Subscribe options

Select your newsletters:


Please enter your email address:

@

News & Media

Latest ITER Newsline

  • Bookmark | The Future of Fusion Energy

    To write about fusion is to walk a fine line between the temptation of lyricism and the arid demands of scientific accuracy. Whereas the general media tends to [...]

    Read more

  • Image of the week |The shine of silver

    All ITER components are precious. But some look more precious than others. A vacuum vessel sector, a toroidal field coil, a cryopump, or a divertor cassette a [...]

    Read more

  • JT-60SA | "ITER satellite" to begin operating next year

    In a major assembly milestone for the JT-60SA tokamak, the 12-metre-tall central solenoid was successfully installed by overhead crane on 8 May. Japanese televi [...]

    Read more

  • ITER physics school | Ten years of lectures now available

    The lectures from ten ITER International Schools held since 2007 have been collected and are now available through a dedicated webpage on the ITER website. I [...]

    Read more

  • "Vigyan Samagam" | India showcases megascience

    From micro to macro—specifically, from the India-based Neutrino Observatory (INO) that will study neutrino mass ordering events lasting 10-43 seconds, to the La [...]

    Read more

Of Interest

See archived entries

The Seismic Pit basemat is now complete

An important milestone in the project's schedule: the pouring, on 22 December, of the twenty-first and last concrete slab of the Seismic Pit Basemat. (Click to view larger version...)
An important milestone in the project's schedule: the pouring, on 22 December, of the twenty-first and last concrete slab of the Seismic Pit Basemat.
There is no traditional ceremony attached to the completion of the foundations for a future home as there is one, called a Topping Out, to celebrate the laying of a roof.

Had there been one, ITER, F4E and their contractor GTM could have raised a glass to an important milestone in the project's schedule: the pouring, on 22 December, of the twenty-first and last concrete slab of the Seismic Pit basemat.

Work on this 1.5-metre-thick structure began before dawn on a warm August day six months ago. Since then, some 18,000 m³ of concrete have been poured over a dense array of steel rebar and stirrups—some 3,400 tonnes of metal in all.

In order to insure close-to-perfect homogeneity of the basemat, each slab had to be poured in one continuous operation lasting no more than an extended workday. Considering that the pumps could deliver an average of 100 m³ of concrete per hour, the 11,500 m² surface of basemat was broken down into 21 sections, each to be filled successively with 800 m³ of concrete.

In order to ensure ''close to perfect'' homogeneity, each slab had to be poured in one continuous operation lasting no more than an extended workday. (Click to view larger version...)
In order to ensure ''close to perfect'' homogeneity, each slab had to be poured in one continuous operation lasting no more than an extended workday.
This slab-by-slab technique also reduced the forces exerted by concrete "shrinkage" on the steel rebar.

The Seismic Pit basemat was designed to be extremely strong. It supports the anti-seismic pillars and bearings upon which the Tokamak Complex basemat will rest, and will ultimately bear the 360,000 tonnes of the Tokamak Complex.

A central area of the basemat—approximately 80 m²—was reinforced to bear the weight of the mammoth central column assembly tool that will operate during the machine assembly phase on the Tokamak Complex basemat. This extra strength was achieved through an increased density of stirrups.

Upon the now-finalized basemat, 159 seismic bearings (out of a total of 493) remain to be installed over the next two months. Twenty percent of the retaining walls have been completed and two parallel operations will commence this spring: a much smaller (5,500 m²) and relatively shallow excavation for the Assembly Building basemat and, prior to rebar reinforcement, horizontal wooden formwork and scaffolding for the next basemat that will be poured: the Tokamak Complex basemat.


return to the latest published articles