Nuclear energy, derived from splitting the atom, is an important component of current UK electricity generation because it is low carbon and it is not affected by the weather. In order for the UK to reach its commitment for net-zero carbon dioxide emissions by 2050, nuclear power offers a way to offset the UK's previous reliance on electricity production by burning of coal and gas, whilst underpinning periods when renewable sources of electricity (off-shore wind and solar) are interrupted. The fuel from which nuclear energy is derived currently is made from uranium. Fuel for all but one of the UK's existing nuclear power stations is manufactured at Westinghouse Springfields Fuels Ltd., near Preston. However, in the next 10 years, all of these power stations are scheduled to close. In order to offset this loss in low-carbon electricity, new reactor designs are being considered because the requirements of nuclear power have changed since the current generation of operating reactors were built in the 1960s-1980s: modular designs are favoured now in place of large reactors built at site, that will be easier and cheaper to build, and which provide more flexibility over the power that they provide. In the short-term, the UK is considering small modular reactors 'SMRs', that are smaller versions of a long-established design, and advanced modular reactors 'AMRs', which will operate at higher efficiencies at higher temperatures. The UK is well-placed to compete for the manufacture of the fuel for these new reactors because Springfields has more flexibility concerning the range in uranium composition open to it than many of its competitors, but it will need to be competitive on cost. A principal opportunity to reduce the cost of nuclear fuel manufacture is to reduce the likelihood that fuel produced in the factory is not compliant with customer requirements. When this happens, the fuel has to be recycled through the process, unnecessary energy is consumed in recycling it, time is lost and waste is generated. In this research we shall study the uranium manufacturing process in the UK with the aim to investigate whether it can be made responsive to change in order to increase its efficiency and cost effectiveness. We have selected two examples where unexpected change can undermine compliance: uranium enrichment and pellet quality. Uranium enrichment concerns the proportion of 235U present in the fuel; 235U is the isotope that is responsible for most of the energy that is generated. It is a key component of the fuel specification and, because enrichment is not constant across a reactor core, the enrichment of each pellet matters. Enrichment is influenced by changes in the feedstock (uranium hexafluoride) and by faults that might evolve in the manufacturing machinery. We will explore whether the most advanced ways of detecting gamma rays available today can be employed to yield a measurement of enrichment at various points in the process. We will explore whether these measurements can be used to constitute data to be used to adjust the process to avert a change in enrichment, so that the effect on the enrichment of a given pellet can be minimised and hence the need for a whole batch to be recycled is removed. Pellet quality is premised on several factors: one is whether it is cracked or not. Pellets are checked by a variety of means including manually by experts at the end of the manufacturing process. At this stage microscopic cracks can be present occurring after the pellets are baked implying that they could be weakened beyond what is suitable for use in a reactor or that their thermal conductivity may not be uniform etc. We shall explore the use of hyperspectral and high-resolution imaging for this purpose, with the aim of deriving data for use in rendering the process responsive, so that, for example, an evolving flaw in a machine that is causing cracking can be removed before a whole batch is affected.

This project is a collaborative effort between universities, a national laboratory, and industry partners across the US and UK. The project aims to assess the benefits and implications of using Accident-Tolerant (or Advanced Technology) Fuels, or ATFs, in a variety of Small Modular Reactor (SMR) designs. ATFs have the potential to significantly improve safety and economic performance of reactors. The increased safety margin that they offer can be translated into either more straightforward and short licencing process, and relaxation of requirements on safety equipment, or substantial power uprate, or both - all ultimately leading to cost savings. Multiple ATF concepts have been proposed in recent years, offering a range of potential performance improvements. Their technology readiness level, however, also varies widely - from conceptual ideas to nearly commercially available products already being marketed to the industry. SMR designs are equally diverse. Even though they may share many features of Light Water Reactor technology, they differ substantially in size, coolant circulation driving force (natural or forced convection), arrangement of primary coolant loop components (integral or loop), approach to reactivity control etc. Therefore, the benefits ATFs can offer if used in these SMRs will differ. The main objective of this project is to quantify these benefits for a subset of promising SMR-ATF combinations. UK Government have committed significant financial support to the development of SMR technology proposed by Rolls-Royce as part of its overall net-zero decarbonisation strategy. Furthermore, substantial expertise in nuclear fuel manufacturing and other fuel cycle services are considered strategic assets for the UK. The UK research team contributing to this project in partnership with Rolls-Royce and Westinghouse-Springfields will focus on the analysis of ATF options applied to the UK-based Rolls-Royce SMR. We will assess and compare the ATF options with respect to their in-core neutronic and thermal-hydraulic behaviour under normal operation, transients, and accident conditions, as well as compare their effects on the back end of the fuel cycle. This project will help to guide the future Rolls-Royce SMR and ATF development effort both nationally and internationally.

Ceramic-matrix composites (CMCs) have the qualities of being strong, tough, lightweight and stable at high temperatures; they are considered as a serious material candidate to replace superalloys for many applications, such as in the core of gas-turbine engines with the aim of increasing operating temperatures, reduce the need for air cooling, and thus enable superior fuel efficiency to reduce harmful emissions. Over the last ~20 years, CMCs have been used in the augmentor sections of large military engines. Followed major investment from numerous companies and R&D organisations, mainly in the US, EU and Japan, new carbide technologies have been developed to aid the transition of CMCs to commercial gas-turbine engines, not to mention future applications in hypersonics. Despite the fast-growing CMC market, there is not yet an established CMC materials supply chain in the UK. Internationally, the design and processing of the CMCs also are still a challenge due to their complex microstructure (fibre, matrix and porosity). Therefore, there is an important opportunity for the UK to participate and ultimately lead, or at least share in, the global effort in CMC development. These are definitely the prime structural materials of the immediate future. As a structural material, the mechanical performance of CMCs at elevated temperatures has been a critical factor for consideration in materials validation and adoption. To achieve an optimised design for a particular application, a sound understanding of the evolution of damage and failure mechanisms in CMCs, and how they relate to the intrinsic processing-microstructure-property relationships under extreme conditions, is undoubtedly the key. This sets the imperative and the horizon of the proposed work programme. In this project, a unique and step-changing, real-time, 3D imaging method will be used to capture the deformation and fracture of CMCs at ultrahigh temperatures (~1000C to 1800C) representative of potential service conditions. By combining with techniques such as diffraction, micro-scale mechanical and multi-scale modelling methodologies, the underlying mechanics controlling the damage evolution in these materials at unprecedented temperatures can be understood and related to processing for improved material design. The materials studied in this project will be processed or designed in the UK with the aim of enhancing UK-based industrial expertise in CMCs, but also access to international materials that are available. The primary materials of interest are two CMC types that are of high demand in aerospace, automotive and energy applications: continuous fibre reinforced SiC-SiC and alumina-alumina CMCs with the former being most important as a game-changer for advanced, lightweight, super-efficient propulsion units. However, compared to conventional superalloys, these materials are new; what has been lacking from a scientific perspective has been their characterisation in terms of two key aspects: (i) the local properties of the individual constituents, fibre/matrix interfacial strength and residual stresses in the fibre/matrix as a function of process parameters, and (ii) the real time imaging of their damage accumulation leading to crack initiation, in relation to their 3D microstructures, at realistic service conditions, i.e., ultrahigh temperatures, to simulate the working environment of these CMCs. This project will target at both material types with the support from materials processing partners (e.g., Birmingham Univ.) and end-users (e.g., Rolls-Royce plc, Cross-Manufacturing and Westinghouse). Last but not the least, this project will work closely with modelling experts (e.g., Oxford Univ., Delft Univ. of Technology, and Institute Eduardo Torroja of Construction Sciences) by providing experimental results over multiple length-scales to develop a framework of a microstructure-based mechanistic model for the evaluation of the damage tolerance of CMCs.

The primary motivation of the ENEN+ project is to substantially contribute to the revival of the interest of young generations in the careers in nuclear sector. This is to be achieved by pursuing the following main objectives: • Attract new talents to careers in nuclear. • Develop the attracted talents beyond academic curricula. • Increase the retention of attracted talents in nuclear careers. • Involve the nuclear stakeholders within EU and beyond. • Sustain the revived interest for nuclear careers. The ENEN+ consortium will focus on the learners and careers in the following nuclear disciplines: • Nuclear reactor engineering and safety, • Waste management and geological disposal, • Radiation protection and • Medical applications. Integration of further nuclear disciplines (e.g., nuclear chemistry, decommissioning, fusion engineering…) and sustainability of the ENEN+ accomplishments beyond the project life of is foreseen within the existing ENEN Association and its members and partnering of ENEN association with ongoing and proposed projects. The attraction, retention and development of the new nuclear talent can only be sustained beyond the project life through strong partnership of all nuclear stakeholders. Involvement of various nuclear stakeholders including academia, industry, international organisations (ENS, FORATOM, IAEA, NUGENIA) and Technical support organisations in the ENEN+ consortium is therefore of primary importance for the success and sustainability of the proposed activities also beyond the life of ENEN+. A mobility fund of more than 1.000.000EUR for European students researchers and learners is established in the project.

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.