Truck-portable nuclear reactors go where the power is needed

Published in

Purdue Engineering Review

3 min readFeb 28, 2023

Conceptual illustration of a nuclear microreactor inside a truck for transport (Purdue University image)

Nuclear energy is critical for a sustainable future because it is not only a reliable energy source but also one of the lowest CO2 emitters. A recent report from the United Nations Economic Commission for Europe (UNECE) indicated that the lifecycle greenhouse gas emissions per kilowatt of energy generated by nuclear power are less than half those of solar energy or wind energy.

Solar and wind energy, even though their output can be intermittent, still are vital to a sustainable energy mix. With the increase in distributed energy sources such as wind and solar power, and distributed loads in modern smart grids, it is essential to keep reliable, clean nuclear power generating units also distributed. That means we need smaller nuclear power units.

Small modular reactors (SMRs) are nuclear power plants that are rated to produce electrical power from 50 MW to 300 MW, which is a substantially lower power rating than for most existing power plants in the U.S. and elsewhere in the world. Microreactors are nuclear power plants rated from about 100 kW to 50 MW.

One major advantage of microreactors is that they can be built in a factory and manufactured at a large scale, reducing on-site construction costs and making nuclear energy more economical. They also have very low refueling needs — you only need to refuel these reactors once every eight to 10 years, which makes them attractive even for remote applications.

The differentiating capability of these microreactors is that they can deliver power to a specific site for a set amount of time and then can be transported on a truck in a standard shipping container to another location when an energy need arises.

To ensure safe transport, it’s crucial that we characterize the safety features of the microreactors. For example, our team is investigating whether these reactors have sufficiently robust passive safety features to allow them to be transported safely. We must understand their physical design attributes in order to develop appropriate and effective safety envelopes. The microreactors also need to be autonomous to keep operational costs low.

We’re working in a scaled experimental facility to study the passive heat removal from the nuclear reactor core to the environment, analyzing whether the nuclear reactor dissipates its residual or decay heat without any intervention. Our team has developed in-situ thermographic imaging to map simulated reactor core temperatures, and built several computational models that are being validated with experimental data. These models will tell us what the power levels and size constraints on each of these microreactors would be. This research is funded by Department of Energy Nuclear Energy University Programs and the Nuclear Regulatory Commission.

Optimistically, the microreactors we are modeling can be operated safely and securely within the next five to 10 years. The vision is that they can be deployed as stand-alone units or within modern grids as power or heat sources that can deliver on the promise of divergent applications. For example, imagine using a microreactor to fully power a large farm — which always needs intense amounts of energy for fertilizer production or for operating combines or tractors.

This can be the future of the clean and sustainable world, with clean energy supporting many different sectors and uses. Microreactors are perfectly suited for achieving this goal.