On 2 September TerraPower and GE Hitachi Nuclear Energy (GEH) launched its ‘Natrium’ reactor and energy system architecture. This nuclear technology features a cost-competitive sodium cooled fast reactor combined with a molten salt energy storage system. Building on the technology used in solar thermal generation, Natrium energy storage and flexible power production is said to offer clean energy in time and on a scale that could help meet climate goals. 

The novel architecture simplifies previous reactor types, in that non-nuclear mechanical, electrical and other equipment will be housed in separate structures, reducing complexity and cost. The design is intended to produce significant costs savings by allowing major portions of the plant to be built to industrial standards. The structure uses fewer equipment interfaces and reduces the amount of nuclear-grade concrete by 80% compared to large reactors. Natrium reactors are designed to provide ‘firm, flexible power that seamlessly integrates into power grids with high penetrations of renewables.’

The system features a 345 MWe reactor and can be optimised for specific markets. For instance, its thermal storage has the potential to boost the system’s output to 500 MWe of power for more than five and a half hours when needed. This allows for a nuclear design that follows daily electric load changes and helps customers capitalise on peaking opportunities driven by renewable energy fluctuations. 

“TerraPower values collaboration with GE Hitachi to make nuclear generation as affordable as possible,” said Chris Levesque, TerraPower president and CEO. “Our … development capabilities … financing credibility and achievable funding strategy mean that the Natrium technology will be available in the late 2020s, making it one of the first commercial advanced nuclear technologies.” 

“Our collective experience brings unparalleled capabilities in design and construction that ensure the Natrium product can drive value for our customers,” said Jay Wileman, GEH president and CEO. “We designed this system with operator input to potentially increase their revenues by 20% through the use of energy storage.” 

The Natrium system is said to demonstrate the benefits of modern virtual design and construction tools and has attracted the attention of numerous utilities through the US Department of Energy’s Advanced Reactor Demonstration Programme. PacifiCorp, a subsidiary of Berkshire Hathaway Energy, Energy Northwest and Duke Energy have expressed their support for the commercialisation effort.