Abstract
Proposed fusion and advanced (Generation IV) fission energy systems require high
performance materials capable of satisfactory operation up to neutron damage levels
approaching 200 atomic displacements per atom with large amounts of transmutant
hydrogen and helium isotopes. After a brief overview of fusion reactor concepts and
radiation effects phenomena in structural and functional (non-structural) materials, three
fundamental options for designing radiation resistance are outlined: Utilize matrix phases
with inherent radiation tolerance, select materials where vacancies are immobile at the
design operating temperatures, or construct high densities of point defect recombination
sinks. Environmental and safety considerations impose several additional restrictions on
potential materials systems, but reduced activation ferritic/martensitic steels (including
thermomechanically treated and oxide dispersion strengthened options) and silicon
carbide ceramic composites emerge as robust structural materials options. Materials
modeling (including computational thermodynamics) and advanced manufacturing
methods are poised to exert a major impact in the next ten years.