The applicability of metallic powder based production methods such as HIP or additive layer manufacturing (ALM) are restricted by an inability to define the process parameters with sufficient accuracy to provide the quality required for industrial production. Similarly the implementation of the joining technologies needed for component fabrication is limited by a lack of understanding of both the gas-liquid phase interactions and the effect of the solid state phase transformations that occur in the relevant alloy systems. Traditional solutions, based on practical trials and physical assessment, are both costly and time consuming and for the long service lives encountered in the energy and propulsion industries are not feasible while empirically based phenomenological modelling approaches cannot provide the required fidelity. To address these industrial needs a multiscale modelling approach is proposed which combines experimental validation with the application of materials modelling, at the short length scales required to capture the relevant physics, together with the development of techniques to incorporate the predicted behaviour in a consistent manner at higher length scales for application to component level simulations. The multiscale model integration will consist of a number of component parts commencing with new multiphysics based computational fluid dynamics calculations of the short length scale fluid flow and liquid/gas interactions in welding and additive manufacturing. These will provide data on porosity formation which will be combined with cellular automata predictions of grain structure. Novel methods will be developed to combine this fine scale data in a finite element based crystal plasticity framework to define representative volume elements for modelling the macroscopic behaviour in component stress analysis. The component level simulation work will build upon the EPSRC Manufacturing Fellowship of Prof Smith on a whole-life approach to high integrity welding technologies by utilising the knowledge gained on the effect of the microstructural changes imposed by welding. These have a profound influence on a weld's resistance to in-service degradation and upon its sensitivity to the presence of cracking. The microstructural characterisation data available on 316L stainess steel from the Fellowship work will also provide a basis for the model validation. A key part of the developments in this project will be the extension, from typical single value deterministic models, to statistically based descriptions of material properties and process variability. This is a challenging activity but it is essential that modelling tools become capable of predicting the scatter that is seen in real materials. A successful solution will not only generate novel science but will clearly lead to the development of probabilistic lifing methods with risk based outputs for decision making which have clear benefits for industry. This approach provides the prospect of a better understanding of in-service performance of components and welds in both the existing UK nuclear reactor fleet and in any industrial sector where long term structural performance is important. Similar developments in the US have led to a new field known as Integrated Computational Materials Engineering (ICME). This is a multi-disciplinary approach to product design that offers huge economic potential and the successful implementation of ICME will revolutionise the way components are being designed and manufactured. This proposal will address the modelling and design challenge using an ICME based approach on industrial demonstrators of 316L stainless steel HIPped and TIG welded parts. The demonstrators, supplied by the partners from the aerospace and energy industries, will show the benefits that can be achieved in different market sectors. The proposed programme will be the first attempt in the UK to use ICME tools on large industrial scale demonstrators.

Since the 2004 Energy Act, nuclear fission has rapidly grown, and continues to grow, in significance in the UK's Energy and Net Zero Strategies. Government's Nuclear Industrial Strategy states clearly that the nuclear sector is integral to increasing productivity, driving growth across the country and meeting our Net Zero target. Nuclear is, and will continue to be, a vital part of our energy mix, providing low carbon power now and into the future, and the safe and efficient decommissioning of our nuclear legacy is an area of world-leading expertise. In order for this to be possible we need to underpin the skill base. The primary aim of SATURN is to provide high quality research training in the science and engineering underpinning nuclear fission technology, focussed on three broad themes: Current Nuclear Programmes. Decommissioning and cleanup; spent fuel and nuclear materials management; geological disposal; current operating reactors (AGRs, Sizewell B, propulsion); new build reactors (Hinkley C, Sizewell C, possibly Wylfa Newydd; Future Nuclear Energy: Advanced nuclear reactors (light water reactors, including PWR3, gas cooled reactors, liquid metal cooled reactors, other concepts); advanced fuel cycles; fusion (remote handling, tritium); Nuclear Energy in a Wider Context: Economics and finance; societal issues; management; regulation; technology transfer (e.g. robotics, sensors); manufacturing; interaction of infrastructure and environment; systems engineering. It has become clear that skills are very likely to limit the UK's nuclear capacity, with over half of the civil nuclear workforce and 70% of Subject Matter Experts due to retire by 2025. High level R&D skills are therefore on the critical path for all the UK's nuclear ambitions and, because of the 10-15 year lead time needed to address this shortage, urgent action is needed now. SATURN is a collaborative CDT involving the Universities of Manchester, Lancaster, Leeds, Liverpool, Sheffield and Strathclyde, which aims to develop the next generation of nuclear research leaders and deliver underpinning (Technology Readiness Level (TRL) 1-3), long term science and engineering to meet the national priorities identified in Government's Nuclear Industrial Vision. SATURN also provides a pathway for mid technology level research (TRL 4-6) to be carried out by allowing projects to be based partly or entirely in an industrial setting. The consortium partners have been instrumental in a series of highly successful CDTs, Nuclear FiRST (2009-2013), NGN (Next Generation Nuclear, 2013-2018) and GREEN (Growing skills for Reliable, Economic Energy from Nuclear, 2018-2023). In collaboration with an expanded group of key nuclear industry partners SATURN will create a step-change in PhD training to deliver a high-quality PhD programme tailored to student needs; high profile, high impact outreach; and adventurous doctoral research which underpins real industry challenges.

In UK Energy strategy, nuclear fission is growing rapidly in significance. Government's recent Nuclear Industrial Strategy states clearly that the UK should retain the option to deploy a range of nuclear fission technologies in the decades ahead, and that it should underpin the skill base to do so. The primary aim of Next Generation Nuclear is to provide high quality research training in the science and engineering underpinning nuclear fission technology, focused particularly on developing a multi-scale (from molecular to macroscopic), multi-disciplined understanding of key processes and systems. Nuclear fission research underpins strategic UK priorities, including the safe management of the historic nuclear legacy, securing future low carbon energy resources, and supporting UK defence and security policies. It has become clear that skills are very likely to limit the UK's nuclear capacity, with over half of the civil nuclear workforce and 70% of Subject Matter Experts due to retire by 2025. High level R&D skills are therefore on the critical path for all the UK's nuclear ambitions and, because of the 10-15 year lead time needed to address this shortage, urgent action is needed now. Next Generation Nuclear is a collaborative CDT involving the Universities of Lancaster, Leeds, Liverpool, Manchester and Sheffield, which aims to develop the next generation of nuclear research leaders and deliver underpinning (Technology Readiness Level (TRL) 1-3), long term science and engineering to meet the national priorities identified in Government's Nuclear Industrial Vision. Its scope complements the Nuclear IDC (TRL 4-6), with both Centres aiming to work together and exploit potential synergies. In collaboration with key nuclear industry partners, Next Generation Nuclear will build on the very successful Nuclear First programme to deliver a high quality training programme tailored to student needs; high profile, high impact outreach; and adventurous doctoral research which underpins real industry challenges.

The early years of the 21st century have seen energy policy return to the political agenda both in the UK and internationally. Growing concerns about environmental, economic and social issues associated with energy production (climate change, the depletion of hydrocarbon resources, declining public trust in science and technology and increasing energy prices) have led to a reappraisal of the wider energy scene and of individual energy technologies. The return of various nuclear power options to the list of candidate technologies being actively considered is but one element of this change. One potential advantage of nuclear power is that it may help us to reduce CO2 emissions and therefore mitigate some of the climate change concerns, However, it is far from clear how sustainable the nuclear option is overall, compared to other generating options. Issues such as health and safety, investment risks, security, public trust and perception are also important for understanding of the full sustainability implications of nuclear generation. Furthermore, the nuclear power industry is faced with many uncertainties, including financial, technical and regulatory. Decommissioning and high-level waste disposal are prime examples of areas where these uncertainties exist. The public attitude toward nuclear power in general ranges from ambivalent to negative; there is, however, a growing public awareness and concern about the impacts of global warming which may start to influence the change in public opinion. Therefore, any decisions about the future of nuclear power will need to take into account these and other relevant issues, taking an integrated, balanced and impartial approach to evaluating the relative environmental, economic, social and political sustainability of nuclear power.This project proposes to develop such an integrated approach and apply it to sustainability appraisals of nuclear power relative to other energy options. The main objectives of the project are:1. development of a rigorous, robust and transparent multicriteria decision-support framework for sustainability assessment of energy options;2. sustainability assessments of the nuclear option within an integrated energy system;3. engagement with and communication of the results of research to relevant stakeholders.The outputs of the project will help to inform the debate on the future of nuclear power in the UK.

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.