As part of its new energy security strategy, the UK government wants to deliver 24 gigawatts nuclear power by 2050. The Nuclear Advanced Manufacturing Research Centre (Nuclear AMRC), based in South Yorkshire with specialist manufacturing centres throughout the UK, is looking into how advanced manufacturing can help us get there.
Udi Woy is one example of such a process. [UW], Nuclear AMRC Additive Manufacturing Technology Lead, who is responsible for developing the centre’s strategy for AM and AM-focused projects, recently spoke to TCT about the centre’s work with DED, where AM is uniquely equipped to meet the demands of the nuclear market, and future application opportunities.
TCT: Hi Udi. Tell us about the types of AM technologies you’re working with at the Nuclear AMRC.
UW: We primarily use Directed Energy Deposition, (DED). PBF (Powder Bed Fusion), which is also very interesting, is not the main focus of our research. DED is preferred due to its flexibility and ability of scaling. When you’re looking at large-scale or ultra large-scale products and parts, one of the main considerations from an R&D perspective is to investigate the scaling factors because it has a significant bearing on the industrial relevance of our outputs. With AM, you don’t have a linear relationship between inputs and outputs. You can concentrate heat in small areas if you are making a small part. However, if you are building a larger part, you concentrate heat not only locally but also over the entire build. If you’re using DED, even if you’re using powder bed, you’re cooling at different rates, you’re heating at different rates. This has implications beyond the localised heat input. You need to scale your design requirements accordingly.
We were very clear from the beginning about bulk additive manufacturing applications. The emphasis on bulk meaning we’re appropriately scaling the research, the requirements, the parameters, we’re appropriately controlling all of the factors that are of interest in industry so when they come to adopt the process and take the parameters, it’s immediately relevant to the work that they want to do.
TCT: Could you give us examples of AM being used in this sector?
UW: While the process is somewhat similar to other industries, where prototyping and tooling are used to start, there are opportunities to make high entropy materials. These materials are more difficult to process but have the required characteristics to produce critical components and parts. We are very interested in developing qualification methods around both the application and the alloy. For instance, on one of the projects we’ve been investigating 316L and we’ve produced debris filters, which are usually used in fuel assemblies. It’s difficult to fabricate using traditional methods without the proper tooling. It is also expensive. AM can be used to produce things like these.
On the other side, we are focusing on obsolescence and legacy parts. It’s more difficult to restore or maintain legacy parts because they have been in service for a while. It’s not like you are starting with a blank canvas. You can make errors and scale it back to start over.
In terms of where AM could be used is in addressing the requirements for obsolescence and management of legacy parts. We are not yet there, so I said “could” because the current applications are in prototyping and tooling. The stricter the regulations are, the older the component, and the higher the safety and performance requirements.
TCT: You spoke on a panel at TCT 3Sixty about the opportunities for designing parts that are easy to maintain. Is AM redesigning important? Or are certification requirements making it difficult to redesign for AM?
UW AM is a method of creating the material. It doesn’t have to look identical, but it does not mean that it’s similar. The whole purpose of nuclear is to make sure that all critical requirements are met. Also, in terms qualification, ensure that your product or material conforms to any existing codes or standards that apply to similar products. But the approach for demonstrating compliance or equivalence is where you have a lot of work in the creation of standards and implementing nuclear design codes and standards for additive because some may be transferable, in terms of maybe the base material or if you’re using wire for DED, but there are other elements that are specific without any basis for comparison.
Because durability and maintenance are closely linked, I believe that a part should last at least 60 years. You also need to be capable of maintaining it for that long. To understand how it behaves you need to look at fatigue. Over time things wear down. Your normal wear and tear is not the only thing you need to look at. You also have to take into account your operating environment.
TCT: Also, you mentioned the sustainability possibilities, particularly in relation to large structures. Could you please elaborate?
UW: Forging reactor pressure vessels requires heavy engineering and plans. Special tooling and methods are also required. AM is being used in the industry for prototyping, tooling, and other purposes. We can also explore new ways to think about sustainability. My research with another partner has focused on stacking different materials and using AM to layer them or get the final dimensions. This allows me to be more creative in how I apply technology. The most important question I believe is: How can advanced manufacturing technologies be used to improve manufacturing efficiency and address future and present challenges? For example, I believe AM could be used to enable large-scale on-site manufacturing. There are so many things we could do but the question is, how can we further exploit it? Although we are not where we want to be, I believe we are moving in the right direction.
TCT: Which AM capabilities are needed to increase in order to meet nuclear sector demands?
UW Combining skills training with experience would be a great combination. This is basically looking at the sector’s challenges and how AM could help. My apprenticeship was completed with a toolbox that I had to construct. Our CEO spoke of how he made his own tools and toolbox. The next generation can print the toolbox and the tools. It’s just about attracting the next generation nuclear professionals. AM is so attractive because you can create exactly what you want, and you can review those designs eventually, but the freedom to start there creates that freedom. This is what I believe is the most important thing going forward, because nuclear technology is not something that can be done in a few years. It’s a long-term strategy. This strategy isn’t just for now. It’s also for the next generation and all generations before it. How can we tie it all together? AM can bring all these perspectives together around one technology and one approach to working. This opens up a world of possibilities but you must start somewhere. AM is an accessible method of starting that journey. It also introduces the next generation of nuclear manufacturing to the entire world. The goal is to provide clean energy for the future.
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