Oak Ridge National Laboratory (ORNL)

Reduced-activation ferritic-martensitic (RAFM) steels are critical structural materials for fusion-energy subsystems such as integrated first-wall and blanket technology. Current RAFM steels cannot operate above ~550° C (1020° F). Castable nanostructured alloys (CNAs), recently developed at laboratory scale, can potentially achieve significantly higher temperatures, offering a pathway to more efficient operation, however. ORNL will establish a new class of RAFM steels based on carbide-strengthened CNAs to demonstrate industry-scale CNA production viability. The innovations could better enable fusion energy system design and fabrication and benefit other industries that use similar materials for similarly demanding applications. High-strength CNAs with superior microstructure and optimal chemistry are expected to improve reliability and expand the performance envelope for fusion reactors while reducing costs. These CNAs can improve safety while reducing material volume requirements and improving environmental sustainability via reduced low-level waste volume. This approach can potentially reduce the required mass and costs of RAFM materials in future fusion power plants by a factor of two while allowing for improved levelized cost of energy via higher-temperature blanket operation.

Successful development of fusion energy science and technology could lead to a safe, carbon-free, abundant energy source for developed and emerging economies.