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News & Media

Latest ITER Newsline

  • Without minimizing challenges, Council reaffirms commitment

    On 24 October 2007, the ITER Organization was officially established following the ratification by the seven ITER Members of the project's constitutive document [...]

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  • Heat waves

    Plasma is like a tenuous mist of particles—light atoms that have been dissociated into ions (the atom nucleus) and free-roaming electrons. In order to study pla [...]

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  • What a difference ten days make

    There was a time when progress in Tokamak Complex construction was easy to follow.Excavation in 2010; the creation of the ground support structure and seismic f [...]

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  • What's in the box?

    At ITER, even the opening of a box takes on a spectacular dimension. The operation requires a powerful crane, a full team of specialists and, as everything ITER [...]

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  • EU Commission has "positive appreciation" of ITER progress

    On 14 June, the European Commission issued a Communication presenting the revised schedule and budget estimates for European participation in ITER. Its object? [...]

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Of Interest

See archived articles

Pouring the protective circle

-R.A.

Since construction of the ground support structure for the Tokamak Complex began in 2010, huge volumes of concrete have been poured to form the edifice's seismic foundations, retaining walls, and basemat. Since November 2014 work has been underway on the Complex's basement-level walls and pillars.

In the early hours of Wednesday, 21 October, workers poured the first 200° segment of the bioshield, in an all-day operation that took some 15 hours to complete. (Click to view larger version...)
In the early hours of Wednesday, 21 October, workers poured the first 200° segment of the bioshield, in an all-day operation that took some 15 hours to complete.
But concrete pouring in a nuclear building is never routine, with each pour day marking the end of months of calculations, modellization and painstaking preparation.

For the ITER bioshield—the 3.2-metre-thick "ring fortress" surrounding the machine, whose role is to protect workers and the environment from the radiation generated by the fusion reaction—preparations have been particularly complex. Realizing a "perfect pour" for such a massive and strategic structure is so important that it was practised in a specially constructed full-scale mockup on the platform.

The density of the lattice of steel reinforcement makes the use of traditional concrete vibrators—used to encourage the concrete to reach every recess—impractical. As a consequence, an extra-fluid, self-compacting concrete was selected by the contractors and trialled in the on-site mockup.

At the end of the day 600 m³ of concrete were in place (centre circle), filling over half of the bioshield's circumference. (Click to view larger version...)
At the end of the day 600 m³ of concrete were in place (centre circle), filling over half of the bioshield's circumference.
The conclusive results allowed pouring operations to begin. In the early hours of Wednesday, 21 October, workers poured the first 200° segment of the bioshield, in an all-day operation that took some 15 hours to complete.

As dusk settled on the ITER site 600 m³ of concrete were in place, filling over half of the bioshield's circumference. The pouring of the remaining 160° segment is scheduled in January 2016.


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