As U.S. Companies Build the Future of Nuclear, Argonne Lends Critical Support

By: Argonne National Laboratory via Business Wire

August 24, 2025 at 15:00 PM EDT

In May, the United States took another step toward building the country’s first advanced nuclear reactors at an industrial site. The project at a chemical plant in southeast Texas includes four small modular reactors being developed with support from the U.S. Department of Energy’s (DOE’s) Argonne National Laboratory.

Together with nuclear industry partners, Argonne scientists build on foundational knowledge to innovate new reactor concepts that are expected to be more flexible in site selection and scale and also less costly. These include reactors that could use recycled fuel, power remote communities or military bases, and generate less waste than current reactors to help meet the fast-paced energy needs an AI- and data-driven future demands.

Maryland-based reactor developer X-energy is one of several American companies that collaborate with Argonne to develop the next generation of nuclear energy systems. Its reactors will use a type of fuel called TRISO, a fuel highly resistant to melting down in a high-temperature reactor, which leads some to call it the most robust nuclear fuel on Earth.

The fuel is packed into billiard-ball-size “pebbles” that are fed into the reactor by the tens of thousands. Argonne scientists are providing detailed computational fluid dynamics simulations that describe all the pebbles in the reactor core. The research improves understanding of the fuel pebbles’ thermal efficiency and determines reactor efficiency and safety under different conditions. Additionally, Argonne studies the dynamics of water and vapor in the steam generator that will convert heat from the fuel pebbles into electricity.

With companies like California-based Oklo, Argonne explores ways to extract more power from used nuclear fuel, most of which has the potential to be recycled.

Oklo also used Argonne’s Mechanisms Engineering Test Loop facility and Thermal Hydraulic Experimental Test Article pool-type sodium facility to help validate reactor thermal hydraulic and safety analysis codes used in their license application to the U.S. Nuclear Regulatory Commission.

Companies such as Pennsylvania-based Westinghouse rely on Argonne’s suite of software and codes. These tools promote safety and fuel performance analysis in liquid-metal-cooled nuclear reactors, determine coolant flow and temperature distributions, and analyze neutronics and fuel cycle characteristics.

In work funded partly through DOE’s Office of Technology Commercialization, Westinghouse and Argonne use the WATTS platform to develop optimal design solutions for concepts used in Westinghouse’s eVinci microreactor.

Argonne’s work benefits the U.S. nuclear industry at large. Other recent industry partnerships include ARC Clean Energy, Constellation Energy, Dominion Energy, Electric Power Research Institute, Exelon, Framatome, General Atomics, General Electric-Hitachi Nuclear Energy, HolosGen, Kairos Power, Moltex Energy, TerraPower, Terrestrial Energy and Westinghouse, among others. All of these partnerships seek to bring together the unique capabilities of private industry and the vast resources of a national laboratory to advance cutting-edge solutions to the nation’s nuclear energy needs.

Full story can be read here.