70+

Portion of US funding

invested domestically for

design and fabrication

of components

100%

Access to the research

facility and scientific

findings

35

Nations 

collaborating to 

build ITER

Fusion reactions power the sun and the stars, and fusion has the potential

to produce clean, safe, abundant energy on Earth. By fusing light hydrogen atoms such as 

deuterium and tritium, fusion reactions can produce energy gains about a million times 

greater than chemical reactions with fossil fuels. Fusion is not vulnerable to runaway reactions, 

and long-term waste is easily managed.

The ITER project seeks to demonstrate the scientific and technological feasibility of fusion energy by 

building the world’s largest and most advanced tokamak magnetic confinement fusion experiment. 

The ITER tokamak will demonstrate a sustained burning plasma, an essential step for fusion 

energy development. 

The United States signed the ITER Agreement in 2006, along with China, the European Union, India, 

Japan, Korea, and the Russian Federation. The ITER members—representing 35 countries, more 

than 80% of annual global GDP, and half the world’s population—are now actively fabricating and 

shipping components to the ITER site in France for assembly of the first “star on Earth.” 

The ITER Tokamak

Fusion thermal power has already been demonstrated in 

tokamaks; however, for practical fusion, sustained, selfheating fusion reactions are essential. The ITER tokamak 

is designed to achieve an industrial-scale burning plasma 

producing 500 megawatts of fusion thermal power. 

ITER’s plasma volume is more than eight times greater 

than that of the largest existing tokamak. 

When complete, the ITER tokamak will weigh more 

than 25,000 tons and over a million components will 

be integrated into this complex machine. The building 

that contains it will be the largest on the ITER site, 

extending approximately 200 feet above ground and 40 

feet below ground.

9%

Amount of ITER

construction costs

funded by the

United States

ITER: Unprecedented Global 

Collaboration for Fusion Energy

OAK RIDGE NATIONAL LABORATORY

Illustration of ITER 

tokamak with plasma

Source: US ITER
Construction of the ITER facility in Cadarache, France, began in 2010. The United States began deliveries to ITER 

in 2014. Hundreds of deliveries to ITER have been completed, and fabrication of multiple systems is under way. 

Source: ITER Organization

US Innovation

US contributions to ITER are overseen by the US Department of Energy, with the US ITER project office managed by Oak Ridge National 

Laboratory. Princeton Plasma Physics Laboratory and Savannah River National Laboratory serve as partner labs. US ITER R&D, design, and 

fabrication rely on industries, universities, and national laboratories in nearly all states plus the District of Columbia. 

US hardware contributions to ITER require exceptional scale, power, and precision, challenging US industry to produce: 

• Miles of superconductors for magnet systems

• A 1,000 metric ton, 13 tesla central solenoid electromagnet (the “heart” of ITER)

• High-powered microwave and radio-frequency transmission lines

• Cryogenic pellet plasma fueling with demanding repetition rates

• High-throughput tritium processing systems

• Instrumentation for nuclear environments

CONTACT:

US ITER Project Office

1055 Commerce Park Drive, 

Oak Ridge, TN 37830

Oak Ridge National Laboratory is managed by UT-Battelle LLC for the US Department of Energy January 2022

www.usiter.org

@US_ITER

U.S. fusion and related industries benefit from the technologies, know-how, 

and experience that results from U.S. engagement in ITER.

—National Academies of Sciences, Engineering, and Medicine (2021). Bringing Fusion to the U.S. Grid.

Source: US ITER Source: US ITER

Source: US ITER