Contractor Ferrovial is part of a consortium chosen to design and build a nuclear fusion research centre in Cadarache, southern France.
Contractors Vinci and Razel-Bec are also part of the consortium working on the €230M (£187M) project. It will commence in January 2013 and is due to be completed in 2018.
The consortium will design and build 11 buildings and storage areas on the 42ha site, including the Tokamak complex which will hold the reactor.
The project will be 30 times bigger than the Joint European Torus, which is the largest of its kind in the world at the moment. The Fusion for Energy Project (F4E) is the main civil engineering contract of international nuclear fusion research and engineering project ITER.