Scope

Under the guidance of the Nuclear Science Committee (NSC) and under the mandate of the Working Party on Materials Science Issues in Nuclear Fuels and Structural Materials (WPFM), the Expert Group on Structural Materials (EGSM) has been established in 2023 and its work covers materials science aspects of structural materials. The EGSM is tasked to conduct joint and comparative studies to:

• improve the understanding and modelling of the behaviour of structural materials under extreme conditions (such as high temperature, high dose rate and corrosive chemical environment) and for long service lifetime; and
• support the development, selection and characterisation of innovative structural materials with enhanced performances compared to currently deployed materials.

The EGSM aims to develop/evaluate experimental methods and data assessment and preservation, together with the advancement of multi-scale modelling and simulation, with a focus on their mutual support to progress validated predictive methodologies for assessment and/or design purposes.

The structural materials that are considered under the scope of the EGSM may comprise, but are not limited to:

• metallic structural materials currently deployed in the nuclear fleet;
• structural materials envisaged for future fission or fusion reactors;
• advanced materials in terms of chemical composition and microstructure, developed to have unique properties (the development of such materials may be achieved through integrated computational materials engineering);
• materials or material structures elaborated by novel pathways (i.e. fabrication routes such as additive manufacturing and/or joining processes) applied to existing or new structural materials; and
• advanced materials in terms of design and architecture (e.g. functionally graded materials), including coated systems. Some examples of systems could be thin films or coatings deposited by processes such as physical vapour deposition (PVD), high-power impulse magnetron sputtering (HiPIMS), laser processes, and cold spray.

Objectives

The EGSM develops and maintains international co-operation between member countries on a range of scientific and engineering subjects, such as:

• multi-scale modelling and simulation of structural materials for nuclear systems to investigate their response to extreme operating conditions. Support of the development and implementation of advanced computational techniques for scale bridging and model integration spanning from physics-based computation to data driven modelling;
• verification and validation of simulations and model predictions through uncertainty analysis, evaluation of approximations, benchmarking of material behaviour simulation tools, and comparison with analytical solutions, as well as experimental data;
• enhancement of the exploitation of systematic nuclear materials experimental characterisation through the establishment of protocols of execution, data collection and data analysis;
• engagement with experimental campaigns, such as those performed within the NEA Framework for Irradiation Experiments (FIDES-II), to optimise the link between the irradiation experimental data generated and the needs of the modelling and simulation community;
• acceleration of nuclear materials discovery by integrating combinatorial fabrication processes, high throughput characterisation techniques, materials modelling and data analysis including machine learning and artificial intelligence;
• assessment of the current status and future needs for qualification of structural materials;
• identification of technology readiness level of materials selected for deployment;
• identification of existing databases and common activities aimed at developing best practices for data formatting and preservation;
• support for the creation of relevant task forces to address specific technical issues; and
• organisation of workshops related to structural materials for nuclear energy.