We have organised our research into five integrating themes that span departments across the University of Cambridge.
The safe disposal of waste is a critical issue for the current generation of nuclear power stations and will continue to be one for future designs. Deep geological disposal is the most practical and accepted solution, but research and development is required to give greater certainty about long-term containment and to reduce costs. The Departments of Engineering, Earth Sciences and Materials collaborate in this area. In Engineering, our geotechnical engineers are working on these issues bringing their expertise in soil mechanics, tunnelling, earthquakes, soil liquefaction and soil remediation, together with structural design, to find practical approaches to identifying the best sites for disposal, designing the best disposal method, monitoring its performance and planning for intervention in the event of failure (Professor Robert Mair, Professor Malcolm Bolton, Dr Gopal Madabhushi and Dr Abir Al Tabbaa).
The Department of Earth Sciences has strengths in understanding the subsurface geophysics of repository site, as well as near field geochemistry in high level containment areas. It combines quantum mechanical and classical atomistic modelling with fundamental experimental methods to elucidate the behaviour of solids and fluids in repository settings. For example, the Department has used experiment, simulation and ab-initio computational studies to quantify the number of atoms displaced by the alpha-decay of pollutants e.g. plutonium, uranium and thorium in minerals and provided a detailed understanding of the related damage and the dissolution of the minerals. This work is critical for safe storage of nuclear waste. Research includes: mineralogical models for long term behaviour of high level nuclear waste, ceramic waste forms, geophysical stability of repository site, clay mineral barriers and radionuclides in the environment.
Related Projects in the Department of Materials Science & Metallurgy include:
AK (Tony) Cheetham, FRS (Goldsmiths' Professor of Materials Science)
Reactor Waste: Materials chemistry of fission products, particularly oxides of technetium. Collaborations with Los Alamos National Laboratory and University of Nevada, USA.
DJ (Derek) Fray, FRS, FREng (Professor of Materials Science)
Reactor Waste: Electrochemical reprocessing of oxide fuel rods.
Process Heat Applications of Fusion Energy
Together with Professor Bartek Glowacki, Professor Nuttall has led discussion of a possible early commercialisation of nuclear fusion energy for thermochemical hydrogen production. The concept is known as 'Fusion Island' (video). Fusion Island envisages the use of large magnets (superconducting and normal) cooled with liquid hydrogen. As such it leads Glowacki and Nuttall to propose an early launch of a liquid hydrogen economy based on the use of hydrogen as a coolant as well as an energy carrier. The application of liquid hydrogen for magnetism applications is termed 'hydrogen cryomagnetics'. Fusion Island has benefited from assistance from a wide range of universities and laboratories internationally including the Cambridge-MIT Institute Partnership Programme (2007).
Fusion Island was a runner up for the East of England Energy Group's Innovation Awards 2006 and was shortlisted for The Engineer magazine's Technology and Innovation Awards 2008.
(Copyright image used with permission)
System Dynamics of Energy-Related Resources
Professor Nuttall has supervised research students considering resource depletion and supply via the application of System Dynamics. Studies to date have included European natural gas supply and future helium production and price. (DOI links:doi:10.1016/j.techfore.2008.06.002 and doi:10.1016/j.resourpol.2009.10.002 respectively). The helium study was generously sponsored by UKAEA Fusion and BOC Ltd. The work motivated the 'Future for Helium' conference held in Cambridge in March 2009 and led to a book published by Routledge in 2012.
There is active research into the potential of proposed future systems for commercial electricity and process heat production. Engineering expertise is coupled with expertise in energy and nuclear policy through a joint appointment between Engineering and the Judge Business School. This has resulted in the recent publication of a well-received book on the subject entitled "Nuclear renaissance: technologies and policies for the future of nuclear power" (Professor Bill Nuttall). Future systems of interest include Pebble Bed Modular Reactors and, in particular, Accelerator Driven Subcritical Reactors (ADSRs). ADSRs have some apparently attractive features compared to conventional fission reactor technology: greater intrinsic safety because the core is subcritical; and the potential to transmute into short-lived or stable isotopes long-lived fission product and actinide waste arising from other nuclear reactors. Importantly they can also use thorium fuel, which offers further benefits: thorium is more abundant than uranium; it is potentially more proliferation resistant; and it creates less heavy actinide waste (Dr Geoff Parks and Professor Bill Nuttall).
Previously Professor Nuttall was UK Director of the Cambridge-MIT Institute Energy Security Initiative, which operated from 2005-2008. More recently Professor Nuttall has become involved in issues relating to the global expansion of nuclear energy and concerns to minimise risks associated with nuclear weapons proliferation.
Nuclear Energy Technology and Policy
Professor Nuttall is an Associate of the Electricity Policy Research Group, one of the world's leading energy policy research teams supported by the UK Research Councils, the European Union and the Energy Industry. Professor Nuttall's EPRG research has been published in the EPRG Working Papers series and has included collaborative work in the following areas: nuclear energy economics, nuclear infrastructure finance, nuclear energy safety and environmental regulation, nuclear waste management, and nuclear energy technology flexibility and reliability.
The Department of Earth Sciences conducts research into the fundamental science of material performance in nuclear applications. Key amongst these is radiation damage, which is quantified through experiment and high energy molecular dynamics simulations. New methods (nuclear magnetic resonance) to measure radiation damage have been developed at Cambridge for U/Th and 'nuclearised' and implemented at key nuclear licensed research institutes worldwide (ITU Euratom research centre and Pacific Northwest National laboratory) for transuranics [Farnan]. The NERC e-Science centre based in ESC has developed a UK code for radiation damage (DLPOLY_3) that uses realistic energies capable of simulating more than 1 billion atoms [Dove]. Fundamental calculations using ab initio electronic methods have been used to investigate electronic heating and its effect on material properties during damage events [Artacho]. Theoretical work on the multicomponent elastic behaviour of partially radiation damaged materials connects the research on fundamental scale of measurement and simulation to the operational performance of materials destined to be nuclear waste forms, nuclear fuels or claddings [Salje]. A similar approach is involved in the aqueous durability testing of nuclear waste form materials using high precision ICP mass spectrometry and normal or superheated water [Farnan].
Related Projects in the Department of Earth Sciences include:
- Fundamental aspects of radiation damage: separation of the effects of heavy recoil and alpha particle damage (Australian Nuclear Science and Technology Organisation (ANSTO) / Bill and Melinda Gates Foundation)
- Radiation damage and plutonium substitution in phosphate nuclear waste forms for UK legacy pyroprocessing wastes (Atomic Weapons Establishment, Aldermaston)
- Radiation damage in monolithic silicon carbide and direct measurement of SiC in intact TRISO Gen IV fuel systems (F-Bridge - Basic Research for Innovative Fuel design for Gen IV systems Euratom FP7 programme)
- Direct observation of adventitious oxygen in hyperstoichiometic UO2+x by O-17 NMR (Los Alamos National Laboratory - Seaborg Institute)
- Phase separation of molybdate phases from borosilicate melts (Commissariat à l'Energie Atomique, VALRHO)
- Development of combined NMR and EPR methods to use actinide (5f) paramagnetic shifts to probe structure in nuclear materials, Environmental and Molecular Sciences Laboratory, Pacific Northwest National Laboratory.
Nuclear power plants place unusual demands on the materials from which they are constructed. The materials must perform reliably and predictably over extremely long time spans while accumulating radiation damage. These requirements create needs for: a fundamental understanding of radiation damage and long-term materials performance; application of this understanding to methods of measuring and defining performance for a wide range of materials; and translation of this understanding into engineering practice.
The Department of Engineering is a leader in modelling materials at the atomic scale and relating this model to micro- and macro-scopic performance. In partnership with Cambridge's Departments of Materials Science and Physics, the University has considerable strength in this area. Engineering has also developed products and services for materials selection based on its fundamental research in this area (Professor David Cebon, Professor Mike Ashby, Dr Gabor Csanyi and Dr Hugh Shercliff).
In addition, the Department works on modelling, designing and testing new materials including metal lattices and foams. These can be combined with cladding to create new blast resistant materials. The work was originally motivated by marine applications and has proved successful in this domain; it may well find applications in nuclear engineering (Professor Norman Fleck and Dr Vikram Despande).
The Department has expertise in high integrity welds (in collaboration with TWI), the impact of noise and vibration on joints, fracture mechanics and reliability. The Electrical and Information Engineering Divisions bring expertise of non-destructive testing and modern imaging techniques, including 3D imaging and the development of machine learning to detect anomalies.
And finally, the embodied energy of the chosen construction materials has a significant impact on the overall energy balance and sustainability of the power station, because of the tonnage required for blast and radiation protection. The Department's work under its theme of sustainable development is highly relevant: reducing the energy costs of producing steel and concrete; and finding low-carbon alternatives to traditional construction materials (Dr Abir Al Tabbaa, Dr Janet Lees, Dr Julian Allwood and Dr Claire Barlow).
Related Projects in the Department of Physics include:
- Computational modelling of solids, ab initio methods for structure and dynamics: http://www.tcm.phy.cam.ac.uk/research.html
- Fracture Physics: http://www.phy.cam.ac.uk/research/smf/fracture.php
- Centre for Scientific Computing: http://www.csc.cam.ac.uk/academic/mphil/index.shtml
Related Projects in the Department of Materials Science & Metallurgy include:
HKDH (Harry) Bhadeshia, FRS FREng (Tata Steel Professor of Metallurgy)
Reactor Materials: Modelling and prediction of irradiation and corrosion damage in fission and fusion reactor materials
Fluid dynamics and thermodynamics
The Department has core strengths in computational fluid dynamics and thermodynamics, which are closely coupled to leading-edge experimental work. These are essential for modelling and optimising designs. The team can work at both the system level and at the levels of detail necessary to refine critical features of heat exchangers, turbines, etc. Research expertise extends into two-phase flows and other multi-physics modelling. The systems-level work can integrate the models of electrical sub-systems described below (Professors Ann Dowling, John Young, Bill Dawes and Howard Hodson, and Dr Rob Miller and Dr Alex White).
Electrical machines and systems
A successful reactor system requires efficient and reliable generators. ADSRs also require accelerator technology that can operate with maintenance programmes and unscheduled outages that match the requirements of the commercial electricity sector. The Department has a world-leading Electrical Engineering Division with expertise in modelling, designing and building electrical machines, magneto-dynamics, superconducting magnets and fault current limiters (Professor Gehan Amaratunga, Professor David Cardwell, Dr Tim Coombs, Dr Richard McMahon and Dr Patrick Palmer).
The Department is actively engaged in research at the forefront of power grid modelling and design. This includes developing new semiconductor technology for making truly decentralised grids integrating micro-generation a reality and modelling the stability of the grid under changes in demand and production (Professor Gehan Amaratunga, Dr Florin Udrea and Dr Glenn Vinnicombe).
The Structures Group combines experimental observations, analysis and computer simulation to address structural engineering challenges of a fundamental nature. The work ranges from the mathematics of novel deployable and multi-stable structures (Dr Simon Guest and Dr Keith Seffen) to the development of tools for assessing the safety of ageing reinforced concrete bridges (Dr Cam Middleton and Dr Chris Burgoyne).
The team collaborates with our geotechnical engineers to research and develop new methods of monitoring ageing structures, analyse defects and execute repairs. This includes laying fibre optic sensors within the structure, placing large numbers of low-cost wireless sensors across structures and regularly checking for significant external changes using robotic vision systems (Professor Kenichi Soga, Professor Roberto Cipolla and Dr Cam Middleton).
Design for safety critical systems
The Engineering Design Centre is dedicated to improving the design process. It is one of the UK's Innovative Manufacturing Research Centres and is recognised by the EPSRC to be internationally leading. Its work on process, knowledge and change management are all highly applicable to nuclear engineering. The Centre's work on safety in combination with the Control Group's expertise in fault tolerant control creates unique capability in design for safety critical systems (Professor John Clarkson and Professor Jan Maciejowski).
Technology and supply chain management
The Department's Institute for Manufacturing is researching and developing advanced techniques for planning major technical programmes and designing global supply chains. The work on technology management includes, among many approaches, a highly-refined roadmapping methodology, which has been applied to set government policies, work with leaders from industrial sectors and develop detailed corporate strategies. The research on global supply chains has been executed in close collaboration with major corporates from around the world. The Institute has demonstrated the high-value of it bringing together the technology experts in the Department with leaders from industry to draw their ideas and knowledge into a structured whole. The Institute can play a key role in developing a coherent, robust and profitable plan for developing new nuclear energy systems. Its work on the innovation process can also help the industry create the right environment for invention and entrepreneurship in this sector (Professor Mike Gregory, Dr David Probert, Dr Yongjiang Shi, Dr Elizabeth Garnsey, Dr Tim Minshall and Dr Ken Platts).
Sustainability is clearly a key element of reactor system design. It extends beyond considerations of fuel availability, financial costs and energy balances; it has to include wider environmental impacts, social acceptability and economic performance. The Department of Engineering has a Centre for Sustainable Development dedicated to these analyses and decision-making processes. It draws on experts throughout the Department and has established collaborative links with the Judge Business School, the Economics faculty and Social Sciences (Professor Peter Guthrie, Dr Geoff Parks and Dr Bill Nuttall).