US-based GE Hitachi Nuclear Energy (GEH) and Advanced Reactor Concepts (ARC Nuclear) on 12 March signed a memorandum of understanding (MOU) to collaborate on the development and licensing of an advanced small modular reactor (SMR) based on Generation IV sodium-cooled fast reactor technology.

The aim is to initially deploy the SMR design in Canada. The companies said they will pursue a “preliminary regulatory review” by the Canadian Nuclear Safety Commission. The commercialisation programme also includes the near-term goals of confirming projected construction and operating costs, as well as finding a lead-plant owner/operator for the reactor.

GEH and ARC Nuclear have each developed advanced reactor designs based on the EBR-II, an integral sodium-cooled fast reactor prototype which was developed by Argonne National Laboratory and operated for more than 30 years at Idaho Falls, Idaho. Both designs share fundamental features, such as high energy neutrons, liquid sodium cooling and metallic fuel, which together deliver inherent safety performance and more economically competitive plant architecture compared to traditional water-cooled reactors. GEH said that, while there are more than 90 advanced nuclear technology and SMR designs under various stages of development, GEH and ARC Nuclear view sodium fast reactors as being “the most mature advanced reactor technology with decades of real operating experience from more than 20 previous reactors”.

GEH's Prism reactor has a rated thermal power of 840MWt and an output of 311MWe. Two Prism reactors make up a power block, producing a combined total of 622MWe of electrical output. The use of passive safety, digital instrumentation and control, and modular fabrication techniques expedite plant construction The design uses metallic fuel, such as an alloy of zirconium, uranium, and plutonium, and can therefore be used to close the nuclear fuel cycle, recycling used nuclear fuel to generate energy. It is designed to be refuelled every 12-24 months. GEH has previously proposed the Prism reactor to manage the UK's plutonium stockpile.

ARC's ARC-100 modular 100MWe model would use a 'novel' metal alloy fuel, with the uranium-fuelled reactor core submerged in a tank of liquid sodium at ambient pressure. It would have a refuelling interval of 20 years. ARC Nuclear chairman and CEO Don Wolf said, "ARC Nuclear has a heritage of sodium fast reactor experience that includes key senior scientists and engineers from the EBR-II prototype program – technical leaders involved in developing and demonstrating the fast reactor foundational technology with the US Department of Energy." He added, "We are confident that this collaboration with GEH will more rapidly bring affordable carbon free, utility-scale nuclear power to the evolving energy market landscape."

Last October, GEH and Southern Nuclear signed an MOU to collaborate on the development and licensing of fast reactors including GEH's Prism. The companies also agreed to work together in future US Department of Energy advanced reactor licensing programmes.