New Nuclear Manufacturing (NNUMAN) is a major programme delivering new long-term research into innovative manufacturing techniques for the future needs of the UK nuclear industry. The programme focuses on early-stage research into a range of manufacturing technologies, the most promising of which will go into advanced development at the Nuclear Advanced Manufacturing Research Centre (Nuclear AMRC) and National Nuclear Laboratory (NNL).
The programme, managed by the Dalton Nuclear Institute at The University of Manchester and supported by the Nuclear AMRC at the University of Sheffield, has received £4 million funding from the Engineering and Physical Sciences Research Council, with the two universities committing a further £4 million, and further financial and in-kind support coming from industry.
NNUMAN addresses the fundamentals of advanced manufacturing for new reactors and the next generation of nuclear power stations. This key research effort is driving progress towards new, high productivity nuclear manufacturing technologies and their transition from the laboratory to production-readiness.
NNUMAN involves multidisciplinary research projects at the universities of Manchester and Sheffield, involving a high level of academic and technical support and training for the next generation of nuclear manufacturing scientists and engineers.
Innovative joining technologies
The strict quality standards and slow product cycle of the nuclear industry have historically limited the uptake of many innovative welding and joining technologies. The Dalton Nuclear Institute brings together expertise from The University of Manchester to advance the most promising techniques and study their microstructural effects to prove their fitness for current and future nuclear applications. Techniques under investigation include narrow groove arc welding, electron beam and laser welding of reactor steels.
Advanced machining and surfacing
Future designs for large nuclear vessels and components will require more efficient machining techniques for both existing and future reactor materials. The Nuclear Advanced Manufacturing Centre at the University of Sheffield is leading research to develop and characterise optimised cutting techniques, which include key aspects of machine dynamics. This research explores highly innovative approaches for machining very large components, for example using deep-hole drilling and using machining robots with indoor positioning systems, together with assisted machining techniques.
Near-net shape and engineered structures
Components such as reactor vessel nozzles and valve bodies are usually machined down from forgings or billets. By producing raw parts that are closer to their final shape, manufacturers could significantly reduce material waste, cost and lead times. The Dalton Nuclear Institute is testing ‘near-net’ production processes for nuclear applications. These new processes include Hot Isostatic Press (HIP) techniques (currently used in aerospace, and oil and gas industries, where research is concentrated on developing a detailed understanding of the correlation between powder properties, manufacturing process and finished material properties), weld-based additive manufacturing and the fabrication of specialist ceramic and coated materials required for advanced nuclear fuels.
Advanced Nuclear Fuel
Research into improvements in fuel cladding that provide greater margin under accident conditions (Accident Tolerant Fuels) have included the investigation of use of new fuel cladding materials such as silicon carbide composite where joining provides a challenge. More generally, the design of advanced fuels tends to build on scientific discovery and new knowledge at a more fundamental level. NNUMAN has 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.
Underpinning materials research in NNUMAN
New manufacturing technologies can change the stress state, material and microstructural properties of components and affect their behaviour in a nuclear environment. As components in next generation reactors may be in use for over 60 years, it is vital to thoroughly understand these changes and build corresponding modelling and predictive approaches, which in turn will feed through to code case development.
The Materials Performance Centre at The University of Manchester leads NNUMAN’s research in this area and performs studies and tests which underpin all other parts of the NNUMAN programme. NNUMAN projects also make use of the advanced environmental testing facilities at The University of Manchester and the Dalton Cumbrian Facility to study the effects of radiation on the structure and performance of materials.