On January 30, 2003, just 6 weeks after the release of the interim report of the National Research Council’s (NRC’s) Burning Plasma Assessment Committee,1 the focus and priority of the U.S. fusion energy sciences program changed. President George W. Bush announced “that the United States will join an ambitious international research project to harness the promise of fusion energy, the same form of energy that powers the Sun.”2 The President’s announcement described the International Thermonuclear Experimental Reactor (ITER) as “the largest and most technologically sophisticated fusion experiment in the world.” The President also acknowledged the NRC’s recommendation for U.S. participation in ITER and further explained, “This step is critical to the development of fusion as a viable energy source. Recent scientific developments have advanced knowledge of this field to the point that scientists now believe ITER can demonstrate the feasibility of this technology as part of an ongoing effort to develop a practical energy-generating device. If successful, ITER would create the first fusion device capable of producing thermal energy comparable to the output of a power plant, making commercially viable fusion power available as soon as 2050.”
The importance of a burning plasma experiment as a required step in the development of practical fusion energy has been appreciated for decades.3 “A burning plasma experiment would address for the first time the scientific and technological questions that all energy-producing fusion schemes must face.”4 As explained in the 1999 Fusion Energy Sciences Advisory Committee (FESAC) report Burning Plasma Physics, “Producing and understanding the dynamics of a burning plasma will be an immense physics challenge and the crucial next step in establishing the credibility of fusion as a source of energy.”5 This finding was also enunciated by previous review panels, which additionally noted the required international, scientific, and political support for the endeavor to construct and operate a burning plasma experiment.6 The President’s Committee of Advisors in Science and Technology (PCAST) report of the Fusion Review Panel7 and the 1996 report of the Fusion Energy Advisory Council (FEAC), Restructured Fusion Energy Sciences Program, recommended that the United States should “pursue fusion energy
1 National Research Council (NRC), Letter Report: Burning Plasma Assessment (Phase 1), The National Academies Press, Washington, D.C., 2002.
3 See, for example, U.S. Department of Energy (DOE), Final Report of the Fusion Policy Advisory Committee, delivered to Energy Secretary Watkins, Washington, D.C., September 1990.
4 National Research Council (NRC), Letter Report: Burning Plasma Assessment (Phase 1), The National Academies Press, Washington, D.C., 2002, p. 3.
5 DOE, Burning Plasma Physics, DOE/SC-0041, Fusion Energy Sciences Advisory Committee, Washington, D.C., September 1999.
6 See, for example, NRC, Cooperation and Competition on the Path to Fusion Energy: A Report, National Academy Press, Washington, D.C., 1984.
7 President’s Committee of Advisors on Science and Technology, The U.S. Program of Fusion Energy Research and Development, Fusion Review Panel, Washington, D.C., July 1995.
science and technology as a partner in the international effort.”8 The report of the NRC Fusion Science Assessment Committee recommended that “solid support should be developed within the broad scientific community”9 for U.S. participation in a burning plasma experiment, and the Secretary of Energy Advisory Board Task Force on Fusion Energy urged “solid support for it throughout the political system.”10
These previous reports, the successful production of 11 MW fusion power in the Tokamak Fusion Test Reactor experiment11 and 16 MW in JET,12 and the plan for the U.S. magnetic fusion burning plasma experimental program as developed through the FESAC and Snowmass processes were reviewed by the 2004 NRC Burning Plasma Assessment Committee.13 The committee’s key recommendation was as follows: “The United States should participate in the International Thermonuclear Experimental Reactor (ITER) project. If an international agreement to build ITER is reached, fulfilling the U.S. commitment should be the top priority in a balanced U.S. fusion science program.” Following this recommendation, the Department of Energy (DOE) Twenty-Year Outlook14 listed ITER as the highest priority within the Office of Science.
Following decades of effort, including the International Tokamak Reactor project (1978-1987)15 and the ITER Engineering Design Activity (1992-1998),16 both facilitated through the International Atomic Energy Agency (IAEA), an international agreement to build and operate a burning plasma experiment was finally formalized in Paris with the signing of the Agreement on the Establishment of the ITER International Fusion Energy Organization for the Joint Implementation of the ITER Project in November 2006.17 The ITER International Fusion Energy Organization is a public international organization, with limited privileges and legal immunities, involving the United States with China, the European Union, India, Japan, the Republic of Korea, and the Russian Federation. At the signing ceremony, DOE Undersecretary for Science Raymond Orbach explained, “ITER is the first stand-alone, truly international, large-scale scientific research effort in the history of the world.” After an international design review was completed in 2008,18 ITER construction began in 2010 in Cadarache, France.19 In 2012, by French Order, ITER became the first of a kind licensed basic nuclear fusion facility.20
By 2013, the estimated cost of ITER construction had grown substantially, and the schedule had slipped by more than a decade. As a consequence, the ITER Council charged an independent team, chaired by William Madia, former director of Oak Ridge National Laboratory and Stanford University vice president for the Stanford Linear Accelerator Center, to determine the causes for ITER’s cost increases and schedule delays and to make management recommendations. Additionally, a bipartisan
8 DOE, A Restructured Fusion Energy Sciences Program, Fusion Energy Advisory Committee, Washington, D.C., January 1996.
9 NRC, An Assessment of the Department of Energy’s Office of Fusion Energy Sciences Program, The National Academies Press, Washington, D.C., 2001.
10 DOE, Realizing the Promise of Fusion Energy, Final Report of the Secretary of Energy Advisory Board, Task Force on Fusion Energy, Washington, D.C., August 1999.
11 Hawryluk et al., Results from deuterium-tritium tokamak confinement experiments, Rev. Mod. Phys. 70:537, 1998.
12 Keilhacker et al., High fusion performance from deuterium-tritium plasmas in JET, Nuc Fusion 39:209, 1999.
13 NRC, Burning Plasma: Bringing a Star to Earth, The National Academies Press, Washington, D.C., 2004.
14 DOE, Facilities for the Future—A Twenty Year Outlook, Office of Science, Washington, D.C., November 2003.
15 See INTOR TEAM, International Tokamak Reactor: Phase 2A, Part III, IAEA, Vienna, 1988.
16 R. Aymar, Present status and future prospect of the ITER project, J Nucl Mater 258:56, 1998.
18 R. Hawryluk et al., Principal physics developments evaluated in the ITER design review, Nuclear Fusion 49:065012, 2009.
19 M. Banks, Construction begins, but ITER’s costs spiral, Phys. World 23(7), 2010.
20 Implementation at ITER of the French Order of 7 February 2012, concerning basic nuclear installations within the European Domestic Agency, P. Wouters et al., Nucl. Fusion 57:100401m, 2017.
group of leaders in the U.S. Senate requested the Government Accountability Office to investigate the cost and feasibility of ITER and its effect on U.S. fusion programs.21 These reports helped to motivate significant management improvements taken by the ITER Council,22 which included the accelerated appointment of a new ITER director general.
In March 2015, Benard Bigot accepted the directorship of the ITER project and created an action plan to implement the recommendations from the 2013 management review. Following these management improvements, the resource-loaded plan to first plasma was approved by the ITER Council in June 2016. The ITER Council Working Group on the Independent Review of the Updated Long-Term Schedule and Human Resources completed its review in April 2016, and DOE approved the project execution plan for U.S. contributions to ITER in January 2017.23
Today, ITER construction and fabrication occurs throughout the 100-acre ITER site; more than 1,200 workers are on site; all major buildings are under construction, including cryogenic, tritium, and diagnostic buildings; and four of six levels of the concrete bioshield for the tokamak have been completed. Important milestones have been achieved,24 including completion of the first 2 of 18 110-ton toroidal field coils by a consortium of European manufacturers in May 2016 and by the Japanese industry in February 2017, followed by the completion of the first of two 800-ton vacuum vessel sector sub-assembly tools by Korean manufactures in May 2017. Within the United States, components for the steady state electrical network were delivered in October 2017, and General Atomics, Inc. (San Diego, California) successfully completed heat treatment of the first of eight central solenoid coils that, when completed, will be more than 50 feet tall and will be the most powerful pulsed superconducting magnet in the world. It is noteworthy that after nearly 2 years since the creation of the updated long-term schedule, the ITER Council reported the project has so far remained on schedule for first plasma in 2025,25 and all 25 milestones due by the end of second-quarter 2017 have been achieved.26
Achievement of government consensus on rejoining ITER, along with broad support within the U.S. scientific community, was a major accomplishment over the past decade. With this achievement came a necessary change in focus and priority of the U.S. fusion energy sciences program. As determined by the 2004 NRC Burning Plasma Assessment Committee, “once the [ITER] decision is made, fulfilling the international commitment to help construct the ITER facility and participate in the ITER program will necessarily become the highest priority in the program.”27 The NRC Burning Plasma Assessment Committee further recommended, “A prioritization process should be initiated by the Office of Fusion Energy Sciences to decide on the appropriate programmatic balance, given the science opportunities identified and the budgetary situation of the time.” Four years later, the NRC Committee to Review the DOE Plan for U.S. Fusion Community Participation in the ITER Program28 recommended that steps should be taken to “seek greater funding stability for the international ITER project to ensure that the United States remains able to influence the developing ITER research program, to capitalize on research
21 U.S. Government Accountability Office, Fusion Energy: Actions Needed to Finalize Cost and Schedule Estimates for U.S. Contributions to an International Experimental Reactor, Report to Congress, GAO-14-499, Washington, D.C., June 2014.
22 DOE, U.S. Participation in the ITER Project, Report to Congress, Washington, D.C., May 2016.
23 DOE, Project Execution Plan for U.S. ITER Subproject-1, DOE Project No. 14-SC-60, Office of Science, Fusion Energy Sciences, Washington, D.C., January 2017.
24 Ned R. Sauthoff, “Perspectives from the US ITER Project,” presented to the NAS Committee for a Strategic Plan for U.S. Burning Plasma Research on August 29, 2017.
26 Ned R. Sauthoff, “Perspectives from the US ITER Project,” presented to the NAS Committee for a Strategic Plan for U.S. Burning Plasma Research, August 29, 2017.
27 NRC, Burning Plasma: Bringing a Star to Earth, The National Academies Press, Washington, D.C., 2004.
28 NRC, A Review of the DOE Plan for U.S. Fusion Community Participation in the ITER Program, The National Academies Press, Washington, D.C., 2009.
at ITER to help achieve U.S. fusion energy goals, to participate in obtaining important scientific results on burning plasmas from ITER, and to be an effective participant in and beneficiary of future international scientific collaborations.”
Following these NRC recommendations, ITER became a primary research focus of the U.S. program. For fiscal year (FY) 2014, the U.S. ITER Project received about 40 percent of the U.S. fusion program budget.29 The DOE Office of Fusion Energy Sciences (FES) annual budget requests to Congress FY2015 through FY2017 stated that the results from U.S. fusion research “support U.S. goals for future scientific exploration on ITER.”
This focus resulted in significant burning plasma research advancements and improved confidence in ITER burning plasma performance. However, other fusion energy science and technology efforts that did not directly support ITER were reduced or eliminated in order to emphasize research in support of ITER. DOE’s FY2005 budget request to Congress called for reduced U.S. fusion technology efforts. In a letter to FESAC, Undersecretary Orbach wrote that “funding for the energy relevant technology research and development will wait for the results of ITER” and further explained, “Until we are confident that we understand the science of fusion, we would be taking an unacceptable risk to commit the sums required to develop the technology needed to apply that science.”30 The National Compact Stellarator Experiment under construction at the Princeton Plasma Physics Laboratory was canceled in 2008 in part owing to the higher priority given to participation in ITER, which is based on the tokamak and not the stellarator concept. Exploratory fusion experiments at the intermediate-scale were eliminated in the FY2011 budget in favor of research that “can contribute to our understanding and optimizing the tokamak configuration and configurations closely related to it.”31 The DOE’s FY2013 request for fusion energy science proposed an “overall reduction in domestic research” while making “a modest increase in funding for scientific collaborations on major international facilities.” In inflation adjusted amounts, funding for domestic fusion research has declined since 2002 while U.S. participation in international research has increased.32
The current priorities of the U.S. DOE/FES program aim to establish a knowledge base that supports U.S. goals for future scientific exploration on ITER. Using input from three community workshops, the 2015 Ten-Year Perspective for the DOE/FES program emphasizes three research areas: (1) massively parallel computing with the goal of validated whole‐fusion‐device modeling, (2) materials research as it relates to plasma and fusion science, and (3) research in the prediction and control of transient events that can be deleterious to toroidal fusion plasma confinement.33 Research in these areas address two frontiers in fusion and plasma science: “the physics of self-heated burning plasma state” using ITER as the vehicle for gaining access to this state, and the “great scientific challenge for fusion is to develop materials that can tolerate the extreme conditions created by burning plasma in a fusion reactor.” The U.S. DOE/FES program budget is constructed from three elements34: (1) Burning Plasma Science: Foundations; (2) Burning Plasma Science: Long Pulse; and (3) Burning Plasma Science: High Power. Each of these three program elements significantly contribute to developing the predictive understanding needed for ITER operations and providing solutions to high‐priority ITER research needs. A fourth element, Discovery Plasma Science, supports research that advances fundamental plasma understanding and explores ways to control and manipulate plasmas for non-fusion applications.
29 DOE FY2015 budget request.
31 T. Feder, U.S. narrows fusion research focus, joins German stellarator, Phys. Today, September 2011, p. 30.
32 Based on appropriated budgets reported in the DOE Fusion Energy Sciences annual budget requests to Congress for FY2003 and FY2017.
33 DOE, The Office of Science’s Fusion Energy Sciences Program: A Ten‐Year Perspective, Report to Congress, Washington, D.C., December 2015.
34 See DOE Fusion Energy Sciences annual budget requests to Congress for FY2015 through FY2017.
The 2015 Ten-Year Perspective states (p. ii) the overall mission of the U.S. DOE/FES program is “to expand the fundamental understanding of matter at very high temperatures and densities and build the scientific foundation needed to develop a fusion energy source.”35 By comparison, EUROfusion (the consortium agreement of research organizations and universities from 26 European Union countries plus Switzerland, Ukraine, and formerly the European Fusion Development Agreement) is guided by a roadmap to supply fusion electricity to the grid by the 2050s.36 Similar national roadmaps leading to the demonstration of fusion power guide research in China37 and Japan.38
Presently, the U.S. fusion research program is focused on future scientific exploration of the burning plasma state in ITER. If the United States were to withdraw from participation in the ITER project, no alternate plan exists for accessing critical next-step burning plasma research at a scale leading to commercial fusion energy. Furthermore, the May 2016 Secretary of Energy’s Report to Congress states, “ITER remains the best candidate today to demonstrate sustained burning plasma, which is a necessary precursor to demonstrating fusion energy power.”39
The baseline cost and schedule for U.S. contributions to the ITER’s first plasma subproject are now formalized.40 Through FY2016, the United States has contributed one-third of its obligated construction costs to first plasma, or $1,138 million. Including contingency, the remaining U.S. hardware and cash contributions to first plasma construction is an additional $2,210 million over the next decade. Post-first plasma construction leading to experiments with a burning plasma will require at least $1,500 million additional summed over the decade after first plasma. Continued U.S. participation in the ITER project requires an additional $100 million to $125 million annually for more than two decades, and, “future budget planning for continued support for ITER needs to be considered within the context of the total budget for SC [Office of Science], and not merely within the FES program.”41
These newly baselined cost and schedule estimates for ITER, which is a major component of the U.S. fusion energy program, and the need for scientific and technological advances in addition to those that will be made with ITER, define the context for the committee’s consideration of elements within a long-term U.S. fusion energy research strategy.
35 DOE, The Office of Science’s Fusion Energy Sciences Program: A Ten-Year Perspective, Report to Congress, Washington, D.C., December 2015.
36 European Fusion Development Agreement (EFDA), Fusion Electricity: A Roadmap to the Realization of Fusion Energy, November 2012, https://www.euro-fusion.org/wpcms/wp-content/uploads/2013/01/JG12.356-web.pdf.
37 Wu et al., Identification of safety gaps for fusion demonstration reactors, Nature Energy 1:16154, 2016.
38 Yamada et al., Japanese endeavors to establish technological bases for DEMO, Fusion Eng and Design 109:1318-1325, 2016.
39 DOE, U.S. Participation in the ITER Project, Report to Congress, Washington, D.C., May 2016.
40 DOE, Project Execution Plan for U.S. ITER Subproject-1, DOE Project No. 14-SC-60, Office of Science, Fusion Energy Sciences, Washington, D.C., January 2017.
41 DOE, U.S. Participation in the ITER Project, Report to Congress, Washington, D.C., May 2016.