At the heart of the ITER scientific installation is the Tokamak Complex, a 400,000-tonne edifice that reunites the Tokamak, Diagnostic and Tritium buildings.
Eighty metres tall (including basement levels), 120 metres long and 80 metres wide, the Tokamak Complex will dominate the ITER platform when it is completed. The seven-storey structure will house not only the ITER Tokamak, but also more than 30 different plant systems that are necessary for the machine's operation.
The Tokamak Complex is a nuclear-rated structure of reinforced concrete, supported on aseismic isolators. The roof is 60 metres above ground level; the basement floor is approximately 11 metres below. The mid-plane of the machine has been located approximately at the level of the platform.
Construction will require 16,000 tonnes of rebar, 150,000 m³ of concrete, and 7,500 tonnes of steel for the building structures. The European Domestic Agency awarded the civil works contract
in December 2012 to the French-Spanish consortium VFR (comprising French companies VINCI Construction Grands Projets, Razel-Bec, Dodin Campenon Bernard, Campenon Bernard Sud-Est, GTM Sud and Chantiers Modernes Sud, and the Spanish firm Ferrovial Agroman). The construction contract signed for the Tokamak Complex also includes the construction of the ITER Assembly Building; the radio frequency heating building; areas for heating, ventilation and air conditioning; a cleaning facility and site services building; the cryoplant compressor and coldbox building; the control buildings; the fast discharge and switching network resistor building; and three bridges. A second contract, signed in 2013
, covers the mechanical and electrical equipment in the building suite (electricity, lighting, fire protection, elevators, HVAC ...).
Following the completion of Tokamak Complex foundations
in August 2014, work proceeded on the concrete walls and floors of the structure (outlined in green in the drawing above
). Tens of thousands of embedded plates have been cast into the concrete of the floors, walls and ceilings of the building to provide anchoring for the systems and equipment.
In parallel, contractors completed the ITER bioshield—a circular structure in the centre of the Tokamak Building that forms the machine well, or pit. Six-storeys tall and pierced all around by openings for systems and equipment, the bioshield is up to 3.2 metres thick.
Following the completion of the crane hall, a vast open space at the top of the Tokamak Building that allows the cranes to access the Tokamak Pit, the European Domestic Agency Fusion for Energy transferred the building to the ITER Organization in March 2020 for the start of machine assembly. The construction team is now focused on completing the Tritium Building. To follow ITER machine assembly, please visit these pages.