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News & Media

Latest ITER Newsline

  • A wide angle on progress

    Whether captured from the top of a crane or from a drone hovering at an altitude of a few dozen metres, the ITER site isalways spectacular. After almost seven y [...]

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  • Inside the arena

    A visit to the deep "well" where the ITER Tokamak assembly will begin next year begins with a journey underground ... through a maze of giant pillars, [...]

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  • 10,000 tonnes of magnets to cool

    In ITER, huge volumesof liquid helium will be circulated throughout a complex, five-kilometre network of pipes, pumps and valves to keep the 10,000-tonne magnet [...]

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  • Heaviest convoy yet

    The triple convoy that reached ITER on Thursday 13 April wasthe heaviest ever organized since the beginning of "highly exceptional" deliveries in Janu [...]

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  • Gouging the giant's eye

    On the side of the ITER bioshield that faces the main ITER office building, four large openings have been preserved to allow passage for the neutral beam inject [...]

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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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