The ITER-FEAT building layout—design considerations for the reduction in scale1

The original ITER tokamak (1998) power was 1.5 GW. Later, ITER received a mandate to reduce the project to ∼50% of the 1998 cost. The main structure on the site is the tokamak building, which is the most clearly defined and estimated, and is used as the focal point for the comparison with the new ITER-FEAT design. The ITER-FEAT power was reduced to ∼500 MW, which is considered to be the smallest size able to deliver the specified plasma performance. To provide adequate services to the smaller ITER-FEAT, and with lessened access to the machine itself, some interesting building design approaches were required: especially the consideration of more complex steel plate and beam reinforced concrete; and the use of heavy concrete for more compact shielding. Further, the overall site layout was condensed with an aim to provide the ‘minimum yet adequate’ support. In addition, some buildings are designed to serve dual purposes to provide additional cost savings. The current compact design now occupies an area of only 25 ha. All these factors were combined to provide buildings and a layout that are compact yet functional, as well as cost effective.