What lies beneath the lid at the Tokamak pit?

Fusion for Energy 25 September 2017

Aerial view of the Toakamak Building with the metallic lid installed, Caracrache, September 2017 © ITER Organization

​ITER has often been described as a “Pharaonic” project due to its ambition and immense size. It will consist of 39 buildings and infrastructures stretching over a land measuring 42 hectares in the South of France. Those familiar with the spectacular buildings of the Pharaohs can confirm that the secrets beneath their façade have added a twist to their construction. The same applies to ITER. The progress of the buildings, the digging of underground galleries and the arrival of more components transmit a feeling of excitement and curiosity.

Aerial view of the ITER construction site, Cadarache, September 2017 © ITER Organization

During this summer at the Tokamak building, the workforces of the Vinci Ferovial Razel (VFR) consortium have been working relentlessly, while advancing on the slab of the second floor (level 1) and its peripheral walls. Meanwhile, in the structure of the bioshield, this massive cylindrical wall that will act as a safety barrier between the ITER machine and the edifice, a metallic lid has been installed. From up above it looks like a massive disc which is covering a section of the cylinder. Aren’t you curious to know what lies beneath?

“We started the assembly of the lid in July and it was fully installed in mid-August” says Romaric Darbour, F4E’s Deputy Project Manager for Buildings Infrastructure and Power Supplies, supervising the construction. ” The lid has an impressive 30 m diameter and beneath it, workers from Nuvia, one of F4E’s contractors, are building a crown made of reinforced concrete, on which thick steel plates will be anchored to support the Tokamak machine which will weigh 23 000 T. A crane is operating in its inner-space to allow construction to advance and works are expected to last for almost a year.” In parallel, the construction works on the rest of the bioshield, above the lid, keep advancing in order to reach the fifth floor (level L4) by February 2018. “When the works are completed, the lid will be lifted to its final position to the fourth floor of the bioshield (level L3)” he explains. Civil engineering works have also been making progress at the Diagnostics building, where the slab of the fourth floor (level 3) has been reinforced.

View of the Toakamak Complex and Assembly Hall, ITER construction site, Cadarache, September 2017 © ITER Organization

The Assembly Hall, the building overlooking the Tokamak pit where the massive components will be put together, has opened its door to suppliers to start delivering pieces of equipment. The first tooling equipment has arrived from Korea and its assembly is starting after it leaves the Clean Facility, which has been completed since June. Its annexes are also progressing and will be ready by the end of December.

Installing the first pieces of equipment inside the ITER Assembly Hall, September 2017 © LNM-Engage
A few metres away from the Tokamak complex stands the Cryoplant facility, which boasts a brand new façade. The last layer of cladding is nearly put in place and the building is ready to house the equipment that has already been delivered.

The landscape of the site has substantially changed due to digging and drilling of various galleries. One can describe it as a massive labyrinth of pipes and cables inserted underground where the fluids and power of the machine will flow. Almost 20% of the works have been completed and the pace is accelerating.

A labyrinth of pipes crosscutting the ITER construction site, August 2017 © ITER Organization
At the far end of the site, a water basin which compares to 10 Olympic-size swimming pools for a total of 26 000 m3. It is ready to store the water that will flow in and out of the ITER machine in order to cool down its high temperatures. In a few weeks, the cooling towers are expected to be installed.

Aerial view of the works in progress at the area of the water basin and cooling towers, ITER construction site, September 2017 © LNM-Engage

Works have also been advancing in facilities dealing with power conversion and electricity. The main structure of the Magnet Power Conversion building has been installed and cladding is on-going. On the power supplies side, the construction of the Electrical Power Distribution building is on-going and its external façade has been completed.

View of the works in progress of the Magnet Power Conversion building, ITER construction site, August 2017 © ITER Organization