viabiIity of fission/fusion plutonium. In both types of hybrid, the total energy breeders. First, advanced-converter fission reactors released (or made available) is much larger than that that use uranium much more efficiently than present g available from fusion reactions alone. light-water reactors would be less sensitive than pres- Since most of the energy generated in a power-only ent reactors to the price of uranium. Development of hybrid is due to fission reactions, the amount of fu- these more efficient reactors would further delay the sion power generated by such a device need not be time when breeders would become attractive. Sec- large. Therefore, the fusion core of a power-only hy- ond, any discussion of hybrid breeders must compare them to pure fission breeders, which can also produce ~Weapons-related DOE facilities are not now sub)ect to the same process ot Nucledr Regulatory Comm!sslon and Natlona[ Envlronmenta[ Poi Icy Act fissionable fuel. Such a comparison is beyond the review that governs civilian nuclear facl I itles. However, publ IC pressure tor scope of this study. Increasing the regulation of mtlltary reactors IS growing. aEnergy multiplication occurs because a fission reaction releases about 10 times as much energy as a fusion reaction. Each excess neutron that Induces 9Energy gain IS discussed I n the section of ch. 4 titled ‘‘Sclentklc Progress. ’ a tlsslon reaction in the blanket releases many times more energy than It originally carries. (The same energy multlpllcatlon occurs when flsstonable 1~Natlonal Research COU ncil, Out/ook fOf t/7e ~usfon HyLmd and Trmum- material produced In a tuslon reactor IS removed to fuel external reactors, Breedlng Fumm Reactors, op. cit., p 8, The study esttmated fission/fusion except that the addltiona I energy IS released In the cxterna 1 reactors and not breeders to become economically viable when the price of uranium oxide In the fusion blanket. ) re~che> trom $100 to $300 per pound; the price currently 15$17 per pound App. A—Non-Electric Applications of Fusion ● 203

Other Isotope Production preservation, the annual growth in this demand over the next several years has been estimated at 6 to 25 With the possible exception of tritium and fission- percent.14 able fuels, no materials have yet been identified that would justify building a fusion reactor for the sole Radioactive (Fission) Waste Processing purpose of producing them. To be economically worthwhile, high-value materials would have to be In theory, the neutrons from a fusion reactor could produced from inexpensive ones through reactions be used to change radioactive fission wastes into with fusion neutrons. In addition, extraction of the shorter lived materials that would decay more quickly, desired isotope from the fusion blanket could not be posing less long-term hazard. However, several studies too expensive. Furthermore, the amount of the main the 1970s analyzed fusion’s capabilities to proc- terial produced in a fusion reactor must not be so large ess radioactive waste from fission reactors, and the compared to the demand that it would saturate the results were not promising.15 These studies deter-

market{ driving down the price and destroying the mined that extremely high levels of fusion reactor per- value of the material. formance and decades of neutron irradiation would it would be much easier to justify producing spe- be required, along with advanced isotope and chem- cial materials or isotopes in a fusion reactor if electri- ical separation processes. Even if these requirements city were produced at the same time. A recent study were met, it was unclear whether this approach of- 60 has identified cobalt-60 ( Co) as an isotope that might fered a net advantage over waste burial. The benefit be economically produced in a fusion electric gener- of reducing the long-term hazard associated with fis- ating station.11 However, demand for 60Co would have sion wastes would have to be balanced against the to be much greater than it is now for this process to technological difficulties associated with transforming be viable, since the amount of 60Co that could be pro- them, as well as the short-term risk of releasing these duced annually in a single fusion reactor is much wastes i n an accident at the processing faciIity. larger than the present annual demand. Cobalt-60 is an intensely radioactive material whose Other Possible Nonelectric primary use is in sterilizing medical products, with sec- Applications of Fusion ondary uses in providing cancer radiation therapy and food preservation via irradiation. Food preservation, Synthetic Fuels in particuIar, couId be a rapidly growing application. Furthermore, 60Co also could be used to treat sewage Currently, about two-thirds of all energy used in the by sterilizing it, although this application has yet to United States is consumed directly by users in the form be commercialized. It is possible, therefore, that 60Co of fossiI fuel; only one-third is used to generate elec- demand might increase substantially.12 tricity, Although the trend in future energy use is The worldwide demand for replenishing existing towards increasing electrification, many requirements 60C0 stocks is currently estimated to be about 11 for non-electric sources of energy such as liquid or 13 megacuries per year, most of which is produced by gas fuels will likely remain. Atomic Energy of Canada, Ltd. in the heavy-water It may be possible to take advantage of the high tem- moderated CANDU reactors operated by Ontario peratures present in fusion reactors, along with the Hydro. A commercial fusion power reactor could pro- electricity generated by them, to generate hydrogen duce hundreds of megacuries of 60Co per year with gas by decomposing water into hydrogen and oxygen. a blanket optimized for 60Co production. Therefore, Hydrogen has applications either directly as a fuel or this application is viable only at greatly increased de- in the synthesis of liquid fuels. The GA fusion appli- mand levels; depending on its increased use for food cations study indicated that fusion might be an economically competitive source of hydrogen i n the long term but did not demonstrate a clear advantage over I I B A, Engholm, E,T, Cheng, and K R, Schultz, ‘‘Radlolsotope Produc-tlon high-temperature fission-based sources of hydrogen In Fusion Reactors, ” GA Technologies Inc. San Diego, CA (undated) Thl~ that could also be available by the time fusion is com- article was prepared as part ot’ the “Fusion Appllcatlonf Studv” by K.R Schultz, et al., 1986. mercialized. lzlbld., p, 2.

I lone Curie of any radioactive substance IS the amount that procluce~ ~ ~ X 101~ radloactl~e dtslntegratlons per second: 1 rnegacurle IS 1 mllllon ( urle~ One curie ot pure ‘co would have a mass ot 0.88 mllllgram, and 11 rnegac w rles w ou Id have ~ mas; of 9 7 kl Iograms (2 1 pou rids) (Actual ‘{ICO \ou rce~ do not consist ot pure bOCo In practice, less than 10 percent of the cobalt I ~1 bid. , p 3 I n a boCo source consists of the b(]Co Isotope I I n 1984, the prlc e ot ‘IqCO w a~ ) ‘For a rei icui ot thwe stuciles ~ee Schultz, et al , Fusion 4pp/IcaIIon\ S(ud) about !$ 1 00 per cu rle (Ibid , pp. 2-3 I Op Cit. pp Y-1 o 204 ● Starpower: The U.S. and the International Quest for Fusion Energy

Process Heat cated solely to the production of process heat. There does not even appear to be significant economic ad- Another energy requirement currently satisfied by vantage associated with recovering waste heat pro- non-electric sources of energy is process heat. Proc- duced as a byproduct of electricity generation. Proc- ess heat is less transportable than electricity; it must ess heat does not appear to be an attractive use for be used at locations close to the generating site. More- fusion reactors as long as fossil fuels are available. over, although there are many users of process heat, This conclusion is supported by present-day experi- few require more than a few hundred megawatts ence with nuclear fission powerplants, which are not each. Essentially all of these users now use fossil fuels. used for process heat production in the United States. Present fusion reactor designs would produce on the In the far future, if fossil fuels become too expensive order of 3,000 megawatts of heat (corresponding to or too difficult to use in an environmentally sound 1,000 to 1,200 megawatts of electricity at 35- to 40- manner, fusion could become attractive as a source percent conversion efficiency), and there would be of process heat due to lack of an alternative. little motivation to construct such a fusion plant dedi- Appendix B Other Approaches to Fusion

The main body of this report has discussed magnetic The issues addressed by inertial confinement fusion confinement fusion, the approach to controlled fusion research in the United States concern the individual that the worldwide programs emphasize most heav- targets containing the fusion fuel; the input energy ily. However, two other approaches to fusion are also sources, called drivers, that heat and compress these being investigated. All three approaches are based on targets; and the mechanism by which energy from the the same fundamental physical process, in which the driver is delivered–or coupled–into the target. Due nuclei of light isotopes, typically deuterium and tri- to the close relationship between inertial confinement tium, release energy by fusing together to form heav- fusion target design and thermonuclear weapon de- ier isotopes. Some of the technical issues are similar sign, inertial confinement fusion research is funded among all the fusion approaches, such as mechanisms by the nuclear weapons activities portion of the De- for recovering energy and breeding tritium fuel. How- partment of Energy’s (DOE’s) budget. Inertial confine- ever, compared to magnetic confinement, the two ap- ment research is conducted largely at nuclear weap- proaches discussed below create the conditions nec- ons laboratories; its near-term goals are dedicated essary for fusion to occur in very different ways, and largely to military, rather than energy applications, and some substantially different science and technology a substantial portion of this research is classified. issues emerge in each case. There are two near-term military applications of inertial confinement fusion—one actual and one not yet Inertial Confinement Fusion1 realized. First, because the physical processes in a pellet micro-detonation resemble those in a nuclear The inertial confinement approach to fusion research weapon, inertial confinement experiments now con- has been studied for some two decades, and its cur- tribute to validating computer models of these proc- rent budget almost half that of the magnetic confine- esses, to collecting fundamental data on the behavior ment program. In inertial confinement fusion, a pel- of materials in nuclear weapons, and to developing let of fusion fuel is compressed to a density many times diagnostic instruments for actual nuclear weapons that of lead, and then heated and converted to plasma, tests. These activities can be conducted today with ex- by bombarding it with laser or particle beams (see fig- isting high-energy inertial confinement drivers. ure B-1 ). At this density, about 10 billion times the den- These applications could be greatly intensified, and sity of a magneticalIy confined plasma, the confine- a second set of applications would arise, if a labora- ment time needed is so small (less than one-billionth tory facility producing substantial pulses of inertially of a second) that it shouId be possible to generate net confined fusion energy could be developed. No such fusion power before the pellet blows itself apart. The facility yet exists. Such a facility could simulate the pellet’s own inertia is sufficient to hold it together long effects, particularly the radiation effects, of nuclear enough to generate fusion power, detonations on systems and components. This appli- Inertial confinement already has been demonstrated cation might be particularly important if a Compre- on a very large scale in the hydrogen bomb, an iner- hensive Test Ban Treaty prohibited underground tests tially confined fusion reaction whose input energy is of nuclear weapons. provided by a fission (atomic) weapon. The challenge The near-term, military inertial confinement research of laboratory-scale inertial confinement research is to effort also contributes information that would be es- reproduce this process on a much smaller scale, with sential to any longer term commercial applications. a source of input energy other than a nuclear weapon. For example, both military and civilian applications In a hypothetical inertial confinement reactor, micro- of inertial confinement fusion (other than the com- explosions with explosive yields equivalent to about puter program and diagnostic development activities one-tenth of a ton of TNT would be generated by ir- that are being conducted today) require that an iner- radiating fusion pellets—called targets—with laser or tial confinement target generate several times more particle beams; these explosions would be repeated energy than is input to it. Such an accomplishment, several times a second. which would show the scientific feasibility of inertial fusion, is beyond the capability of any existing lab- ‘The U S inertial con flnem[~nf tuilon rewarch program I\ rm Ie\\ ed I n ,] oratory device. (Of course, thermonuclear weapons recent report by the Nat Ion,l I Rew,] rc h LOU nc I I Ret ~e~t of rhe Dep.] rfment have already demonstrated the scientific feasibility of of f m’rqi s /neflI,I/ Conflnemenf Fu\lon Progr,]rn {Wf,]sh I ngton, DC Nattona I A( .I(l(>rm}, l)rf>~i I W() I very-large-scale inertial confinement fusion. )

205 206 . Starpower: The U.S. and the International Quest for Fusion Energy

Figure B-1.— Inertial Confinement Fusion Process

Heating Compression Ignition Burn Laser or particle beams Fuel IS compressed by The fuel core reaches Thermonuclear rapidly heat the surface rocket-like blowoff of high density and ignites. burn spreads of the fusion target, the surface material rapidly through the forming a plasma compressed fuel. yielding envelope. many times the input energy.

SOURCE Lawrence Livermore National Laboratory, “ICF Reaction, ” Energy and Technology Review, April-May 1986

The technical requirements for commercial appli- to the reaction chamber, the driver would not have cations of inertial confinement fusion go considerably to be designed to withstand this environment. In the beyond the requirements for weapons effect simula- core of a magnetic confinement fusion reactor, on the tion and would require still further scientific and tech- other hand, systems both for supporting and maintain- nological development. Due to the relatively low ef- ing the plasma and for recovering the energy and ficiencies (e.g., 10 to 25 percent) at which the drivers breeding tritium fuel are located in high radiation, high operate, each target explosion must generate several neutron-flux environments. A second potential advan- times more energy than it is driven with to reach tage of inertial confinement arises from the relatively breakeven. An additional factor of 4 to 10 is required relaxed vacuum requirements inside the reaction beyond breakeven to produce substantial net output. chamber, which would permit the use of neutron ab- In a commercial reactor, therefore, as much as 100 sorbing materials such as liquid lithium inside the first times as much energy must be released in a pellet ex- structural wall of the reactor. Use of such neutron ab- plosion as is required to heat and compress the pellet sorbers would lessen neutron irradiation levels in the to the point where it can react. Furthermore, commer- reactor’s structural elements, increase the lifetimes of cial energy production requires that pellets be deto- those elements, and lessen induced radioactivity nated several times a second, far more frequently than levels. needed for military applications. Finally, cost-effective- On the other hand, inertial confinement also has ness, reliabiIity, and high efficiency are much more disadvantages compared to magnetic confinement. in- important for energy applications than miIitary ones; ertial confinement is inherently pulsed; the systems successful commercialization will depend on how needed to recover energy and breed fuel in the re- well the technology addresses the commercial require- action chamber have to withstand explosions equiva- ments discussed in chapter 5. lent to a few hundred pounds of TNT several times A significant potential advantage of inertial confine- a second. Inertial confinement reactors must focus ment over magnetic confinement is that the complex high-power driver beams precisely on target in this and expensive driver system can be located some dis- environment. Furthermore, the energy gains needed tance away from the reaction chamber. Because ra- for these facilities must be much larger than those of diation, neutron-induced activation, and thermal stress a magnetic confinement device to make up for driver due to the microexplosions could be largely confined inefficiencies. App. B—Other Approaches to Fusion . 207

Four principal driver candidates are now being stud- Cold Fusion ied in the U.S. inertial confinement research program. Two of them —solid-state or glass lasers and light-ion2 Another approach to fusion, presently at an em- accelerators—have by far the largest facilities; the bryonic stage of development, is fundamentally differ- other two principal candidates—gas lasers and heavy ent from either the magnetic or inertial confinement ion accelerators—are in lesser stages of development. concepts. This approach, called ‘‘cold fusion” or Major U.S. glass lasers are located at Lawrence Liver- “muon-catalyzed fusion, ” might make it possible to more National Laboratory in California and the Uni- bypass the requirement for extremely high tempera- versity of Rochester Laboratory for Laser Energetic in tures that make the magnetic and inertial approaches New York. The Livermore facility, the most powerful so difficult.4 laser in the world, does both classified and unclassi- If it were possible to “shield” the electric charge fied inertial confinement research; the University of of one of the nuclei in a fusion reaction, one nucleus Rochester facility conducts only unclassified research could get very close to another nucleus without be- on a laser fusion approach that is not as relevant to ing repelled. In this case, fusion reactions could oc- weapons applications as is the approach pursued at cur at far lower temperatures than wouId otherwise Livermore. The largest light-ion accelerator in the be required, since the extreme temperatures needed

world is located at Sandia National Laboratory in New to overcome the mutual repulsion of two electrically Mexico; like the Livermore facility, it conducts both charged nuclei would be unnecessary. Such shield- unclassified and classified research. The krypton-fluo- ing can in fact be provided by a subatomic particle ride gas laser, the third driver candidate being stud- called the muon. The muon—like the electron—has ied, is being developed at Los Alamos National Lab- a charge that cancels out the charge of a hydrogen oratory. Other contributors to the laser and light-ion nucleus. But unlike the electron, the muon binds so inertial confinement programs are the Naval Research tightly to the nucleus that the nuclear charge is shielded Laboratory and KMS Fusion, Inc., the only private cor- even down to the distances where fusion reactions can poration significantly involved. take place. Therefore, once a muon becomes bound A fourth driver candidate—the heavy-ion accelerator to a nucleus, the combination can approach a sec- —is much less developed than the laser or light-ion ond nucleus closely enough to fuse without the need drivers. Unlike light-ion and laser research, heavy-ion for extreme temperature. accelerator research is a non-military program funded If the muon is freed in the subsequent fusion re- by the Office of Energy Research, the same DOE of- action, it can become captured by another hydrogen fice that funds the magnetic confinement fusion pro- nucleus to repeat the process. I n this way it serves as gram. 3 Heavy-ion experimental work is limited to ac- a catalyst, enabling fusion energy to be released with- celerator technology, and in the United States it is out itself being consumed. However, since the muon concentrated at Lawrence Berkeley Laboratory in Cali- is unstable, muon catalysis can be practical only if fornia. each muon generates more than enough energy dur- Other national fusion programs conduct inertial ing its 2.2-microsecond Iifetime to make its own re- confinement research, but at a significantly lower level placement. of effort than their magnetic fusion programs. Inter- Muon-catalyzed fusion reactions were actually ob- national collaboration is much more restricted in in- served in high-energy physics experiments in the ertial fusion than it is in magnetic fusion due to U.S. 1950s. However, the muons were rarely observed to national security constraints. On balance, the iner- induce more than one fusion reaction each before tial confinement program involves scientific and decaying, compared to the hundreds of reactions per technological issues that are quite distinct from those muon that would be necessary to make the process relevant to magnetic fusion. A detailed comparison worthwhile. More recent experimental and theoreti- of the relative status and prospects of inertial con- cal work has shown that the number of fusion reactions finement and magnetic confinement fusion is be- that can be catalyzed by a single muon depends on yond the scope of this assessment. parameters such as the density and temperature of the deuterium-tritium mixture into which the muon is injected. Experiments have shown that muons are capable of catalyzing many more reactions during their lifetime than had been thought many years ago.

2Llght Ions are Ions of IIght elementj such as Ilthlum

‘The heav}-lorl research program IS f,] r smal Ier than the magnetic contl ne- 4A d Iscusston of recent muon -cata lyzeci tuslon rewarc h IS gI\ en I n ‘C-dd ment program and IS managed by a dltterent pafl ot the D(>E Offlce of Energy Nuclear Fusion, ” by Johann Ratelskl ~nd Ste\ en E Ionw In the july I ’18- Research Is+ue ot Sclerrt(fjc Arnerlcan pp 84-89 208 ● Starpower: The U.S. and the International Quest for Fusion Energy

Whether this process can ever yield net energy pro- Iimits to how many fusion reactions can be induced duction depends on increasing the number of fusion by a single muon. If muon-catalysis proves to be fea- reactions per muon, The number is not yet high enough sible in principle, a substantially increased level of ef- for the process to be scientifically feasible, and fun- fort and a more detailed comparison of its potential damental limits may prevent it from ever being so. benefits and liabilities to those of the other fusion ap- Muon-catalysis research, currently at a very prelimi- proaches may be warranted. nary stage, focuses primarily on understanding the Appendix C Data for Figures

Chapter Three

Data for Figure 3-1 .— Historical Fusion Funding, 1951-88 (millions of 1986 dollars)

Operating Capital equipment Construction Budget Budget Budget Budget Year authority authority Index authority Index authority Index 1951 -53 ...... 1.1 1.1 0.200 a a 1954 ...... 1.8 1.8 0.202 a a 1955 ...... 6.1 4.7 0.203 a 1.4 0.162 1956 ...... 7.4 6.6 0.202 a 0.8 0.167 1957 ...... 11.6 10.7 0.205 a 0.9 0.175 1958 ...... 29.2 18.4 0.212 a 10.8 0.182 1959...... 28.9 27.0 0.218 a 1.9 0.189 1960...... 33.7 31.0 0.220 2.2 0.260 0.5 0.196 1961 ...... 30.0 29.0 0.224 1.0 0.260 a 1962...... 24.8 23.0 0.226 1.8 0.261 a 1963...... 25.5 24.2 0.228 1.3 0.262 a 1964...... 22.6 21.0 0.231 1.6 0.263 a 1965...... 23.1 21.3 0.234 1.8 0.266 a 1966...... 23.1 21.8 0.238 1.3 0.269 a 1967...... 23.9 22.4 0.243 1.5 0.276 a 1968...... 26.6 24.7 0.252 1.8 0.285 0.1 0.247 1969...... 29.7 26.5 0.263 1.6 0.295 1.6 0.264 1970...... 34.3 27.7 0.277 2.0 0.305 4.6 0.284 1971 ...... 32.2 28.3 0.291 2.1 0.319 1.8 0.310 1972...... 33.3 31.0 0.310 2.1 0.327 0.2 0.344 1973...... 39.7 37.0 0.320 2.5 0.334 0.2 0.368 1974...... 57.4 52.9 0.353 4.3 0.351 0.2 0.393 1975...... 118.2 97.9 0.382 19.8 0.376 0.5 0.444 1976...... 166.3 131.1 0.429 17.0 0.489 18.2 0.484 TQ b ...... 52.9 42.6 0.429 4.5 0.489 5.8 0.484 1977...... 316.3 195.0 0.459 23.0 0.518 98.3 0.516 1978...... 332.4 206.7 0.493 29.6 0.568 96.1 0.564 1979...... 355.1 211.3 0.529 27.2 0.619 116.6 0.613 1980...... 350.3 235.1 0.588 29.8 0.684 85.4 0.675 1981 ...... 393.6 258.3 0.674 36.9 0.777 98.5 0.746 1982...... 451.2 295.1 0.766 42.0 0.847 114.1 0.814 1983...... 461.3 373.8 0.829 39.5 0.893 48.0 0.865 1984...... 468.4 391.1 0.892 37.8 0.947 39.5 0.882 1985...... 429.6 369.6 0.938 27.5 0.954 32.5 0.934 1986...... 361.5 320.5 1.000 28.3 1.000 12.7 1.000 1987 (estimate). . 327.3 302.2 1.043 17.1 1.051 8.0 1.025 1988 (request). . . 320.1 286.1 1.080 18.1 1.088 15.9 1.060 aNo expenditures occurred in this category during the war bThe start of the fiscal year was changed in 1976 from July 1 to October 1. TQ represents the budget for the transition quarter from July 1, 1976 to September 30, 1976

SOURCE U.S Department of Energy, Officeof Energy Research, letter to OTA project staff, Aug 15, 1966, updated by personal communication to OTA staff Sept 2,1987

209 210 ● Starpower: The U.S. and the International Quest for Fusion Energy

Data for Figure 3-2.— Historical Fusion Funding, 1951-88 (millions of current dollars)

Presidential Total Presidential Total budget request budget authority budget request budget authority Year budget authority (in millions) Year budget authority (in millions) 1951-53 ...... a 1.1 1972 ...... a 33.3 1954 ...... a 1.8 1973 ...... a 39.7 1955 ...... a 6.1 1974 ...... a 57.4 1956 ...... a 7.4 1975 ...... 102.3 118.2 1957 ...... a 11.6 1976 ...... 144.2 166.3 1958 ...... a 29.2 TQ b ...... 44.4 52.9 1959 ...... a 28.9 1977 ...... 291.1 316.3 1960 ...... a 33.7 1978 ...... 370.9 332.4 1961 ...... a 30.0 1979 ...... 334.0 355.1 1962 ...... a 24.8 1980 ...... 364.1 350.3 1963 ...... a 25.5 1981 ...... 403.6 393.6 1964 ...... a 22.6 1982 ...... 460.0 451.2 1965 ...... a 23.1 1983 ...... 444.1 461.3 1966 ...... a 23.1 1984 ...... 467.0 468.4 1967 ...... a 23.9 1985 ...... 482.7 429.6 1968 ...... a 26.6 1986 ...... 390.0 361.5 1969 ...... a 29.7 1987 (estimate)...... 333.0 341.4 1970 ...... a 34.3 1988 (request) ...... 345.6 1971 ...... a 32.2 aPresidential budget requests before 1975 were not available from DOE. bThe start of the fiscal year was changed in 1976 from July 1 to October 1. TQ represents the budget for the transition quarter frorn July l, 1976 to September 30,1976,

SOURCE: US. Department of Energy, Office of Energy Research, letter to OTA project staff, Aug. 15, 1986.

Chapter Six

Data for Figure 6-1.— Federal Funding of Plasma Physics in 1984 (millions of 1984 dollars)

Plasma Physics Area DOE NSF DoD NASA NOAA Total General Plasma Physics ...... 3 3 68 0 0 74 Magnetic Conf. Fusion ...... 471 0 0 0 0 471 Inertial Conf. Fusion ...... 170 0 0 0 0 170 Space/Astrophysical Plasma ...... 2 30 5 100 2 139 Total ...... 646 33 73 100 2 854 DOE = Department of Energy NSF = National Science Foundation DoD = Department of Defense NASA = National Aeronautics and Space Administration NOAA = National Oceanic and Atmospheric Administration SOURCE: National Research Council, Physics Through the 1990s: Plasmas and Fluids (Washington, DC: National Academy Press, 1986), p. 33

Data for Figure 6-2.— Defense and Civilian Federal Research and Development Expenditures (billions occurrent dollars)

Year Defense Civilian Total 1982 ...... 22.9 15.8 38.7 1983 ...... 25.6 14.4 40.0 1984 ...... 30.5 15.5 46.0 1985...... 34.7 17.0 51.7 1986...... 37.6 17.0 54.6 1987 (estimate) ...... 41.2 18.6 59.8 1988 (request) ...... 48.1 21.3 69.4 NOTE: Defense: includes Department of Defense along with Department of Energy atomic energy defense activities. civilian: Includes all Federal research and development not included in defense. SOURCE: American Association for the Advancement of Science, AAAS Report XII Research and development FY 1988 (Washington, DC: American Association for the Advancement of Science, 1987) App, C—Data for Figures ● 211

Data for Figure 6-3.— Major Components in Federally Funded Research and Development (in 1987 dollars) and Figure 6-4.— Historical Component Funding Levels for Federal Research and Development (billions of current dollars)

Year Defense Energy Space Health Science Other 1982 ...... 22.9 3.5 3.6 4.1 1.5 3.1 1983 ...... 25.6 2.9 1.7 4.5 1.6 3.7 1984...... 30.5 2.6 2.0 5.1 1.9 3.9 1985...... 34.7 2.5 2.4 5.8 2.1 4.2 1986...... 37.6 2.4 1.9 5.9 2.1 4.7 1987 (estimate) ...... 41.2 2.2 2.4 7.0 2.2 4.8 1988 (request) ...... 48.1 2.0 3.1 9.0 2.6 4.7 NOTE Defense Includes Department of Defense along with Department of Energy atomic energy defense activites Energy Includes Department of Energy activites, Iess general science and defense, Nuclear Regulatory Commission, and Environmental Protection Agency Space includes National Aeronautics and Space Ad. ministration less space applications and aeronautical research Health includes Department of Health and Human Services, Veterans Administration, Depart- ment of Education, and Environmental Protection Agency Science includes National Science Foundation and Department of Energy high energy physics and nuclear physics SOURCE American Association for the Advancement of Science, AAAS Report X// Research and Development FY 1988 (Washington, DC American Association for the Advancement of Science, 1987)

Data for Figure 6-5.— Annual Appropriations of DOE Civilian Research and Development Programs (millions of current dollars)

Year Solar/renewables a Fusion Fission Fossil Conservation 1980 ...... 731.4 350.3 847.8 847.8 296.1 1981 ...... 711.2 393.6 817.0 821,3 292.5 1982 ...... 341.1 451.2 819.4 566.8 151.9 1983 ...... 261.2 461.3 701.7 310.9 133.5 1984 ...... 211.9 468.4 622.9 331.5 150.1 1985 ...... 201.7 429.6 412.6 349.4 175.5 1986 (estimate) ...... 173.6 361.5 358.1 343.0 170.9 1987 (estimate) ...... 146.3 341.4 329.3 451.0 160.7 1988 (request) ...... 93.5 345.6 336.4 368.5 80.1 aSolar/Renewables Includes Solar, Geothermal, and Hydroelectric programs. SOURCE: Fusion—U S Department of Energy, Off Ice of Energy Research, letter to OTA project staff, Aug 15, 1986 Others –’’Analysis of Trends in Civilian R&D Ap- propriations for the U.S. Department of Energy, ” prepared by Argonne National Laboratory, August 1986, table B 3, p 49

Data for Figure 6-6.— Major DOE Civilian Research and Development Funding at National Laboratories in Fiscal Year 1987 (millions of 1987 dollars)

Solar and Other Renewable ...... $114.5 Electric Systems ...... 19.6 Environment ...... 133.3 Conservation ...... 49.5 Fossil Energy ...... 116.6 Supporting Research...... 360.0 Nuclear Energy ...... 254.3 Magnetic Fusion ...... 245.6 SOURCE U S Department of Energy. FY 1988 Congresslonal Budget Estlmates for /laboratory/P/anf, January 1987 212 ● Starpower: The U.S. and the International Quest for Fusion Energy

Chapter Seven

Data for Figure 7-1 .—Comparison of International Fusion Budgets (current dollars) and Figure 7.2.—Comparison of International Equivalent Person-Years

United States: Fusion budget Average industrial hourly Year (in millions $) wage ($) Person-years 1980 ...... 350.3 7.27 23,165 1981 ...... 393.6 7.99 23,683 1982 ...... 451.2 8.50 25,520 1983 ...... 461.3 8.84 25,088 1984...... 468.4 9.16 24,584 1985...... 429.6 9.57 21,582 1986...... 361.5 10.04 17,310

Japan: Fusion budget Fusion budget Average industrial Average industrial Year (yen) (in millions $) hourly wage (yen) hourly wage($) Person-years 1980 ...... 52,256 230 1,293 5.70 19,430 1981 ...... 61,115 277 1,373 6.22 21,400 1982 ...... 72,025 289 1,225 5.72 24,300 1983 ...... 69,112 291 1,490 6.28 22,300 1984 ...... 60,392 251 1,561 6.50 18,600 1985 ...... 65,154 271 1,640 6.83 19,100 1986 ...... 64,861 381 1,704 10.02 18,300

European Community: Fusion budget Fusion budget Average industrial Year (MECU) (in millions $) hourly wage($) Person-Years 1980 ...... 190 264 5.93 21,404 1981 ...... 225 254 5.35 22,815 1982 ...... 300 297 5.20 27,457 1983 ...... 300 300 5.06 28,532 1984 ...... 350 298 4.60 31,086 1985 ...... 350 245 4.06 28,977 1986 ...... 375 338 5.60 28,990 SOURCE: U.S. Department of Energy, Office of Energy Research, staff memorandum to file. Oct.9, 1986

Data for Figure 7-3.— Comparison of international Fusion Budgets by Percentage Gross National Producta

United States European Community Japan Year GNP Fusion/GNP GNPb Fusion/GNP GNP Fusion/GNP 1980 ...... 2,632 0.0133 1,962 0.0135 899 0.0271 1981 ...... 2,958 0.0133 2,131 0.0119 964 0.0287 1982 ...... 3,069 0.0147 2,277 0.0130 1,060 0.0273 1983 ...... 3,305 0.0139 2,394 0.0125 1,138 0.0256 1984 ...... 3,363 0.0128 data unavailable data unavailable aAll Gross National Products are shown in billions of current dollars bThe GNP for the European Community is computed by adding the GNP’s of the major EC countries (Belgium, France. Federal Republic of Germany, Greece, Italy, Netherlands, and the United Kingdom) SOURCE. Gross National Products found in Statistical Abstract, No 1742 Appendix D List of Acronyms and Glossary

Acronyms FRC –field-reversed configuration (see Glossary) AEC –Atomic Energy Commission GA –GA Technologies Inc.; San Diego, ASDEX-U –Axisymmetric Divertor Experiment California Upgrade; Garching, Federal Repub- GNP –gross national product lic of Germany IAEA –International Atomic Energy Agency ATF –Advanced Toroidal Facility; Oak Ridge ICRH —ion cyclotron resonance heating National Laboratory, Oak Ridge, Ten- (see Glossary) nessee IEA –International Energy Agency CERN –European Laboratory for Nuclear Re- IFF –Integrated Fusion Facility search (after its original French INTOR —International Tokamak Reactor acronym) ITER —International Thermonuclear Experi- CIT –Compact Ignition Tokamak; proposed mental Reactor for the Princeton Plasma Physics Lab- JAERI –Japan Atomic Energy Research in- oratory, Princeton, New Jersey stitute COCOM –Coordinating Committee JET –Joint European Torus; Abingdon, UK CPMP –Comprehensive Program Management JIFT –Joint Institute for Fusion Theory; Uni- Plan versity of Texas at Austin, Texas, and CPRF –Confinement Physics Research Facil- Nagoya University in Japan ity; under construction at Los Alamos JT-60 –Japan Tokamak-60 National Laboratory, Los Alamos, New LANL –Los Alamos National Laboratory; Los Mexico Alamos, New Mexico D Ill –Doublet ill; GA Technologies Inc., LCT –Large Coil Task; Oak Ridge National San Diego, California Laboratory, Oak Ridge, Tennessee D II I-D –Doublet Ill Upgrade; GA Technol- LLNL —Lawrence Livermore National Labora- ogies, San Diego, California tory; Livermore, California D-D Reaction– Deuterium-deuterium fusion reaction LMFBR –liquid metal fast breeder reactor (see Glossary) (fission–see Glossary) D-T Reaction —Deuterium-tritium fusion reaction LWR –light-water reactor (see Glossary) (fission–see Glossary) DoD –U.S. Department of Defense MFAC —Magnetic Fusion Advisory Committee DOE –U.S. Department of Energy MFECC –Magnetic Fusion Energy Computing dpa –displacements per atom Center; Lawrence Livermore National EC –European Community Laboratory, Livermore, California ECRH —electron cyclotron resonance heating MFEE Act –Magnetic Fusion Energy Engineering (see Glossary) Act of 1980 (Public Law 96-386) EPRI —Electric Power Research Institute; MFPP –Magnetic Fusion Program Plan Palo Alto, California MFTF-B –Mirror Fusion Test Facility B at ERAB –Energy Research Advisory Board Lawrence Livermore National Labora- ERDA –Energy Research and Development tory, Livermore, California Administration MIT –Massachusetts Institute of Technol- ESECOM –Senior Committee on Economic, Safety, ogy; Cambridge, Massachusetts and Environmental Aspects of Mag- NASA –U.S. National Aeronautics and Space netic Fusion Energy Administration ETR —engineering test reactor (see Glossary) NET —Next European Torus (proposed Euro- eV —electron volt (see Glossary) pean engineering test reactor) FED –Fusion Engineering Device NIH –U.S. National Institutes of Health FER –Fusion Experimental Reactor (proposed NRC –U.S. Nuclear Regulatory Commission Japanese engineering test reactor) NSF –U.S. National Science Foundation FPA —Fusion Power Associates; Gaithers- OER –Office of Energy Research in the U.S. burg, Maryland Department of Energy

213 214 ● Starpower: The U.S. and the International Quest for Fusion Energy

OFE –Office of Fusion Energy in the Office the proper design and operation of active safety sys- of Energy Research, U.S. Department tems. See “Passive protection. ” of Energy Advanced tokamak: A tokamak incorporating features OHTE –Ohmically Heated Toroidal Experi- such as steady-state current drive or shaping of the ment; GA Technologies Inc., San plasma in order to attain higher performance or Diego, California more efficient operation than the conventional ORNL –Oak Ridge National Laboratory; Oak tokamak. See “Tokamak” or “conventional Ridge, Tennessee tokamak.” OTR –Operational Test Reactor (proposed Afterheat: Heat produced by the continuing decay Soviet engineering test reactor) of radioactive atoms in a nuclear reactor after fis- PBX-M –Princeton Beta Experiment Modifica- sion or fusion reactions have stopped. Afterheat i n tion; Princeton Plasma Physics Lab- a fission reactor originates primarily in the fuel rods; oratory, Princeton, New Jersey in a fusion reactor it would result mainly from in- PPPL –Princeton Plasma Physics Laboratory; duced radioactivity in the reactor structure. Princeton, New Jersey Alpha particle: A positively charged particle, identi- Q –Energy Gain (see Glossary) cal to a helium-4 nucleus, composed of two pro- RF —radiofrequency tons and two neutrons. An alpha particle is emit- RFP —reversed-field pinch (see Glossary) ted in the radioactive decay of many naturally TEXT –Texas Experimental Tokamak; Uni- occurring radioisotopes such as uranium and tho- versity of Texas Fusion Research Cen- rium; it is also one of the products of the D-T fu- ter in Austin, Texas sion reaction. TEXTOR –Tokamak Experiment for Technology Alternate confinement concept: A fusion magnetic Oriented Research; Julich, Federal confinement concept other than the tokamak. Republic of Germany Anomalous transport: Loss of energy from tokamak TFTR –Tokamak Fusion Test Reactor; Prince- plasmas due to escaping electrons that occurs at ton Plasma Physics Laboratory, Prince- a rate several times higher than that predicted by ton, New Jersey present theory. TMX —Tandem Mirror Experiment; Lawrence Ash: The end-product of a fusion reaction. For the D-T Livermore National Laboratory, Liver- fusion reaction, the “ash” is helium gas. more, California Atom: A particle of matter indivisible by chemical TMX-U –Tandem Mirror Experiment Upgrade; means that is the fundamental building block of a Lawrence Livermore National Labora- chemical element. The dense inner core of the tory, Livermore, California atom, called the nucleus, contains protons and Tokamak –Toroidal magnetic chamber, in Rus- neutrons and constitutes almost all the mass of the sian (see Glossary) atom. The nucleus is surrounded by a cloud of or- TPA –Technical Planning Activity biting electrons. Atoms contain equal numbers of TSTA –Tritium Systems Test Assembly; Los positively charged protons and negatively charged Alamos National Laboratory, Los electrons and as a whole are electrically neutral. Alamos, New Mexico An atom is a few billionths of an inch in diameter, UCLA –University of California at Los Angeles and several sextillion (1 followed by 21 zeros) UFA –University Fusion Associates atoms are found i n an ordinary drop of water. UK –United Kingdom Atomic nucleus: See “Nucleus.” Auxiliary heating: External systems that heat Plasmas to higher temperatures than can be reached from Glossary the heat generated by electric currents within the plasma. Neutral beam heating and radiofrequency Acid deposition: A consequence of fossil fuel com- heating are both examples of auxiliary heating bustion in which combustion byproducts emitted systems. as gases react in the atmosphere and are depos- Axial: The direction in a cylinder parallel to the cen- ited on earth in the form of acidic substances. Also tral axis of the cylinder. called “acid rain. ” Background radiation: Naturally occurring sources of Activation product: Material made radioactive through radiation. Primary sources are cosmic rays and nat- exposure to neutrons in fission or fusion reactors. urally occurring radioactive isotopes that are found Active protection: The condition in which the safety in the earth or are produced in the atmosphere by of a nuclear reactor can be assured only through cosmic rays. App. D—List of Acronyms and Glossary ● 215

Balance of plant: Those systems in a fusion reactor fuel use may affect global climate. See “Green- not associated with producing or controlling the fu- house effect.” sion reaction. Systems i n the balance of plant con- Central cell: In the tandem mirror confinement convert the heat produced by fusion reactions into cept, the central cell is the region where most of electricity. See also “Fusion power core.” the power-producing fusion reactions would occur. Beta: The ratio of the outward pressure exerted by the Plasma in the central cell is kept from escaping by plasma to the inward pressure that the magnetic electric fields generated by the end cells. See “End confining field is capable of exerting. Beta is equiva- Centrifugal injector: Device that uses centrifugal force lent to the ratio of the energy density of particles to inject pellets of frozen fuel into fusion plasmas. in the plasma to the energy density of the confin- Chlorofluorocarbons: Manmade chemicals, used as ing magnetic fields. refrigerants, industrial solvents, and for other pur- Beta particle: A high-energy electron emitted in the poses, which have heat-retaining properties similar to decay of certain radioactive isotopes. carbon dioxide when released into the atmosphere. Bilateral agreement: An agreement between two Cladding: In a fission reactor, the material that en- nations. closes nuclear fuel. Biologically active: Substances that are absorbed by Classical confinement: The best possible plasma con- living organisms and are utilized in biological proc- finement, in which the only mechanism by which particles escape the plasma is through rare, but in- esses. Radioactive substances that are biologically active (e. g., radioactive iodine or strontium iso- evitable, collisions between plasma particles that topes) become incorporated into living organisms. cause them to migrate across the magnetic field towards the plasma edge. Classical confinement is Blanket: Structure surrounding the plasma in a fusion also referred to as “classical diffusion. ’ reactor within which the fusion-produced neutrons Classification: Restricting the dissemination of certain are slowed down, heat is transferred to a primary information for reasons of national security. Only coolant, and tritium is bred from lithium. people holding security clearances granted by the Breakeven: The point at which the fusion power gen- government are permitted access to classified in- erated in a plasma equals the amount of heating formation. power that must be added to the plasma to sustain Closed confinement concept: Magnetic configuration its temperature. in which the plasma is confined by magnetic lines Breakeven-equivalent: Attainment in a non-tritium- of force that do not lead out of the device. Closed containing plasma of conditions (temperature, den- confinement concepts all have the basic shape of sity, and confinement time) that would result in a doughnut or inner tube, which is called a torus. breakeven if the plasma contained tritium. Because Collaboration: An intensive type of international co- plasmas not containing tritium are far less reactive operation involving a substantial degree of program than those containing tritium, the actual amount integration, funding commitment, and joint man- of fusion power generated by a breakeven-equiva- agement. Ient plasma will be far less than would be produced Commercial feasibility: Fusion power’s acceptance under actual breakeven conditions. in the marketplace as a source of energy that is Breeder reactor: A nuclear reactor that produces environmentally and socially acceptable and eco- more fissionable fuel than it consumes. Breeders nomically competitive when compared to alternate produce fissionable fuel by irradiating fertile ma- sources of energy. terials with neutrons. See “Fertile material.” Compact toroids: A class of magnetic confinement Breeding ratio: The number of tritium atoms pro- configurations in which the chamber containing the duced in the blanket of a fusion reactor for each plasma need not have a central hole through which tritium atom consumed in the fusion plasma. external magnet coils must pass. Examples are the Burn control: The mechanism by which the power spheromak and the field-reversed configuration. level of a self-sustaining fusion reaction is regulated. Compression heating: Method of heating a plasma by Capital-intensive: An energy-generating technology compressing it into a smaller volume. The plasma in which most of the cost of energy is due to the is compressed by modifying the external magnetic fixed cost of the capital investment in the generat- fields. ing station, as opposed to variable fuel or opera- Conceptual design: The basic or fundamental design tions and maintenance expenditures. of a fusion reactor or experiment that sketches out

Carbon dioxide (C02): An inherent product of the device characteristics, geometry, and operating fea- combustion of fossil fuels. Buildup of carbon di- tures but is not at the level of detail that would per- oxide i n the earth’s atmosphere as a result of fossil mit construction.

72-678 0 - 97 . (5 .

216 ● Starpower: The U.S. and the International Quest for Fusion Energy

Confinement: Restraint of plasma within a designated an alpha particle and a neutron and releasing 17.6 volume. In magnetic confinement, this restraint is million electron volts of energy. The D-T reaction accomplished with magnetic fields. is the most reactive fusion reaction. Confinement concept: A particular configuration of Decay heat: See “Afterheat.” magnetic fields used to confine a fusion plasma. Decommissioning: The steps taken to render a plant, Various confinement concepts differ in the shape particularly a nuclear reactor, safe to the environ- of their magnetic fields and in the manner in which ment at the end of its operating lifetime. these fields are generated. Dense z-pinch: An open confinement concept in Confinement parameter: The product of plasma den- which a strong electrical current is suddenly passed sity and confinement time that, along with temper- through a fiber of frozen D-T fuel, turning it into ature, determines the ratio between power produced a plasma and at the same time generating a power- by the plasma and power input to the plasma. Also ful encircling magnetic field to confine the plasma. called “Lawson parameter. ” The dense z-pinch is in a very preliminary stage of Confinement time: A measure of how well the heat development. in a plasma is retained. The confinement time of Density: Amount per unit volume. By itself, the term a plasma is the length of time it would take the “density” often refers to particle density, or the plasma to cool down to a certain fraction of its ini- number of particles per unit volume. However, tial temperature if no heat were added. other quantities such as energy density or power Confining magnets: External magnets used to gener- density (energy or power per unit volume, respec- ate the confining magnetic fields in a fusion device. tively) can also be defined. Containment building: In a fission reactor, the con- Detritiation systems: Systems to remove tritium from tainment building is a thick concrete structure sur- air or water that are important to ensure the safety rounding the pressure vessel that encloses the re- of tritium-handling facilities. actor core and other components. It is designed to Deuterium (D or 2H): A naturally occurring isotope prevent radioactive material from being released of hydrogen containing one proton and one neu- to the atmosphere in the unlikely event that any- tron in its nucleus. Approximately one out of 6,700 thing should escape from the pressure vessel. The atoms of hydrogen in nature is deuterium. Deu- need for containment buildings for fusion reactors terium is one of the fuels (along with tritium) needed has not vet been determined. for the D-T fusion reaction, the most reactive fu- Conventional tokamak: A tokamak device not incor- sion reaction. porating advanced steady-state current drive or Diagnostics: The procedure of determining (diagnos- plasma shaping technology. See “Tokamak,” “Ad- ing) exactly what is happening inside an experi- vanced tokamak. ” mental device during an experiment. Also, the in- Coolant: Fluid that is circulated through a component struments used for diagnosing. or system to remove heat. In a fusion reactor, the Diffusivity: The ability of a substance, especially a gas, coolant would flow through the blanket to remove to diffuse through another substance. the heat generated by fusion reactions. Direct conversion techniques: Conversion of the ki- Cooperation: In the context of international activities, netic energy of plasma particles directly into elec- cooperation refers to all activities involving nations trical energy without first converting it into heat. or individuals from different nations working to- Since conversion into heat and the subsequent re- gether. conversion to electricity impose inherent inefficien- Critical temperature: The temperature below which cies, direct conversion could improve the efficiency a superconducting material loses all resistance to of a fusion generating station. electricity. See “Superconductivity.” Divertor: A component of a toroidal fusion device Curie: A unit of radioactivity. One curie of a radio- used to shape the magnetic field near the plasma active substance is that amount that undergoes 3.7 edge so that particles at the edge are diverted away x 1010 (37 billion) nuclear transformations per from the rest of the plasma. These particles are second, swept into a separate chamber where they strike D-D reaction: Fusion reaction in which one nucleus a barrier, become neutralized, and are pumped of deuterium fuses with another. Two different out- away. In this way, energetic particles near the comes are possible: a proton plus a tritium nucleus, plasma edge are captured before they can strike or a neutron plus a helium-3 nucleus. the walls of the main discharge chamber and gen- D-T reaction: Fusion reaction in which a nucleus of erate secondary particles that would contaminate deuterium fuses with a nucleus of tritium, forming and cool the plasma. Diverters have also been App. D—List of Acronyms and Glossary ● 217

found to be responsible for establishing a mode of Energy gain (Q): The ratio of the fusion power pro- enhanced tokamak confinement called the “H- duced by a plasma to the amount of power that mode. ” See “H-mode scaling.” must be added to the plasma to sustain its tem- Driven fusion reactor: A fusion reactor operating be- perature. low breakeven that must be driven with more Engineering feasibility: The ability to design and con- energy than it produces. Such a reactor might serve struct all the components, systems, and subsystems to generate neutrons for a fusion materials test fa- required for a fusion reactor. cility. Engineering test reactor: A next-generation fusion ex- Electromagnetic radiation: Radiation consisting of periment to study the physics of long-pulse ignited associated and interacting electric and magnetic plasmas, provide opportunities to develop and test fields that travel in a wave at the speed of light. Ra- reactor blanket components under actual fusion dio waves, microwaves, light, x-rays, and gamma conditions, and integrate the various systems of a rays are all forms of electromagnetic radiation; they fusion reactor. differ from one another in wavelength and fre- Equivalent Q: For a plasma not containing tritium, a quency. measure of what Q would have been i n a tritium- Electron: An elementary particle with a unit negative containing plasma that attained the same temper- electrical charge and a mass 1/1 837 that of a pro- ature and confinement parameter. See “Confine- ton. In an atom, electrons surround the positively ment parameter. ” charged nucleus and determine the atom’s chemi- External heating: See “Auxiliary heating. ” cal properties. External magnets: Magnet coils outside the fusion Electron cyclotron frequency: The frequency at plasma that generate those confining magnetic which electrons in a plasma gyrate about magnetic fields that are not generated by currents within the field lines. The electron cyclotron frequency in- plasma itself. creases with increasing magnetic field strength and Fast breeder reactor: A fission reactor in which fast is typically hundreds of gigahertz, substantially neutrons are used both to induce fission reactions higher than the ion cyclotron frequency. See also in the fuel, producing power, and to react with fer- “ion cyclotron frequency. ” tile materials, converting them to more fissile fuel. Electron cyclotron resonance heating (ECRH): A See “Fast neutron,” “Fertile material, ” and “Fis- process in which only electrons gain energy from sile material. ” an applied radiofrequency field operating at the Fast neutron: A neutron with energy greater than electron cyclotron frequency. The electrons then 100,000 electron volts. heat other plasma particles through collisions. Fertile material: Material that is not fissile but can be Electron temperature: The temperature of the elec- converted to fissile material through neutron irradi- trons in a plasma. Electron temperature can differ ation. See “Fissile material. ” from ion temperature. Some of the mechanisms by Field-reversed configuration (FRC): A magnetic con- which energy is lost from the plasma, in particular finement concept with no toroidal field, in which radiation losses, depend on electron temperature. the plasma is essentially cylindrical in shape. The Electron volt (eV): A unit of energy equal to the FRC is a form of compact toroid. energy that can be acquired by singly charged par- Financial liability: Costs, including those associated ticle (e.g., an electron) from a one-volt battery. with death, injury, property damage, and loss of Since the temperature of a system is proportional revenue, to which an electric utility would be ex- to the average energy of each particle in the sys- posed in the event of the worst credible accident tem, temperature is also measured in electron volts; attributable to a generating station. at a temperature of 1 eV, equal to 11,6050 K, the average energy of each particle is roughly 1 eV. As Fine-scale plasma instabilities: Turbulence and other a unit of energy, one eV equals 1.602 X 10-19 Joule, instabilities occurring over distances the size of the 3.827 X 10-20 calorie, 1.519 X 10-22 Btu, or 4.45 orbits of individual plasma particles (electrons and X 10-26 kilowatt-hour. ions) about magnetic field lines. Also called “micro- End cell: In the tandem mirror confinement concept, in stabilities.” the end cell is a magnetic mirror used to plug each First wall: The first physical boundary that surrounds end of the central cell. The function of the end cell the plasma. The first wall can refer either to the sur- is to generate an electric field that will keep the face of the blanket that faces the plasma, or to a plasma in the central cell from leaking out. See also separate component between the blanket and the “Central cell.” plasma. 218 ● Starpower: The U.S. and the International Quest for Fusion Energy

Fissile material: Material that can be used as fuel in “H-mode” scaling: A mode of tokamak behavior in fission reactors. which confinement time does not degrade as in- Fission: The process by which a neutron strikes a nu- creased amounts of auxiliary power are used to cleus and splits it into fragments. During the proc- heat the plasma. This scaling has been observed ess of nuclear fission, several neutrons are emitted in tokamaks that have diverters, and it is believed at high speed, and heat and radiation are released. to be closely related to conditions at the edge of Fission/fusion hybrid: A reactor using a fusion core the plasma. See “L-mode scaling. ” to produce neutrons that in turn either induce fis- Half-life: The time required for one-half of the atoms sion reactions or breed fissile fuel in the reactor of an unstable radioactive element to decay into blanket. Fission/fusion hybrid reactors can produce atoms of other substances, Each radioisotope has energy, fissile fuel, or both. a unique half-life, which can range from fractions Flux: The amount of a quantity (heat, neutrons, etc.) of a second to billions of years. passing through a given area per unit time. Heads-of-state agreement: An agreement between Fossil plant: A powerplant fueled by coal, oil, or gas. nations signed by their respective heads-of-state, Fusion: The process by which the nuclei of light ele- For the United States, the head-of-state is the ments combine, or fuse, to form heavier nuclei, re- President, leasing energy. Heat exchanger: A device for transferring heat from Fusion power core: That portion of a fusion reactor one fluid to another without allowing them to mix. containing all the systems having to do specifically Heat exchangers are used in nuclear reactors to with the fusion process, such as the plasma cham- transfer heat out of the reactor core without cir- ber, the blanket, the magnets, and the heating, fuel- culating the coolant, which becomes radioactive, ing, and impurity control systems. through the rest of the generating station, Fusion self-heating: Heat produced within a plasma Heat load: The amount of heat that a reactor com- from fusion reactions. Since alpha particles pro- ponent must withstand. Both the choice of materi- duced in fusion reactions remain trapped within the als for the component and the amount of cooling plasma, they contribute to self-heating by transfer- that must be provided to it depend on the compo- ring their energy to other plasma particles in colli- nent’s anticipated heat load. sions. Fusion-produced neutrons, on the other Helium nucleus: See “Alpha particle, ” hand, escape from the plasma without reacting fur- Hertz: One cycle per second; a measure of frequency. ther and do not contribute to self-heating. High energy gain: A fusion reaction producing many Gauss: A measure of magnetic field strength. The (1 O or so) times as much power as must be input strength of the earth’s magnetic field on the earth’s to the reaction to maintain its temperature. surface is about one-half gauss; magnetic confine- High-level waste: Radioactive waste that is extremely ment fusion devices typically have maximum mag- radioactive and would pose a serious health and netic field strengths of tens of thousands of gauss. environmental risk if released into the environment. Gigahertz: A measure of frequency equal to 1 billion Disposal of high-level waste must minimize the pos- hertz, or 1 billion cycles per second. See “Hertz.” sibility of its release. Gravitational confinement: The fusion process that Hydrogen (H): The lightest element. All hydrogen occurs in the sun and other stars in which fusion atoms have nuclei containing a single proton and plasmas are confined by the gravitational fields gen- have a single electron orbiting that nucleus. Three erated by their own masses. Enormous masses (con- isotopes of hydrogen exist, having O, 1, or 2 neu- siderably more than that of the planet Jupiter) are trons in their nuclei in addition to the proton. The required for gravitational confinement. term hydrogen is also used to refer to the most com- Greenhouse effect: Possible warming of the earth due mon isotope, technically called “protium,” that has to excess heat trapped in the atmosphere by inno neutrons in its nucleus. creasing levels of carbon dioxide and other “green- Ignition: The point at which a fusion reaction be- house gases.” comes self-sustaining. At ignition, fusion self-heating Greenhouse gases: Gases such as chlorofluorocar- is sufficient to compensate for all energy losses; ex- bons, methane, nitrous oxide, and carbon dioxide ternal sources of heating power are no longer nec- that, in the upper atmosphere, have the property essary to sustain the reaction. of retaining heat that would otherwise escape from Impurities: Atoms present in a plasma that are heav- the earth to space. Accumulation of such gases may ier than fusion fuel atoms. Impurities are undesira- affect global climate. See “Greenhouse effect. ” ble because they dilute the fuel and because they App. D—List of Acronyms and Glossary ● 219

increase the rate at which the plasma’s energy is die away. If a ball sitting in the bottom of a bowl radiated out of the plasma. is disturbed, for example, it wiII eventualIy come Induced radioactivity: Radioactivity created when to rest again at the bottom of the bowl. non-radioactive materials are bombarded by neu- Insulator: Material that does not conduct electricity. trons and become radioactive. Radioactivity can be Ion: An atom (or molecularly bound group of atoms) induced in essentially any material by exposure to that has become electrically charged as a result of neutrons, but the half-life and intensity of this radio- gaining or losing one or more orbital electrons. A activity depends strongly on the material. completely ionized atom is one stripped of all its Industrial base: The industrial capability to design and electrons. manufacture the components of a fusion plant, to Ion cyclotron frequency: The frequency at which ions construct such plants, and to accomplish the pre- in a plasma gyrate about magnetic field lines. The processing and reprocessing of fuels. ion cyclotron frequency increases with increasing Inertia: Inertia is the property of an object to resist magnetic field strength and is typically tens to hun- external forces that would change its motion. Un- dreds of megahertz. See also “electron cyclotron less acted upon by external forces, an object at rest frequency.” will remain at rest, and an object moving in a Ion cyclotron resonance heating (lCRH): A process straight line at constant speed will continue to do in which only ions gain energy from an applied so. Under the influence of external forces, objects radiofrequency field operating at the ion cyclotron with differing inertias wiII respond at different rates. frequency. The ions then heat other plasma parti- The inertia of an object depends solely on its mass. cles through collisions. Inertial confinement: An approach to fusion in which Ion temperature: The temperature of the ions in a intense beams of light or particles are used to com- plasma. Ion temperature can differ from electron press and heat tiny pellets of fusion fuel so rapidly temperature. Since it is the ions that fuse i n fusion that fusion reactions occur before the pellet has a reactions, it is the ion temperature that determines chance to expand. The pellet’s own inertia, or its the fusion reaction rate. See also “Electron tem- initial resistance to expansion even when it is be- perature.” ing blown apart, holds the pellet together long Ionization: The process of removing or adding an enough for fusion energy to be produced. electron to a neutral atom, thereby giving it an elec- Information exchange: Sharing technical approaches tric charge and creating an ion. The term is also and experimental data through any or all of sev- used to denote removal of an electron from a par- eral channels, including meetings, conferences, tially ionized atom to make a more completely symposia, workshops, and publication in techni- ionized one. cal journals. Ionizing radiation: Radiation energetic enough to ion- Inherent safety: In this report, inherent safety is the ize matter that it passes through. Depending on its abiIity to assure, solely through reliance on passive intensity, ionizing radiation poses a health risk. Ex- systems and laws of physics, that no immediate off- amples are alpha and beta particles, emitted by site fatalities can result from any mechanical mal- radioactive substances, and electromagnetic radi- function, operator error, or natural disaster. True ation having frequencies in the far ultraviolet, x-ray, inherent safety can be assured only by having so and gamma ray regions. little hazardous material that even complete release Isotope: Different forms of the same chemical element could not cause an off-site prompt fatality, or by whose atoms differ i n the number of neutrons i n having so little stored energy that even if all the the nucleus. (All isotopes of an element have the stored energy were released at once, the resultant same number of protons in the nucleus and the explosion or fire would not be powerful enough same number of electrons orbiting the nucleus. ) to disperse a fatal dose of hazardous material, See Isotopes of the same element have very similar “Active protection” and “Passive protection. ” chemical properties and are difficult to separate by Instabilities: Small disturbances that become ampli- chemical means. However, they can have quite fied, or become more intense, once they begin. A different nuclear properties. cone balanced upside-down on its tip is subject to Joint construction and operation: Pooling resources an instability, since once it begins to wobble, it will to construct and operate an experimental facility become more unbalanced until it falls over. A jointly. stable system, on the other hand, responds to dis- Joint planning: Activities between nations that coordi- turbances by opposing them. Small disturbances nate experimental and theoretical programs and in a stable system decrease in intensity until they identify areas of future cooperative research. 220 ● Starpower: The U.S. and the International Quest for Fusion Energy

Joint research: Making major national facilities avail- Low-level waste: Waste containing sufficiently low able to researchers from other nation’s programs levels of radioactivity that it does not pose a major in exchange for financial or technical contributions. health or environmental risk. Disposal of low-level Kinetic energy: Energy of motion. The energy released waste does not require the stringent precautions in a fusion reaction is originally in the form of ki- necessary for high-level waste. netic energy of the reaction products. When these Magnetic confinement: Any means of containing and reaction products (alpha particles and neutrons) isolating a hot plasma from its surroundings by collide with atoms or nuclei in the plasma or in the using magnetic fields. reactor structure, they slow down and their kinetic Magnetic field: The property of the space near a mag- energy is converted into heat. net that results, for example, in the attraction of iron “L-mode” scaling: Mode of tokamak behavior in to the magnet. Magnetic fields are characterized which confinement time degrades as increasing by their direction and their strength. Electrically amounts of auxiliary heating power are input into charged particles moving through a magnetic field the plasma. See “H-mode” scaling. at an angle with respect to the field are bent in a Large-scale plasma instabilities: Deformations of both direction perpendicular to both their direction of the overall confining magnetic field and the plasma motion and the direction of the field. Particles mov- that can lead to sudden escape of the entire plasma ing parallel to a magnetic field are not affected. from confinement. Therefore, magnetic fields cannot prevent plasma Laser fusion: A form of inertial confinement fusion in particles from escaping along field lines. which a small pellet of fuel material is compressed Magnetic field line: A (possibly curved) line whose and heated by a burst of laser light. See “lnertial direction at every point is given by the direction confinement .“ of the magnetic field through that point. Electrically Lawson parameter: See “Confinement parameter.” charged particles in a magnetic field tend to gyrate Light-water reactor (LWR): A fission reactor in which around magnetic field lines; they can travel along ordinary water is used as coolant and as a neutron the field lines much more easily than they can cross moderator. See “Neutron moderator. ” field lines. Limiter: Device placed inside the plasma chamber to Magnetic mirror: A generally axial magnetic field that intercept particles at the edge of a plasma. By has regions of increased intensity at each end “scraping off” these particles from the plasma edge, where the magnetic field lines converge. These re- the limiter defines the size of the plasma. gions of increased intensity “reflect” charged par- Liquid-metal fast breeder reactor: (LMFBR) A fission ticles traveling along the field lines back into the fast breeder reactor with a liquid metal coolant. See central region of lower magnetic field strength. “Fast breeder reactor.” Magnetohydrodynamics (MHD): The study of elec- Lithium (Li): A light, chemically reactive metal that trically conducting fluids under the influence of can be converted i n the blanket of a fusion reactor electric and magnetic fields. MHD theory can be into the tritium fuel needed for fusion reactions. used to provide a good approximation to plasma Load change, capability for: The mechanical and behavior in many instances. thermal characteristics of an electric generating sta- Megahertz: One million hertz, or one million cycles tion that limit its rate of response to changes in load per second. See “Hertz.” or that restrict the time required for startup or Microinstabilities: See “Fine-scale plasma insta- shutdown. bilities.” Long-lived radioactivity: Radioactive isotopes having Minimum-B mirror: An open magnetic confinement long half-lives. concept with a magnetic field that is low in strength Low-activitation materials: Materials that, under neu- in the central region but that gets stronger in all tron irradiation, do not generate intensely radio- directions away from the center. Particles in a active, long-lived radioactive isotopes. Examples in- minimum-B mirror tend to be “reflected” by the clude certain vanadium alloys and ceramics such higher field regions back towards the center. Never- as silicon carbide. Fusion reactors made of low- theless, losses from the minimum-B mirror are too activation materials would accumulate far less great for it to be a viable fusion concept by itself. radioactivity over their lifetimes than reactors made Minimum load: The power output level below which with more conventional materials such as steels. a generating plant cannot operate continuously. Low-activation materials also produce less afterheat Ministerial agreement: An agreement signed by the following a reactor shutdown than more conven- secretaries or ministers of the involved departments tional materials. See “Afterheat.” App. D—List of Acronyms and Glossary ● 221

or ministries. In the United States, ministerial agree- Ohmic heating: Heating that occurs when an elec- ments in fusion are signed by the Secretary of tric current is passed through a resistive medium. Energy. Although plasmas are excellent conductors of elec- Multilateral agreement: An agreement between three tricity, they are nevertheless resistive enough to be or more nations. heated when they carry large electric currents. Neutral beam heating: Heating a confined plasma by Ohmic heating becomes less efficient as the plasma injecting beams of energetic (typically greater than gets hotter, and most confinement configurations 100 keV) neutral atoms into it. Neutral atoms can therefore require auxiliary (or non-ohmic) heating cross magnetic lines of force to enter the plasma, to reach ignition. where they transfer their energy to plasma parti- Open confinement concept: Magnetic configuration cles through collisions. In these collisions, the neu- in which the magnetic field lines leave the system. tral beam particles become ionized, and, like the The magnetic mirror is one example. other electrically charged plasma particles, are then Order of magnitude: A factor of 10. confined by the magnetic fields. Outage rate: The percentage of time that an electric Neutron: A basic atomic particle, found in the nucleus generating station is unavailable due to component of every atom except the lightest isotope of hydro- failures or other unforeseen conditions that require gen, that has no electrical charge. When bound the unit to be removed from service. within the nucleus of an atom, the neutron is sta- Overnight construction cost: Total construction cost ble. However, a free neutron is unstable and de- of a facility if it could be built instantaneously. Over- cays with a half-life of about 13 minutes into an night construction cost does not include allowances electron, a proton, and a third particle called an for inflation, nor does it include finance charges antineutrino. The mass of a free neutron is 1.7 X such as the interest payments on funds borrowed 10-24 grams. to begin construction. Neutron flux: A measure of the intensity of neutron Oxidation chemistry: Study of chemical reactions of irradiation. It is the number of neutrons passing substances with oxygen. through 1 square centimeter of a given target in 1 Part-load efficiency: The ratio of the change in effi- second. ciency of an electric generating station to the change Neutron irradiation: Exposure to a source of neu- in load when the load is decreased from full load trons. Both fission and fusion reactors can provide to half. neutron irradiation. Particle collisions: A close approach of two or more Neutron moderator: A material that slows neutrons particles during which quantities such as energy, down without absorbing them. momentum, or charge are exchanged. Neutron multiplier: A substance that reacts with neu- Passive protection: Ability to ensure the safety of a trons to produce additional neutrons. reactor without the use of active safety systems. Neutron wall loading: The energy per unit area per Various degrees of passive protection exist. At one unit time (or energy flux) carried by neutrons into level, the safety of a reactor design might be en- the first wall of a fusion reactor. The higher the neu- sured provided that certain passive systems and tron wall loading, the more rapidly the first wall will components (e.g., coolant loops or tanks) remained suffer radiation damage, the more radioactivity will intact. Before the safety of such a plant could be be induced, and the more frequently first wall com- demonstrated, it would have to be proven that no ponents will have to be replaced. credible accident could interfere with the opera- Non-ohmically heated plasma: Plasma heated with tion of those passive systems or components. At a auxiliary or external heating. much more stringent level of passive protection, Nuclear fission: See “Fission. ” called “Inherent safety, ” materials properties and Nuclear fusion: See “Fusion. ” the laws of physics alone would be sufficient to Nuclear grade: Designation given to components ensure the safety of the reactor. No assumptions used in important safety-related systems in nuclear concerning the integrity of any reactor systems or reactors certifying that the components meet strin- components would need to be made. Such an “in- gent quality control standards, herently safe” reactor would remain safe even if Nuclear physics: The study of atomic nuclei and nu- it could somehow be crumpled up into a ball. See clear reactions. also “Active protection” and “Inherent safely. ” Nucleus (nuclei): The central core of an atom, con- Personnel exchange: The transfer of personnel be- sisting of protons and neutrons, that contains over tween different nation’s programs through visits or 99.95 percent of the atom’s mass. assignments. 222 ● Starpower: The U.S. and the International Quest for Fusion Energy

Plant capital cost: The total cost necessary to bring Project Sherwood: The code-name under which fu- the plant to commercial operation. It includes the sion research was secretly conducted in the United costs of items such as engineering and design work, States from 1951 until 1958. materials, construction labor, construction manage- Proliferation: The development of nuclear weapons ment, interest during construction, escalation, sales by countries not now possessing them. Proliferation tax, equipment, and land. refers primarily to fission-based nuclear weapons. Plant licensability: How readily a generating technol- Prompt fatalities: Deaths due to the immediate effects ogy such as fusion can be expected to receive reg- of a reactor accident or malfunction. Since deaths ulatory approval. from radiation overdoses are not instantaneous ex- Plant life: The total time a plant can be operated be- cept at extremely high doses, prompt fatalities in- fore decommissioning. clude those due to radiation overdoses acquired Plasma: An ionized gaseous system composed of ap- soon after an accident even if death does not oc- proximately equal numbers of positively and neg- cur immediately. Prompt fatalities do not, however, atively charged particles and variable numbers of include deaths many years later from cancer that neutral atoms. The charged particles interact among may have been induced by radiation exposure. themselves, with the neutral particles, and with ex- Proof-of-concept experiment: Experiment done at a ternally applied electric and magnetic fields. The relatively early stage of development of a confine- plasma state is sometimes called “the fourth state ment concept to determine the limits of plasma sta- of matter” due to the fundamental differences i n bility, explore how the confinement properties behavior between plasmas and solids, liquids, or appear to scale, and develop heating, impurity con- neutral gases. trol, and fueling methods. Successful completion Plasma current: Electrical current flowing within a of such an experiment verifies that the confinement plasma. In many confinement schemes, plasma concept appears capable of operating successfully currents generate part of the confining magnetic on a scale much closer to that needed in a reactor. fields. Proof-of-principle experiment: Experiment one stage Plasma exhaust: Particles escaping from the plasma beyond the “proof-of-concept” stage to determine that are collected by limiters or diverters. optimal operating conditions, to establish that the Plasma physics: The study of plasmas. concept is capable of being scaled to near-reactor Plant safety: The capability of the plant to be built level, to extend methods of heating to high power and operated with minimal injury to plant person- levels, and to develop efficient mechanisms for fuel- nel or to the public and minimal damage to prop- ing and impurity control. erty internal or external to the plant. Protium (H or 1H): The most common isotope of Plutonium (Pu): An element that fissions easily and hydrogen, accounting for over 99 percent of all can be used as a nuclear fuel for fission reactors hydrogen found in nature. The nucleus of a pro- or fission weapons. Plutonium is not found in na- tium atom is a single proton with no neutrons. ture, but it can be produced by irradiating uranium Proton: An elementary particle with a single positive with neutrons in a nuclear reactor. electrical charge. Protons are constituents of all Pneumatic injector: Device that injects fuel pellets atomic nuclei. The atomic number of an atom is into plasmas at high speed by accelerating them equal to the number of protons in its nucleus. with compressed gas. Pulsed operation: Non-continuous operation of a fu- Poloidal direction: On a torus, the poloidal direction sion reactor. This term refers to reactors that must runs around the torus the short way, perpendicular periodically stop and restart. In pulsed operation, to the toroidal direction. See “Toroidal direction. ” individual pulses may last as long as hours. Poloidal divertor: A type of divertor. See “Divertor.” Pumped limiter: A limiter that collects particles at the Post-shutdown systems: Systems in a nuclear reactor plasma edge, allows them to recombine into neu- that must operate after the reactor is shut down to tral gas atoms, and pumps the gas out of the vacuum ensure that the afterheat does not build up to a level chamber. A pumped limiter can operate for a high enough to damage the reactor or pose a safety longer period of time than a simple limiter, which hazard, Such systems would be unnecessary in re- does not remove the collected particles and can actors not generating much afterheat, or ones in therefore become saturated. See “Limiter.” which the afterheat could be removed by purely Pure fusion reactor: Reactor that generates all its passive means. energy from fusion reactions in the plasma and Power density: The amount of energy generated per tritium-breeding reactions in the blanket. A pure unit time per unit volume of a reactor core; the fusion reactor is distinguished from a fission/fusion power per unit volume. hybrid reactor, which either generates energy or App. D—List of Acronyms and Glossary ● 223

produces fissionable fuel by including fertile or fis- experiment must achieve reactor-level values of sile material in the reactor blanket. See “Fission/fu- beta and must demonstrate temperature, density, sion hybrid. ” and confinement times sufficient for the produc- Quality of confinement: See “Confinement pation of net fusion power. Furthermore, its heating, rameter. ” fueling, and other technologies must also be able Radiation: The emission of particles or energy from to support a reactor-level plasma. atomic or nuclear processes. Radiation is also Rem: A measure of the effect of radiation on biologi- sometimes used as a shorthand for “electromag- cal systems (acronym for Roentgen equivalent man). netic radiation, ” which refers specifically to emit- Different types of radiation (e.g., alpha particles, ted energy and does not include particles. beta particles, neutrons, and gamma rays) have Radiation dose: A general term denoting the quan- different biological effects. Therefore, doses are cor- tity of radiation absorbed. rected by a different factor for each type of radia- Radiation exposure: The amount of radiation pass- tion to convert them into reins. One rem of any ing through a particular target. type of ionizing radiation produces the same bio- Radiative cooling: Loss of heat from a system through logical effect as one Roentgen of ordinary x-rays. electromagnetic radiation. Since electromagnetic Remote maintenance: Conducting maintenance on radiation carries energy away, a system that radi- reactor systems or components by remote control, ates will cool down. rather than “hands-on. ” Remote maintenance will Radioactive inventory: The total amount of radio- be required in fusion reactors and in many future active material present. fusion experiments because the radioactivity levels Radioactive material: A material of which one or near and inside the plasma chamber will be too more constituents exhibits radioactivity. high to permit human access. Radioactivity: The inherent property of the nuclei of Resistance: The difficulty with which an electric cur- unstable isotopes to spontaneously emit particles rent passes through a material. For a given amount or energy and transform to other nuclei. Such radio- of electric current, the higher the resistance, the active isotopes can be either natural (e.g., carbon- more electrical energy will be dissipated as heat. 14, which is produced by cosmic rays interacting Reversed-field pinch: A closed magnetic confinement with the earth’s atmosphere) or manmade (e.g., concept having toroidal and poloidal magnetic plutonium). fields that are approximately equal in strength, and Radiofrequency power: Electromagentic radiation in which the direction of the toroidal field at the having frequencies in the radio or microwave por- outside of the plasma is opposite from the directions of the electromagnetic spectrum and extend- tion at the plasma center. ing up to the infrared band. Roentgen: A measure of radiation intensity. Radiofrequency (RF) heating: Heating a plasma by Routine release: Releases that occur as a result of nor- depositing radiofrequency power in it. Only radia- mal, or routine, plant operation. tion at certain specific frequencies—e.g., the elec- Runaway reaction: A reaction whose rate increases tron cyclotron frequency or the ion cyclotron as the power level rises, In such a reaction, any rise frequency–will be absorbed by the plasma. See in output power increases the reaction rate, boost- “Electron cyclotron resonance heating” or “Ion cy- ing the output power still further, and so on. Such clotron resonance heating. ” a reaction is unstable, growing larger and larger un- Radioisotope: A radioactive isotope; in particular, a til some other mechanism—e.g., exhaustion of radioactive isotope of a substance whose naturally fuel–limits the reaction power. occurring isotopes are not radioactive. Scaling: Extension of results or predictions measured Reactive: Able to participate easily in chemical or nu- or calculated under one set of experimental con- clear reactions. ditions to another situation having different condi- Reactor potential: A qualitative description of a fu- tions. One of the most important functions of a sion confinement concept denoting how easy it confinement experiment is to determine how con- would be to design, build, operate, and maintain finement properties scale with parameters such as a fusion reactor based on that concept, as well as device size, magnetic field, plasma current, tem- how acceptable such a reactor’s environmental, so- perature, and density. It is important to understand cial, economic, and safety characteristics would be. the scaling properties of a confinement concept— Reactor-scale experiment: Experiment to test a con- either empirically or theoretically—to assure that finement concept by generating a plasma equiva- future experiments have a reasonable probability lent to that needed in a full-scale reactor. Such an of succeeding. 224 . Starpower: The U.S. and the International Quest for Fusion Energy

Scaling relationship: The trend in behavior of a pa- duced by the power source to boil water into rameter as other parameters are varied. See “Scaling.” steam, which is passed through a turbine to turn Scientific feasibility: The successful completion of ex- an electrical generator. periments that produce high-gain or ignited fusion Stellarator: A toroidal magnetic confinement device reactions in the laboratory using a confinement in which the confining magnetic fields are gener- configuration that lends itself to development into ated entirely by external magnets. a net power producing system. Superconductivity: The total absence of electrical re- Self-regulating: A system which, when disturbed in sistance in certain materials under certain condi- some way, will respond in a manner that tends to tions. Until recently, superconductivity had only compensate for the disturbance. A self-regulating been found to occur in certain materials cooled to reaction would be the opposite of a runaway one; within a few degrees of absolute zero. Since late if the reaction power level were to increase, the 1986, however, a new class of materials has been system would respond by lowering the reaction discovered that become superconducting at tem- rate, permitting the power level to drop back down peratures far higher than the materials previously again. Such a system is also called “stable. See also known. An electrical current that is established in “Runaway reaction” and “instabilities.” a superconducting material will persist as long as Shield: A structure interposed between reactor com- the material remains below its critical temperature. ponents, such as magnetic field coils, and the fu- See “Critical temperature.” sion plasma to protect the components from the System studies: Studies presenting preconceptual de- flux of energetic particles produced in the plasma. signs for fusion reactors that serve to uncover po- Simple magnetic mirror: A magnetic field consisting tential problems and determine how changes in de- of a cylinder filled with an axial magnetic field of sign choices affect reactor characteristics. System relatively constant strength, with regions of stronger studies are particularly valuable in guiding the magnetic field at each end. The stronger field re- reseach program by identifying areas where further gions tend to “reflect” plasma particles back into research and development can have the greatest the cylinder. However, too many particles never- impact. theless escape out the ends of the cylinder for the Tandem mirror: Type of open magnetic confinement simple mirror to be a viable fusion concept. configuration in which both ends of a simple mag- Volubility: Ease with which a substance dissolves in netic mirror, called the central cell, are plugged by another substance. end cells to improve confinement. Each end cell Spheromak: A magnetic confinement concept in is itself a magnetic mirror that generates an elec- which a large fraction of the confining magnetic tric field to prevent particles in the central cell from fields are generated by currents within the plasma. escaping, See “Central cell” and “End cell. ” The spheromak is a form of compact toroid. Technological feasibility: In this report, acquisition Spin: An inherent property possessed by subatomic of both sufficient scientific understanding and suffi- particles analagous to the rotation of the earth. Just cient engineering and technological capability to as the spin axis of the earth points towards the design and build a fusion reactor; attainment of North star, the spin axis of a subatomic particle both scientific feasibility and engineering feasibility. points in some direction. The spin axis of a suba- Temperature: A measure of the average energy of a tomic particle can be oriented in a particular direc- system of particles. Given sufficient time and enough tion by use of a magnetic field. interaction among the different portions of any sys- Spin polarization: Preparation of many particles, such tem, all portions will eventually come to the same as deuterium and tritium nuclei, so that their spins temperature. In short-lived plasmas, however, the point in the same direction. If the spins of deu- ion and electron temperatures usually differ be- terium and tritium are polarized, the D-T reaction cause of insufficient interaction between the two. rate is enhanced. Plasma temperatures are measured in units of elec- Spin-offs: The secondary, or auxiliary, benefits of tron volts, with 1 electron volt equal to 11,6050 K. high-technology research and development pro- Thermal instability: Potential instability in a burning grams in applications other than those which are plasma arising from the fact that the fusion reaction the primary motivation for research. rate increases strongly with temperature. It is not Steady-state operation: Continuous operation, with- yet known to what extent burning (ignited) plasmas out repeated starting and stopping. will be subject to this instability, or whether other, Steam generator and turbine: In an electric generat- self-regulating aspects of plasma behavior will pre- ing station, the steam generator uses the heat pro- dominate. See “Runaway reaction.” App. D—List of Acronyms and Glossary ● 225

Thermonuclear fusion: See “Fusion. ” “Thermonu- Treaty: The highest level of formality for an interna- clear” refers to the extreme temperatures required tional agreement. Treaties involving the United for the fusion process to take place. States must be ratified by a two-thirds majority of Thermonuclear weapons: Nuclear weapons utilizing the U.S. Senate. the fusion process, also called hydrogen bombs. Tritium (T or 3H): A radioisotope of hydrogen that has Thermonuclear weapons are very large-scale exam- one proton and two neutrons in its nucleus. Tritium ples of the inertial confinement approach to fusion. occurs only rarely in nature; it is radioactive and Theta pinch: A pulsed device in which a fast-rising, has a half-life of 12.3 years. In combination with strong (100 kilogauss) magnetic field compresses deuterium, tritium is the most reactive fusion fuel. and heats a plasma column in a few microseconds. Tritium breeding: Production of tritium in the blan- The magnetic field is parallel to the axis of a plasma ket of a fusion reactor by irradiating lithium nuclei column. with fusion-produced neutrons. Lithium nuclei un- Tokamak: A magnetic confinement concept whose dergo nuclear reactions with neutrons that yield principal confining magnetic field, generated by ex- tritium nuclei and alpha particles. ternal magnets, is in the toroidal direction but that Turbulence: Random or chaotic flow of a fluid, such also contains a poloidal magnetic field that is gen- as that of water in the rapids of a river. erated by electric currents running within the Umbrella agreement: General agreement between plasma. The tokamak is by far the most developed nations establishing a willingness to cooperate in magnetic confinement concept. See also “Conven- a specific subject area and outlining general pro- tional tokamak” or “Advanced tokamak.” cedures, but not specifying particuIar activities or Toroidal direction: On a torus, the toroidal direction terms. runs around the torus the long way, in the direc- Unit rating: The electrical capacity of a generating tion that the tread runs around a tire. More gener- station. ally, “toroidal” refers to devices in the shape of a Uranium (U): A very heavy, radioactive element torus. found in nature that can be used as nuclear fuel. Torus: The shape of a doughnut, automobile tire, and Two uranium isotopes are important in nuclear inner tube. energy: uranium-235 can undergo nuclear fission, Transformer: Device in which a changing electrical and uranium-238, the most plentiful isotope, can current in one electrical conductor generates a be used to produce plutonium. changing magnetic field, which in turn induces Waste handling and disposal: The in-plant handling, electrical current in a second conductor. The plasma on-site disposal (or transportation), and off-site dis- current in a conventional tokamak is established posal of waste materials formed as byproducts of by a transformer in which one of the conductors the energy production processes. is a set of coiIs located in the hole in the center of the plasma torus and the second conductor is the plasma itself. Index Index

Accidents, risk and severity of fusion reactor, 17-18, Coal 106-108 domestic reserves of, 19, 119 Acid deposition, 29, 119 technologies, 119-120 Advanced fuel cycles See also Fossil fuels concepts for, 90-92, 116 Collaboration reactor safety, radioactive waste production, and, 18, applicability of existing projects to future fusion, 108, 109-110 170-173, 173 Advanced Toroidal Facility (ATF), 142, 60, 143 benefits and risks of, 25, 164, 166, 190 Afterheat, 18, 106, 110, 111 costs of international, 25, 164-165, 193, 194 Agreements international, on fusion facility construction and major international, 158-163, 158 operation, 10, 15, 24-25, 156, 158-163, 183-185 types of international cooperative, 157-158, 157 management approaches to, 170-173 Alcator project, 146, 23, 147 obstacles to, 25-26, 166-170, 194 American Physical Society, 131 prospects for, 24-25, 182-185 Argonne National Laboratory, 93 report’s definition of, 156 Atomic Energy Act of 1954, 40 See also Cooperation Atomic Energy Commission (AEC), 8, 9, 40-44 Colleges. See Universities Auburn University, 147 Commercialization Austria, 159, 184, 185 fusion power, 5, 8, 15-16, 19, 30, 101, 116-119, Axisymmetric Divertor Experiment (ASDEX), 71, 159, 72 123-125, 150-151, 189, 190, 192, 193, 195, 197, 99, 100 Balance of plant, systems in, 12, 72, 73, 73 public urgency for, 3, 19-20, 124, 125 Beta parameter, scientific progress in improving, 70-71, transition in responsibility and, 23, 150-151 80-81, 92, 94 Compact Ignition Tokamak (CIT) Bilateral agreements funding for, 95-97 Japan-European Community, 182 operation of, 190, 197 United States-European Community, 163 preliminary design of, 96 United States-Japan, 161-163 recommended construction and costs of, 13, 52-53, United States-U.S.S.R., 163 138-139 Blanket Compact toroids, 61-63 development program, 97-98 Comprehensive Program Management Plan of 1983 function and development of fusion reactor, 81-84 (CPMP), 51 radioactivity of, 109 Compression heating, 74, 76 Breakeven Confinement confinement time required for, 33 concepts, 8, 11-13, 34-35, 47-48, 57-65, 12, 57 experiments, 9, 46 conclusions concerning approaches to, 65-66 scientific progress in attaining, 68-70 future issues involving, 94-95 Breeder reactors, 18, 44, 46 interrelationship with temperature, 33, 70 DOE deemphasization of, 48 plasma parameters achieved by various concepts of, weapons grade materials produced by, 112 69 See also Fission/fusion hybrid reactors Confinement parameters. See Lawson parameters Breeding ratio, 82, 84 Confinement Physics Research Facility (CPRF), 61 Budget, Bureau of the, 44 Congress, U.S. Bureau of Mines, U. S., 113 AEC abolishment by, 9 energy supply concern in, 47 California, 21, 41, 141, 148 fusion power development and, 35-36, 44 wind energy use in, 123 MFEE Act, passed by, 9, 51 Canada, 172 Cooperation Carbon dioxide (CO2 ), accumulation from fossil fuel administrative issues and international, 169-170 use, 5, 29, 119, 120-121 incentives for, 24, 25, 155, 164-166 Carter, Jimmy, DOE creation by, 9, 48 international, in fusion R&D, 3, 6, 9, 14, 15, 24-26, Chernobyl (U.S.S.R.), 107, 121 44, 63, 66, 139, 155-186 Climate, CO2 effects on, 5, 29, 112, 119, 120-121 obstacles to international, 25-26, 166-170 Closed confinement concepts, 58-63 possible areas for international, 182-183 See also Confinement report conclusions on international, 185-186

229 230 . Starpower: The U.S. and the International Quest for Fusion Energy

report’s definition of, 156 magnetic field exposure guidelines of, 108-109 types of, and levels of agreement, 156-158, 157 National laboratories, 21, 41, 140-143, 141 See a/so Collaboration Office of Energy Research, 48 Coordinating Committee (COCOM), 166 Office of Fusion Energy, 21, 23, 93, 132 Cornell University, 147 plasma physics funding by, 20, 131-132, 132 costs Tritium Systems Test Assembly operation by, 88 blanket design and reactor, 83 Department of Health and Human Services (DHHS), CIT, 13, 52-53, 138-139 135 difficulty in estimating future reactor, 113-116 Deuterium (D) engineering test reactor, 98, 99, 114, 190 in fusion reactions, 6, 30-31, 113 of first wall/blanket test program, 97 supply of, 19, 113 of fusion reactors, 113-116, 190 See a/so D-T reaction; Fuel; Hydrogen fusion’s commercial acceptance and electricity, Development 117-118 alternate paths for concept, 66-67, 67 future fusion research, 15, 26,99-101, 113-116, 155, classification of confinement concepts by level of, 12, 156, 190, 191, 192, 193, 194, 195, 197 57 long-term burn device, 97, 98 plasma physics, 20, 31-33, 39, 131-132 magnetic confinement systems development, 94-95, technical issues in fusion, 94-98, 189-191 96, 97, 190, 191, 192, 193, 194, 195, 197 Diverters, 80, 93 of materials irradiation test facilities, 97 Division of Plasma Physics of the American Physical near-term fusion research, 21-22, 134-139, 22, 134, Society, 131 135, 136, 137, 138, 139 Doublet Ill (D Ill) tokamak of nuclear-technology study device, 98 international cooperation on, 62-163 superconducting magnets effect on reactor, 85, 86, management of, 171-172 96, 115 Doublet II I-D (D III-D) tokamak, 59, 71, 148, 15, 75, See also Economics; Funding 162 Critical temperature, 85, 86 Economics D-D fusion reaction, 31, 92 of international cooperation on fusion research, 3-4, D-T fusion reaction, 32 15, 24, 25, 26, 155, 164-166 accident risk from, 17-18, 106-108 of nuclear fission power, 121-122 breakeven experiments using, 9, 46 renewable energy source, 123 in dense z-pinch confinement, 64 safety assurance levels and fusion reactor, 115 disadvantages of, 91 See a/so Costs, Funding energy released from, 6, 31 Education, fusion program’s benefits to, 20, 132, 140 plasma heating from, 74-75 Efficiency remote maintenance for, experiments, 88, 90 energy, 119, 120, 121, 190, 192 See also Fuel energy conversion, 96, 116 D-T fusion reactors plasma current generation, 79 opposition to constructing, 46-47 Electric Power Research Institute (EPRI), 48 principal locations of potential hazardous agents in, fusion acceptance poll by, 118, 118 109 fusion research by, 149 See also Reactors Electricity 3 D- He fuel cycle, 91-92, 116, 91 comparison of prospective long-range, supply options, See also Advanced fuel cycles; Fuel 123, 124 Decay heat. See Afterheat production as long-term fusion research goal, 8, 16, Defense 30, 105 applications of fusion research, 35, 39-40, 133 systems in a fusion station generating, 12, 72, 13, 72

concerns about international collaboration{ 26, 164, Energy 166-167 advantages of fusion power as source of, 3, 19, 29-30, plasma physicists working in, 21, 132 113, 117, 118, 123, 124 Dense z-pinch, 64-65, 66, 65 availability of fusion, 116-117 Density, plasma, and confinement time, 33-34 conversion by fusion blanket, 81-82 Department of Defense (DoD), 21, 133, 140 demand and fusion development, 19-20, 124, 125 Department of Energy (DOE) desirability of fusion, 117-119 fusion development policy, 3, 13, 14, 16, 23, 24, 26, direct, conversion techniques, 92, 116 30, 48-50, 52, 53, 93-94, 105 feasibility of fusion as a source of, 5, 8, 15-16, 30, fusion research management by, 9, 40, 48-52 116-117, 123-125 international activities in fusion cooperation report by, Federal funding of non-fusion, R&D, 134-139, 138 192-193 fusion as an, program, 16-20, 31, 105-128 Index ● 231

fusion’s context, 19-20, 125, 190 See a/so Coal; Natural gas; Oil loss mechanisms in plasma heating, 74, 76 France, 86, 184 near-term benefits of fusion, program, 20, 133, 190 See a/so European Community (EC) projections of global primary consumption of, 125, Fuel 126 advanced fusion, cycles, 18, 90-92, 108, 109-110, released by D-T reaction, 6, 31 116, 91 renewable sources of, 9, 47, 122-123 fission reactor, supply, 122 source problems, as incentive for fusion development, injection of, 18, 76-79, 106, 78 5-6, 9, 17-18, 19-20, 29-30, 192, 193, 195-196, 197 production of, from fusion reactors, 16, 81, 82-83, 84, See a/so individual sources of 85, 88, 91, 105, 112, 181 Energy gain (Q), 67-68 supply of, for fusion reactors, 5, 19, 113 Energy Research Advisory Board (ERAB), 119 See also individual fuel types fusion program review by, 50, 51-2, 52-53 Funding industry representatives on, 148 D Ill-D, 162-163 international cooperation panel of, 168 European Community fusion program, 161 Energy Research and Development Administration Federal, of non-energy R&D, 134-139, 134, 135, 136, (ERDA), 9, 40, 47, 50 137 Engineering test reactor (ETR), 9, 47, 139 Federal, plasma physics, 20, 131-132, 132 costs of, 98, 99, 114, 190 magnetic fusion research, 3-4, 9-10, 12-13, 15, 21-22, See also International Thermonuclear Experimental 23, 26, 30, 40, 44, 46, 47, 48-51, 95, 121-122, Reactor (ITER) 134-139, 4, 5, 22, 41, 42, 134, 138, 139, 141 England. See United Kingdom (U. K.) See a/so Costs; Economics Environment Fusion Engineering Design Center, 142 fossil fuel’s pollution of, 5, 29, 119-121 Fusion Engineering Device (FED), 50 fusion reactors’ effects on, 5, 18, 29-30, 31, 81, 83, Fusion Experimental Reactor (FER), 182 109-112, 110, 111 Fusion power core systems, 12, 48, 72, 73, 74-90, 14, Environmental Protection Agency (EPA), 135 73 ESECOM report, 106 Fusion self-heating, 74, 76 levels of safety assurance derived from, 107-108 Fusion Working Group, 184 radioactive waste hazard and, 109-110 reactor costs examined in, 115 GA Technologies, Inc., fusion research by, 59, 61, 71,

Europe. See European Community (EC) 148, 149{ 162-163 European Atomic Energy Community, 159 General Atomic Corp., 41, 144 European Community (EC) General Electric Co. (GE), 41, 44 ETR plans of, 98 Geneva Summit of 1985, 179, 181, 184 fusion goals of, 29, 180 Georgia Institute of Technology, 147 fusion program status by, 16, 48 Germany, Federal Republic of, 63, 71, 159 fusion research in, 60, 61, 62, 63, 86 See a/so European Community (EC) international cooperation by, 140, 158, 159, 160-161, Gorbachev, M., 179, 181, 184 163, 170-171, 172-173, 180, 189 Gravitational confinement, 34 JET development by, 158, 160-161 See a/so individual countries of Hawaii, 123 European Laboratory for Nuclear Research (CERN), 172 Helium, 31 European Space Agency, 172 High energy gain, 8, 30 Hiroshima University, 163 Facilities Hitachi Corp. 149 cost of fusion research, 138-139, 190-191, 139 H-mode scaling, 93 development of future fusion research, 12-15, 94-98, Hydrogen 138-139, 190-191 as fuel in fusion reaction, 6, 9, 17-18, 29, 30-31, 46, joint construction and operation of, 24-25, 156 64, 74-75, 88, 90, 91, 106-108 siting fusion, 26, 115, 160, 168 isotopes of, 30-31 See also Reactors; individual facilities See also Deuterium; Tritium Field-reversed configuration (FRC), 62, 74, 63 FINESSE study, 97, 98 Ignition First wall. See Blanket confinement time required for, 33 Fission/fusion hybrid reactors, 16, 19, 105, 112, 114, research, 13, 95-97 202 scientific progress in reaching, 68, 69, 94 See a/so Breeder reactors sustainability of fusion reaction when reaching, 8, 30 Fission reactors, safety of, 18-19, 106 See a/so Plasma Fossil fuels, 5, 29, 119-121 — —

232 ● Starpower: The U.S. and the International Quest for Fusion Energy

Incentives Large Helical System, 60 fossil fuel curtailment, 121 Lawrence Berkeley Laboratory for fusion development, 5-6, 9, 17-18, 19-20, 29-30, inertial confinement fusion research at, 207 117-118 Lawrence Livermore National Laboratory (LLNL) Industry fusion research at, 21, 41, 48, 64, 86, 141 base for fusion, 118, 150-151 inertial confinement fusion research at, 207 competitiveness of United States, 164, 167-168 See also National laboratories; Research fusion research involvement by, 6, 22-23, 41, 44, 51, Lawson parameters, 34, 42 147-151, 22, 134, 138, 147 of advanced fuels, 91 fusion research “spin-offs” used in, 133 magnets obtaining high, 93 plasma physicists in, 132 TFTR-achieved, 52 See a/so Private sector increase in, due to tokamaks, 44, 45 Inertial confinement, 35, 205-207, 206 Licensing. See Regulation Institute for Plasma Physics, 159 Lithium Integrated Fusion Facility (IFF), 116 supply, 19 International Atomic Energy Agency (IAEA), cooperation tritium breeding and, 82-83, 84, 113 facilitation by, 158-159, 185 Los Alamos National Laboratory (LANL) International Energy Agency (IEA), cooperation fusion research at, 21, 41, 48, 61, 62, 65, 88, 142-143 facilitation by, 159-160, 163, 171 inertial confinement fusion research at, 207 International Fusion Superconducting Magnet Test See also National laboratories; Research Facility, 159, 89, 160 Macrotor, 146 International Thermonuclear Experimental Reactor Magnetic confinement, 11-12, 34 (ITER) status and comparison of international, programs, 16, collaboration in design of, 98 48, 155, 174-178, 174, 175, 176, 177, 178 potential for collaboration on, 179-185 See also Confinement proposed development of, 14, 26, 53, 183-185 Magnetic fields siting decision for, 168 in closed confinement configurations, 58-59, 58 status of, 184-185 motion of charged particles in, 34, 63, 34 See also Engineering test reactor potential hazards from, 108-109, 109 International Tokamak Reactor (lNTOR), 159 use of, for plasma confinement, 11-12, 34, 47-48, management of, 170, 184-185 57-66, 12, 57 Issues Magnetic field utilizaiton factor. See Beta parameter fusion power core system, 75, 77-79, 80, 81, 83-84, Magnetic Fusion Advisory Committee (MFAC) 85, 86-88 CIT review by, 96, 97 technical, in fusion development, 94-98, 189-191 industrial participation in fusion findings by, 149, 150 industry representatives on, 148 Japan university research funding by, 145 ETR plans of, 98 Magnetic Fusion Energy Computing Center (MFECC fusion goals of, 29, 182 Act), 133, 141 fusion program status is, 16, 48 Magnetic Fusion Energy Engineering Act of 1980 (MFEE fusion research in, 60, 61, 62, 63, 64, 86 Act), 9, 50-51, 191 international cooperation by, 159, 161-163, 172-173, Magnetic Fusion Engineering Center, proposed creation 181-182, 184 of, 50 role of industry in fusion development in, 149 Magnetic Fusion Program Plan, 1985 (MFPP), 10, 52 Japan Atomic Energy Research Institute (JAERI), 149, Magnetic mirrors, design and development of, 48, 50, 159 63-64, 64 Joint European Torus (JET), 16, 48, 158, 160-161, 163, Magnets 180, 15, 161 function and development of fusion reactor, 85-88, costs of, 95 115-116 management of 170-171 See also Magnetic fields shielding use in, 85 Maintenance, remote, for fusion reactors, 88-90 Joint Institute for Fusion Theory (JIFT), 163 Manhattan Project, 39 JT-60 Tokamak (Japan), 16, 48, 17, 183 Massachusetts Institute of Technology (MIT), 64, 146, cost of, 95 147 Materials KMS Fusion, Inc. and neutron irradiation, 183 inertial confinement fusion research at, 207 development for fusion reactors, 84, 97 production in fusion reactors, 203 Large Coil Task (LCT), 86, 159 requirements for fusion reactors, 19, 113 management of, 171 superconducting, 84, 85, 86-88, 96, 115 Index . 233

testing, 97 Oak Ridge National Laboratory (ORNL) McCormack, Mike, 50 magnetic fusion research by, 21, 41, 46, 48, 142 MFTF-B, 48, 64, 141, 49, 87 materials needs study by, 113 COSt Of, 138 pellet fueling technology development by, 77 superconducting magnets in, 86 See a/so National laboratories Military. See Defense Office of Fusion Energy (OFE) Mirror Fusion Test Facility-B. See MFTF-B research by, 21, 23, 132 Mitsubishi Corp., 149 Technical Planning Activity coordination by, 93 Mitterand, F., 184 Office of Technology Assessment (OTA) Model C Stellarator, 46, 10, 45 fusion energy context workshop by, 36, 123 Modeling issues in international cooperation workshop by, 36, global energy demand, 125, 126 166 fusion generating stations, 105 objectives of fusion assessment by, 35-36 fusion scaling relationship, 58, 71-72 report findings of, 4-6 See a/so System studies selected studies examining other energy technologies Monitoring by, 119 reactor blanket modification, 112 Ohmic heating, 61, 74, 148-149 tritium processing, 88 Ohmically Heated Toroidal Experiment (OHTE), 61, Multilateral agreements 148-149, 24, 149 international, 158-161 Oil, 120 See a/so Cooperation; Collaboration See a/so Fossil fuels Muon-catalysis, approach to fusion, 207-208 Open confinement concepts, 63-65 See a/so Confinement National Academy of Sciences Operational Test Reactor (OTR), 181 fusion personnel estimates by, 140 physics research review by, 39 Pennsylvania State University, 147 See a/so National Research Council Perhapsatron, 9, 43 National Aeronautics and Space Administration (NASA), Personnel 133, 135 international exchange by, 156, 159, 161, 163 National Committee on Radiation Protection and magnetic fusion, 21, 139-140 Measurements, 109 Petroleum, 120 National Institutes of Health (NIH), 135 See a/so Fossil fuels National laboratories Phaedrus, 64, 146 fusion R&D conducted by, 21, 41, 140-143 Phillips Petroleum Co., 148 General Atomics as, 44 Physics, 35, 147 personnel in, 21, 132, 140 plasma, 10, 20, 31-33, 39, 46, 131-132, 197 See a/so Facilities; individual laboratories Plasma National Research Council behavior of burning, 95-97 fission/fusion hybrid reactors, report by, 114 burn control, 80-81 international cooperation report by, 156, 165 confinement concepts, 8, 11-12, 34-35, 47-48, 57-66 plasma physics report by, 132 current generation, 79 See a/so National Academy of Sciences definition of, 8, 31-33, 33 National Science Foundation (NSF) energy loss mechanisms, 74, 76 general science research by, 135 fueling, 76-79, 78 plasma physics funding by, 132 heating, 69, 74-76, 77 National security. See Defense instabilities in, behavior, 11, 33, 42, 44, 57, 64, 68, Natural gas, 120 76, 80-81 Naval Research Laboratory, 62, 65 reaction product control, 79, 80 inertial confinement fusion research at, 207 research, 44, 59, 93 Neutral beams See a/so Magnetic fields injecting, to generate current, 79 Plasma physics plasma fueling using, 76 advances in, 10, 20, 31-33, 39, 46, 131-132, 197 plasmas heated with, 68-70, 74, 75, 93 Federal funding of, 20, 131-132, 132 New Jersey, 21, 41, 140 Plutonium, 40 New Mexico, 39 breeding in nuclear reactors, 112 Next European Torus (NET), 170, 180 declassification of, generation technology, 43 Nixon, Richard M., 47, 163 Policy Nixon-Brezhnev Accord, 163 fusion energy promotion, 117 Nuclear Regulatory Commission, U.S. (NRC), 110, 135 Japan’s energy, 29, 182 234 “ Starpower: The U.S. and the International Quest for Fusion Energy

U.S. fusion development, 3-4, 14, 23, 24, 26, 48-50, nuclear weapon proliferation potential of fusion, 52, 53, 93-101, 127-128, 182-185, 189-197 18-19, 48, 112, 122 world fusion development, 29, 99, 101, 127-128, routine emissions from fusion, 111-112 179-185 shutdown and emergency cooling systems of, 18, 106 Politics See a/so Facilities, individual types of D-T experiment’s effect on, 46 Reagan, Ronald, energy policy of, 51, 136, 179, 181, international cooperation and, 25, 26, 160, 163, 165, 184 181 Regulation Princeton Beta Experiment (PBX), 71 fusion power, 8, 16, 30, 117, 118, 118 Princeton Beta Experiment Modification (PBX-M), 59, 71 impact of reactor cost of, 114, 115, 116 Princeton Large Torus, 77 Renewable energy sources, 9, 47, 122-123 Princeton Plasma Physics Laboratory (PPPL), 142 Rensselaer Polytechnic Institute, 147 CIT facility at, 53, 138-139 Research fusion research at, 21, 41, 59, 62, 70-71, 95-97, 140 advanced fuel, 90-92 spin polarization research at, 90-91 causes of growth in fusion, 9, 46 TFTR construction at, 47, 49 closed confinement concept, 48, 59, 60, 61, 62-63 See a/so National laboratories cost of, facilities, 138-139, 190-191, 139 Princeton University, 140 costs of fusion, 15, 99-101, 113-116, 155, 156, 190, Private sector 191, 192, 193, 194, 195, 197 fusion research involvement in, 6, 21, 22-23, 41, 44, declassification of fusion, 9, 42-44, 155 51, 117, 147-151, 22, 134, 138, 147 defense-related fusion, 35, 39-40 plasma physicists in, 132 funding fusion, 3-4, 9-10, 12-13, 15, 21-22, 23, 26, 30, See also Industry 40, 44, 46, 47, 48-51, 95, 134-394, 5, 22, 41/ 42 Process heat, production by fusion, 203 goal of current fusion, 8, 16, 30, 105 Project Sherwood, 8, 40-42 history of magnetic confinement fusion, 8-10, 39-53 declassification of, 42-44 ignited plasma, 13, 52 Protium. See Hydrogen inertial confinement, 35, 205-207 Public opinion international cooperation in fusion, 3, 6, 9, 14, 15, on fusion power acceptability and development, 3, 8, 24-26, 44, 53, 155-186, 193-194 9, 30, 46, 202 issues affecting future fusion, policy, 24-26, 94-98, on nuclear fission power, 121, 122 189-191 Pumped limiters, 80 on magnetic fields’ safety risk, 108-109 materials, 157 Q. See Energy gain muon-catalysis, 207-208 near-term benefits from fusion, 6, 20, 131-134, 191 Radiation nuclear fission technology, 122 damage to blanket materials, 83 open confinement concept, 64 routine emissions from fusion reactors of, 111-112 participants in magnetic fusion, 21-23, 29, 40-41, Radioactive waste, fusion reactor, 18, 29-30, 83, 140-151 109-110, 110 plasma heating, 75-76, 93 Radiofrequency (RF) plasma physics, 59, 197 heating, 74, 75-76, 93 progress and future directions in fusion, 9, 48-50, injecting, power to generate current, 79 93-101, 189-197 Reaction superconducting materials, 86-88 requirements for fusion, 6-8, 29, 30, 31-35, 7, 32 Research and development (R&D) See. Development; runaway, 18, 106 Research Reactor potential, 66 Reversed-field pinch, 60-61, 78, 79, 61 Reactor relevance, 48, 50 energy gain as measure of, 67-68 Safety Reactors assurance levels, 107-108, 115 blanket design’s influence on, 83 fission reactor, 121 breeder, 19, 44, 46, 48, 112 fusion reactor, 5, 17-18, 30, 31, 81, 93, 106-108 characteristics of fusion, 16-20, 105-106, 127 occupational, on fusion reactor site, 108-109, 109 confinement concept requirements for viable fusion, shielding and personnel, 85 66 tritium processing, 88 development of, 8, 9, 12, 46, 47, 48, 49, 51, 52, 53, Sandia National Laboratory 72-73, 139 inertial confinement fusion research at, 207 fusion test, 9, 14, 26, 47, 53, 98, 168, 179-185 Scaling, 58, 71-72 Index ● 235

H-mode, 93 plasma heating, 74-76, 93 Schedule, future fusion R&D, 3-4, 15-16, 98-99, reactor-relevant, 48, 50 116-117, 127-128, 190, 194, 196, 99, 100 renewable energy, 9, 47, 122-123 Science. See Research; Technologies transfer of, 24, 25, 26, 158 Second Geneva Conference on the Peaceful Uses of Temperature, fusion reactions and, 6-8, 31-33, 42, 69, Atomic Energy, 44 70 Self-reference, 235 Tennessee, 21, 41, 142 Senior Committee on Economics, Safety, and Testing. See Research Environmental aspects of magnetic fusion energy. Texas Experimental Tokamak (TEXT), 146 See ESECOM report Theta pinch. See Reverse-field pinch Shielding Three Mile Island (U.S.), 121 ‘ radioactivity of, 109 Tokamak Fusion Test Reactor (TFTR 40, 11, 47 reactor, 84-85 breakeven experiments using, 70 Siting, facilities, 26, 115, 160, 168 construction of, 47, 49 Soviet Union cost Of, 95, 138 ETR plans of, 98 planning for, 9, 16, 47 fusion goals of, 29, 180-181 shielding use in, 85 fusion research in, 16, 48, 60, 62, 63, 64, 86 Tokamaks international cooperation by, 159, 163, 180-181, 184 breakeven experiment results using, 68-70 plasma confinement breakthrough by, 9, 44-46, 59 cooperation on experiments using, 159-160 Space station, proposed management of, 172-173 fusion requirement demonstration by, 11-12, 57, 58, Special Nuclear Materials, Atomic Energy Act’s 59, 65 definition of, 40 ignition experiments using, 70 Spectra Technologies, 62 major world, 59 Spheromak, 61, 78, 79, 62 progress in parameters of, 93, 94 Spin polarization, 90-91 Soviet development of, 9, 44-46, 59 STARFIRE, 115 See a/so Confinement; Magnets, Magnetic fields, as reference base for ESECOM report, 108, 110, 110, individual devices 111 Tore Supra tokamak (France), 86, 163 Stellarator, 59-60, 60 Toroidal chamber with magnetic coil. See Tokamak conversion of, into tokamak, 46, 59 Torus, magnetic fields encircling, 58, 59, 60-61, 58 international cooperation on, 159 Toshiba Corp., 149 Strategic Defense Initiative (SDI), 21, 133, 140, 167 Transfer Superconducting materials currency, 169, 171, 172 recent advances in, 86-88 technology, 24, 25, 26, 158 use in magnet coils, 84, 85, 86, 88, 96, 115 Tritium (T), 40 Swiss Institute for Nuclear Research, 159 breakeven attainment research, 46, 47, 70 Synthetic fuels, production by fusion, 203 breeding in fusion reactor blanket, 81, 82-83, 84, 85, System studies, 12, 48 88, 91, 201-202 on fusion-generated electricity costs, 114 declassification of, generation technology, 43 generating stations, 105 in fusion reactions, 6, 30-31 See a/so Modeling hazards from accidental release of, 18, 106, 108 routine atmospheric releases of, 111 Tandem Mirror Experiment (TMX), 48 See a/so Hydrogen Tandem Mirror Experiment Upgrade (TMX-U), 48, 64, Tritium Systems Test Assembly (TSTA), 88, 143, 90 91 Truman, Harry, 39 Tandem mirrors, 63-64, 65, 141, 64 T-7 tokamak (Soviet Union), 86 TARA device, 64, 147 T-1 5 tokamak (Soviet Union), 15, 48, 86, 180-181, 88 Technical Planning Activity (TPA), 93-95, 97, 98-101, 116 Umbrella agreements, 157-158, 159, 161-163 Technologies United Kingdom advances in fusion, 72-73, 93, 97-98 fusion research in, 62, 63 declassification of nuclear, 43-44 JET facility located in, 160, 161 fossil fuel, 119-121 verification of Soviet tokamak results by, 45-46 fusion energy competitiveness with other energy, See a/so European Community (EC) 19-20, 105, 119-126 United Kingdom Atomic Energy Agency, 161 magnetic fusion research “spin -off,’ 6, 20, 22, 44, United States 132-133 commitment to international cooperation, 168 nuclear fission, 43-44, 121-122 ETR plans of, 98 pellet fueling, 76-79, 93, 78 fusion goals of, 29, 179 236 ● Starpower: The U.S. and the International Quest for Fusion Energy

fusion program status in, 16, 48 inertial confinement fusion research at, 207 fusion research in, 49, 59, 60, 61, 62-63, 64, 86 University of Texas, 146, 163 international cooperation by, 10, 26, 156, 159, University of Washington, 147 161-163, 171-173, 179, 184 University of Wisconsin, 64, 146, 147 stature of, and fusion research, 20, 44, 45, 133-134, Uranium 192, 196, 197 breeding in nuclear reactors, 112 Universities supply of. 19, 43, 122 DOE support of, 21, 132 Utilities ‘ ‘ ‘ fusion R&D conducted by, 21-22, 41, 132, 139, fusion energy’s acceptability to, 116, 117-119, 190, 143-147, 145 118 See a/so Private sector fusion research “spin-off” technology and, 133 University Fusion Associates (UFA), 21, 146 See a/so Private sector University of Arizona, 147 University of California Versailles economic summit, 183-184 at Irvine, 147 at Los Angeles (UCLA), 146, 147 Wastes, from fusion reactors, 18, 29-30, 83, 109-110, at Santa Barbara, 147 110 University of Illinois, 147 Western Europe. See European Community (EC) University of Maryland, 62, 147 University of Michigan, 147 ZT-40, 144 University of Rochester

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