International thermonuclear experimental reactor

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International thermonuclear experimental reactor

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.

ITER will be the first fusion device to produce net energy. ITER will be the first fusion device to maintain fusion for long periods of time. And ITER will be the first fusion device to test the integrated technologies, materials, and physics regimes necessary for the commercial production of fusion-based electricity.

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 35-year collaboration to build and operate the ITER experimental device, and together bring fusion to the point where a demonstration fusion reactor can be designed.

ITER Project Details

The ITER project aims to show that nuclear fusion—the power source of the sun and stars—is technically feasible as a source of energy. Despite more than 60 years of work, researchers have failed to achieve a fusion reaction that produces more energy than it consumes. ITER, with a doughnut-shaped “tokamak” reaction chamber able to contain 840 cubic meters of superheated hydrogen gas, or plasma, is the biggest attempt so far and is predicted to produce at least 500 megawatts of power from a 50 megawatt input. The project was officially begun in 2006 with an estimated cost of €5 billion and date for the beginning of operations—or first plasma—in 2016. Those figures quickly changed to €15 billion and 2019, but confidence in those numbers has eroded over the years.

The true cost of ITER is almost impossible to define. When the project agreement was drawn up in 2006, all the necessary components were divided up among the partners according to their contributions: 45% for the European Union (as host), and 9% for each of the others. How much each partner pays to have those components manufactured is the partner’s individual concern and is not revealed. In addition to the components, which are shipped to Cadarache as in-kind contributions, each partner must make a cash contribution to the central ITER organization to cover its costs.

The ITER organization’s role is to draw up the design, and then to supervise assembly of the reactor while also satisfying the local French regulators, especially the nuclear safety authority ASN. That has not been an easy job, as the organization does not deal directly with the industrial companies doing the manufacturing; that is handled by each partner’s domestic agency. Last year, a highly critical management assessment faulted the organization for failing to establish a workable “project culture.” Bigot has gone to great lengths to get contractors, domestic agencies, and ITER staff working better together. “I want that the ITER organization and the domestic agencies are never the limiting step for contractors to deliver,” he says. Previously, work on the tokamak building had been held up because ITER staff hadn’t agreed on a final version of its design.


ITER Objectives

The amount of fusion energy a tokamak is capable of producing is a direct result of 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) Produce 500 MW of fusion power:

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

2) Demonstrate 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.

3) Achieve a deuterium-tritium plasma in which the reaction is sustained through internal heating:

Fusion research today is at the threshold of exploring a “burning plasma”—one in which the heat from the fusion reaction is confined within the plasma efficiently enough for the reaction to be sustained for a long duration. Scientists are confident that the plasmas in ITER will not only produce much more fusion energy, but will remain stable for longer periods of time.

4) Test tritium breeding

One of the missions for the later stages of ITER operation is to demonstrate the feasibility of producing tritium 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:

ITER achieved an important landmark in fusion history when, in 2012, the ITER Organization was licensed as a nuclear operator in France based on the rigorous and impartial examination of its safety files. One of the primary goals of ITER operation is to demonstrate the control of the plasma and the fusion reactions with negligible consequences to the environment.

Importance of ITER

Fusion has the potential to play an important role as part of a future energy mix for our planet. It has the capacity to produce energy on a large scale, using plentiful fuels and releasing no carbon dioxide or other greenhouse gases. By fusing two forms of hydrogen, called deuterium and tritium, together, the machine would generate 500 megawatts of power. That is ten times more energy than it would require to operate.

Once completed, ITER would measure 100 feet in diameter and height, representing a new breed of nuclear fusion device. If it reaches its energy output goals, it will be the first machine of its kind to bridge the gap from fusion research in the lab to readily available fusion power for cities.

In the end, experts say it will be worth it. After all, nuclear fusion is the process that powers stars like our Sun and offers a number of advantages to current energy sources if we can harness that power here on Earth:

  1. Fusion generates non-radioactive waste that can be completely recycled within 100 years , unlike the toxic radioactive residue that today’s nuclear fission reactors produce.
  2. There’s no chance of a runaway reaction because any malfunction would halt the fusion process, meaning that fusion reactors don’t run the risk of a nuclear meltdown.
  3. It is a clean source of energy compared to coal, natural gas, and crude oil.
  4. Fusion reactors can run on seawater, offering a relatively renewable source of energy.


At the beginning of the 21st century, human society is faced with a precarious situation of increasing energy demands, especially from growing third world economies like India and China, coupled with a fast depleting conventional energy resources which has been dominated by fossil fuel in the past century. This has led to and can potentially lead to in future conflicts of human societies which can become a serious problem unless a viable extractable alternative energy resource(s) is not obtained quickly.

The ITER India Project

India is providing a tenth of the components for the massive nuclear complex unfolding at Cadarache in France. The cryostat acts like a thermos flask but operates at some of the coldest temperatures ever seen in the universe, working at minus 269 degrees Celsius. This is used to keep the special super conducting magnets at the cold temperature at which they need to operate; the entire fusion system would collapse if it can’t be kept cold.

India is also expected to contribute about 9,000 cores over the next decade to the project, thus paying for a little under 10% of the total cost.

Participation of India in the ITER project, with its immense scientific talent and industrial competence, has provided an opportunity to India to master cutting edge technologies. Once the proof is established that mankind can harness the power of the Sun, India could well build its own fusion reactors after 2050.

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