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News & Media

Latest ITER Newsline

  • Real-time collaboration delivers for fusion computing

    A key computing system for ITER is now being trialled at the European tokamak JET, following collaboration betweenteams at the UK's Culham Centre for Fusion Ene [...]

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  • The balance of power

    It comes as no surprise that the French railway operator SNCF is the largest consumer of electricity in the country—it takes a lot of megawatts to power 500 sup [...]

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  • "Dummy" winding takes shape

    As orange lights flash and machines softly hum, layer one of a 'dummy' pancake winding (the building block of a poloidal field coil) is taking shape on the wind [...]

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  • As big (and heavy) as a whale

    It was pouring when the two 35-metre-long quench tanks were delivered to the ITER site at 2:12 a.m. on Thursday 24 November. And it was still raining heavily on [...]

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  • A passage to India

    108 days, 10,200 kilometres, 16 countries, and only two flat tires. These are the remarkable statistics of a no-less-remarkable journey: a father and son who tr [...]

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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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