ITER — Matej Filipič

The people of ITER

2024

What is ITER?

ITER (“The Way” in Latin)
is one of the most ambitious energy projects in the world today.
In southern France, 35 nations are collaborating to build the world’s largest tokamak, a magnetic fusion device that has been designed to prove the feasibility of fusion as a large-scale and carbon-free source of energy based on the same principle that powers our Sun and stars.
The experimental campaign that will be carried out at ITER is crucial to advancing fusion science and preparing the way for the fusion power plants of tomorrow.
The primary objective of ITER is the investigation and demonstration of burning plasmas—plasmas in which the energy of the helium nuclei produced by the fusion reactions is enough to maintain the temperature of the plasma, thereby reducing or eliminating the need for external heating. ITER will also test the availability and integration of technologies essential for a fusion reactor, such as superconducting magnets, remote maintenance, and systems to exhaust power from the plasma, as well as the validity of tritium breeding module concepts that would lead in a future reactor to tritium self-sufficiency.
Thousands of engineers and scientists have contributed to the design of ITER since the idea for an international joint experiment in fusion was first launched in 1985. The ITER Members—China, the European Union, India, Japan, Korea, Russia and the United States—are now engaged in a decades-long collaboration to build and operate the ITER experimental device, and together bring fusion to the point where a demonstration fusion reactor can be designed.
We invite you to explore the ITER website for more information on the science of ITER, the ITER international collaboration and the large-scale building project that is underway in Saint Paul-lez-Durance, southern France.

What is fusion?

Fusion is the energy source of the Sun and stars. In the tremendous heat and gravity at the core of these stellar bodies, hydrogen nuclei collide, fuse into heavier helium atoms and release tremendous amounts of energy in the process.
Twentieth-century fusion science identified the most efficient fusion reaction in the laboratory setting to be the reaction between two hydrogen isotopes, deuterium (D) and tritium (T), as the DT fusion reaction produces the highest energy gain at the “lowest” temperatures.
Three conditions must be fulfilled to achieve fusion in a laboratory: very high temperature (on the order of 150,000,000 °C); sufficient plasma particle density (to increase the likelihood that collisions do occur); and sufficient confinement time (to hold the plasma, which has a propensity to expand, within a defined volume).
At extreme temperatures, electrons are separated from nuclei and a gas becomes a plasma—often referred to as the fourth state of matter. Fusion plasmas provide the environment in which light elements can fuse and yield energy.
In a tokamak device, powerful magnetic fields are used to confine and control the plasma.

ITER members

As signatories to the ITER Agreement, the ITER Members China, the European Union, India, Japan, Korea, Russia and the United States will share in the cost of project construction, operation and decommissioning, and also share in the experimental results and any intellectual property generated by the project. Twenty years of collaborative research experiments are planned on the machine.
Europe* is responsible for the largest portion of construction costs (45.6 percent); the remainder is shared equally by China, India, Japan, Korea, Russia and the US (9.1 percent each). The Members contribute very little monetary contribution to the project: instead, nine-tenths of contributions will be delivered to the ITER Organization in the form of completed components, systems or buildings. In this way, the scientific and industrial fabric in each Member is prepared for the step after ITER—the conception and realization of the type of prototype fusion reactor that will demonstrate industrial-scale fusion electricity within this half of the century. For all Members, the benefits of participation are significant: by contributing a portion of the project’s costs, Members benefit from 100 percent of the scientific results and all generated intellectual property.
Each Member has created a Domestic Agency to fulfil its procurement responsibilities to ITER. These agencies employ their own staff, have their own budget, and contract directly with industry. Communication between the ITER Organization and the Domestic Agencies is facilitated by state-of-the-art collaborative CAD design tools, integrated project teams for specific components or projects, and video conferencing. The working language for the project is English.
Taken together, the ITER Members represent three continents, over 40 languages, half of the world’s population and 85 percent of global gross domestic product. In the offices of the ITER Organization and the Domestic Agencies, in laboratories and in industry, literally thousands of people are working toward the success of ITER.
The ITER Organization has also concluded non-Member technical cooperation agreements with Australia (through the Australian Nuclear Science and Technology Organisation, ANSTO in 2016); Kazakhstan (through Kazakhstan’s National Nuclear Center in 2017), and Canada.

What will ITER do?

The amount of fusion energy a tokamak is capable of producing correlates directly to the number of fusion reactions taking place in its core. Scientists know that the larger the vessel, the larger the volume of the plasma ... and therefore the greater the potential for fusion energy.
With ten times the plasma volume of the largest machine operating today, the ITER Tokamak will be a unique experimental tool, capable of longer plasmas and better confinement. The machine has been designed specifically to:

1) Achieve a deuterium-tritium plasma in which the fusion conditions are sustained mostly by internal fusion heating.

Fusion research today is at the threshold of exploring a burning plasma. In a burning plasma, the heat from the fusion reaction is confined within the plasma efficiently enough for the self-heating effect to dominate any other form of heating. As the first such burning plasma device in the world, ITER will offer scientists a unique opportunity to chart new territory in controlled nuclear fusion.

2) Generate 500 MW of fusion power in its plasma for long pulses.

The world record for fusion power in a magnetic confinement fusion device is held by the European tokamak JET. In 1997, JET produced 16 MW of fusion power from a total input heating power of 24 MW (Q=0.67). ITER is designed to yield in its plasma a ten-fold return on power (Q=10), or 500 MW of fusion power from 50 MW of input heating power. ITER will not convert the heating power it produces as electricity, but—as the first of all magnetic confinement fusion experiments in history to produce net energy gain across the plasma (crossing the threshold of Q ≥ 1)—it will prepare the way for the machines that can.

Of course, since ITER is an experimental device, the energy balance in focus in the ITER design is that of the fusion process itself. When taking into account the electricity consumption of the whole plant, the ITER design includes redundant systems, exceptional numbers of diagnostics, and other aspects that are inherently inefficient. Future commercial designs, to be successful, will need to have a favourable comparison between output fusion power and electricity production, and the total input electric power.

3) Contribute to the demonstration of the integrated operation of technologies for a fusion power plant.

ITER will bridge the gap between today’s smaller-scale experimental fusion devices and the demonstration fusion power plants of the future. Scientists will be able to study plasmas under conditions similar to those expected in a future power plant and test technologies such as heating, control, diagnostics, cryogenics and remote maintenance.

4) Test tritium breeding.

One of the missions for the later stages of ITER operation is to demonstrate the feasibility of producing tritium from lithium (lithium isotope Li-6) within the vacuum vessel. The world supply of tritium (used with deuterium to fuel the fusion reaction) is not sufficient to cover the needs of future power plants. ITER will provide a unique opportunity to test mockup in-vessel tritium breeding blankets in a real fusion environment.

5) Demonstrate the safety characteristics of a fusion device.

In 2012, when the ITER Organization obtained licensing as a nuclear operator in France, the ITER fusion device became the first in the world to have successfully undergone the rigorous examination of its safety case. One of the primary goals of ITER operation is to demonstrate control of the plasma and fusion reactions with negligible consequences to the environment.

Advantages of fusion

The next decades are crucially important to putting the world on a path of reduced greenhouse gas emissions.
By the end of the century, demand for energy will have tripled under the combined pressure of population growth, increased urbanization and expanding access to electricity in developing countries. The fossil fuels that shaped 19th and 20th century civilization can only be relied on at the cost of greenhouse gases and pollution.
A new large-scale, sustainable and carbon-free form of energy is urgently needed. The following advantages make fusion worth pursuing.

Abundant energy: Fusing atoms together in a controlled way releases nearly four million times more energy than a chemical reaction such as the burning of coal, oil or gas and four times as much as nuclear fission reactions at equal mass. Fusion has the potential to provide the kind of baseload energy needed to provide electricity to our cities and our industries.

Millions of years: Fusion in ITER will require two elements: deuterium and tritium. Deuterium can be distilled from all forms of water, while tritium will be produced during the fusion reaction as fusion neutrons interact with lithium. Terrestrial reserves of lithium would permit the operation of fusion power plants for more than 1,000 years, while sea-based reserves of lithium, used in a fusion reactor in its Li-6 isotope form, would fulfil needs for millions of years. A critical challenge is how to breed and recover tritium reliably in a fusion device.

No CO2: Fusion doesn’t emit harmful substances like carbon dioxide or other greenhouse gases into the atmosphere. Its major by-product is helium: an inert, non-toxic gas.

No long-lived radioactive waste: Nuclear fusion reactors produce no high activity, long-lived nuclear waste. The activation of components in a fusion reactor is anticipated to be low enough for the materials to be recycled or reused within 100 years, depending on the materials used in the “first-wall” facing the plasma.

Limited risk of proliferation: Fusion doesn’t employ fissile materials like uranium and plutonium. Radioactive tritium is neither a fissile nor a fissionable material. There are no enriched materials in a fusion reactor like ITER that could be exploited to make nuclear weapons.

No risk of meltdown: A Fukushima-type nuclear accident is not possible in a tokamak fusion device. It is difficult enough to reach and maintain the precise conditions necessary for fusion—if any disturbance occurs, the plasma cools within seconds and the reaction stops. The quantity of fuel present in the vessel at any one time is enough for a few seconds only and there is no risk of a chain reaction.

Cost: The power output of the kind of fusion reactor that is envisaged for the second half of this century would likely be similar to that of a fission reactor, between 1 and 1.7 gigawatts. The average cost per kilowatt of electricity cannot yet be extrapolated, however, as this would require the operational experience which will only be available after ITER has been operated for some years. As with many new technologies, costs will be more expensive at first, when the technology is new, and gradually less expensive as economies of scale bring the costs down.

The ideal future energy mix for the planet would be based on a variety of generation methods instead of a large reliance on one source. As a new source of carbon-free baseload electricity, producing no long-lived radioactive waste, fusion could make a positive contribution to the challenges of resource availability, reduced carbon emissions, and fission waste disposal and safety issues.