Glossary
SMR
A nuclear reactor under ~300 MW per unit, factory-fabricated rather than site-built, positioned as the firm-power option for AI data centers needing new generation faster than conventional plants deliver.
A nuclear reactor sized under ~300 MW electrical, with most components fabricated in a factory and shipped to site rather than poured on- site. The smaller size and modular construction promise shorter build times and lower capital intensity per project than conventional gigawatt-class reactors, though no commercial SMR has yet operated at scale in the US as of early 2026.
For AI infrastructure SMRs entered the conversation in 2024 when Google contracted Kairos Power for ~500 MW of SMR capacity, Amazon took a stake in X-energy, and several hyperscalers entered into options or offtake agreements. The appeal: SMR build times of 5 to 8 years (claimed) versus 15+ years for new conventional reactors, and the option to site multiple units adjacent to a single data center campus.
The skeptical read is that no operator has yet delivered an SMR in the US on the schedule originally announced; the technology may prove commercially viable but the timing to relieve current gigawatt-class power shortages is uncertain.