Simple comparison
Microreactor vs SMR vs large reactor
They all use nuclear fission, but they are designed for very different scales. The easiest way to understand the difference is to start with the load they are trying to serve.
Microreactor
1–20 MW-ish
Small enough to target isolated or specialized loads. Some concepts emphasize transportability and long refueling intervals.
- Smallest load
- Remote / resilient power
- Least commercially mature category
SMR
~50–300+ MW
A middle scale aimed at factory-oriented construction, grids, industry and large dedicated customers.
- Medium load
- Grid + industry
- Several designs in licensing / construction pathways
Large reactor
~1 GW+
Built for major grids and very large, long-duration electricity supply.
- Largest load
- Fixed-site infrastructure
- Most established commercial category
| Microreactor | SMR | Large reactor | |
|---|---|---|---|
| Typical role | Remote / local | Regional / industrial | Major grid generation |
| Transportable? | Some designs aim for it | Usually not after installation | No |
| Can provide heat? | Many concepts can | Many designs can | Possible, project-dependent |
| Main trade-off | Small output, early market | Modularity vs project economics | Huge output, very large project |
Try a scenario
Start with the load instead of the label.
Scale reference
U.S. EIA — large reactors, SMRs and microreactors