International Thermonuclear Experimental Reactor


Le réacteur expérimental thermonucléaire international (ITER) est un réacteur expérimental de fusion nucléaire dont le but de tester la faisabilité scientifique et technique de la fusion nucléaire et qui doit démontrer que cette fusion est utilisable comme source d'énergie à grande échelle, non émettrice de CO2, pour produire de l'électricité.

A project on an international scale

The ITER project, as its name suggests, is an international project involving 35 countries including the European Union, the United States, the United Kingdom, Switzerland, India, China, Russia, South Korea and Japan.

The project is located at the Cadarache site (in the Bouches-du-Rhône region, north of Aix-en-Provence) and is a purely scientific project, with no plans for commercial exploitation. Its tokamak (experimental magnetic confinement device), the largest ever built, has the ambitious mission of demonstrating that nuclear fusion can be a large-scale energy source.

The idea was born in November 1985 at the Geneva summit, when Mikhail Gorbachev invited US President Ronald Reagan to work together on a peaceful fusion reactor project. More than 30 years later, their idea has united all the major powers and is beginning to take shape near Cadarache, the site chosen in 2005.

ITER's objectives

The amount of fusion energy a tokamak can produce depends on the number of fusion reactions taking place in its core. The larger the vessel (and therefore the larger the plasma volume), the greater the potential for fusion energy production.

The ITER Tokamak, with a plasma volume ten times larger than the largest fusion facility in operation today, will be a unique experimental instrument capable of generating long-lived plasma.

ITER has been specifically designed with 5 main objectives in mind:

Produce 500 MW of fusion energy: The record for thermonuclear fusion power belongs to the European JET tokamak. In 1997, this tokamak produced 16 MW of fusion power for a total thermal power of 24 MW. This ratio of 0.67 is to be increased to 10 with ITER with a fusion power of 500 MW for an input power of 50 MW. 

Demonstrate the integrated operation of fusion plant technologies. With this very large machine, scientists will be able to study plasma under conditions similar to those in a fusion power plant and test technologies such as heating, control, diagnostics, cryogenics and remote maintenance.

Building a self-sustaining deuterium-tritium plasma.

Today, fusion research is about to study the 'burning plasma', which is basically a plasma in which the heat from a fusion reaction is retained efficiently enough to sustain a reaction. The larger ITER plasma will produce much more fusion power and remain stable for longer periods of time.

Experimenting with Tritium production.

One of ITER's missions is to demonstrate the possibility of producing Tritium inside the Vacuum Vessel. The world's supply of Tritium is by no means sufficient to meet the needs of future fusion power plants. ITER therefore offers a unique opportunity to test models of tritium blankets in a fusion reactor environment.

Demonstrating the safety of a thermonuclear device. A major milestone in the history of fusion was reached in 2012 when the ITER Organization, after a thorough review of its safety records, received approval to build the ITER nuclear facility and became its nuclear operator. One of ITER's main objectives is to demonstrate that the thermonuclear reactions occurring in the plasma do not affect people and the environment. 

ITER project under development

Progressively, from 2020 onwards, the ITER Organization will begin to integrate and assemble various components of the machine. The test phase, designed to verify the correct functioning of all systems, will prepare the machine for use.

Successfully integrating and assembling more than one million components (ten million parts) produced in ITER member plants around the world and delivered to the ITER site presents a logistical challenge and requires unusual technical solutions. In May 2020, the first major activity of the assembly phase was successfully completed: the installation of the Cryostat base (a steel piece weighing 1250 tonnes). All subsequent assembly sequences of the machine have been carefully defined and coordinated in various ITER offices around the world.

In July 2020, the assembly phase of the machine officially started within the programme. As of December 2021, the programme has completed 75.8% of the tasks required to produce the first plasma, and the first plasma date is set for December 2025.