Despite nuclear’s flaws, innovation promises to make it more viable and practical in a decarbonized, decentralized grid. One of the most tantalizing advancements in the nuclear world is the advent of small modular reactors (SMRs). The core technology is the same as conventional nuclear power: nuclear fission. But SMRs are a fraction of the size of conventional nuclear reactors, and their modular design allows their systems and components to be factory-assembled and transported as one unit to be installed on site
As you might expect, SMRs produce less energy than large reactors: less than 300 megawatts compared to over 1,000 megawatts. For scale, a typical SMR produces the power equivalent of dozens of utility-scale wind turbines while a conventional reactor produces as much power as hundreds of those turbines. And smaller size removes some of the economies of scale advantages that larger reactors enjoy.
But their size and modular design means SMRs can be located on sites not suited for large nuclear power plants. In this respect, SMRs might be better suited to take advantage of arguably nuclear power’s greatest strength relative to wind and solar: its power density.
Wind and solar require a lot of land and raw materials to produce a given amount of power. Nuclear material is much more power-dense, so a global proliferation of SMRs could neatly complement a renewable-dominated grid without the large footprints and regulatory complexities of conventional reactors. Some SMRs can produce the same amount of power as a solar or wind farm on strikingly less land. SMRs could work well in locations unable to support large reactors, in addition to powering smaller electrical markets and grids, isolated areas, and sites with limited water. With smaller size comes a friendlier environmental footprint on surrounding areas.
Since they can be pre-fabricated and then installed on site, SMRs are generally cheaper and faster to build than large reactors. Simpler designs allow for simpler and more automated safety protocols, greatly reducing the risk of accidents.
All in all, SMRs build on the best aspects of nuclear energy with added benefits from their smaller size. Nonetheless, they might actually produce more radioactive waste than larger reactors according to recent research. A Stanford study made this conclusion specifically in regards to two aspects of nuclear waste: neutron leakage and spent fuel discharge. The researchers found that overall, small modular designs are inferior to conventional reactors with respect to radioactive waste generation, management requirements, and disposal options.
The first truly modular SMR prototype became operational in Russia in 2020 so the technology is quite new and unproven from a commercial standpoint. Dozens of designs have been proposed or are in progress but it remains to be seen just how widely SMRs will be adopted across the world over the coming decades.
In short, SMRs counteract many of the aforementioned downsides of large nuclear reactors, which are cumbersome and ill-adapted to a more resilient and decentralized energy future. But the cold reality is that nuclear power, no matter how big or small, must be carefully managed to prevent catastrophic damage to surrounding communities.