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News & Media

Latest ITER Newsline

  • Neighbours | In goes the antenna

    Just a short distance from the ITER site, the Institute for Magnetic Fusion Research (IRFM) is modifying the Tore Supra plasma facility which, once transformed, [...]

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  • Remote handling | Off-site test facility for design evaluation

    Through a technical collaboration established between the ITER Organization and the UK Atomic Energy Authority (UKAEA) in 2017, the UKAEA's centre for Remote Ap [...]

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  • Poloidal field coils | A tailor-made ring

    They work like tailors, carefully taking measurements and cutting immaculate fabric with large pairs of scissors. But they're not making a white three-piece sui [...]

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  • Fusion world | Record results at KSTAR

    Experiments in the Korean tokamakKSTAR in 2017 achieved record-length periods of ELM suppression by the application of three-dimensional magnetic fields with in [...]

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  • JT-60 SA| Cryostat ready for Europe-Japan tokamak

    The cryostat vessel body of the JT-60SA tokamakhas been successfully manufactured and pre-assembled at a factory in Spain, and will soon be transferred to the J [...]

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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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