Can nuclear reactors really travel by truck? The tiny power plants raising huge questions about cost, safety and security

A conventional nuclear plant is built on a huge scale. A single reactor can produce around 1,000 megawatts of electricity for a large grid. Microreactors take almost the opposite approach.

These systems are designed to be small enough for transport by truck, trailer or cargo aircraft. They can produce up to about 10 megawatts and, in some designs, carry enough fuel to operate for years without refuelling. The idea is to turn the reactor into a self-contained power source rather than another piece of permanent grid infrastructure.

That could matter in places where building a conventional power station makes little sense. Developers are looking at remote Alaskan communities, mining sites, data centres and military bases. The US Department of Defense is supporting four demonstration programmes, with the first projects expected to be tested as early as 2027.


Radiant Nuclear is among the companies working on the concept. Its plan is to assemble and fuel reactors in Tennessee before sending them to customers. The company sees them as a possible replacement for diesel generators in locations that need dependable power away from the main grid.

Can nuclear reactors really be small enough to travel by road?

Electricity is only part of the pitch. A small nuclear reactor also produces heat, and that could be useful for industrial sites that already need large amounts of thermal energy.

Researchers at the University of Illinois Urbana-Champaign are working with NANO Nuclear Energy on a proposed microreactor beside an existing campus power facility. The project is intended to show how a reactor could work alongside conventional infrastructure instead of operating as an isolated power plant.

The system is expected to produce steam at about 550°C. Some of that output could support electricity generation, while remaining heat could be used for buildings.

Industrial applications are more complicated. Steelmaking, for example, can require temperatures above 1,600°C. A microreactor cannot provide that temperature directly through its steam output. One proposed solution is to use electricity from the reactor to run additional heaters.

That could allow a single nuclear installation to supply both power and part of the heat needed at a factory. It is a different proposition from simply selling electricity to the grid.

The economic case remains unsettled. Large nuclear plants benefit from economies of scale because construction and operating costs are spread across a much larger electricity output. Microreactors give up much of that advantage.

Energy researchers have questioned whether civilian projects can compete with cheaper power sources such as solar, wind and natural gas. Supporters counter that factories could eventually produce large numbers of identical reactors, reducing manufacturing costs through repetition.

There is another expense that is harder to avoid. A factory handling nuclear fuel and assembling complete reactors would need substantial safety and regulatory infrastructure. Those costs could be difficult to spread among customers when each reactor is intended for a relatively small, remote site.

Transport creates another problem.

Microreactors designed for long operating periods may use high-assay low-enriched uranium, or HALEU, with enrichment reaching 20% uranium-235. Conventional commercial reactor fuel is typically enriched to around 3% to 5%.

Radiant Nuclear has proposed placing neutron-absorbing control blades into the reactor during transport. The aim is to keep the nuclear reaction suppressed while the unit is moving.

Researchers at the University of Nevada, Reno are studying the risks of transporting these systems. Their concern is partly about scale. A few shipments are one thing. A large industry moving hundreds or thousands of fuelled reactors over long distances would create many more opportunities for accidents.

The fuel also raises a security question. Uranium at or above 20% enrichment is classified as highly enriched uranium and can be used directly in nuclear weapons. That makes the movement and storage of HALEU a concern beyond ordinary transport safety.

If microreactors become widespread, international inspectors could also face a much larger monitoring task. The International Atomic Energy Agency currently uses physical inspections to track nuclear materials and verify safeguards. Thousands of small reactors scattered across remote locations would make that job considerably more difficult.

The technology is moving ahead before all of those questions have been settled. The US government wants demonstration reactors operating before the end of the decade, while companies are preparing designs for testing.

The central question is no longer whether a nuclear reactor can be made small enough to move. It is whether the economics, transport arrangements, security measures and regulatory system can keep pace with the idea.