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

  • Data | Archiving 20 gigabytes per second—and making it usable

    One of the main deliverables of ITER is the data itself—and there will be a tremendous amount of it to store and analyze. During First Plasma, the highest produ [...]

    Read more

  • Electrical tests | High voltage, high risk

    In the southern part of the construction platform, a one-hectare yard hosts some of the strangest-looking components of the entire ITER installation. Rows of to [...]

    Read more

  • Vacuum vessel | First sector safely docked

    It was 8:00 p.m. on Tuesday 6 April and something quite unusual happened in the ITER Assembly Hall: applause spontaneously erupted from the teams that h [...]

    Read more

  • Remote ITER Business Meeting | Virtual interaction, tangible opportunities

    While the advent of Covid-19 has not stopped the relentless advancement of the ITER Project, it has certainly prompted ingenuity in how ITER conducts its work. [...]

    Read more

  • Manufacturing | Europe completes pre-compression rings

    The French company CNIM (Toulon) has produced a tenth pre-compression ring for the ITER Project on behalf of Fusion for Energy, the European Domestic Agency. Th [...]

    Read more

Of Interest

See archived entries

Tokamak Complex

Paint it white

Room by room, level by level, the raw concrete of the Tokamak Complex is being covered with coats of smooth, shiny white paint. The figures are mind-boggling: in the lowest level of the Tokamak Building (B2) where the teams are working currently, close to 28 tonnes of resin, primer and paint are needed to cover the floor, walls and ceiling of the vast galleries surrounding the central Tokamak Pit.

150 tonnes of resin, primer and paint to transform the raw concrete surfaces of the Tokamak Complex into a pristine jewel box. (Click to view larger version...)
150 tonnes of resin, primer and paint to transform the raw concrete surfaces of the Tokamak Complex into a pristine jewel box.
An equivalent tonnage will be required for each of the other main levels of the concrete building, bringing the total to approximately 150 tonnes. The same treatment will be applied to the inner walls of the Tokamak Pit—a total surface of more than 3,000 m²—and to the Diagnostics and Tritium buildings.

In the Diagnostics Building, paint provides for cleanliness and a dust-free environment. Everywhere else in the Tokamak Complex, it is an element of nuclear safety. In a nuclear building, the coating on the floors, walls and ceilings must present a perfectly smooth surface in order to be decontaminated in case of an incident or accident. (Proven decontamination techniques include water projection, adhesive foam, etc.)

Just like in a home-painting job, surfaces must be prepared and elements such as switches, electrical outlets and door frames must be protected by masking tape. In ITER, these simple tasks take on mammoth proportions: sandblasting the walls and ceiling prior to applying the primer, for example, requires more than 100 tonnes of abrasive material per level, and there are up to 19,000 embedded steel plates per level in the Tokamak Building that require masking.

Like at home ... but on a much larger scale. These workers use rollers around the pre-taped embedded plates. (Click to view larger version...)
Like at home ... but on a much larger scale. These workers use rollers around the pre-taped embedded plates.
Home painting jobs rarely include floors but in ITER they do—and the quality of the job is paramount in terms of nuclear safety. Floors need to be perfectly leak-tight and act as a "drip tray" in case of a leakage of effluents.

Whereas walls and ceiling are sandblasted to optimize paint adherence, the floors are submitted to the "bombardment" of small steel balls—a technique called "shot peening"—that creates a pockmarked surface facilitating the binding of the first layer of coating to the concrete surface.

The shot-peening operation is followed by the application of a coat of thick primer, followed by four layers of super-smooth resin—not only on the floor proper but up the wall to a height of about 30 centimetres. All in all, a six-millimetre-thick resin coating.

One of the reasons why home paint jobs are preferably done in the spring is air temperature. A balmy 20 °C is ideal, but in the vast volumes of the Tokamak Building this is not easy to achieve—particularly in the Tokamak Pit, whose open volume is in excess of 25,000 m³.

Next week, when painting begins inside this 30-metre high, 30-metre-in-diametre cylinder, the inside temperature will not rise above 10 °C. Teams have planned industrial hot air blowers to progressively bring the temperature to the required 20 °C and maintain it throughout the 2.5-month duration of the works.

The Tokamak Building in raw concrete conveyed a feeling of brute force, consistent with the massive challenges of construction. Once painted white, it will provide a pristine jewel box for the most complex and sophisticated research installation ever built.


return to the latest published articles