What is a small modular reactor?
A small modular reactor is a nuclear fission reactor with an electrical output below 300 MW, roughly one-third of a conventional plant. Its modular design allows factory prefabrication and on-site assembly. That makes SMRs cheaper and faster to build than traditional nuclear plants, and lets operators add capacity in steps as energy demand grows.
Key facts:
- Output is typically below 300 MW per unit, versus around 1,000 MW for a large reactor.
- Modules are built in a factory and assembled on-site, which cuts cost and build time.
- Only Russia (2020) and China (2023) operate an SMR commercially today.
With demand for steel continuing to rise, particularly in emerging economies, reducing emissions per tonne of steel is now as important as reducing total emissions from steel production.
Why SMRs, and why now?
Global electricity demand is projected to grow 75% by 2050, driven in large part by AI data centers and the broader electrification of the economy. Tech giants need round-the-clock clean power that solar and wind alone cannot always provide. Nuclear is both carbon-free and always-on, which makes it one of the few sources that can meet that growth while keeping net-zero targets within reach.
The benefits of SMRs
The appeal of SMRs lies in their flexibility and reliability. Because the modules are factory-built and assembled on-site, SMRs deploy faster and at lower upfront cost than conventional gigawatt-scale plants, with capacity added incrementally as demand rises rather than all at once.
Their smaller footprint also suits them to sites close to the facilities they power, such as data center campuses. And like all nuclear power, the electricity they produce is carbon-free and available around the clock, a baseload complement to intermittent renewables like solar and wind.
