Applying Quantum Mechanics to Alloy Design for Nuclear Reactor Steels

3 Jun 2013, 09:30 → 5 Jun 2013, 17:00 Europe/London

CSEC Seminar Room 3808 (Erskine Williamson Building)

Derek Hepburn (The University of Edinburgh), Frank Bergner (HZDR), Graeme Ackland (University of Edinburgh), Janne Wallenius (KTH), Lorenzo Malerba (SCK.CEN), Maria-Jose Caturla (Universidad de Alicante), Pär Olsson (KTH), Sergei Dudarev (CCFE)

The n-FAME (nuclear Fe Alloys: Modelling and Experiments) workshop is organized in the framework of the Joint Programme on Nuclear Materials (JPNM) of the European Energy Research Alliance (EERA). The latter is an alliance of leading public research organizations with the goal to contribute to achieving the SET-Plan objectives of low-carbon energy-mix by 2050 and accelerate the development of energy technologies, by:
 

• Strengthening, expanding and optimizing EU energy research capabilities
• Pooling and integrating activities and use of resources
• Sharing national facilities & expertise, overcoming fragmentation
• Realizing pan-European research Joint Programmes
• Combining national and Community sources of funding
• Streamlining and coordinating national and European energy R&D programmes
• Developing links and sustained partnerships with industry

 

As part of the objective of low-carbon energy, a new generation of nuclear reactors, Gen IV, and associated fuel cycles, characterized by increased safety, security, efficiency, and sustainability can be developed by acting now. In this framework, the JPNM is one of the many joint programmes of the EERA aimed at ensuring the availability of qualified structural and clad materials to safely withstand severe conditions and requirements foreseen in Gen-IV nuclear systems, namely high temperature, high fuel burn-up (i.e. high neutron dose), corrosive environments. This requires solutions to general outstanding issues for nuclear materials that are key for safety and efficiency:
 

• Screening of existing materials, development of innovative materials
• Fabrication issues (processing, welding, joining, …)
• Experimental characterisation and qualification/validation
• Pre-normative research

The development of models that predict the behaviour of materials, making use of computer simulation tools capable of reproducing the changes they undergo in operation, is one especially important challenge in support of the safe, sustainable and economic exploitation of current and future nuclear power plants.

 

The n-FAME workshops are organised in this framework as a forum for scientific discussion between researchers working actively with experiments and models to understand in depth the behaviour of steels used for nuclear energy when subjected to irradiation. Irradiation (mainly neutrons) modifies the macroscopic mechanical properties of all materials, specifically steels, by producing changes at the nanoscale level. As a consequence, physical models must address the problem starting from what happens to the atoms that form the material, and spanning from there all scales, up to the plant component. This requires the combination of advanced modelling tools, largely based on computer simulation, and refined experiments, in a so-called multiscale modelling approach. Of all scales, the n-FAME workshops tend to focus on the behaviour at the small ones, which are addressed using fully physical approaches and require the use of extremely sensitive materials characterisation techniques, in order to make the link with experiments. As such, ab initio calculations and interatomic potentials, applied in molecular dynamics or kinetic Monte Carlo models are the main focus on the modelling side, together with experiments that make use of techniques such as transmission electron microscopy, positron annihilation, atom probe tomography, small-angle neutron scattering, and many others. However, the intention is also to create a link with higher scale models of use for the description of the mechanical behaviour of materials, starting from dislocation dynamics to crystal plasticity up to homogenization techniques for the analysis of large pieces of materials, as well as mechanical probing such as in tensile or impact tests.

Slides nFAME_FeCr_workshop_Edinburgh_June2013_presentations.zip