Steve Martin was ahead of his time when he told us “Let’s get small!” While you usually think of a nuclear reactor as a big affair, there’s a new trend towards making small microreactors to produce power where needed instead of large centralized generation facilities. The U.S. Department of Energy has a video about the topic, you can watch below.
You probably learned in science class how a basic nuclear fission reactor works. Nuclear fuel produces heat from fission while a moderator like water prevents it from melting down both by cooling the reactor and slowing down neutrons. Control rods further slow down the reaction or — if you pull them out — speed it up. Heat creates steam (either directly or indirectly) and the steam turns a conventional electric generator that is no more high tech than it ever has been.
One of the key benefits of a small reactor is that it is transportable. That means you can build them in an efficient central location and move them where you need them. Generally, these new reactors have passive safety systems, automated control systems, and can operate for a decade without new fuel. While there are several technologies in development, the Department of Energy says that the earliest available microreactors will use gas or heat-pipe cooling. Liquid metal and molten salt systems are also promising but probably will arrive later.
Of course, small is a relative term. These reactors produce from 1 to 20 megawatts of power and look like they might fit on a large truck. We don’t expect a nuclear-powered laptop anytime in the near future.
Maybe these new reactors will benefit from additive manufacturing. Of course, submarines and naval surface ships have had tiny and reliable reactors for a long time. One obvious application for a transportable reactor is to power a means of transportation.