The International Thermonuclear Experimental Reactor (ITER) design has evolved to a level of maturity that has enabled the building designers to define the major dimensions and characteristics of the cluster of buildings that contain the tokamak and adjacent support equipment. Three-dimensional building models developed in a CATIATM database provide the framework for the equipment layout.

This paper describes the preliminary layout of all major pieces of equipment, large bore pipes, ducts, busbars and other services. It is anticipated that some features of the layout will change as equipment design is advanced and future decisions are made, but these changes are not expected to alter the basic building design and any necessary changes are facilitated by the 3-D CATIA™ models.

Accommodating the initial assembly and major maintenance (disassembly) scenarios of the tokamak significantly influenced the design solutions selected. Major maintenance considerations also provide conceptual feasibility for decommissioning activities. Equipment access and removal pathways for all equipment that must be replaceable have been provided in the buildings for both non-radioactive and radioactive or contaminated components.

Extensive shielding studies have led to inherent and engineered protective measures for workers and equipment. Building ventilation systems are designed such that contaminated atmospheres may be isolated, recirculated, filtered and detritiated, with ultimate release through a tall exhaust stack.

Because the ITER site may not be known before 1998, the building and equipment designs have been configured so they can be adapted to potentially more demanding site-specific conditions such as higher seismicity, winds, aircraft impact and extreme low temperatures without requiring major redesign. A solid starting point for the detailed design work that must be completed in the next two years has been established. Continued collaboration between the ITER Joint Central Team and the Four Party Home Teams will provide the fully integrated engineering design for future decisions on the construction of ITER.