The Nuclear Futures Institute will be hosting Materials for Nuclear Techologies: Challenges, Problems and Solutions
Date: 3rd July, 2023 9am – 5pm
Please note this conference will be in person, but is a hybrid. Online attendance is welcome.
Teams Link:
Bangor is situated in North Wales between the sea and Snowdonia National Park.
There are a number of exciting nuclear new build projects in the region and the Nuclear Futures Institute has been formed to support them.
There are good transport links to Manchester, Birmingham and London via direct train.
Croeso i Gymru! – Welcome to Wales!
How much will the conference cost to attend?
This conference is free to join.
- 9.20 – 9.30 Welcome (Dr. Alberto Fraile)
- 9.30 – 10.10 Dr. Dominik Legut: “Thermal expansion & thermal conductivity of actinides – from first principles”
- 10.10 – 10:30 Coffee break
- 10.30 – 11.10 Dr. Eduardo Oliva: “Multiscale-multiphysics models for fusion plasmas”
- 11.10 – 11.45 Dr. Abdullah Mamun: “Testing and modelling of nuclear structural materials”
- 11.45 – 13.30 Lunch break
13.30 – 14.00 Dr. Tamsin Whitfield: “Quantitative estimates of corrosion and oxidation hazards in fusion environments” - 14.00 – 14.20 Coffee break
- 14:20 – 15:00 Dr. Tessa Davey: “First-principles calculations of high entropy transition metal carbides”
- 15:00 – 15:15 Dr. Mehdi Ghardi: “He Incorporation in Nuclear Waste Glass: Insight from DFT”
- 15.15 – 15.35 Coffee break
- 15:35 – 16:00 Dr. Alberto Fraile “Hypervelocity impacts on plasma facing materials”
- 16:00 – 16:15 Jorge Suárez-Recio “Enhancing effects of nanostructured-W on the behaviour of Light Impurity Atoms”
- 16:15 – 17:00. FLASH presentations (10 m). NFI Students
- 17:00 – End
The 1st “Materials for Nuclear Technologies; Challenges, Problems and Solutions” workshop will take place the 3d of July 2023.
This workshop covers experimental studies and computer simulations using High Performance Computing (HPC) in the field of fission & fusion research. These include, but are not limited to, the following areas:
- DFT and MD simulations of materials for extreme environments
- Multi-physics and Multi-scale analyses and modelling
- Breeder blankets and plasma facing materials
- Edge and plasma-material interactions
- High Entropy Alloys
- Nuclear fuels (fission)
- Hydrogen retention
The language of the workshop will be in English, and it will be open to all.
Early Career participants will receive expert reviewer feedback with an opportunity for recognition of outstanding presentations.
Speakers
- Prof. Dominik Legut (IT4Innovations – Technical University of Ostrava, Czech Republic)
- Dr. Eduardo Oliva (Universidad Politecnica Madrid, Madrid, Spain)
- Dr. Abdullah Mamun (NFI, Bangor University, UK)
- Dr. Tamsin Whitfield (UKAEA, UK)
- Dr. Theresa Davey (University of Tohoku, Japan)
- Dr. Jorge Suárez-Recio (University of Oviedo/Universidad Politécnica de Madrid, Spain)
- Dr. Mehdi Ghardi (NFI, Bangor University, UK)
- Dr. Alberto Fraile (NFI, Bangor University, UK)
- + NFI students
For more information, please contact: a.fraile@bangor.ac.uk
We are looking forward to welcoming you to the workshop!
Book of abstracts
Dominik Legut.
Thermal expansion and thermal conductivity of actinides from first principles
There are number of 1:1 properties that could be directly compared between quantum mechanical calculations (using density functional theory) based on lattice dynamics and the experimental measurements. One of the examples is lattice heat capacity, thermal expansion, and thermal conductivity. The latter two are the key parameters of the potential nuclear fuels, the former one can shed much light on the magnetic systems of actinide hydrides. Actinides and especially their carbides as prospective nuclear fuel materials for the generation IV reactors were investigated using the density functional theory. We demonstrate that their electronic, magnetic, elastic, and thermal properties can be at present well described if the spin-orbit interaction and partial delocalization 5f electrons is properly included in the computational approaches. One can well reproduce not only basic electronic structure but also elastic constants, phonon dispersions, and their density of states, provided by XPS, UPS, BIS, and inelastic neutron scattering data [1-4]. Often, the localization of the 5f electrons could be captured using a moderate value of the on-site Coulomb interaction parameter. The case studies include a realistic description of the ground-state properties of elemental metals as Th, U and their monocarbides ThC and UC. In this study, published in Ref. 2 and 4, the realistic description of the electronic structure and lattice dynamics (phonons) explains why there is much higher thermal expansion in pure actinides (as Th) comparing with respective actinide monocarbides. The modeling also gives an insight up to which temperature the heat transport depends on lattice vibrations and where the electron transport starts to dominate. We analyzed the force constants of defected systems in order to reveal the effect of the oxygen impurity and vacancy at carbon site on the thermal expansion, summarized in Ref. 4. Additionally investigated thermodynamic properties, such as for instance heat capacity, were compared to the experimental data in the large temperature scan showing very excellent agreement up to 2000K and explained some additional features of phonon DOS not presented before. In the second part, we present the calculations of the stability, mechanical, and magnetic properties of the uranium hydrides including 3 different cubic compounds, α- and β-UH3 and UH2, all undergoing ferromagnetic ordering. Our first-principles calculations revealed a complex (non-collinear) magnetic order in β-UH3. Unlike the other uranium hydrides, α-UH3 and UH2, β-UH3 with two different U sites exhibits a site-dependent size and direction of U magnetic moments. While the U moments at the 2a sites are locked in the body diagonal direction, the moments at the 6c sites are inclined by approx. 15 degrees. The difference stems from 5f orbital moments. Comparison of results for all 3 species reveals that the U U spacing is not the primary parameter to control the magnetism in uranium hydrides. Further insight is provided by evaluating individual exchange interactions between different neighbours, yielding the transition temperatures in a reasonable agreement with the experiment [5-7] as well as the lattice dynamics of all uranium-based hydrides[8].
References:
[1] U. D. Wdowik, P. Piekarz, D. Legut, and G. Jaglo, Phys. Rev. B 94, 054303 (2016).
[2] L. Kyvala and D. Legut, Phys. Rev. B 101, 075117 (2020).
[3] Y. Yun, D. Legut and P. M. Oppeneer, J. Nucl. Mat. 426, 109 (2012).
[4] U. D. Wdowik, V. Buturlim, L. Havela, and D. Legut, J. Nucl. Mat. 545, 152547 (2021).
[5] L Havela, M Paukov, M Dopita, L Horak, D Drozdenko, M Divis, I Turek, D Legut, L Kyvala, T Gouder, A Seibert, and F Huber. Inorg. Chem. 57, 14727 (2018).
[6] J. Prchal, V. Buturlim, J. Valenta, M. Dopita, M. Divis, I. Turek, L. Kyvala, D. Legut, L. Havela, J. Magn. Mag. Mater. 497, 65993 (2020).
[7] L. Havela, M. Paukov, M. Dopita, L. Horak, M. Cieslar, D. Drozdenko , P. Minarik, I. Turek, M. Divis, D. Legut, L. Kyvala, T. Gouder, F. Huber, A. Seibert, E. Tereshina-Chitrova, J. Elect. Spectr. and Rel. Phenom. 239, 146904 (2020).
[8] L. Kývala, L. Havela, A. P. Kądzielawa, and D. Legut, J. Nucl. Mater. 567, 153817 (2022).
Eduardo Oliva
Multiscale-multiphysics models for fusion plasmas
The study and simulation of plasmas, whether for fusion applications, astrophysics or resulting from the interaction of intense lasers and matter, is a complex challenge. The computational model must tackle several physical processes (plasma hydrodynamics, energy transport, electron collisions, wave and beam propagation, etc) with characteristic timescales that span several orders of magnitude (from femtosecond to nanosecond scales or even larger times). In this talk we will briefly explain a radiative hydrodynamics model of plasmas and its applications in Inertial Confinement Fusion, Laboratory Astrophysics and Plasma-Based Lasers.
Abdullah Mamun
Testing and modelling of nuclear structural materials
Structural materials in nuclear plants operate under harsh service conditions of high temperature, pressure, radiation damage and environmental degradation. Furthermore, Gen IV fission reactors and fusion reactors require novel materials which can sustain harsher service conditions. Wide range of materials testing are conducted to estimate the lifetime of these materials and to better understand their degradation behaviour. However, it is not always possible to conduct full length scale materials testing due to associated cost, time, and engineering challenges. Targeted testing at the appropriate length scales supported by high fidelity materials model is therefore required to predict the degradation behaviour of these materials. In this talk, the presenter will talk about research challenges and opportunities for testing and modelling of nuclear structural materials. In particular, he will focus on meso-length scale testing and modelling and how the understanding from these is used in improving the life assessment methods of nuclear power plants.
Tamsin E Whitfield
Quantitative estimates of corrosion and oxidation hazards in fusion environments
Fusion power is expected to offer a safe, low carbon, clean source of energy. For this potential to become a reality, fusion reactors will need to be designed to overcome the materials and engineering challenges in a safe and sustainable manner. The materials in a fusion reactor face extreme operating conditions: high fluxes of irradiation, high temperatures, high magnetic fields and corrosive media. D-T fusion will produce huge quantities of highly energetic neutrons. These neutrons will irradiate the surrounding material, causing it to become active and form transmutation products, depending on the spectra, flux and precise composition of the materials. Corrosion and oxidation processes, associated with the inimical conditions expected in a real engineering environment and enhanced by radiation damage, risk compromising the integrity of components and lead to production of mobile radioactive material. It is essential that the hazards posed by corrosion products or mobilized oxides are understood and minimized. To achieve this goal, the work here assesses the mobile radiological hazards generated from critical reactor systems, such as corrosion by liquid Li in coolant or breeding loops, or from oxidation of exposed materials.
Estimates are made relative to the potential STEP reactor and modelling has been conducted using the FISPACT-II inventory code to assess the activity and gamma doses that could arise in mobile corrosion products. The results demonstrate that the radiological hazard posed has a strong dependence on both the structural materials, including the presence of key impurities and the environmental conditions. These insights will help to inform safety protocols and maintenance procedures.
Theresa Davey
First-principles calculations of high entropy transition metal carbides
High-entropy or multi-principal component ultra-high temperature ceramics have recently generated significant interest due to their potential improved or tuneable properties such as melting point, hardness, ductility, and oxidation resistance. This work uses first-principles calculations to explore the multi-principal component composition space of the rocksalt structured MC1-x (where the cation M is an equiatomic or non-equiatomic mixture of metallic elements including Ti, Zr, Hf, Nb, and Ta, and the anion C is carbon). Multiatomic mixing (binary, ternary, quaternary, and quinary) on the metallic element lattice of MC1-x is considered at different carbon stoichiometries to begin to map out the thermodynamic properties, with the aim of finding compositions that may be applied in future nuclear technologies.
Jorge Suárez-Recio
Enhancing effects of nanostructured-W on the behaviour of Light Impurity Atoms
University of Oviedo/Universidad Politécnica de Madrid, Spain,
The accumulation of light species is the greatest threat faced by coarse-grained bulk tungsten (CGW) if it is foreseen to operate as a plasma facing material (PFM) in a nuclear fusion reactor. When hydrogen (H) and helium (He) are simultaneously present at high thermal loads, they can induce cracks in CGW, making it unsuitable for use in these reactors. Therefore, it is crucial to develop alternative materials that either prevent or significantly reduce the accumulation of these light species. One proposed alternative is to utilise nanostructured materials, where large densities of grain boundaries (GBs) can serve as preferential channels for the outward diffusion of light species, preventing their accumulation in the bulk material. Additionally, under specific conditions such as fluence and temperature, nanostructured materials may exhibit a self-healing behaviour, which involves the recombination of interstitials and vacancies to restore the pre-irradiation state of the material. The main goal of this presentation is thereby to examine the behaviour of these light species inside nanostructured W (NW), as an alternative to the traditionally proposed CGW, due to its potentially superior radiation resistance.
E. M. Ghardi
He incorporation in nuclear waste glass: Insight from Density functional theory
Nuclear Futures Institute, Bangor University, Gwynedd, LL57 2DG, UK
During storage, helium may build up in nuclear waste due to the decay of radionuclides they contain. The manner in which this is incorporated by the glass network has important implications for the long term performance of the waste form. In particular, the nucleation of He bubbles are the primary cause of swelling in vitrified waste and can also be initiation points for cracking. In this work, Density functional theory calculations are reported to show the effect of He incorporation on the structure of International simple glass. Four sets of calculations were conducted in which the number of He atoms was increased gradually in the glass network. The volume change and incorporation energy associated with these defects were calculated and reported. The size of the interstitial sites and their formation energy are measured and compared to available data in the literature. The electronic density of states and glass structure were used to determine the bonding nature of He atoms.
Alberto Fraile
Hypervelocity impacts on plasma facing materials
Nuclear Futures Institute, Bangor University, Gwynedd, LL57 2DG, UK
Controlling plasma-wall interactions is critical to achieve high performance in present day tokamaks, and this is likely to continue to be the case in the approach to practical fusion reactors. Outstanding technical issues are still to be overcome, for instance erosion/redeposition from plasma sputtering and disruptions, including dust and flake generation. Tungsten (W) is the main candidate-plasma facing components (PFC) for a fusion reactor and will be exclusively used in the ITER divertor [1]. The presence of high velocity impacts has been reported and suggested in several studies, with velocities being around 500 m/s to a few km/s [2, 3].
In this work, the atomistic mechanisms of damage initiation during high velocity (v up to 12 km/s) impact of W projectiles on W has been investigated using parallel molecular-dynamics simulations involving very large samples (up to 200 million atoms). Various aspects of the impact at high velocities where the projectile and part of the target materials undergo massive plastic deformation, breakup, melting or vaporization are analyzed [4]. Different stages of the penetration process are identified. Whether the damage occurring in the subsurface of the target is described by collision cascades or as effect of shock waves will be discussed.
References:
[1] G. Federici et al 2001 Nucl. Fusion 41 1967
[2] Castaldo C. et al 2007 Nucl. Fusion 47 L5–9
[3] S. Ratynskaia et al 2008 Nucl. Fusion 48 015006
[4] A. Fraile et al 2022 Nucl. Fusion 62 026034
Event Amenities:
Where to Find Us
Organising Committee
Dr. Alberto Fraile
Email:
a.fraile@bangor.ac.uk