As pressurised water reactor (PWR) plant operating lives are extended, there is an increased need for predictive modeling tools to describe materials degradation in order to ensure safe, reliable operation as well as plan for component replacements. Some models presently exist, but are limited in their applicability, and are not able to predict degradation of all alloys used in PWR systems. Specifically, it is important to be able to predict any degradation in Ni-based alloys used in nuclear power plants, thus, this program represents an integrated approach to address thermal and irradiation-induced transformations mechanisms of to important Ni-base materials used in PWRs, Alloys 690 and 625. Alloy 690 is widely used in existing PWR plants due to its superior SCC resistance compared to Alloy 600. Alloy 625 is currently used in more limited applications but offers the benefits of both high strength (in the aged condition) and corrosion/SCC resistance, and is being considered for use in future reactor systems. Research has shown that both alloys can undergo phase changes due to thermal or irradiation exposure. In the precipitation-hardened condition, Alloy 625 "softens" during neutron irradiation as the strengthening precipitates decompose and metastable precipitates form. However, the nature and rates of these transformations as a function of exposure conditions are not well understood. Similarly, the effects of these thermal and irradiation-induced microstructural changes on mechanical properties require evaluation. The proposed program combines thermal and irradiation experiments, mechanical testing, and advanced microstructural characterization using state-of-the art analytical techniques, the results of which will be combined with atomistic, micro-and macro-scale modelling that can be used to predict materials performance. Such a capability will also greatly aid in research to develop optimised existing alloys or new alloys for future nuclear power plants.

The EPSRC Centre for Doctoral training in Materials for Demanding Environments will primarily address the Structural Integrity and Materials Behaviour priority area, and span into the Materials Technologies area. The CDT will target the oil & gas, aerospace and nuclear power industrial sectors, as well as the Defence sector. Research and training will be undertaken on metals and alloys, composites, coatings and ceramics and the focus will be on understanding the mechanisms of material degradation. The Centre will instil graduates with an understanding of structural integrity assessment methodologies with the aim to designing and manufacturing materials that last longer within a framework that enables safe lifetimes to be accurately predicted. A CDT is needed as the capability of current materials to withstand demanding environments is major constraint across a number of sectors; failure by corrosion alone is estimated to cost over $2.2 Trillion globally each year. Further understanding of the mechanisms of failure, and how these mechanisms interact with one another, would enable the safe and timely withdrawal of materials later in their life. New advanced materials and coatings, with quantifiable lifetimes, are integral to the UK's energy and manufacturing companies. Such technology will be vital in harvesting oil & gas safely from increasingly inaccessible reservoirs under high pressures, temperatures and sour environments. Novel, more cost-effective aero-engine materials are required to withstand extremely oxidative high temperature environments, leading to aircraft with increased fuel efficiency, reduced emissions, and longer maintenance cycles. New lightweight alloys, ceramics and composites could deliver fuel efficiency in the aerospace and automotive sectors, and benefit personal and vehicle armour for blast protection. In the nuclear sector, new light water power plants demand tolerance to neutron radiation for extended durations, and Generation IV plants will need to withstand high operating temperatures. It is vital to think beyond traditional disciplines, linking aspects of metallurgy, materials chemistry, non-destructive evaluation, computational modelling and environmental sciences. Research must involve not just the design and manufacturing of new materials, but the understanding of how to test and observe materials behaviour in demanding service environments, and to develop sophisticated models for materials performance and component lifetime assessment. The training must also include aspects of validation, risk assessment and sustainability.

In order to meet UK Government targets to reduce CO2 emissions by 80% by 2050, rapid growth in electricity generation from intermittent renewable energy sources, in particular, wind, is required, together with increasing constraints on the operation and environmental performance of conventional coal and gas-fired plant. Unprecedented demands for operational plant flexibility (i.e. varing power output to reflect demand) will pose new challenges to component integrity in ageing conventional plant, which it is widely recognised will play a crucial role in maintaining security of supply. In parallel, demands on fuel flexibility to reduce emissions, i.e. firing gas turbine plant with low-carbon syngas or biogas and firing/cofiring steam plant with biomass, will create new challenges in plant engineering, monitoring and control, and materials performance. Improved plant efficiency is a key requirement to cut emissions and to make decarbonisation economically feasible. The continuous development of novel, stronger high temperature materials may also enable component replacement, rather than complete new build plant, to maintain the essential reserve of conventional generation capacity. Finally, the decarbonisation transition involves new and complex economic and environmental considerations, and it is therefore important that these issues of sustainability are addressed for the development of future conventional power plant. The research programme will consider the key issues of Plant Efficiency, Plant Flexibility, Fuel Flexibility and Sustainability and how these four intersecting themes impact upon plant operation and design, combustion processes in general and the structural integrity of conventional and advanced materials utilised in conventional power plants. Outcomes from the proposed Research Programme include: - Improved understanding of the complex relationship between plant efficiency, fuel flexibility, plant flexibility, component life and economic viability - Novel approaches for monitoring and control of future conventional power plants - Improved fuel combustion and monitoring processes to allow use of a wider range of fuels - Improved understanding of structural materials systems for use in components with higher operating temperatures and more aggressive environments - Improved coating systems to protect structural materials used in power plant components - New models for optimisation of operating conditions and strategies for future conventional power plants The consortium comprises six leading UK Universities with strengths and a proven track record in the area of conventional power generation - led by Loughborough University, working together with Cardiff and Cranfield Universities, Imperial College London and the Universities of Nottingham and Warwick. The Industrial Partners collaborating in this project include several major UK power generation operators, Original Equipment Manufacturers (OEMs), Government laboratories and Small and Medium Sized (SMEs) companies in the supply chain for the power generation sector. The Energy Generation and Supply Knowledge Transfer Network will be a formal delivery partner of the consortium. The proposal has been developed following extensive engagement with the industrial partners and as a result they have made very significant commitment, both financial and as integrated partners in the research programme.