Metallic Materials as First Wall Materials for Future Fusion Reactors

The loading of the first wall by neutrons, plasma particles and wave radiation is reviewed. For a first wall concept proposed by the NET-team, the cyclic thermomechanical loading conditions of austenitic (316L) and martensitic (MANET, 1.4914) steels are compared. Due to its more favorable thermo-physical properties, the secondary stresses are lower in the martensitic steel so that its fatigue resistance should be superior. The effect of high neutron fluences has, however, yet to be determined. The ductile--brittle transition temperature of martensitic steels may limit the operational temperatures to a lower limit of approx 250 deg C. Finally, consideration is given to the concept of low-activation materials. Graphs. 24 ref.--AA