This shows that, not only from an environmental point of view, but also in terms of its strategic value, the microreactor could be one of the most important energy innovations of the coming period.
Microreactors, also known as nuclear batteries (NB), reflect a completely new approach, as the tendency has been to build huge and expensive power plants capable of generating a lot of energy, and then deliver it to the consumer. The first shift in this approach has been brought about by modular reactors, which can be built more quickly from prefabricated components but deliver slightly less energy than conventional reactors. Modular reactors have been followed by microreactors, which take the combination of factory fabrication, rapid deployment and lower energy output to the extreme. A microreactor delivers ~1-10 megawatts of energy (compared to 100-300 megawatts for modular plants), but is so small that it can be produced in a factory and fit into an average container. And installation does not require lengthy construction: a single NB can be installed in weeks.
But now we’ll take the other end of the story – not about the device itself, but about where and when it might be used, which is interesting not only because of the relatively recent date, but also because it highlights the many advantages of the microreactor. The United States Air Force will be among the first to use such a device, at the Eielson military base in Alaska as early as 2027. The on-base microreactor will provide up to 5 MW of power, putting it in the middle of the energy range typical of microreactors. According to the Air Force announcement, microreactors are particularly suited to provide power and heating for remote bases such as Eielson Air Force Base.
Eielson currently operates from its own coal-fired power plant, which can provide up to 25 MW of power, but typically only delivers 13-15 MW, and requires burning up to 800 tonnes of coal per day. To operate, 90 days’ worth of coal is kept at the base and managed at a local plant so that it can be used. The base is therefore capable of self-supply, but is also connected to the grid. The microreactor, which would therefore operate in the 1-5 MW range and complement the coal plant, will be owned and operated by a commercial company. Incidentally, Eielson was one of the references in the 2018 roadmap published by the Nuclear Energy Institute and endorsed by the Air Force, which also includes a target date of 2027. According to the document, for installations under the Ministry of Defence, 2-10 MW microreactors are an option – which essentially covers these devices.
Obviously, it is a great benefit in terms of emissions if less coal has to be burned to generate power, but microreactors in this military field also have a number of strategic advantages: they reduce the dependence of the installation on the vulnerable electricity grid and they also generate heat in addition to electricity. In addition, the Department of Defense expects that the energy requirements of similar facilities will only increase as more and more sites will be desalinating water, producing hydrogen, and as increased computing power, “robotic” devices and lasers will also work in this direction.
The US regulator, the Nuclear Regulatory Commission (NRC), is currently in the process of licensing one such device, Oklo’s 1.5 MW Aurora microreactor, for which an application was submitted last year. However, as mentioned above, the development of several such devices is in full swing (more specifically, fission).