Steel fortress of science nearing completion
More than 25,000t of steel is being used to construct the £140M ISIS Tar- get Station 2 at the Rutherford Appleton Laboratory in Didcot, Oxfordshire.
Contained inside a steel-framed structure, which was erected by Severfield-Reeve, the scientific facility will house a proton beam which will be fired down a 140m-long tunnel to a tungsten target, which then creates neutrons to be used in ex- periments.
Approximately 20,500t of steel slab surrounds the beam’s tunnel and the target as a protection against radiation.
The structure which houses the target is called the monolith and it is 7.5m high with a diameter of 12m. The walls are a combination of 4m thick steel encased in 1m of concrete, while below ground there is a further 1,000t of steel to shield ground water from radiation.
Jonathan Carkeet, ISIS Installa- tion Manager, said because of the strength required in the structure, the frame has twice the amount of steel – 2,000t in total – required for a normal building.
“The ISIS building has a floor loading of 50t per square metre, this is unique and reflects the amount of steel used in the installation, particu- larly the monolith.”
Most of the internal steel has been engineered, supplied, fabricat- ed and installed by Corus Northern Engineering Services (CNES). For the tunnel and monolith it has installed slabs made from low manganese, low cobalt steel in order to mitigate radiation problems.
To protect the target alone CNES has installed a complex jigsaw of steel slabs which measure 12m wide by 7m high.
Dave Gallagher, CNES Project Manager, said: “This is an enormously complicated structure.
“The pieces will fit together, like a giant 3D jigsaw so that the beam is prevented from penetrating the steel slab walls.”