Low‐Activation Compositionally Complex Alloys for Advanced Nuclear Applications—A Review

Compositionally complex alloys (CCAs) are advanced metallic materials composed of at least three primary elements. Low‐activation CCAs (LACCAs), which primarily consist of low‐activation elements, offer distinct advantages such as rapid compliance with operational standards and safe recyclability, enhancing their commercial viability. LACCAs have demonstrated significant potential in extreme high‐temperature irradiation environments, making them promising candidates for structural materials in future nuclear reactors. This review provides a comprehensive overview of research progress in LACCAs for nuclear applications, addressing their manufacturing techniques, microstructural characteristics, mechanical properties, oxidation resistance, and irradiation response. Future directions include optimizing manufacturing, enhancing tensile properties, leveraging simulations and AI for alloy design, and developing heat treatments to improve irradiation resistance.