What is a small modular reactor?
An SMR is a nuclear reactor designed to be smaller in output than a conventional large reactor, with a design approach that emphasizes factory-made modules or components. “Small” does not mean pocket-sized, and “modular” does not automatically mean portable.
EIA describes microreactors as generally 20 MW or less. They target small, remote or specialized loads.
- Remote sites
- Microgrids
- Some transportable concepts
EIA uses about 300 MW per unit or less as the broad SMR scale. Designs vary widely in technology.
- Grid power
- Data centres
- Industrial heat
EIA notes large designs typically sit around 550–1,500 MW per unit; some current designs are larger.
- Large grids
- Long-lived baseload
- Large industrial systems
“Small” and “modular” describe different things.
Lower output per unit
It is small relative to a conventional gigawatt-scale reactor — not necessarily physically tiny.
More factory-oriented construction
Major components or modules can be fabricated in a factory and transported to the site for installation or assembly.
Portable
Some microreactors are designed for transportability. Many SMRs are still fixed nuclear power plants with normal siting, licensing and security requirements.