Microreactor Ecosystem Overview

Max output and refueling duration for top microreactor companies

10MWe is enough electricity each year to power about 8,000 American homes, charge 25,000 electric vehicles (EVs), operate a medium-scale data center, or desalinate enough water to fill the Empire State Building 18 times.

Microreactors will be fueled prior to arrival on site. After some number of years, the fuel will begin to run low, at which point a new reactor is shipped and installed.

Reactor Types

All giga-scale nuclear reactors use pressurized water to keep the uranium reaction at a constant temperature and to transfer heat from the uranium reaction to turbines that generate electricity. Most of the leading microreactor developers take a different approach, as described below. (So far, none of the leading developers uses molten salt.)

Aalo Atomics Antares Nuclear BWXT HolosGen Last Energy Oklo - 15MWe Oklo - 50MWe Radiant USNC Westinghouse X-energy Liquid Metal Reactor (LM): Uses liquid metal, like sodium or lead, as a coolant to efficiently transfer heat at low pressure. High-Temperature Gas-cooled Reactor (HTGR): Uses a gas, typically helium, as a coolant and operates at very high temperatures (but low pressure) for increased efficiency. Pressurized Water Reactor (PWR): Uses water as both a coolant and moderator under high pressure to keep it liquid at high temperatures.

Reactor Fuel

Broadly speaking, reactor fuels govern the performance and safety of nuclear reactors, with different fuels offering different advantages depending on the reactor design.

Aalo Atomics Antares Nuclear BWX Technologies HolosGen Last Energy Oklo - 15MWe Oklo - 50MWe Radiant USNC Westinghouse X-energy UZrH: A nuclear fuel combining uranium with zirconium hydride, used in compact microreactors for efficient moderation. TRISO: Uranium particles, often made from HALEU, are coated in ceramics, providing high resilience to heat and radiation for advanced reactors. (X-energy uses a proprietary form of TRISO they call TRISO-X.) UO₂: Common nuclear fuel made of uranium oxide pellets, widely used in both traditional and microreactors. HALEU (non-TRISO): Uranium enriched to 5-20% U-235, offering higher energy density and efficiency for advanced microreactors, used outside the TRISO format.