Nuclear Fusion- an Energy Source that is not yet Fully Mastered

Research into nuclear fusion has been a focus for scientists worldwide for several decades now. While some progress has been made in different areas, there is still a long road to travel with no guarantee of future success. A worldwide effort is being made to reach the next level through the ITER project.

Bird's eye view of the ITER site at Cadarache in June 2010. In the foreground the still empty storm drain and the four basins for monitoring water quality.
© ITER Agency France

50 Years of Research...

Since the 1960s¹, researchers have managed to produce nuclear fusion reactions in donut-shaped magnetic confinement devices.

Known as tokamaks (acronym from the Russian Toroidalnaya Kamera Magnitnymi Katushkami or toroidal magnetic chamber), they are found in Japan, the United Kingdom, and France.

   • In 1997, the Culham Tokamak JET in the United Kingdom produced a record 16 megawatts (MW) in one second^2-3. However, to produce this energy 23 MW was required from an external source!

   • The Cadarache Tokamak Tore-Supra in France set another record by maintaining plasma at over three times the sun's temperature (about one million degrees at the corona) for over 6 minutes.

• The Tokamak JT 60 in Japan achieved record temperatures of some 200 million degrees.

The whole world is cooperating to advance nuclear fusion.

True. Many countries are cooperating in nuclear fusion research through the ITER project (International Thermonuclear Experimental Reactor). China, the European Union, India, Japan, South Korea, Russia, and the United States⁴ are working together to build a prototype of a large fusion nuclear reactor. This project will pool all the knowledge and expertise acquired over the last 50 years. ITER's stated aim is to "demonstrate, technically and scientifically, that fusion could become an energy source by 2050"⁵. The ITER project will be located in Cadarache⁶ in the South of France and testing will begin in 2018.

... with Progress yet to Come

The international scientific community is currently developing the ITER project⁷ to build an experimental thermonuclear reactor. Research on nuclear fusion presents several different challenges:

   • Obtaining sufficiently high temperatures to make fusion possible.

   • Prolonging fusion time so that the reactor works non-stop.

   • Obtaining more energy after fusion than is required to produce fusion.

Commercial electricity produced through nuclear fusion is not expected to see the light of day for another few decades.

To achieve this, the ITER project will have to:

   • Make metallic alloys for the inside walls of the machine that can withstand temperatures close to those on the sun's surface (no known material can currently do this);

   • Ensure that plasma heating systems (the state of matter when heated to a very high temperature) can last over time;

   • Control the stability of the plasma over time. To do this, the teams will use high-performance computer-developed models;

   • Develop recovery and storage procedures for radioactive ash from the tritium used in the manufacturing process.

Because of all these obstacles, commercial electricity produced through nuclear fusion is not expected to see the light of day for another few decades. When and if this happens, it will be a real revolution in three major aspects:

   • An almost inexhaustible supply of energy

   • An energy source that generates little radioactive waste⁸

and

    • An energy source free of greenhouse gas emissions.

ITER already has a successor.

True. The Atomic and Alternative Energies Commission (CEA), which is involved in the ITER project, is optimistic. According to the Commission, "experiments conducted over many years mean that we are confident that we will achieve the goals set in order to develop an energy production process through nuclear fusion"⁹. Evidence of this confidence in the future lies in the fact that ITER sponsors are already planning the next phase- a tool that demonstrates the feasibility of nuclear fusion on an industrial scale. This tool is called Demo. However, the prototype, operated by the European Union and Japan, will not be coming on stream anytime soon. It will not be launched until after the ITER operating phase, in 2040 or thereabouts.

[1] http://www.itercad.org/projet_1.php
[2] http://www.achats-industriels.com/dossiers/227.asp
[3] http://www.cite-sciences.fr/francais/ala_cite/science_actualites/sitesactu/question_actu.php?id_article=668&langue=fr
[4] http://www.iter.org/default.aspx
[5] http://www.itercad.org/question_1.php
[6] http://www.itercad.org/question_7.php
[7] http://www.itercad.org/question_1.php
[8] http://www.itercad.org/question_3.php
[9] http://www.itercad.org/question_1.php