The 42-hectare ITER construction platform is the centre of intense activity that will know no pause this summer. But the Newsline team is taking its annual break and will resume reporting in September... Construction is underway on six buildings, at various stages of advancement, and preparatory ground works have begun for three others. In June, the workforce directly involved in the construction of the ITER installation passed the milestone of 1,500 people.   This summer issue of Newsline aims to document all of the latest construction progress at the heart of the world-spanning ITER Project, six years after construction began in earnest in Saint-Paul-lez-Durance, France.   We'll be back in September.

Tritium, one of the two heavy isotopes of hydrogen, is as rare as it is precious. In the present state of technology, it is one of the indispensable ingredients to achieving fusion energy. Tritium is a radioactive isotope of hydrogen and, as such, demands to be treated with extreme care and precaution. In the ITER installation, an entire building is devoted to its storage, handling and processing.   Following the installation earlier this year of six water detritiation tanks on the lower basement level (B2) of the Tritium Building (part of the Tokamak Complex), work is now underway on the floor slab of the B1 basement level.   Workers are carefully positioning hundreds of embedded plates into the dense rebar lattice before concrete pouring operations. Embedded plates offer extremely robust anchorage for the installation of equipment.

In the on-site winding facility where Europe will manufacture four of ITER's poloidal field coils, the winding tooling is now in place alongside a newly assembled "round table," which goes by the official name of "double pancake impregnation station." Impregnation is the second phase of fabrication, which intervenes after winding. The flat, coiled double pancakes are impregnated with epoxy resin in order to provide rigidity and electrical insulation, an operation performed under vacuum and high temperature.   While the installation of the new station is finalized, the winding of a double pancake "pre-dummy" is underway next door in the clean area. The operation, which aims to qualify equipment and processes, will be followed by the manufacturing of an actual real-size dummy for poloidal field coil #5 (17 metres in diameter).

A building that is 45 metres long, 49 metres wide and 26 metres high—that is what it will take to host the powerful radiofrequency sources that will contribute their power to heating the ITER plasma. Located adjacent to the Assembly Hall, the Radiofrequency Heating Building will be home to the 24 ITER gyrotrons that will each generate microwave beams over a thousand times more powerful than a home microwave oven. The building will also host the generators that produce high-power radio frequency waves for the two 45-tonne antennas of the ion cyclotron resonance heating system.     Steel reinforcement work and concrete pouring are underway now on the building's foundation slab. Both systems will be connected to the ITER Tokamak by way of transmission lines and will deliver a total of 40 MW of heating power to the plasma.   Equipment installation is scheduled in late October 2017 and building handover, once all equipment is installed, in August 2018.

With work beginning on the ground level (L1) of the Diagnostics Building, the concrete and steel of the Tokamak Complex will soon be flush with the ITER platform. The 90 x 130 metre "Pit" of yesterday is gone but the central, perfectly round assembly area for the Tokamak remains ... In the centre of the Tokamak Complex worksite, 6 concrete plots out of 11 have been poured for the Tokamak Building's B1-level basemat, as well as 6 massive columns out of 18. Pouring and rebar installation continues for successive levels of the ITER bioshield, the 3.2-metre-thick "ring fortress" surrounding the machine whose role is to protect workers and the environment from the radiation generated by the fusion reaction.   The landscape in the area is now dominated by the black, temporary facade of the Assembly Building, now adorned with a giant poster of the ITER machine. Eventually, as the Tokamak Building rises to meet the Assembly Building, the cladding will be removed and the two buildings will be joined into one.

Inside the completed Site Service Building, finishing works are underway.   The 80 metre-long building located near the Assembly Hall will accommodate and distribute a large number of industrial support services and systems (chiller plants for air conditioning, demineralized water, air compressors, etc.) that are indispensable for operating the ITER installation.   The Cleaning Facility (in white) will be the only way into the Assembly Hall for Tokamak components. The metal frame is nearly complete on the southeast end of the building, not far from the Cryostat Workshop (at far right). Significantly smaller than the Assembly Hall at 19.5 metres tall and 48 metres long, the Cleaning Facility will host the equipment for "cleaning" the ITER components prior to their entry into the pre-assembly arena.   The Cleaning Facility will also operate as an airlock between the Assembly Hall and the outside environment. In order to minimize the amount of dust entering the clean environment of the Assembly Hall, the building's two large doors will not be opened at the same time.

In order to maintain 10,000 tonnes of magnets at superconducting temperature, to cool the thermal shield and to feed the cryopumps, ITER will need to circulate huge quantities of cooling fluids. As a consequence, the ITER cryoplant (worksite pictured) will be deliver 75 kW of combined cooling power.   The soccer-field-size installation will comprise three identical plants to store and circulate liquid helium (at a temperature of 4 K or minus 269 °C) throughout the installation.   Helium is not the only ultra-cold fluid that the cryoplant will produce. Liquid nitrogen, at a temperature of minus 196 °C, will be used as a "pre-cooler" in the liquid helium plants.   On the site of the cryoplant, not far from the Poloidal Field Coils Winding Facility, the foundations are in place. Work is now focused on the construction of the columns that will support the cranes for the installation's maintenance and on the slabs that will support the heavy megawatt-class screw compressors and high-speed turbines.   The building structure should be delivered in April 2017.