Engineers in Wyoming have installed a full-scale digital simulator to prepare operators for a new class of nuclear power plant.
The equipment arrived at the Kemmerer construction site for Bill Gates-backed TerraPower’s Natrium reactor. Built by Curtiss-Wright, the system acts as an exact digital twin of the future facility. It gives technicians their first hands-on access to the plant’s controls well before the reactor goes live in 2030.
Training operators early is a critical hurdle for any non-traditional nuclear design. The simulator runs on a software engine called 3KEYMASTER, which models physics in real time. It calculates how fluids circulate, how temperatures shift, and how the core behaves during unexpected equipment trips. Operators can rehearse emergency drills, test automated safety actions, and log the hours required for federal operating licenses.
At the same time, the system doubles as a testbed for engineers. Curtiss-Wright is also building the plant’s physical brain—its Distributed Control Systems and automated Reactor Protection System. By running those control programs through the simulator, technicians can identify software bugs and verify hardware responses years ahead of fuel loading.
Different from standard reactors
The facility itself operates differently from standard commercial reactors. Most nuclear plants in the United States use light water under intense pressure to cool their cores. The Natrium design uses liquid metal sodium instead. Liquid sodium carries heat efficiently while remaining a liquid at very high temperatures.
Because it boils at nearly 900°C, the system operates at close to normal atmospheric pressure. This removes the need for the massive, thick-walled containment domes that define conventional nuclear stations.
The design also breaks with tradition by separating power generation from nuclear heat production. The reactor generates heat to support a baseline electrical output of 345 megawatts, routing that thermal energy through a molten salt storage system. When grid demand is low, the reactor keeps running at full power while excess thermal energy accumulates in the hot salt tanks.
When local demand spikes, operators draw down that stored heat to generate additional steam. This system can boost electrical output to 500 megawatts for over five hours without changing the reactor core’s baseline output.
Mastering two separate disciplines
Handling this design requires operators to master two separate disciplines at once. They must monitor liquid metal hydraulics in the core while simultaneously running a fast-response thermal storage system. The newly installed simulator lets them practice balancing those heat transfers without affecting reactor stability.
The Kemmerer unit is being built under the US Department of Energy’s Advanced Reactor Demonstration Program. If the site proves viable, TerraPower plans to use this operating model to deploy commercial fleets across the country.
“Building the world’s most advanced reactor demands an equally advanced approach to operator training,” concluded George Piccard, Vice President of Plant Operations at TerraPower.
“By working with Curtiss-Wright to deliver the Natrium Training Simulator, we are laying the foundation to scale a qualified nuclear workforce across every future Natrium plant and ensuring our operators are fully prepared long before the plant comes online.”