The Development of Advanced Technologies and Modelling Capabilities to Improve the Safety and Performance of Nuclear Fuel
Lead Research Organisation:
University of Manchester
Department Name: Mechanical Aerospace and Civil Eng
Abstract
The main factors that limit the performance of nuclear fuels are related to cladding failure due to interactions with the fuel pellet and reactor coolant. Improvements to our understanding of the cladding failure mechanisms will enhance our ability to predict their effects, leading both to improvements in the safety and operation of current fuels, and to technological developments that will produce improved fuel, cladding, and coating materials. The research tasks below seek to address each of these issues in turn, from the perspective of both current and advanced fuel designs.Aomistic modelling research will focus on the input that atomic scale simulations make in describing the behaviour of micro-structural defects. This will refine our understanding of the fundamental physical processes that degrade fuel performance, and will result in improvements to current semi-empirical fuel performance models. The simulations will focus upon the interaction of fission products, radiation damage and dislocations, processes responsible for macroscopic observables such as fission gas release and irradiation induced creep.Fuel and cladding dimensional changes resulting from thermo-mechanical and irradiation conditions produce complex pellet-clad mechanical interactions (PCMI) that are known to cause fuel failure, especially under accident conditions. Models for PCMI failure based on ramp-test data have been developed, but these are highly empirical and therefore of limited applicability. However, advances in finite element (FE) modelling now permit the development of detailed models, and techniques such as the extended FE method can be applied to model crack growth and crack tip stresses and strains accurately whilst taking into account residual and applied stress redistribution. This research will investigate the development of pellet crack patterns and pellet-clad interface stresses under both normal and off-normal conditions. Mechanistic models for pellet failure and cladding damage will be developed.Research into composite cladding will investigate the potential for silicon carbide composites to provide significantly better performance compared with existing cladding materials. A new approach will be investigated, based on a solid SiC inner tube wrapped with SiC fibers and bonded using SiC vapour infiltration. The research will address fundamental aspects of this new concept, including: characterisation of the relationship between both design and manufacturing parameters and mechanical strength; ability of the tube to remain impermeable against fission products; and resistance to oxidation and fission product attack at high temperatures. Although UO2 has been used for many years as a fuel material, promising new materials have ben developed that could offer advantages in terms of safety and performance. The objective of this research is to identify alternative fuel materials and fuel forms; to evaluate their physical properties such as thermal conductivity; assess their reactivity with water using autoclave testing; and to assess industrially-feasible manufacturing routes. Candidate materials include alloys such as U3Si2, U-Mo, U-Zr and covalent compounds such as carbides and nitrides (in the latter case with additives to reduce the reaction rate in water). TRISO coated fuel particles manufactured by chemical vapour deposition (CVD) have demonstrated remarkable performance, but are known to be susceptible to attack by fission products such as Pa. This research will provide a fundamental understanding of these issues and will investigate alternative materials and processes to provide improved performance. The high temperature mechanical properties of coatings will be examined to understand the effects of manufacturing conditions. The mechanisms of fission product transport will be studied with a view to introducing materials and microstructural changes that will improve performance in this respect.
Planned Impact
Private sector beneficiaries of the research will include designers and suppliers of nuclear fuels; suppliers of intermediary products such as fuel cladding and components; providers of specialist licensing services such as consultancy groups; and operators of nuclear power plants. In the longer term, improvements in coated particle technology will assist implementation of the HTR system, that can supply high temperature heat to a range of industries. All of the proposed research is linked with improvements in the performance and safety of nuclear fuel, which is expected to translate directly into reduced risk, providing a direct benefit to the public. The nuclear regulator will also benefit from access to improved fundamental understanding and modelling methods. The private sector will benefit through improvements in the competitiveness of the products that can be manufactured at the UK's nuclear fuel fabrication facility at Springfields, which will also benefit the supply chain for this business. Specialist consulting organisations will benefit from the analysis that will be required to validate and license any potential new fuel products that arise as a result of the proposed work. Nuclear power plant operators will benefit from improvements to the fuel product capabilities (by extending fuel lifetimes and reducing failure rates, for example), and also from improvements in fundamental understanding of life-limiting phenomena, which will allow better fuel models to be developed, potentially enhancing operational flexibility. The public will benefit from improvements in fuel capability and hence improved safety margins, and may also realise some economic benefit flowing from improvements in plant operations. The proposed work will also enhance the capability of UK academia and result in the training of young researchers who would be of immediate value to both private industry and public sctor bodies. Both Universities have excellent relationships with the nuclear industry and public bodies associated with nuclear energy in the UK. Agreements are in place with a majority of the UK's key nuclear industry and public sector organisations (EDF, British Energy, Westinghouse, Rolls-Royce, National Nuclear Lab, AMEC, Serco, etc.), and many of these have been involved in formulating the proposed research. Accordingly, robust arrangements are already in place for industry collaboration in the proposed research, as evidenced by the attached letters of support for the proposal, and channels for dissemination of the research results are already well established. Engagement will be ensured by working closely with the partner organisations, and providing opportunities for researchers to spend periods of time working with industry partners. The results of the research will be disseminated both at industry-focussed events such as workshops, and at wider events such as seminars. The partners will establish a web-site to engage a wider audience in the outcomes of the research activities, and will utilise their respective public affairs departments to ensure that the research is afforded a high visibility within their respective nuclear-focussed activities. As mentioned, both Universities have extensive collaborative links with private and public sector organisations, including other Universities in the UK and overseas. Both have collaborated together in previous and current EPSRC programmes such as KNOO and DIAMOND. The UK nuclear industry is well placed to exploit the benefits from the proposed research. Both Universities have established mechanisms for ensuring that the benefits of academic research are properly exploited and protected. Impact activities will be co-ordinated by the PI, but undertaken by all academic staff involved as appropriate, and the partners will benefit from the advice and involvement of Dr John Roberts, the External Liason Manager at the Dalton Nuclear Institute.
Publications
Murphy S
(2014)
A comparison of empirical potential models for the simulation of dislocations in uranium dioxide
in Progress in Nuclear Energy
Cooper M
(2014)
A many-body potential approach to modelling the thermomechanical properties of actinide oxides
in Journal of Physics: Condensed Matter
Geng, X
(2014)
A new approach to explain silver migration in SiC
in Proceedings of HTR-2014, Weihai, China
Geng, X
(2014)
A new approach to explain silver migration in SiC
in Proceedings of HTR-2014, Weihai, China
Geng X
(2014)
An Original Way to Investigate Silver Migration Through Silicon Carbide Coating in TRISO Particles
in Journal of the American Ceramic Society
Gentile M
(2013)
Developments in Strategic Materials and Computational Design IV
Rohbeck N
(2014)
Effects of thermal treatment on the mechanical integrity of silicon carbide in HTR fuel up to 2200 °C
in Journal of Nuclear Materials
Rohbeck N
(2016)
Evaluation of the mechanical performance of silicon carbide in TRISO fuel at high temperatures
in Nuclear Engineering and Design
Paul James
(2017)
Joining of silicon carbide for accident tolerant PWR fuel cladding
Mella R
(2015)
Modelling explicit fracture of nuclear fuel pellets using peridynamics
in Journal of Nuclear Materials
Lee W
(2013)
Opportunities for Advanced Ceramics and Composites in the Nuclear Sector
in Journal of the American Ceramic Society
Gentile M
(2015)
Palladium interaction with silicon carbide
in Journal of Nuclear Materials
Murphy S
(2014)
Pipe diffusion at dislocations in UO2
in Journal of Nuclear Materials
Giorgi E
(2018)
Reactive carbothermal reduction of ZrC and ZrOC using Spark Plasma Sintering
in Advances in Applied Ceramics
Nerikar P
(2011)
Segregation of xenon to dislocations and grain boundaries in uranium dioxide
in Physical Review B
Cooper M
(2014)
Swelling due to the partition of soluble fission products between the grey phase and uranium dioxide
in Progress in Nuclear Energy
Rohbeck Nadia
(2014)
The high temperature mechanical properties of silicon carbide in TRISO particle fuel
Turner J
(2013)
The thermal performance of fuel matrix material in a CO2 atmosphere
in Journal of Nuclear Materials
Lumley S
(2014)
The thermodynamics of hydride precipitation: The importance of entropy, enthalpy and disorder
in Acta Materialia
Manara D
(2013)
The ZrC-C eutectic structure and melting behaviour: A high-temperature radiance spectroscopy study
in Journal of the European Ceramic Society
Cooper MW
(2014)
Thermophysical and anion diffusion properties of (U x ,Th1-x )O2.
in Proceedings. Mathematical, physical, and engineering sciences
Harrison R
(2014)
Thermophysical characterisation of ZrC x N y ceramics fabricated via carbothermic reduction-nitridation
in Journal of Nuclear Materials
Mahrenholz, W G
(2014)
Ultra-High Temperature Ceramics: Materials for Extreme Environment Applications
Murphy S
(2015)
Xe diffusion and bubble nucleation around edge dislocations in UO2
in Journal of Nuclear Materials
M Gentile
(2014)
XRD and TG-DSC Analysis of the Silicon Carbide - Palladium Reaction
Description | The research has allowed us to identify promising approaches to the development of new nuclear fuel and cladding materials that offer significant advantages in respect of performance under normal operating conditions, and especially under fault conditions where fuel cooling has been compromised. We have also made significant advances in our understanding of the performance of advanced TRISO coated particle fuels, and in particular the relationships between manufacturing conditions, fuel microstructure, and subsequent in-reactor performance. Finally, we have made considerable advances in our ability to apply molecular dynamics modelling to accurately predict the properties of materials that have not yet been manufactured. This will be invaluable in assessing a very broad range of candidate materials prior to committing experimental resources. |
Exploitation Route | Our findings will be taken forward in the frame of the EPSRC-funded PACIFIC project, and in the frame of additional academic and national laboratory research recommended by NIRAB. The research also has the potential to be utilised by our industrial partners Westinghouse, Rolls-Royce, and NNL. |
Sectors | Energy |
Description | The findings on materials properties for a range of novel fuel compounds have been used within the collaboration to identify promising new fuel materials. Some of our results have already been used by our industry partners (Westinghouse and Rolls-Royce) to identify ways to improve the performance of existing and new fuel products. Specific examples include potential composite fuel materials, such as UO2 with additions such as Mo, and SiC-SiC ceramic cladding materials that offer significantly improved accident performance compared with current Zr-based cladding alloys. The results have also fed directly into the elaboration of UK research policy, via the recommendations of the Government's Nuclear Innovation and Research Advisory Board (NIRAB) in late 2016. |
First Year Of Impact | 2014 |
Sector | Energy,Manufacturing, including Industrial Biotechology |
Impact Types | Economic Policy & public services |
Description | Review of Nuclear Fuel Technology for Future UK Research Needs, delivered to DECC |
Geographic Reach | National |
Policy Influence Type | Citation in other policy documents |
Impact | The NNL/Manchester reports have influenced the development of nuclear research policy within DECC and BIS, and this will have significant impacts on UK economic activities and on research/training/education in nuclear technology. |
Description | German Academic Exchange Service Travel Award |
Amount | € 8,000 (EUR) |
Organisation | German Academic Exchange Service (DAAD) |
Sector | Academic/University |
Country | United States |
Start | 08/2013 |
End | 05/2014 |
Description | Nuclear Fuel Centre of Excellence |
Amount | £8,000,000 (GBP) |
Organisation | Department for Business, Energy & Industrial Strategy |
Sector | Public |
Country | United Kingdom |
Start | 12/2013 |
End | 03/2014 |
Title | Laser-based ceramic joining technology |
Description | A laser-based technique for joining ceramic nuclear fuel components using ceramic brazing has been developed. This can be applied to investigate the production of advanced ceramic fuel claddings that offer significantly greater temperature capabilities compared with existing Zr-alloy claddings. |
Type Of Material | Technology assay or reagent |
Provided To Others? | No |
Impact | The ability to join silicon carbide composite materials offers the possibility of utilising the material to produce fuel rod claddings with very high temperature capabilities. This could provide a large improvement in safety compared with existing metallic cladding materials. The joining capability will enable a range of potential ceramic brazing compounds to be explored, in order to identify compounds that are capable of surviving inside the core of an operating reactor. The University of Manchester, in collaboration with Rolls-Royce, is pursuing a patent for this technique. |
Title | Molecular Dynamics modelling of advanced actinide oxides |
Description | Molecular dynamics techniques have been extended to allow the prediction of fundamental properties such as thermal conductivity for a range of actinide oxides. |
Type Of Material | Model of mechanisms or symptoms - in vitro |
Year Produced | 2011 |
Provided To Others? | Yes |
Impact | The modelling techniques allow the identification of promising fuel materials in advance of experimental preparation and determination of thermo-physical properties. This will result in a more efficient identification of promising new materials, saving experimental time and effort. |
Title | Preparation of TRISO particles with ZrC coatings |
Description | A new capability to produce TRISO coated fuel particles with a ZrC coating has been developed and installed at Manchester. This utilises existing expertise in the production of SiC-coated particles, but extends the capability to develop fuels with a higher temperature capability. |
Type Of Material | Technology assay or reagent |
Provided To Others? | No |
Impact | This will facilitate current research conducted in the frame of EPSRC and European programmes, as well as offering an important new opportunity to conduct further research into Generation-IV fuels in support of the new NIRAB research recommendations for the UK. |
Description | Collaboration with NNL, Westinghouse, and Rolls-Royce |
Organisation | National Nuclear Laboratory |
Country | United Kingdom |
Sector | Public |
PI Contribution | Manchester, NNL, and Westinghouse have jointly contributed to developing a research vision for nuclear fuel in the UK. Manchester and NNL have developed this into a technology review and research plan that has been submitted to DECC, partly via the Government's new Nuclear Innovation and Research Advisory Board (NIRAB). Manchester and NNL have also developed a proposal to Government to establish a new Nuclear Fuel Centre of Excellence (NFCE) for the UK. This proposal has been submitted to BIS, and this has resulted in the award of a grant of £8m to NNL and Manchester to establish a new suite of research facilities. These were officially launched on 13 October 2014. Subsequently, NNL and Manchester submitted proposals to DECC to establish an Accident Tolerant Fuels capability within the NFCE. This resulted in the award of £1.5m to NNL and £1m to Manchester in April 2015. These facilities are of major importance to EPSRC-funded research projects such as PACIFIC. |
Collaborator Contribution | Imperial College have contributed to the development and review of the UK's future nuclear fuel research programme, not least through the contributions of Prof. Robin Grimes and Prof. Bill Lee through their role on NIRAB. |
Impact | In addition to the outcomes listed above, experts from NNL and Westinghouse have assisted in reviewing and guiding the research outcomes. NNL have also assisted in offering training and safety advice to researchers in the collaboration. |
Start Year | 2009 |
Description | Collaboration with NNL, Westinghouse, and Rolls-Royce |
Organisation | Rolls Royce Group Plc |
Country | United Kingdom |
Sector | Private |
PI Contribution | Manchester, NNL, and Westinghouse have jointly contributed to developing a research vision for nuclear fuel in the UK. Manchester and NNL have developed this into a technology review and research plan that has been submitted to DECC, partly via the Government's new Nuclear Innovation and Research Advisory Board (NIRAB). Manchester and NNL have also developed a proposal to Government to establish a new Nuclear Fuel Centre of Excellence (NFCE) for the UK. This proposal has been submitted to BIS, and this has resulted in the award of a grant of £8m to NNL and Manchester to establish a new suite of research facilities. These were officially launched on 13 October 2014. Subsequently, NNL and Manchester submitted proposals to DECC to establish an Accident Tolerant Fuels capability within the NFCE. This resulted in the award of £1.5m to NNL and £1m to Manchester in April 2015. These facilities are of major importance to EPSRC-funded research projects such as PACIFIC. |
Collaborator Contribution | Imperial College have contributed to the development and review of the UK's future nuclear fuel research programme, not least through the contributions of Prof. Robin Grimes and Prof. Bill Lee through their role on NIRAB. |
Impact | In addition to the outcomes listed above, experts from NNL and Westinghouse have assisted in reviewing and guiding the research outcomes. NNL have also assisted in offering training and safety advice to researchers in the collaboration. |
Start Year | 2009 |
Description | Collaboration with NNL, Westinghouse, and Rolls-Royce |
Organisation | Westinghouse |
Country | United States |
Sector | Private |
PI Contribution | Manchester, NNL, and Westinghouse have jointly contributed to developing a research vision for nuclear fuel in the UK. Manchester and NNL have developed this into a technology review and research plan that has been submitted to DECC, partly via the Government's new Nuclear Innovation and Research Advisory Board (NIRAB). Manchester and NNL have also developed a proposal to Government to establish a new Nuclear Fuel Centre of Excellence (NFCE) for the UK. This proposal has been submitted to BIS, and this has resulted in the award of a grant of £8m to NNL and Manchester to establish a new suite of research facilities. These were officially launched on 13 October 2014. Subsequently, NNL and Manchester submitted proposals to DECC to establish an Accident Tolerant Fuels capability within the NFCE. This resulted in the award of £1.5m to NNL and £1m to Manchester in April 2015. These facilities are of major importance to EPSRC-funded research projects such as PACIFIC. |
Collaborator Contribution | Imperial College have contributed to the development and review of the UK's future nuclear fuel research programme, not least through the contributions of Prof. Robin Grimes and Prof. Bill Lee through their role on NIRAB. |
Impact | In addition to the outcomes listed above, experts from NNL and Westinghouse have assisted in reviewing and guiding the research outcomes. NNL have also assisted in offering training and safety advice to researchers in the collaboration. |
Start Year | 2009 |
Description | Annual talk to Cumbria IMechE |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | Yes |
Geographic Reach | Regional |
Primary Audience | Professional Practitioners |
Results and Impact | The talks always stimulate engaging discussions amongst practising engineers. Several attendees remain in regular contact and follow the development of research outcomes. |
Year(s) Of Engagement Activity | 2009,2010,2011,2012,2013,2014 |
Description | Presentation to Edinburgh International Science Festival |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | Yes |
Geographic Reach | International |
Primary Audience | Public/other audiences |
Results and Impact | The talk was followed by an open discussion session that stimulated a long and engaging dialogue with members of the public concerning advances in nuclear fuel technology and the ways in which these could be applied to improve safety and economic benefits. Several members of the public continued to engage by email etc. and continued to engage with research activities undertaken by the academic partners engaged in this grant. |
Year(s) Of Engagement Activity | 2013 |
Description | Smallpeice Trust Talks |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | Yes |
Geographic Reach | National |
Primary Audience | Schools |
Results and Impact | Provided a talk on outcomes of nuclear fuel research and to demonstrate how this can impact on the safety and economics of nuclear power. Several students continue to engage via email after the talks, and some have remained in contact subsequently. |
Year(s) Of Engagement Activity | 2010,2011,2012,2013,2014 |