New nuclear power stations have an essential role to play in delivering our future energy needs. Today’s pressures of an ever-increasing energy demand, low carbon emission targets, and the need for a secure supply of safe, cost-effective energy are all high on the agenda. Twelve new nuclear reactors are already planned for the UK, with the first at Hinkley Point C now given the go-ahead, and some experts believe that even more low-carbon nuclear energy will be needed to meet the UK’s future energy demands and carbon emissions targets.
The £8m New Nuclear Manufacturing (NNUMAN) programme, part-funded by the Engineering and Physical Sciences Research Council (EPSRC), was launched in October 2012 to develop R&D capabilities to support a robust UK manufacturing supply chain for civil nuclear power to meet UK and global energy needs well into the future. The programme, led by The University of Manchester with support from the University of Sheffield, focusses on the scientific underpinning of advanced manufacturing for the next generation of power stations. NNUMAN research is driving the development of new manufacturing approaches for nuclear components and fuels which will enable UK manufacturers to compete on a global as well as a national stage. These new methods will provide faster and cheaper methods of manufacturing nuclear components, whilst also ensuring these are of the highest quality and are capable of operating effectively for many decades in nuclear power stations with a lifespan of at least 60 years.
NNUMAN provides the UK nuclear energy industry with the research and development expertise that is vital for UK companies to improve their manufacturing processes for nuclear components and fuels. NNUMAN is focussed on four areas where research can assist manufacturers to evolve their processes or adopt new techniques that lower costs and/or enhance the safety, longevity and performance of their products. Recognising that the manufacturing process affects the way a component behaves during the lifetime of the nuclear reactor, it is important to understand how innovative manufacturing processes affect performance in the reactor environment to ensure the quality of manufactured components remains high and will not deteriorate during their operational lifespan.
- New ways of joining components. New joining methods under investigation include narrow groove arc-welding techniques, laser and electron beam welding which offer the prospect of a very low incidence of internal defects and optimised microstructures and residual stress. These are being developed for thick section nuclear components and underpinned using a combination of computer modelling and advanced materials testing and analysis.
- Optimised machining of large and heavy components. Advanced machining technologies are being developed through the intelligent design of high-speed, damage-minimising machining, the implementation of robotic processing and the development of assisted machining processes. This work is complemented by detailed and sophisticated material experiments focussed on the performance of machined surfaces under reactor conditions, particularly relating to the onset and development of stress corrosion cracking.
- Developments in near-net shape manufacturing. These reduce energy consumption and material wastage, and also reduce the need for final machining. NNUMAN has concentrated on Hot Isostatic Pressing (HIP) - fusing powders together at high temperature and pressure in a mould, but is also interested in Additive Manufacturing - depositing layers of molten metal to create complex shapes.
- Advanced nuclear fuels. While improvements in fuel cladding tend to occur in the light of recommendations from post-accident investigations, the design of advanced fuels tends to build on scientific discovery and new knowledge at a more fundamental level. We have addressed a number of issues in both of these areas as part of a broader portfolio of research within the UK’s Nuclear Fuel Centre of Excellence. These include the joining of silicon carbide composite cladding, improving the performance of existing ceramic fuel and investigating novel forms of TRISO fuel.
Through a programme of multi-disciplinary research at the universities of Manchester and Sheffield, the next generation of nuclear manufacturing scientists and engineers will also be trained with the highest level of academic and technical support, using world-class facilities and with strong links to industry. They will develop high level skills in readiness to fill new high-quality jobs throughout the supply chain created through the growth in the manufacturing sector linked with nuclear build.
By acting as the research engine for nuclear manufacturing, NNUMAN is driving progress and step-change technologies up the Technology Readiness Scale. The most promising manufacturing processes developed in NNUMAN are being taken forward to prototype in the Nuclear Advanced Manufacturing Research Centre (Nuclear AMRC) and, for nuclear fuel, the National Nuclear Laboratory (NNL) so that the UK manufacturing companies can learn the benefits of the new methods and use them in the future. This will help UK companies to stay at the forefront of innovation in the sector, provide more attractive propositions to clients, and ultimately win manufacturing business in the global nuclear sector with the cost-effective production of high quality nuclear components and fuels.