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News & Media

Latest ITER Newsline

  • 23rd ITER Council | Pace and performance on track

    Working as an integrated team, the ITER Organization and seven Domestic Agencies are continuing to meet the project's demanding schedule to First Plasma in 2025 [...]

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  • Fusion Doctors | ITER hosts the future

    For three days last week, the ITER building was brimming with energy, inspiration and enthusiasm. One hundred and thirty-five young fusion aficionados took over [...]

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  • Fusion world | What's next for the stellarator?

    Earlier this year, the Wendelstein 7-X stellarator fusion project reported record achievements from its most recent experimental campaign. Newsline spoke with t [...]

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  • Metrology and the ITER machine | Perfectly planned points

    Inside of the Tokamak Complex, a network of 2,000 small 'fiducial target nests' will provide the reference datum for the dimensional control and alignment of ma [...]

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  • Breaking news | First component installed next week

    In the third week of November, the ITER Organization will be installing the first component of the machine in the basement of the Tokamak Building. The 10-met [...]

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Of Interest

See archived entries

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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