US-based Curtiss-Wright Corporation has been awarded two contracts to design and supply plant simulation and digital control solutions for TerraPower’s Natrium advanced nuclear reactor.
Under the contracts, Curtiss-Wright will design and deliver the Training Simulator (TSN) and Distributed Control Systems (DCS) for the Natrium plant. The TSN is a full-scope simulator that will replicate plant equipment and simulate system conditions and operations to support operator training and licensing. The DCS is a digital platform that serves as a core component for automating control and operation of plant processes.
In addition, Curtiss-Wright has been selected to develop two separate control systems for the Natrium plant: the NIC (Nuclear Island Control system) and EIC (Energy Island Control system). Previously, the company was selected to develop the Reactor Protection System for the Natrium plant, and the software platform and engineering services for the Natrium Engineering Simulator.
The Natrium reactor design is a 345 MW sodium-cooled fast reactor coupled with a molten salt energy storage system. The first reactor is being built in Kemmerer, Wyoming and TerraPower has said it expects its first Natrium plant to be online in 2030.
In 2020, TerraPower was selected by the US Department of Energy’s Advanced Reactor Demonstration Program (ARDP) to receive initial funding as part of a $3.2bn programme to develop and build advanced nuclear reactors.
The US Nuclear Regulatory Commission (NRC) in May 2024 accepted TerraPower’s construction permit application for review, marking the first time in more than 40 years that the NRC has docketed this type of application for a commercial non-light water reactor.
In his blog, Terrapower Chairman Bill Gates said he expects the NRC review process to take a couple of years. “So in the meantime, TerraPower will continue to build the non-nuclear parts of the facility”. Construction will begin next year on the so-called “energy island,” which is where the steam turbines and other machinery that actually generate power will sit. (The reactor will eventually be part of a “nuclear island,” and the team hopes to start building that in 2026.)”
However, while the TerraPower website provides some details of work done with molten salt, it contains very little information about the reactor technology. It is also notable that none of the contracts signed with suppliers relate to the reactor itself.
Basically, the Natrium reactor is a sodium-cooled fast reactor. Currently, the only commercially operating liquid metal-cooled fast reactors are in Russia, using sodium as the coolant. Development of these reactors took decades supported by full government support. In the US and Europe research on fast reactors took place in the 1960s and 1970s. However, by the early 1990s the US, the UK and Germany had closed down their programmes. France continued with projects for a few more years, finally closing its Superphénix in 1998 and Phénix in 2009. In 2019, France also cancelled the Generation IV ASTRID sodium-cooled fast reactor demonstrator design project.
Although interest is now reviving in Europe and the USA, it remains at the early design phase and is probably decades away from implementation. As an example, India’s prototype sodium-cooled fast breeder reactor began fuel loading in March 2024. The Indira Gandhi Centre for Atomic Research (IGCAR) began to design the reactor in 1980 and construction only began in 2004, 24 years later. Technical and financial problems then caused further delays.
