Subscribe options

Select your newsletters:

Please enter your email address:

@

Your email address will only be used for the purpose of sending you the ITER Organization publication(s) that you have requested. ITER Organization will not transfer your email address or other personal data to any other party or use it for commercial purposes.

If you change your mind, you can easily unsubscribe by clicking the unsubscribe option at the bottom of an email you've received from ITER Organization.

For more information, see our Privacy policy.

News & Media

Latest ITER Newsline

  • Test facility | How do electronics react to magnetic fields?

    A tokamak is basically a magnetic cage designed to confine, shape and control the super-hot plasmas that make fusion reactions possible. Inside the ITER Tokamak [...]

    Read more

  • ITER Robots | No two alike

    More than 500 students took part in the latest ITER Robots challenge. Working from the same instructions and technical specifications, they had worked in teams [...]

    Read more

  • Data archiving | Operating in quasi real time

    To accommodate the first real-time system integrated with the ITER control system, new components of the data archiving system have been deployed. Data archivi [...]

    Read more

  • Repairs | Setting the stage for a critical task

    Like in a game of musical chairs—albeit in slow motion and at a massive scale—components in the Assembly Hall are being transferred from one location to another [...]

    Read more

  • Image of the week | There is life on Planet ITER

    Dated April 2023, this new image of the ITER "planet" places the construction site squarely in the middle. One kilometre long, 400 metres wide, the IT [...]

    Read more

Of Interest

See archived entries

Nuclear doors

Lifting a sixty-tonne leaf

There is a set of doors in the ITER Tokamak Building that makes one feel like Gulliver in Brobdingnag, the land of the giants in Jonathan Swift's novel. Massive in dimension and weight, the doors require a custom-made handling tool for installation.

The leaf mounting tool is one-of-a-kind—created by contractor Cegelec/Sommer to move the massive port cell doors to the concrete pouring station and back to their final installation locations. Coloured in bright red and sitting on eight yellow double wheels, the tool is equipped with two large holding frames that clutch the port cell door like a sandwich. (Click to view larger version...)
The leaf mounting tool is one-of-a-kind—created by contractor Cegelec/Sommer to move the massive port cell doors to the concrete pouring station and back to their final installation locations. Coloured in bright red and sitting on eight yellow double wheels, the tool is equipped with two large holding frames that clutch the port cell door like a sandwich.
Extending out radially from the concrete bioshield—like so many spokes around a central hub—are nine-metre-long chambers called port cells. The trapeze-shaped spaces will accommodate heating pipes, electricity cables, diagnostic lines and maintenance systems as they pass through to the vacuum vessel from outlying galleries. The port cells also have a part to play in shielding workers and the environment from radiation.

This model shows the neutron flux within the Tokamak Building with the highest levels in red and the lowest in blue. The confinement properties of the port cell doors (the dashes in white forming the outer circle) are clearly illustrated. (Click to view larger version...)
This model shows the neutron flux within the Tokamak Building with the highest levels in red and the lowest in blue. The confinement properties of the port cell doors (the dashes in white forming the outer circle) are clearly illustrated.
At the far end of each port cell (relative to the machine) are heavy nuclear doors that act as a confinement barrier preventing neutrons and potential contamination from passing through.

Forty-six nuclear doors will be necessary to close off the same number of port cells. Made of steel, the doors are 4.2 meters wide, 3.8 meters high and 0.8 meters thick. Delivered hollow, they will be filled on site with approximately 7.5 cubic metres of special heavy concrete that—when poured into each door—increases their weight from 30 tonnes to roughly 60 tonnes each.

The French-German engineering consortium Cegelec/Sommer, subcontractor to the European consortium VFR that is in charge of the construction of the Tokamak Complex, is manufacturing the nuclear doors. Cegelec/Sommer has also developed a custom-made lifting device called the "leaf mounting tool." Built to precise ITER specifications, this heavy-duty machine is capable of maneuvering the massive port cell doors within the confined space of the Tokamak Building.

Port cells connect the bioshield wall to the outlying galleries. In the two port cells visible here, work is either underway (left) or completed (right) on the hinge and lock supports for the nuclear doors. (Click to view larger version...)
Port cells connect the bioshield wall to the outlying galleries. In the two port cells visible here, work is either underway (left) or completed (right) on the hinge and lock supports for the nuclear doors.
The machine's hydraulically adjustable lifting straps lift each door off the ground by a few centimeters and hold it in place between the tool's steel frames, while the tool travels to the concrete filling station and back. Eighteen doors will be fitted into three-piece steel doorframes at B1 (upper basement) level, and 14 each on levels L1 (ground level) and L2 of the Tokamak Building.  

Once mounted, the port cell doors will remain closed, only to be opened for machine assembly or future maintenance activities. For operators to have easy routine access to the port cells, regular-sized "personnel access doors" are fitted into the centre of each port cell door.

Sixteen port cell doors have been delivered, and seven have already been filled with heavy concrete. Teams are ready to begin installing the port cell doors into their frames—an activity that will last until mid-2020.



return to the latest published articles