Tokamak Complex | A temporary roof for the bioshield
In August of last year, a circular platform—the "lid"—was installed deep inside of the ITER bioshield, effectively splitting the well-shaped work area into two. The 140-tonne steel structure was designed to protect the workers active in the basement levels while offering storage for the activities underway on the four above-ground levels.
It took three hours for the eight hydraulic jacks, positioned on platforms anchored to the bioshield wall, to pull the 140-tonne ''lid'' to the top of the massive concrete structure.
Now, as teams are preparing for the pouring of the concrete crown and buttressing walls at the lowest level of the Tokamak assembly arena, it was time to hoist the lid some 20 metres to the very top.
The same technique that was used in September 2015 to lift the 800-tonne roof of the Assembly Hall was implemented last Friday 9 March to raise the structure centimetre by centimetre, carefully maintaining its perfectly horizontal position.
The ''lid'' will remain in its present position until April 2020 when it will be removed to allow components into the assembly pit.
Eight hydraulic jacks—positioned on sturdy platforms distributed around the top of the bioshield—slowly pulled on cables that were attached to the lid in an operation lasting three hours.
The bioshield's new "roof" will remain in its present position until April 2020, when the lid will be removed in preparation for the first components to be delivered for installation by the overhead handling cranes.
Click here to read a related report on the European Domestic Agency website.