If you haven’t heard about ITER, chances are you will soon. The scale and scope of the ITER Project rank it among the most ambitious science endeavors of our time. Building began in 2010 on the ITER platform in Cadarache, France where 35 nations are collaborating to realize the world’s largest tokamak fusion device.
100,000 kilometres of niobium-tin (Nb3Sn) superconducting strands are necessary for ITER’s toroidal field magnets. Fabricated by suppliers in six ITER Domestic Agencies—China, Europe, Japan, Korea, Russia and the USA—production began in 2009 and is currently drawing to a close. Over 400 tonnes of this multifilament wire has been produced for ITER at a rate of about 150 tonnes/year, a spectacular increase in worldwide production capacity (estimated, before the scale-up for ITER, at a maximum of 15 tonnes/year). Stretched end to end, the Nb3Sn strand produced for ITER would wrap around the Earth at the equator twice.
2x the thrust of a Space Shuttle lift-off
The structure of the ITER central solenoid—the large, 1,000-tonne electromagnet in the centre of the machine—must be strong enough to contain a force equivalent to twice the thrust of the Space Shuttle at take-off. That’s 60 meganewtons, or over 6,000 tonnes of force.
The ITER machine will weigh 23,000 tons. The metal contained in the Eiffel Tower (7,300 tons) can’t compare … the ITER Tokamak will be as heavy as three Eiffel Towers. The vacuum vessel alone weighs 8,000 tons. Approximately one million components will be integrated into this complex machine.
840 cubic metres
The ITER Tokamak will be the largest ever built, with a plasma volume of 840 cubic metres. In currently operating tokamaks, the maximum plasma volume is 100 cubic metres—achieved by both Europe’s JET and Japan’s JT-60.
At the peak of ITER construction in 2018-2019, 5,000 people are expected at ITER (on the worksite and in the offices), up from 1,400 in 2014. The projected rise is due to a sharp increase in the number of construction workers on the platform.
The heaviest components of the ITER machine will be shipped to the nearest Mediterranean port and then transported along 104 kilometres of specially modified road known as the ITER Itinerary. The dimensions of these components are impressive: the heaviest will weigh nearly 900 tons including the transport vehicle; the largest will be approximately four storeys—or 10.6 metres—high. Some will measure 9 metres across; others 33 metres long.
The Tokamak Seismic Isolation Pit (pictured) houses the anti-seismic foundations of the future Tokamak Complex. Some 400,000 metric tons will rest on the lower basemat, including the Complex foundations and walls and the ITER Tokamak. 400,000 metric tons is more than the weight of New York’s Empire State Building.
The latest figures are in: 83,999 people have visited the ITER site since work began in 2007 to clear and level land for the future scientific installation. In 2014, nearly 17,000 people passed through the ITER Visitors Centre, including some 7,000 schoolchildren.
Every one of the ITER Tokamak’s 18 D-shaped toroidal field coils will weigh 360 tonnes. The coils will be unloaded from ocean-going vessels before being transported along the ITER Itinerary on radio-controlled transporters. 360 tonnes is the approximate weight of a fully loaded Boeing 747-300 airplane. Each toroidal field coil is 14 metres high and 9 metres wide.
The goal of the ITER fusion program is to produce a net gain of energy and set the stage for the demonstration fusion power plant to come. ITER has been designed to produce 500 MW of output power for 50 MW of input power—or ten times the amount of energy put in. The current record for released fusion power is 16 MW (held by the European JET facility located in Culham, UK).
150 million °C
The temperature at our Sun’s surface is 6,000°C, and at its core—15 million°C. Temperature combines with density in our Sun’s core to create the conditions necessary for the fusion reaction to occur. The gravitational forces of our stars can not be recreated here on Earth, and much higher temperatures are necessary in the laboratory to compensate. In the ITER Tokamak, temperatures will reach 150 million°C—or ten times the temperature at the core of our Sun.
The main feature of the 180-hectare ITER site in Saint Paul-lez-Durance, southern France, is a man-made level platform that was completed in 2009. This 42-hectare platform measures 1 kilometre long by 400 metres wide, and compares in size to 60 soccer fields. Building began in August 2010.
The Tokamak Building will be slightly taller than the Arc de Triomphe in Paris. Measuring 73 metres (60 metres above ground and 13 metres below), it will be the tallest structure on the ITER site.