smr

SMR stands for small modular reactor, a class of nuclear reactors designed to be manufactured in factories and assembled on site, with a power output generally up to 300 MWe per unit. The modular approach aims to reduce capital costs and shorten construction times compared with traditional large reactors, enabling incremental capacity and deployment in locations unsuitable for large plants, such as remote communities or industrial sites.

Most SMR concepts are light-water reactors, including designs that place the primary coolant system and other components inside a single vessel. Many incorporate passive safety features and natural circulation to remove decay heat, reducing reliance on active pumps. Proponents argue these features can improve safety margins and construction predictability, while enabling standardized, factory fabrication and simpler on-site operations.

Regulatory pathways vary by country. In the United States, NuScale Power's SMR design received design certification from the Nuclear Regulatory Commission in 2020, the first SMR to achieve this milestone. Other designs have pursued licenses in the United States, United Kingdom, Canada, and additional jurisdictions. Common regulatory considerations include safety analysis, fuel and waste management, site evaluation, and decommissioning, along with ensuring supply chains for standardized components.

As of the 2020s, SMRs are in development with few in commercial operation. Their economics depend on factory fabrication, standardized design, and licensing timelines. Proponents cite reduced upfront capital and scalable deployments; critics point to high unit costs, supply chain constraints, and regulatory hurdles relative to large reactors and other energy options.