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News & Media

Latest ITER Newsline

  • 31st ITER Council | Addressing challenges

    The project's governing body, the ITER Council, convened for the 31st time in its history on 16 and 17 November to evaluate the progress of construction, m [...]

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  • Machine assembly | Key components to be repaired

    When building a machine as large and as complex as ITER, difficulties and setbacks do not come as surprises—they are an integral part of manufacturing, assembli [...]

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  • Space management | Optimizing every square metre

    Building management is a constant challenge at ITER. The American statesman Ben Franklin is credited with saying that a successful organization requires 'a plac [...]

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  • Radio Frequency Building | Installing the first power supply sets

    When the plasma in the ITER vacuum vessel is fed sufficient power, the velocity that the particles acquire causes them to collide, fuse and generate considerabl [...]

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  • Fusion history | H-mode, the discovery that made ITER possible

    Forty years ago, the scientists in the ASDEX tokamak control room at the Max Planck Institute for Plasma Physics (IPP) in Germany sat up straight. Somethin [...]

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Of Interest

See archived entries

Pouring the protective circle

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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