Subscribe options

Select your newsletters:

Please enter your email address:

@

News & Media

Latest ITER Newsline

  • Technology | ITER-like disruption mitigation at KSTAR

    Two weeks ago at the Korean tokamak KSTAR, the technology chosen for disruption mitigation at ITER—shattered pellet injection—was tested for the first time in a [...]

    Read more

  • Cooling system | From river to droplets and mist

    A subterranean river runs through the ITER installation. Rushing through 60 kilometres of piping, passing through dozens of pumps, filters and heat exchangers a [...]

    Read more

  • Image of the week | How quickly it goes!

    There are many challenges in communicating ITER and one is to keep pace (from a visual point of view) with the progress of the Tokamak Building. Since this pi [...]

    Read more

  • FEC2020 | Seeking sponsors for 28th IAEA Fusion Energy Conference

    For only the third time since 1961, the International Atomic Energy Agency's Fusion Energy Conference will be taking place in France—hosted jointly by the Frenc [...]

    Read more

  • Nuclear safety | Under constant scrutiny

    Because one of the elements involved in the fusion reaction is the radioactive isotope tritium, and because the hydrogen fusion reaction itself generates a high [...]

    Read more

Of Interest

See archived entries

Heading WEST for a new life

Robert Arnoux

Most of Tore Supra's in-vessel components are now dismantled. All in all, 1,500 components, representing 65 tonnes of hardware, have been handled. Four years from now, the 26-year-old tokamak will be a brand new machine. © CEA - IRFM (Click to view larger version...)
Most of Tore Supra's in-vessel components are now dismantled. All in all, 1,500 components, representing 65 tonnes of hardware, have been handled. Four years from now, the 26-year-old tokamak will be a brand new machine. © CEA - IRFM
As the CEA-Euratom tokamak Tore Supra undergoes a major transformation to be used as a test bench for ITER, its innards are being progressively disassembled. From huge heating antennas to the intricate network of piping that used to cool the limiteur (Tore Supra's equivalent of a divertor), most of the in-vessel components are now carefully wrapped and stored in an annex of the vast tokamak hall—a spectacular indication of how complex a machine a tokamak can be.

Four years from now, the 26-year-old tokamak will be a brand new machine. Extra magnetic coils will be added to confine the originally circular plasma into an ITER-like "D" shape and the carbon limiteur will be replaced by a tungsten divertor closely resembling that of ITER.

However, in advance of that date (as early as 2016) the machine will be ready to test the first samples of plasma-facing units—an arrangement of small tungsten blocks that, once assembled, will form the new divertor.

The WEST project (W Environment in Steady-state Tokamak), initiated in 2009, is now entering a decisive phase: as dismantling ends (1,500 components, representing 65 tons of hardware, have been handled), industry is beginning to launch pre-series fabrication and a wide international collaboration is being established.

"With this new configuration, the machine's divertor will be exposed to the same heat flux as in ITER," explains Jérôme Bucalossi, who heads the WEST project at CEA's Institut de Recherche sur la Fusion Magnétique (IRFM). Like in ITER, the WEST divertor will have to withstand a 10 MW/m2 heat load, comparable to that which an improbable spaceship would face in the immediate vicinity of the Sun's surface.

How will the tungsten plasma-facing units behave in such an extreme environment? How close to one another should they be assembled? What will be the consequences of a slight misalignment of the individual blocks? WEST should answer these questions that are of vital importance for ITER.

"WEST is more than a test bench for the ITER divertor—it's a 'risk limiter' as well," says Bucalossi. "It will enable us to validate tungsten technology, acquire data on metal fatigue and explore the components' boundary conditions, particularly in terms of adjustment."

Although the design of the ITER divertor is close to finalization, WEST feedback can still have influence on some details. "And as we all know," smiles Bucalossi, "this is where the Devil likes to hide..."
Click here to view a video presenting the WEST project.


return to the latest published articles