Enable Recite

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

  • Inside the pit | From dizzying volume to cramped environment

    There was a time when the assembly pit felt like a huge arena, with toy-like tools scattered on the floor and workers reduced to Playmobil-size figures. Progres [...]

    Read more

  • Fusion world | UKAEA's CHIMERA set to transform fusion component testing

    Construction of a unique testing machine for fusion components is underway at the UK Atomic Energy Authority (UKAEA).  The machine, known as CHIMERA (or Co [...]

    Read more

  • Award | A 30-year friendship with China

    Some thirty years ago, HT-7, China's first superconducting tokamak, was entering operation and experiencing some issues with its ion cyclotron resonance (ICRH) [...]

    Read more

  • Tokamak assembly | Building the feeders, segment by segment

    Through an opening in the Tritium Building just large enough to admit the 11-metre-long components, two magnet feeder segments were introduced this month into t [...]

    Read more

  • Fusion world | Highest French distinction for former ITER Director-General

    Established in 1802 by Napoléon Bonaparte, then the First Consul of the young French Republic, the French Legion of Honour (Légion d'honneur) is the highest of [...]

    Read more

Of Interest

See archived entries

How to make a radial plate in 150 days

A radial plate is but a part of an ITER toroidal field coil; still, it is huge. And size and mass (16 metres tall, 5.5 to 9.8 metric tons) are not its only awe-inspiring characteristics ...

Before welding, grooves are pre-machined into both faces of the ''rough shape'' stainless steel plate. (Click to view larger version...)
Before welding, grooves are pre-machined into both faces of the ''rough shape'' stainless steel plate.
What impresses most is the high-precision manufacturing that the radial plates require. Once the six "rough shapes" that form a radial plate have been pre-machined and welded together (see video below), tolerances cannot exceed one millimetre. At each stage of fabrication, the plate's measurements are verified by laser.

A pre-machined radial plate ready for electron beam welding operations in the CNIM welding shop (Toulon, France). (Click to view larger version...)
A pre-machined radial plate ready for electron beam welding operations in the CNIM welding shop (Toulon, France).
Precision is paramount: 750 metre of jacketed superconducting cable have to fit into the grooves that are machined into the plate's steel. "The trajectory of the conductor must perfectly match that of the grooves," explains an expert at CNIM, the French company responsible for the fabrication of 35 radial plates out of a total of 70 (consortium partner SIMIC, in Italy, is responsible for the others). "If we deviate from the required measurements even by a few tenth of a millimetre, we can throw the plate away. And that would mean several million euros..."

Dimensional checks are performed at every stage of the manufacturing process. (Click to view larger version...)
Dimensional checks are performed at every stage of the manufacturing process.
At CNIM, like at SIMIC, the manufacturing process is long and painstaking. From the pre-machining of the rough shapes, it takes close to 150 days before a radial plate is finalized and ready to be sent to ASG Superconductors SpA, in La Spezia, Italy, where the conductor lengths will be inserted. Seven radial plates are needed for the assembly of each toroidal field coil.

"Another main challenge is the tight schedule," explains the CNIM management. "The expected delivery rate is one radial plate every four weeks. To achieve this, our teams must work around the clock in three 8-hour shifts."

The radial plate is now in the final stage of fabrication. All in all the manufacturing process takes about 150 days. (Click to view larger version...)
The radial plate is now in the final stage of fabrication. All in all the manufacturing process takes about 150 days.
Winning the EUR 160 million European contract for radial plate manufacturing translated into heavy investment for the company. It built a dedicated, 3,000 m² facility, acquired highly sophisticated tools (machining, welding, handling) and hired a specialized workforce of 50.

Read more on the European Domestic Agency website.
Watch this video on the radial plate manufacturing process (courtesy of CNIM).



return to the latest published articles