Integrating Materials Engineering and Design for Fusion

Fusion demonstration (DEMO) concepts are facing challenges in safety and licensing in part due to uncertainties with in-vessel components validation, which relate directly to the materials and design criteria used for assessments. These challenges come from the designed operation under unprecedented operational conditions and reliance on the performance of complex in-vessel components over time spans of years. There are key differences in the structural integrity requirements and associated design criteria for DEMOs and future fusion reactors compared to existing nuclear systems. In this paper, we highlight the justification behind developing DEMO and fusion-specific design criteria by overviewing key shortfalls in existing design codes. Importantly, the key current approaches being undertaken within the EU are described including the development of elastoplastic design rules, evaluation of probabilistic assessments, and multiscale modeling of fusion irradiation effects on materials. Finally, thoughts on potential internationalization of new fusion-specific design codes are postulated.