SMRs could be built in months using 3D printers
Components for small modular reactors (SMRs) could be built in months using 3D printing or additive manufacturing (AM) technology, according to Udi Woy, additive technology lead at the UK's Nuclear Advanced Manufacturing Research Centre (Nuclear AMRC). She said leaps in AM technology are "opening up further opportunities in nuclear build and design", as companies including Rolls-Royce and Westinghouse invest in SMRs. In March, the UK government launched a competition to find the best SMR design.
Investment in additive manufacturing (3D printing) technology would cut lead times for Small Modular Reactors (SMRs) and offer a competitive advantage for low-volume components and material performance analysis, research experts told Nuclear Energy Insider.

The UK government launched in March a competition to find the best value SMR design and has pledged to spend 250 million pounds ($311.2 million) on nuclear R&D projects between 2015 and 2020, including 30 million pounds on an SMR advanced manufacturing program.

The government will assess the cost-competiveness of design proposals as well as the impact on UK manufacturing technology and skills and wants the first SMR plant to be built in the 2020s.

As part of the R&D program, the Nuclear Advanced Manufacturing Research Centre (Nuclear AMRC) is studying the efficiency and quality of the additive manufacturing (AM) process.

Investment in AM technology could dramatically reduce lead times for major components and raise the commercial viability of multiple SMR reactors, Udi Woy, Additive Technology Lead at the Nuclear AMRC, told Nuclear Energy Insider.

SMR Reactor Pressure Vessels (RPV) might take around three years to build using conventional manufacturing but AM could reduce this to less than six months, she said.

Nuclear AMRC’s research will help build an information database on AM processes and equipment and the quality and traceability of components.

“It’s the role of Nuclear AMRC to support the supply chain and instil confidence for them to get involved with AM production. AM is an opportunity for new business models and we want it to be a contender with manufacturers bidding for SMR build work,” Woy said.

Added value

The U.S. nuclear industry is also examining AM’s impact on costs and delivery lead times.

GE Hitachi Nuclear Energy (GEH) announced June 22 it would lead a $2 million AM research project funded by the US Department of Energy. The project aims to improve the efficiency of manufacturing replacement parts for operational plants in a bid to reduce costs.

GEH is using AM to produce spare parts which will be irradiated at the Idaho National Laboratory (IDL) and compared against unirradiated material.

AM reduces lead times and is proving cost-effective, Fran Bolger, Manager, New Product Introduction at GEH, told Nuclear Energy Insider.

“Cost-wise, AM is about on par with traditional [manufacturing] but the cost continues to drop as the technology matures. The parts are produced faster since manufacturing tooling is simplified,” he said.

AM could be particularly cost effective for low volume components and faster production could optimize parts replacement during outages, Bolger said.

Further research is needed into the quality of AM reactor materials, Bolger noted. Research is currently focused on the quality of light water reactor materials such as stainless steel and Inconel, he said.

GEH's AM device can currently accommodate any component that fits within a build envelope of 400 millimetres cubed (400 mm by 400 mm by 400 mm).

Performance enhancing components, such as GEH’s Defender advanced debris filter, are likely candidates for additive manufacturing, as are parts like jet pump anti-vibration solutions offered as upgrades to Boiling Water Reactors, Hollyn Phelps, GEH spokeswoman, told Nuclear Energy Insider in August.

For new plants, it could be applied to parts such as the fine motion control rod drive (FMCRD), and the development of larger 3D printing machines would allow larger, low volume, high quality components to be produced, she said.

According to Bolger, performance improvements or cost reductions could also be applied to technology in fuel and services, an area where further development is required ahead of the first SMR plants.

Joint projects

To qualify for the U.K. SMR competition, designs must allocate a minimum of 40% of total plant costs to in-factory production of modular components to spur competition between advanced manufacturing technology providers and reduce project costs.

Nuclear AMRC has been working with several reactor developers to identify and prioritize advanced manufacturing capabilities.

Partners include Westinghouse, which aims to reach 100% modularity on its SMR build process. Westinghouse is working with the Nuclear AMRC to increase SMR design efficiencies and reduce build times.

"Particular technologies that we are working on at the moment are things like additive manufacturing or 3D printing, advanced modelling technologies, machine and factory automation and Hot Isostatic Pressing," Mick Gornall, Westinghouse's Vice President and Managing Director for the UK and Middle East, said at the SMR UK Summit on October 18.

Many SMR developers have forecast major investment in advanced manufacturing if successful in the SMR competition.

"At the moment we are looking at a 40 million pound program to support the industrialisation of SMRs," David Orr, ‎Senior Vice President Nuclear at Rolls-Royce, the UK engineering group and SMR developer, told a webinar August 16.

This investment would be provided over 2016-2020 and channelled towards advanced manufacturing, in particular the development of modular and standardized processes, he said.

Data advantage

Advancements in AM technology are opening up further opportunities in nuclear build and design, such as quality assurance.

AM can inspect and tailor individual layers of material, which could improve the microstructure of components being manufactured and significantly impact performance, Woy said.

“AM is a more open process because we can see every layer but we are not taking this opportunity [to use the inspection] to influence performance,” she said.

Nuclear AMRC also plans to study ways to capture valuable manufacturing data at the material’s microstructure level, Woy said. This information could be compiled into formats that clients can use for a variety of testing measures.

Hybrid production combining AM with traditional subtractive machine tooling could further reduce costs. For example, hybrid technology could perform metal surface finishing, which is usually carried out on the component after AM processing.

Automated bulk AM is also being studied, Woy said. This would enable AM to work with recognised systems in an end-to-end manufacturing process from design to finished products.

For now, the primary focus is on improving the quality of AM products, but the technology offers more flexibility than traditional construction methods and could be applied to many systems within the nuclear island, Woy said.

By Karen Thomas