Nuclear Materials Group
Investigator: Cameron Macdonald
Title: Neutron irradiation damage modelling in superalloy steels for high temperature fusion applications
Supervisors: Dr. Mark Wenman & Prof. Robin Grimes
Industrial Partner: Duc Nguyen-Manh (Culham Centre for Fusion Energy)
Duration: 05/10/2020 - 05/10/2024 (Nuclear Energy Futures CDT)
Description: Nuclear fusion promises to be an invaluable energy source for the world going forward. However, there are several challenges to be overcome before it can be implemented, not the least of which is developing structural materials which can withstand not only the superstellar temperatures within the core during a fusion burn but also the intense neutron radiation produced by the fusion process. This project will employ computational modelling methods such as molecular dynamics (MD) and density functional theory (DFT) in order to develop an understanding of how the thermal and mechanical properties of an Fe-NiAl superalloy steel behave in such an extreme environment and whether or not it would be a viable structural material for fusion reactors.
Dr Daniel King
Name: Dr Daniel King
Supervisor: Dr Mark Wenman
Project Title: Atomic scale modelling of zirconium alloys
Project Description: This work is funded by the EPSRC - mechanistic understanding of irradiation damage in fuel assemblies (MIDAS) grant (EP/S01702X/1) - that was awarded to Manchester University in partnership with Oxford University and Imperial College London. Dr King is developing cutting edge models using a combination of quantum mechanics (QM) and molecular mechanics (MM) to simulate dislocation structures in Zr alloys, created by irradiation damage, and their interactions with alloying elements and impurity species. This is important to determine the shortcomings of current empirical model predictions and to formulate robust predictive models that can simulate the material evolution in light water reactor operation.
Investigator: Ryan Stroud
Supervisor: Mark Wenman
Funding: EPSRC and EDF Energy
Duration: 01/10/2020 to 01/10/2024
Title: Atom probe tomography and microscale mechanical testing of neutron irradiated PWR reactor pressure vessel steel
The extension of existing nuclear reactors can provide low carbon energy towards the ambitious national target of net-zero by 2050. This project aims to understand the effect of pre-strain on solute clustering in neutron irradiated reactor pressure vessel steel, where the pre-strain is used to replicate in service conditions. By using atom probe tomography and other supplementary techniques, measurements will be taken to determine the significance of the interaction between the neutron irradiation and the pre-strain.
Jana Smutna - Understanding the role of hydrogen-dislocation interactions...
Title: Understanding the role of hydrogen-dislocation interactions in the corrosion and hydrogen uptake of irradiated zirconium fuel cladding alloys
Supervisor: Mark Wenman
Co-supervisor: Andrew Horsfield, Adrian Sutton
Industrial partner: Carrie Miszkowska (Rolls Royce)
Abstract: Zirconium alloys are predominantly used in nuclear fuel cladding. The lifetime of these alloys is limited by the pickup of hydrogen from the surrounding water coolant, and subsequent formation of hydrides. In addition to the alloy composition, the defects, dislocations and dislocation loops caused by radiation damage affect the hydrogen pickup fraction and corrosion rate. The mechanistic understanding of the interactions between hydrogen and radiation damage (especially dislocation loops) requires computational modelling techniques able to simulate thousands of atoms. The empirical potentials available at the moment for the Zr-H system (most notably EAM) do not provide sufficient accuracy, and DFT calculations are too slow for use on the system sizes required. The aim of this project is a development of DFTB (Density Functional Tight Binding) potential for the Zr-H system, where electronic structure is included explicitly. This should provide a model much faster than DFT codes, but more accurate and more transferable than empirical potentials. This will allow for modelling of hydrogen in irradiated zirconium alloys.