The OECD Nuclear Energy Agency (NEA) and Ciemat co-organised the Seventh International Workshop on Structural Materials for Innovative Nuclear Systems (SMINS-7), with the support of industry, Newcleo, Naarea, French Alternative Energies and Atomic Energy Commission (CEA), as well as the International Atomic Energy Agency (IAEA), the Joint Programme on Nuclear Materials of the European Energy Research Alliance (EERA-JPNM), CONNECT-NM Co-funded European Partnership on Nuclear Materials and Centro Superior de Investigaciones Científicas (CSIC) in Spain.

Materials research is a field of growing relevance for advanced nuclear systems, such as generation IV reactors, small modular reactors, advanced modular reactors and micro reactors, transmutation systems and fusion devices. For these different systems, structural materials must be selected or developed to address the specific challenges of their foreseen operational environments. This requires both cross-cutting research programmes and advanced experimental/simulation facilities to characterise and evaluate the performance of materials.

The purpose of this workshop was to stimulate an exchange of information on current materials research programmes for different innovative nuclear systems, with a view to identifying and developing potential synergies.

The workshop covered fundamental studies, modelling and experiments connected with the discovery, design, development, manufacturing and joining, qualification and behaviour in operation of innovative structural materials, including cladding materials, for advanced nuclear systems such as thermal, fast and sub-critical reactors, as well as fusion systems.

Fundamental studies, materials design, materials processing and joining, evolution of material properties:

• Identification of mechanisms driving the response of materials under the conditions expected in innovative nuclear systems. These mechanisms may be described at the atomic or at higher scale, following multiscale approaches. Problems of scale bridging are of special interest along with advanced simulation techniques and data driven modelling/learning.
• Ion and neutron irradiation, as well as corrosion and high temperature exposure experiments, and subsequent characterisation of materials microstructure, degradation modes, time-dependent properties, mechanical properties, thermal properties, radiation tolerance, environmental resistance.
• Novel and advanced methods (including numerical approaches) for the production and optimisation of materials and components: for instance, high-performance coating, additive manufacturing, laser sintering, and innovative joining techniques for similar and dissimilar materials.

Metallic alloys, ceramic and ceramic composites, advanced/novel materials for nuclear applications:

• In- and out-of-core applications and relevant materials characterisation, both microstructural and mechanical; data availability and gaps; experimental and modelling needs for specific components; advanced manufacturing techniques; qualification path in connection with their use in advanced systems; link between R&D, standardisation and experimental protocols; discussions on design code development and implementation plans.
• Advanced/novel materials can be: steels and other metallic alloys with superior properties for use in innovative nuclear systems; complex concentrated alloys; functionally gradient materials; nano-grained materials; grain boundary engineered materials; nano-precipitation-strengthened materials and micro-laminates; prospective materials.

Please note that fuel-cladding interactions and zirconium alloys for fuel cladding were not covered in this edition of the workshop. Other novel materials for accident tolerant fuel cladding in LWR systems were within the scope of the meeting.

Plenary lectures and technical sessions were organised according to the topics listed above.

A workshop discussion session on Materials challenges for advanced and small modular reactors: From the need for innovation to licensing was organised. Participants to this panel included:

• Cécile Petesch, Senior expert codification and standardisation, RCC-MRx Sub-Committee Chairwoman, CEA Saclay, France
• Jeremy Rame, Materials Manager, Naarea, France
• Francisco Garcia Ferre, Area Manager - Materials & Chemistry, Newcleo, Italy
• Greg Vetterick, Senior Manager - Materials Development and Qualification – Natrium, Terrapower, United States
• Nadia Maurice, Materials' Strategy Lead, Thorizon, France

A poster session covering all technical subjects was held.

Please see 'Downloads' to the left hand side of the page for the final programme.

When uploading your abstract we also ask that you agree to grant rights for the OECD/NEA to publish the abstract in a summary report on SMINS-7.

Scientific and Organising Committee

Fanny Balbaud (CEA, Chair of the Expert Group on Structural Materials)

Céline Cabet (CEA, Co-chair of the Expert Group on Structural Materials)

Lorenzo Malerba (CIEMAT, Co-chair of the Expert Group on Structural Materials)

and Expert Group on Structural Materials (EGSM) members

Local Organising Committee

Mareike Kiwitt (CIEMAT)

Maria Luisa Fernández Vanoni (EERA)

Lorenzo Malerba (CIEMAT)

Marta Serrano (CIEMAT)

All correspondence with regard to the meeting should be addressed to the workshop Secretariat: