Safety design for ITER and fusion power reactors

The present paper outlines key design features of relevance for the safety of international thermonuclear experimental reactor (ITER) and fusion devic es of reactor scale. These features support the intrinsic safety characteri stics of fusion. The most important safety function is the confinement of r adioactivity. The first barrier is based on the vacuum Vessel (VV) and its extensions. A pressure suppression system limits the maximum pressure of th e VV in the event of loss of coolant. The second barrier is the Cryostat an d its extensions. Outward leakage from the second confinement can be captur ed in surrounding rooms where necessary. Open penetrations of the VV will b e protected by at least two separate barriers such as windows or valves. Nu clear decay heat will be removed passively by the VV cooling system. Other safety systems have been identified which play an important role for both I TER and a fusion power reactor. (C) 2000 Elsevier Science B.V. All rights r eserved.