U.K. nuclear ambitions for a clean energy future and achieving net zero

June 12, 2020, 2:55PMNuclear NewsPaul Nevitt, Dave Goddard, and Robin Taylor

Fig. 1. Geographical spread of U.K. organizations engaged in the U.K. AFCP, including a number of the world leading U.K. universities. Image: NNL

Called “the first significant public investment in a generation,” the U.K. Advanced Fuel Cycle Program (AFCP) is driving innovation to underpin future nuclear deployment in the United Kingdom. Led jointly by the U.K. Department for Business, Energy and Industrial Strategy and the National Nuclear Laboratory (NNL), the program involves more than 40 U.K. organizations, including a number of world-­leading U.K. universities (Fig. 1), and is working with international organizations across more than 10 countries, leveraging U.K. investment into more than £100 million in international programs.

Fig. 2. U.K. fuel and fuel cycle capabilities delivering the U.K. AFCP across multiple organizations.Image: NNL

The program of innovation is delivering new fuel concepts for existing and future reactors, building on world-­leading capability, and reestablishing capabilities aligned to future opportunities. Research and innovation under the AFCP will also enable advanced fuel cycles that offer significant potential to increase sustainability. The program is enabled by the extensive U.K. infrastructure in fuel and fuel cycle, and it will also deliver additional U.K. capability over the course of the program (Fig. 2), developing the United Kingdom into a global hub for fuel cycle innovation and a platform for the technologies of tomorrow.

The U.K. and net zero

Four years after the Paris Agreement, the U.K. government, acting on the recommendation of the Committee on Climate Change, committed to a net--zero carbon emissions target of 2050. It is recognized that urgency is required in the deployment of low--carbon technologies, including nuclear, to meet the net--zero ambitions. To meet demand for zero--carbon electricity by 2050 in the United Kingdom, generation from renewables and nuclear may have to quadruple from today’s approximately 150 TWh of generation to over 600 TWh. This is just electricity and doesn’t consider the broader role that nuclear could play in decarbonization of the fuel supply (e.g., production of hydrogen and synthetic fuels).

What is clear is that the strategies required for cutting emissions require radical initiatives. This will include innovative thinking around the nuclear fuel cycle required to support and underpin any increased nuclear deployment. To achieve net zero, the United Kingdom may choose (or need) to move from the current installed nuclear capacity of less than 10 GW to more than 20 GW, or even more than 40 GW (with multiple technologies).

What the U.K. is doing

The United Kingdom’s nuclear capacity currently accounts for around one--fifth of the electricity supply. The U.K. government’s latest projections for capacity and power generation from nuclear are for 12 GW of new nuclear by 2035. These forecasts reflect some of the recent setbacks in building the planned nuclear sites (down from 16 GW set out in 2013). The U.K. government has placed a lot of emphasis on value for money for consumers and taxpayers. In addition, the feasibility of a regulated asset base funding model is currently being explored. Sustainable funding mechanisms are key.

In addition to a key role in delivering “firm power” (i.e., always available) and electricity, nuclear could play a broader role in providing clean energy in the United Kingdom, for example, by delivering heat and hydrogen in a future net--zero world. Advanced nuclear technologies, defined as small modular reactors, which are smaller versions of today’s light--water reactors, and advanced modular reactors, which adopt next--generation technologies, could work alongside other low--carbon sources in a hybrid energy system to offer cost--effective solutions to a range of energy needs. The United Kingdom’s interest in advanced nuclear technologies cuts across multiple policy goals:

Playing a broad decarbonization role: Advanced reactor designs target a wider range of applications beyond traditional baseload electricity supply.

Delivering low--cost energy: SMRs and advanced modular reactors have the potential to deliver cost reductions through, for example, enhanced passive safety features, step change technology, and production innovations.

Promoting clean growth: The United Kingdom recognizes the potential to become a world leader in developing the next generation of nuclear technologies, creating high-­skilled jobs, and helping to meet decarbonization targets.

The U.K. government has launched several initiatives over the past few years to test the potential application of advanced nuclear technologies more widely, including exploring technical, economic, regulatory, and social perspectives in a future low-­carbon energy system. It has stated that where possible, the market is best placed to identify and bring forward cost-­effective advanced nuclear technologies. However, given uncertainty about the future, the U.K. government also recognizes that it must be prepared to intervene to provide insurance and preserve optionality. A policy framework has been developed to enable the market to operate while keeping in mind the insurance principle. This policy framework includes the Nuclear Sector Deal, regulator readiness, financing, siting and land access, public perception, supply chain development, the Nuclear Innovation Program, and the Advanced Modular Reactor Feasibility and Development project.

Nuclear Innovation Program

In response to the challenge of reducing carbon emissions by 2050 and following the publication of its Clean Growth Strategy, the U.K. government established the £505-­million Energy Innovation Program, administered through the Department for Business, Energy and Industrial Strategy, with funding across the government spending review period between 2016 and 2021. Of this £505 million, £180 million was earmarked for nuclear technologies under the auspices of the Nuclear Innovation Program, building on recommendations from the Nuclear Innovation and Research Advisory Board.

Fig. 3. U.K. Nuclear Innovation Program (NIP). Image: NNL

This is the first significant U.K. public spending on future nuclear (fission) energy research and development in over 20 years, a welcome change from the decline of spending that characterized previous decades and building on the United Kingdom’s research capabilities in waste, decommissioning, and fusion. The Nuclear Innovation Program looked to fund R&D in six key areas (Fig. 3). This funding builds on the nuclear academic base in the United Kingdom’s universities and targets innovation opportunities in the mid-­technology readiness level space, developing capability in the U.K. national laboratories and U.K. industry toward demonstration and commercialization.

Advanced Fuel Cycle Program

In 2019, following two years of significant progress and innovation in the advanced fuels and spent fuel recycle innovation areas of the Nuclear Innovation Program, further significant investment was committed to bring these areas together. The Advanced Fuel Cycle Program was, therefore, established. The AFCP will initially run to March 2021 and accounts for a significant proportion of the total Nuclear Innovation Program investment (over £40 million). The AFCP focuses on innovation across a number of technologies with a range of deployment time frames. It is recognized as a key underpinning program supporting the U.K. clean energy and net-­zero ambitions. The program has strategic objectives to develop across the so-­called four Cs:

Capability: Secure, maintain, and renew the skills and experience needed to ensure that nuclear can continue to play a part in delivering secure, low-­carbon energy in the global market.

Capacity: Develop the capacity and credibility of the U.K. supply chain to support programs and leverage greater commercial exploitation of domestic and global nuclear markets.

Cost reduction: Seek to reduce the costs of the future nuclear life cycle.

Collaboration: Increase engagement with key international partnerships and seek to leverage synergies with bilateral and multilateral programs.

The following provides further details on some of the work under the AFCP on advanced fuels and advanced fuel recycling.

Advanced fuels

Advanced fuels development focuses on making safer and more economic fuels for current and future reactors, which is crucial if the United Kingdom is to retain an indigenous fuel manufacture capability. However, it is recognized that new fuel development is a significant undertaking in terms of time and cost. The route to market is over 10 years in duration and costs in the tens of millions. Therefore, the United Kingdom is investing now to ensure that the fuels of the future are available to underpin U.K. nuclear ambitions. It is also recognized that international collaboration is essential to support and enable fuel development and manufacture in the United Kingdom.

The current U.K. AFCP focuses on three fuel types: accident tolerant (or advanced technology) fuels (ATF), coated particle fuels, and fast reactor fuels.

Accident tolerant fuels: To develop fuels with improved safety, performance, and efficiency. Innovation is focused on developing, fabricating, and irradiating test fuel and cladding toward commercial products.

ATFs are now being defined as fuels that combine accident tolerance, i.e., improved behavior during a severe accident (design basis and beyond design basis), with properties that reduce the number of fuel failures and increase the reactor’s capacity factor.

The ATF program in the United Kingdom has been aligned with the Westinghouse EnCore ATF products through its subsidiary Springfields Fuels Limited, as it is the only fuel vendor with an operational fuel manufacturing site in the United Kingdom. Westinghouse and its network of partners have developed EnCore fuel with support from the U.S. Department of Energy’s Accident Tolerant Fuel Program. Through U.K. government investment in the AFCP, the United Kingdom is able to align with the Westinghouse program, which provides significant leverage on the U.K. public investment.

The ATF program is focusing on three areas:

Fig. 4. Cr coated Zr alloy cladding tubes coated by AFCP partner Teer Coatings. Photo: NNL

Coated zirconium cladding: Developing an innovative coating technology and scaling it up to be able to coat full-­length (>4 m) rods for irradiation testing on the path toward commercial product development (see Fig. 4).

High-­density fuels: Developing novel fuel manufacturing routes for uranium nitride fuels and developing designs for scale-­up to prototype size.

Silicon carbide (SiC) composites: Developing innovative technologies for the fabrication of SiC composite tubes and joints.

Coated particle fuels: To reestablish a capability to manufacture coated fuel kernels and to investigate the production of fuel elements in prismatic, pebble, or rod/pellet form.

There is significant and growing interest in coated particle fuel technology related to the development and deployment of high-­temperature reactors. HTRs have the potential to play a broader role than just generating electricity in national and international decarbonization ambitions. For these technologies to be successful, a secure fuel supply will be required. The United Kingdom is looking to reestablish capabilities to manufacture coated particle fuels, starting with investment in capabilities through the AFCP:

Fig. 5. Equipment for casting of CPF kernels installed at the NNL facility at Springfields in Lancashire. Photo: NNL

Kernel fabrication: Installation and active commissioning of kernel production equipment (see Fig. 5) within NNL’s Nuclear Fuel Centre of Excellence at the Clean Energy Technology Park at Springfields, with a program to demonstrate the control of kernel production processes.

Kernel coatings: Installation and commissioning of coating technology at the University of Manchester’s Henry Royce Institute, with the demonstration of deposition of pyrolytic carbon and SiC coatings on kernels.

Fast reactor fuels: To develop a capability to deliver test fuel. The program will focus on plutonium-­based fuels for fast reactor technologies, maintaining and developing cutting-­edge skills in transuranic materials handling.

The fast reactor fuels program recognizes the need to maintain and develop the capability to support longer-­term options that could underpin U.K. policy. The United Kingdom has a long history in the development and operation of fast reactor technology and the supporting fuel and fuel cycles. Until the mid-­1990s, the United Kingdom operated and fueled the sodium-­cooled Prototype Fast Reactor in Dounreay, Scotland.

Fig. 6. Glovebox facilities for the manufacture of mixed-oxide fuels at NNL Central Laboratory, Sellafield. Photo: NNL

The current program on fast reactor fuels focuses on installing the capability to research and optimize the manufacture of fast reactor fuel pellets at NNL’s Central Laboratory at Sellafield in Cumbria. The aim will be to manufacture fast reactor specification mixed-­oxide fuel in the United Kingdom for the first time in over 20 years (see Fig. 6). This program will also develop broader capabilities that will contribute to the Generation IV International Forum (GIF) on the development of sodium fast reactor technology. The United Kingdom ratified the GIF framework agreement in 2018.

Advanced fuel recycling

Advanced fuel cycles offer significant potential to increase sustainability and minimize the burden on the geological repository from the management of spent nuclear fuel, factors that may be critical in enabling the expanded use of nuclear energy. In the field of spent fuel recycling, the AFCP is exploring novel technologies that provide substantial opportunities to reduce fuel cycle costs, reduce wastes and environmental impacts, and enhance safety, security, and proliferation resistance compared to current reprocessing technology. Advanced technologies that are flexible and possibly modular or scalable and that can be adapted to various future scenarios are being targeted by the program.

Two main technology options are being investigated:

Advanced reprocessing and waste management based on aqueous separations: An investigation is being conducted into an advanced PUREX process that aims to rationalize PUREX reprocessing (as used in the United Kingdom, France, Russia, and elsewhere at industrial scale) into a much smaller single-­cycle process, as well as more innovative processes that separate the actinides as a group. These group actinide extraction processes use alternative solvents that are easier to decompose to gases.

Fig. 7. Single cycle Advanced PUREX process. Photo: NNL

In addition to the core separations processes, the program includes the development of new or improved technologies to manage both high-­level and intermediate-­level liquid wastes and capture off-­gases, including the immobilization of the wastes into suitable waste forms. Aqueous reprocessing options for both thermal reactor (LWR) and fast reactor fuels are part of the AFCP. A recent highlight has been the lab-­scale active testing of a single-­cycle advanced PUREX process using a complexing agent (aceto-­hydroxamic acid) in place of the traditional uranium (IV) and hydrazine reducing agent to produce a mixed uranium-­neptunium-­plutonium product rather than a pure plutonium product (see Fig. 7). The process can be run in small, intensified centrifugal contactors that substantially reduce the size of the plant (see Fig. 8).

Fig. 8. Three stages of pilot scale centrifugal contactors (installed at the University of Leeds under AFCP). Photo: NNL

Pyro-­electrochemical (“dry”) processes in molten salts: This complementary approach is based primarily on the electro-­refining of metal fast reactor fuels, similar to the technologies developed by Idaho National Laboratory. A strong focus is being placed on salt chemistry and engineering to rebuild U.K. expertise in this field and better understand the issues around industrialization. As well as the core metal electro-­refining processes, the program is looking at the extensions of pyro-­processing to oxide fuels, via electro-­reduction, and some of the cross-­cutting challenges with molten salt reactor technologies. Finally, off-­gas capture and salt waste treatment and immobilization are key waste management methods.

A programmatic approach is being taken to ensure that integrated recycling and waste management strategies are developed for both fuel cycle options. The AFCP sees aqueous and pyro-­chemical routes as complementary technologies, depending on the future fuel cycle scenarios envisaged.

The integrated waste strategy will follow the waste hierarchy to ensure that reprocessing wastes are minimized at the source and internally recycled as much as possible, and that the necessary waste management infrastructure is fully optimized to minimize costs and impacts of geological disposal. In addition, opportunities to recycle or repurpose potentially useful products from wastes for other applications (e.g., isotopes for space power or medical applications) will be evaluated.

The AFCP has 10-­year technology road maps to develop, test, and ultimately demonstrate these new recycle technologies with spent fuels by around 2030. However, at the end the current phase, in 2021, the United Kingdom will already be in the position, with established capabilities and infrastructure, to collaborate internationally in the development of advanced recycle technologies and the delivery of future advanced fuel cycle options. These may well be critical enablers to support the increasing role of nuclear energy in a future low-­carbon world.

International engagement

Collaboration with other nations will be a fundamental part of U.K. policy to successfully realize the opportunities of nuclear and advanced nuclear technologies. International collaboration will be particularly important in unlocking the benefit of the economy of multiples. Nuclear nations and regulators will need to work together to set standards that minimize additional regulatory costs when technologies cross borders and enable wider markets to be opened. Collaboration and cooperation will be essential in the development of advanced fuels and the broader enabling advanced fuel cycles.

The United Kingdom has long been an active participant in international organizations and programs across the fuel cycle, including the Generation IV International Forum, the OECD Nuclear Energy Agency, the Euratom Fission/Fusion Research and Training Program, the International Atomic Energy Agency, and the international community facilitated by the United Nations.

Developing advanced fuel and fuel cycle capability and infrastructure in the United Kingdom through the AFCP enables international partners to utilize the United Kingdom’s R&D capabilities. The United Kingdom is aiming to be an innovation hub to support future technology platforms. World-­class research is being carried out across the world, and thus working with leading international organizations and laboratories accelerates progress in the United Kingdom and internationally.

Acknowledgements: The Advanced Fuel Cycle Program would not be possible without the ongoing support from the U.K. government and the Department for Business, Energy and Industrial Strategy. It is not possible to mention all of the individuals and organizations involved, but the authors want to thank all those who have contributed—and continue to contribute—to the success of the AFCP.

Paul Nevitt (paul.nevitt@uknnl.com), the lead author, is the technical director of the Advanced Fuel Cycle Program; Dave Goddard (dave.-t.-goddard@uknnl.com) is a laboratory fellow in nuclear fuel manufacturing at the National Nuclear Laboratory; and Robin Taylor (robin.j.taylor@uknnl.com) is a senior fellow in actinide chemistry at NNL.

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