Fusion Energy
May 24, 2023
Fusion Energy
The federal government has supported fusion energy
Developing fusion energy remains technically challenging.
research and development (R&D) for decades. In recent
No grid-connected fusion reactors currently exist. Current
years, congressional interest in fusion has grown in
systems are all designed for R&D, and none of them
response to scientific progress by fusion researchers, the
include systems to convert the released energy into
emergence of a growing commercial fusion industry, and
electricity. Fusion ignition (defined as a fusion reaction that
hope that future fusion power plants can contribute to the
releases more energy than the amount consumed to initiate
nation’s electricity needs without emitting carbon dioxide—
and maintain the reaction) has not yet been achieved in the
a greenhouse gas that contributes to climate change.
most commonly proposed power plant configuration.
Extensive R&D remains necessary on aspects such as the
What Is Fusion?
materials and magnets needed for reactor construction, the
Fusion is a nuclear process in which the nuclei of two light
development and testing of competing reactor designs, and
atoms (such as hydrogen) join, or fuse, to form a heavier
the integration of reactor designs with systems for
nucleus, releasing energy. Fusion is, in that sense, the
converting heat to electricity.
opposite of fission—the nuclear process that powers
today’s nuclear power plants—in which the nucleus of a
Plasma Confinement
heavy atom (such as uranium) splits into two lighter nuclei.
A key challenge for maintaining a controlled fusion
Fusion of hydrogen into helium is the power source that
reaction is confining the fuel. Fusion reactions take place in
makes the Sun shine. On Earth, explosive fusion powers
hot, dense, ionized gas called plasma. The plasma fuel for
nuclear weapons, but controlled fusion for electricity
the reaction must be confined to keep it hot and dense so
production is yet to be demonstrated.
the reaction can continue. The Sun’s plasma is confined by
the pull of the Sun’s own gravity. For fusion power plants
Why Fusion Energy?
on a human scale, two other strategies have been
A fusion power plant would have a number of advantages
developed: magnetic confinement and inertial confinement.
over today’s fission-based nuclear reactors. First, it would
not require nuclear fuel such as uranium or plutonium. The
In magnetic confinement, the plasma is held in place using
use of these fuels in fission reactors has raised concerns
magnetic fields. This is the most common choice both for
about nuclear weapon proliferation, since their availability
current research reactors and for planned power plant
may facilitate weapon development. In addition, the United
designs. A widely used configuration known as a tokamak
States has fraught relationships with some countries that are
uses powerful magnets to confine the plasma within a
major uranium sources, such as Russia. In contrast, the
toroidal (donut-shaped) reaction vessel, with the magnetic
most common fusion reactor designs are fueled by a
fields keeping the plasma away from the walls of the vessel
mixture of two hydrogen isotopes: deuterium and tritium.
to prevent damage and unintended cooling of the plasma.
Deuterium is abundant and available domestically. Tritium
can be manufactured from lithium, potentially in fusion
In inertial confinement, powerful lasers create rapid fusion
reactors themselves, and is sourced mostly from Canada.
reactions in short bursts, with each reaction completing
before the plasma fuel has time to disperse. This approach
Safety is also a potential advantage for fusion when
is used, for example, in the National Ignition Facility (NIF)
compared with fission. Fusion reactors do not pose a
at the Department of Energy (DOE) Lawrence Livermore
meltdown risk—the challenge for fusion is keeping the
National Laboratory. While the NIF is intended primarily
reaction going, not keeping it under control or removing
for research to improve stewardship of the U.S. nuclear
residual heat as with fission. Unlike fission, fusion creates
weapons stockpile, its demonstration of fusion ignition in
little radioactive waste, although structural materials in the
December 2022 has increased interest in inertial
reactor may become somewhat radioactive over time
confinement designs for future power plants.
through a process known as neutron activation.
Federal Fusion R&D
The operation of a fusion reactor would not directly emit
Most federally funded fusion energy R&D is supported by
carbon dioxide, unlike power plants based on the
the DOE Office of Science through its Fusion Energy
combustion of fossil fuels. The manufacturing of reactor
Sciences program. The program has a budget of $763
components and the construction of the reactor itself would
million in FY2023, which the Administration has proposed
likely result in some carbon dioxide emissions; that is true
to increase to $1.010 billion in FY2024. The main emphasis
of any large facility, including facilities for electricity
has been on magnetic confinement, though in recent years
production from renewable sources such as wind and solar.
the program has expanded its efforts on inertial
confinement. The program has also historically focused
mostly on basic research, though in recent years it has
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Fusion Energy
pivoted toward a greater emphasis on applied research. The
$5 billion. These companies are pursuing a wide variety of
ITER facility (see below) is a priority for the program,
designs, using a variety of fuels. Magnetic confinement of
accounting for $242 million of its budget in FY2023.
deuterium-tritium fuel is the most common approach, as in
the federal R&D effort, but the approaches taken by the
The DOE Advanced Research Projects Agency–Energy
commercial sector are more diverse than current federal
(ARPA-E) also supports some fusion energy projects, along
programs, and more often use design strategies traditionally
with other projects across the full range of energy
seen as alternative. Most companies are targeting delivery
technologies. In general, ARPA-E focuses more on applied
of electricity to the grid by the mid-2030s. Some observers
research and commercialization than the Office of Science
consider that an ambitious goal.
does. It also generally requires cost-sharing, which the
Office of Science generally does not. Current ARPA-E
Recent Legislation, Regulatory Action,
programs with a fusion focus include Breakthroughs
and Policy Studies
Enabling Thermonuclear-Fusion Energy (BETHE, total
Congress has taken several legislative actions regarding
funding $35 million) and Galvanizing Advances in Market-
fusion energy in recent years. Section 2 of the Nuclear
Aligned Fusion for an Overabundance of Watts (GAMOW,
Energy Innovation Capabilities Act of 2017 (P.L. 115-115),
total funding $29 million). In November 2022, ARPA-E
Section 3 of the Nuclear Energy Innovation and
issued a request for information on potential future R&D
Modernization Act (P.L. 115-439), and Section 2002 of the
programs on enabling technologies for improving fusion
Energy Act of 2020 (P.L. 116-260, Division Z) all defined
power plant performance and availability.
the term advanced nuclear reactor (in different contexts) to
include fusion reactors, making fusion R&D potentially
In the DOE National Nuclear Security Administration, the
eligible for various DOE nuclear energy programs
Inertial Confinement Fusion program is focused on the use
previously focused exclusively on fission. Section 2008 of
of fusion science to improve stewardship of the U.S.
the Energy Act of 2020 mandated a policy pivot in the
nuclear weapons stockpile. Its FY2023 budget is $630
Fusion Energy Sciences program from basic research
million. The program includes the NIF, mentioned above,
toward commercialization and public-private partnerships.
among other activities. Although the program’s emphasis is
Section 10105 of the CHIPS and Science Act (P.L. 117-
on nuclear weapons applications, some of its scientific
167) reauthorized the Fusion Energy Sciences program,
advances may also be applicable to fusion energy,
including a mandate for the establishment of national teams
especially to reactor designs based on inertial confinement.
to design a pilot plant “that will bring fusion to commercial
viability.” Section 50172(a)(3) of the Inflation Reduction
ITER
Act of 2022 (P.L. 117-169) provided supplemental
ITER (formerly an acronym for International
appropriations to the Fusion Energy Sciences program for
Thermonuclear Experimental Reactor) is a fusion energy
construction and equipment, largely related to ITER.
research and demonstration facility currently under
construction in France. ITER is an international
In 2021, the Nuclear Regulatory Commission (NRC) began
collaboration involving the United States, China, the
to consider options for a regulatory framework for fusion
European intergovernmental organization Euratom, India,
power plants. In early 2023, NRC staff submitted a report to
Japan, South Korea, and Russia. Demonstrating “burning
the Commissioners evaluating three options: (1) regulating
plasma” (operation at or near ignition) in a magnetic
fusion energy systems as “utilization facilities,” similar to
confinement design is the facility’s key goal. Its planned
the framework currently used for fission-based reactors; (2)
capabilities also include extensive instrumentation for
regulating them under the “byproduct material” framework
advancing the scientific understanding of fusion plasmas, as
(10 C.F.R. Part 30), which would address any radioactive
well as opportunities for testing specialized materials for
material present in a fusion facility but not the detailed
use in fusion applications.
operation of the facility; and (3) a hybrid approach
combining the first two options, with the utilization
The ITER project has a history of budget and schedule
facilities component deferred unless detailed designs
challenges. The total U.S. share of the project’s cost is
emerge with greater risk profiles or other concerns than
currently estimated at $6.5 billion, mostly through in-kind
currently contemplated facilities. The staff report
contribution of reactor-component design and fabrication.
recommended the hybrid option, but in April 2023, the
This represents about 10% of the total international cost.
Commission voted to adopt the byproduct material option,
The project expects to create its first plasma in 2028, with
which the commercial fusion industry generally considers
full operations due to start in 2035 and an expected useful
the least burdensome.
life of 35 years. DOE plans to confirm a revised cost and
schedule baseline during 2023. The potential impact of
Recent policy studies include a long-range plan issued in
ITER’s funding needs on resource availability for domestic
2020 by DOE’s Fusion Energy Sciences Advisory
U.S.-based fusion R&D has sometimes been a concern in
Committee, titled Powering the Future: Fusion and
both Congress and the scientific community, especially in
Plasmas; a 2021 study by the National Academies of
times of a tight fiscal environment.
Sciences, Engineering, and Medicine, titled Bringing
Fusion to the U.S. Grid; a White House summit in 2022 on
Commercial Fusion Industry
Developing a Bold Decadal Vision for Commercial Fusion
A new development in recent years is the emergence of a
Energy; and a 2023 technology assessment by the
commercial fusion industry, involving several dozen
Government Accountability Office, titled Fusion Energy:
companies and announced private investment approaching
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Fusion Energy
Potentially Transformative Technology Still Faces
Daniel Morgan, Specialist in Science and Technology
Fundamental Challenges.
Policy
IF12411
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