The U.S. Is Testing Tiny Nuclear Reactors That Can Go Practically Anywhere

Gizmodo

12-07-2025

In contrast to other technological advances, the objective for next-generation nuclear reactors seems to be to scale down, not up—an initiative backed by the Department of Energy (DOE).
Earlier this month, the DOE announced a conditional agreement made with private firms Westinghouse and Radiant to conduct the first reactor tests at its Demonstration on Microreactor Experiment (DOME) facility, located at Idaho National Laboratory.
These experiments, featuring two trailer-sized microreactors, will be 'the first of their kind in the world' and will assist in meeting 'the nation's demand for more abundant, affordable, and reliable power,' the DOE stated in a press release.
The microreactors eVinci (Westinghouse) and Kaleidos (Radiant) each produce only 5 megawatts and 1.2 megawatts of power. The DOE defines microreactors as small reactors that generate between 1 and 50 megawatts of power. That's tiny compared to traditional reactors, which are capable of generating around 833 times the power of Kaleidos.
That being said, these microreactors aren't meant to power crowded cities. Rather, the compact efficiency of microreactors could greatly benefit small, remote sites that run on less efficient sources. The average U.S. household consumes about 30 kilowatt-hours, or 0.03 megawatts worth of electricity daily—meaning, in theory, Kaleidos on its own could supply many homes in a distant rural area.
Not only that, these microreactors are relatively easy to assemble and transportable by train, truck, or plane. That makes them potentially useful in unexpected situations such as blackouts caused by natural disasters or cyberattacks. For eVinci and Kaleidos in particular, the DOE's intention is to employ the microreactors as a possible power source for remote data centers and an alternative to diesel generators, respectively.
'Microreactors will play a big role in expanding the use of nuclear power in the United States,' added Mike Goff, the Acting Assistant Secretary for Nuclear Energy, in the same release. 'These DOME experiments will test new reactor designs that will be counted on in the future to reliably power our homes, military bases, and mission-critical infrastructure.'
The first fueled experiments at DOME are slated to begin as early as spring 2026, operating for up to six months to test technological ability and efficiency.