A thriving nuclear industry is crucial to the UKs energy security and to clean up the legacy of over 50 years of nuclear power. The research performed in the ICO (Imperial Cambridge Open universities, pronounced ECO!) CDT will enable current reactors to be used longer, enable new reactors to be built and operated more safely, support the clean up and decommissioning of the UKs contaminated nuclear sites and place the UK at the forefront of international programmes for future reactors for civil and marine power. It will also provide a highly skilled and trained cohort of nuclear PhDs with a global vision and international outlook entirely appropriate for the UK nuclear industry, academia, regulators and government. Key areas where ICO CDT will significantly improve our current understanding include in civil, structural, mechanical and chemical engineering as well as earth science and materials science. Specifically, in metallurgy we will perform world-leading research into steels in reactor and storage applications, Zr alloy cladding, welding, creep/fatigue and surface treatments for enhanced integrity. Other materials topics to be covered include developing improved and more durable ceramic, glass, glass composite and cement wasteforms; reactor life extension and structural integrity; and corrosion of metallic waste containers during storage and disposal. In engineering we will provide step change understanding of modelling of a number of areas including in: Reactor Physics (radionuclide transport, neutron transport in reactor systems, simulating radiation-fluid-solid interactions in reactors and finite element methods for transient kinetics of severe accident scenarios); Reactor Thermal Hydraulics (assessment of critical heat flux for reactors, buoyancy-driven natural circulation coolant flows for nuclear safety, simulated dynamics and heat transfer characteristics of severe accidents in nuclear reactors); and Materials and Structural Integrity (residual stress prediction, fuel performance, combined crystal plasticity and discrete dislocation modelling of failure in Zr cladding alloys, sensor materials and wasteforms). In earth science and engineering we will extend modelling of severe accidents to enable events arising from accidents such as those at Chernobyl and Fukushima to be predicted; and examine near field (waste and in repository materials) and far field (geology of rocks surrounding the repository) issues including radionuclide sorption and transport of relevance to the UKs geological repository (especially in geomechanics and rock fracture). In addition, we will make key advances in development of next generation fission reactors such as examining flow behaviour of molten salts, new fuel materials, ultra high temperature non-oxide and MAX phase ceramics for fuels and cladding, thoria fuels and materials issues including disposal of wastes from Small Modular Reactors. We will examine areas of symbiosis in research for next generation fission and fusion reactors. A key aspect of the ICO CDT will be the global outlook given to the students and the training in dealing with the media, a key issue in a sensitive topic such as nuclear where a sensible and science-based debate is crucial.

The EPSRC Centre for Doctoral Training (CDT) in Nuclear Energy Futures aims to train a new generation of international leaders, at PhD level, in nuclear energy technology. It is made up of Imperial College London (lead), Bristol University, Cambridge University, Open University and Bangor University. These institutions are some of the UK's leading institutions for research and teaching in nuclear power. The CDTs key focus is around nuclear fission i.e. that is the method of producing energy by splitting the atom, which currently accounts for 11% of the world's electricity and 20% of the UK's electricity, whilst producing very low levels of carbon emissions (at levels the same as renewable energy, such as wind). The CDT whilst focused on fission energy technologies will also have PhD projects related to fusion nuclear energy and projects needed or related to nuclear energy such as seismic studies, robotics, data analytics, environmental studies, policy and law. The CDT's major focus is related to the New Nuclear Build activities at Hinkley Point, Somerset and the Anglesey site in north Wales, where EDF Energy and Horizon, respectively, are building new fission power plants that will produce around 3.2 and 2.7 GWe of nuclear power (about 13% of the UK current electricity demand). The CDT will provide the skills needed for research related to these plants and potential future industry leaders, for nuclear decommissioning of current plants (due to come off-line in the next decade) and to lead the UK in new and innovative technologies for nuclear waste disposal and new reactor technologies such as small modular reactors (SMRs). The need for new talented PhD level people is very high as many of the UK's current technical experts were recruited in the 1970s and 80s and many are near retirement and skills sector studies have shown many more are needed for the new build projects. The CDT will champion teaching innovation and will produce a series of bespoke courses that can be delivered via on-line media by the very best experts in the field from across the CDT covering areas such as the nuclear fuel cycle; waste and decommissioning; small modular reactors; policy, economics and regulation; thermal hydraulics and reactor physics as well as leading on responsible research and innovation in the sector. The CDT is supported by a wide range of nuclear companies and stakeholders. These include those involved in the new build process in the UK such as EDF Energy, Hitachi-GE, Horizon and Rolls-Royce, the latter of which are developing a UK advanced modular reactor design. International nuclear stakeholders from countries such as the USA, UAE, Australia and France will support the student development and the CDT programme. The students in the CDT will cover a very broad training in all aspects of nuclear power and importantly for this sector will engage in both media training activities and public outreach to make nuclear power more open to the public, government and scientists and engineers outside of the discipline.

"Weld modelling" is a powerful tool in understanding the structural performance of welded structures. Conventional continuum-mechanics-based predictions of the stresses generated by welding have achieved considerable success in understanding the in-service performance and degradation mechanisms of welds in the UK's nuclear reactor fleet. However their practical use is currently limited to materials that do not undergo so-called solid state phase transformation (SSPT) during welding, since the presence of SSPT makes it necessary to predict changes in the material microstructure in order to predict the stresses. In addition, the microstructural changes imposed by welding have a profound influence on a weld's resistance to creep, thermal ageing, oxidation, stress corrosion and other in-service degradation mechanisms, and upon its sensitivity to the presence of cracking. The Fellowship research programme aims to extend conventional weld modelling into a multi-disciplinary tool that can predict both continuum parameters such as stress & distortion, and microstructural parameters such as grain size and shape, the occurrence of secondary phases, and precipitate distributions, and hence both directly predict long term structural performance and be used for "virtual prototyping " of weld processes and procedures for novel welding processes. Success offers the prospect of better understanding of in-service performance of welds in both the existing UK nuclear reactor fleet, and in any industrial sector where the long term structural performance of welds is important. It will also aid the choice of weldment materials, joint design and welding process for structural welds in new-build nuclear power plants, and in advanced Generation IV designs that may be built on a longer time frame.

Temperature records are critical for understanding past and future climate. However, reconstructing past temperature dynamics is incredibly difficult. Of the currently available terrestrial archives of past temperature, these are often spatially limited, suffer from ambiguity around calibration, or require large sample sizes. These issues have prevented the development of a high resolution, high density network of terrestrial temperature records. This is now often considered the single most significant gap in the palaeoclimate archive. Here, we seek to provide a breakthrough in the field of temperature reconstruction by developing a new palaeothermometer. For this, we use speleothems (cave stalagmites). Speleothems grow in layers, which can be dated like the rings in a tree. The chemistry in each layer offers an unprecedented resolution of environmental information, constrained by an absolute age model over 500,000 years. At the Lancaster Environment centre, we have recently developed a technique which allows phosphate to be extracted from the stalagmite layers. This is a critically important advance in the research field, as phosphate-oxygen isotopes are known to be controlled by temperature dynamics. Our first measurements of the phosphate-oxygen isotope composition in cave drip waters and modern cave calcite provide clear evidence that the cave temperature signal can be captured and stored within the speleothem record. As the internal temperature of shallow cave systems are known to reflect the external average air temperature (plus or minus localised effects), this provides an exciting opportunity through which a truly independent terrestrial temperature record may be built. This research aims to build and test a modern-day calibration between cave temperature and speleothem phosphate-oxygen isotopes. This will enable a platform from which precisely dated, well preserved, independent temperature records can be confidently obtained from the global archive of speleothems at a spatial and temporal scale hitherto unprecedented.

Nuclear fission offers a reliable low carbon source of energy, but, the nuclear waste generated as a result of nuclear reactor operation needs proper treatment and confinement in a durable material to ensure that the biosphere is not contaminated with radioactive elements in the near and long-term future. Geological disposal (GD) - which involves confining the host material inside a safety barrier (usually a metal canister) and then permanent deposition of such wastepackages in a pre-selected geological site - is now an internationally accepted methodology including the UK. Nonetheless, after thousands of years, the outer safety barrier will get corroded and the host material will be exposed to the surrounding geological conditions. When in contact with water/moisture, the radioelements may be released from the host matrix into the surrounding geology from where they can be transported into the biosphere. Understanding long-term changes in the wastepackages -starting from the day of their fabrication - is a key element in addressing the eventual release of the radioisotopes. Besides corrosion, one of the reasons why the wastepackages will change under geological disposal conditions is the fact that radioactive decay of the confined radioisotopes will damage the host matrix at atomic level called as self-irradiation damage. This damage accumulation over hundreds of thousands to millions of years can potentially alter the chemical and mechanical durability of the wastepackages. These irradiation induced modifications can have a significant effect on the eventual release of the radioisotopes. Thus, addressing radiation stability of the wastepackages is an essential part of demonstrating long-term safety of the geological disposal. This research proposal will utilize MIAMI irradiation facility at the University of Huddersfield to study the effects of self-irradiation damage and He accumulation in various types of waste packages ranging from glasses to glass-ceramic composites. Using a transmission electron microscope with in-situ dual-ion-beam irradiation, the irradiation induced modifications will be monitored in real time. The dual-ion-beam irradiation represents the closest analogue to self-irradiation damage in nuclear wasteforms yielding reliable and realistic results. These ion irradiation effects will be compared with actinide doping studies to be undertaken in collaboration with nuclear industry partners, thereby, allowing establishing the irradiation conditions necessary to simulate the self-irradiation damage. The research will be undertaken on leached (gels) and non-leached materials to understand the irradiation induced evolution of the wastepackages and address the effect of radiation damage on the leaching and vice versa. By collaborating with external partners such as ANSTO Australia, CEA Marcoule France, University of Cambridge and, National Nuclear Lab UK, this proposal will bring together the experience and expertise of internationally recognised researchers to develop a better understanding of the wasteform evolution due to self-irradiation damage under geological disposal conditions including leaching.