A review of irradiation damage in additively manufactured stainless steels for next-generation nuclear systems

Advanced nuclear reactor designs, including Generation IV and other emerging reactor concepts, promise enhanced safety, improved efficiency, and reduced nuclear waste compared to current reactor technologies. The development of these systems requires structural materials that can withstand extreme thermal, corrosive, and radiation environments. Additive manufacturing offers unique advantages for such applications, including the fabrication of complex geometries and functionally graded materials through microstructural control. However, the distinctive microstructures produced by additive manufacturing processes may lead to irradiation responses that differ significantly from those of conventional wrought materials. As a result, a thorough understanding of the irradiation behavior of additively manufactured materials is essential before their deployment in nuclear environments. Within nuclear reactors, components experience a wide range of irradiation damage levels, dose rates, and operating temperatures depending on their location and function. Consequently, additively manufactured materials must be evaluated across a broad spectrum of irradiation conditions. Despite growing interest in this area, irradiation data for additively manufactured materials remain scarce and highly fragmented across multiple variables. Although ion irradiation has been widely used to accelerate testing, challenges persist in translating ion irradiation results to reactor service conditions. In this article, existing irradiation response data for additively manufactured austenitic stainless steels are compiled and examined as a representative case. The influence of additively manufactured microstructural features on irradiation behavior is analyzed and discussed using data on three key degradation mechanisms: irradiation hardening, irradiation-assisted stress corrosion cracking, and void swelling. Finally, current knowledge gaps are identified, and recommendations for future research are provided to advance the understanding of irradiation effects in additively manufactured materials and support their qualification for Generation IV and other advanced nuclear systems.