As the world seeks reliable low-carbon energy sources, small modular nuclear reactors have re-emerged as a promising yet debated solution. Their compact, factory-built design and passive safety systems mark a shift from the era of massive nuclear plants toward more flexible, distributed energy generation. With countries starting to deploy first-generation SMRs, questions of safety, cost, waste, and equity will determine whether this technology becomes a bridge to a cleaner energy future or another complex challenge in the global transition.
The Science Brief on Small Modular Nuclear Reactors (SMRs) opens by defining SMRs as advanced nuclear fission reactors producing under 300 megawatts per unit—compact systems manufactured off-site and assembled modularly to reduce cost and construction time. It highlights their potential to complement renewable energy by providing stable, low-carbon power and heat for diverse uses such as desalination and hydrogen production.
The Brief explores major advances in reactor design, safety, and cost optimization, noting the growing number of prototypes worldwide. It then examines persistent challenges, including waste management, supply-chain constraints, regulatory uncertainty, and the risk of proliferation.
It concludes by emphasizing key priorities for the coming decade: developing global safety and monitoring standards, ensuring equitable access and public understanding, and integrating SMRs responsibly into hybrid renewable-nuclear energy systems to advance the transition to net-zero.
Small Modular Reactors are designed to combine the efficiency and flexibility of factory-built systems with advanced safety features, offering a potential path toward low-carbon, scalable, and more adaptable nuclear power.
Additional Resources
- Kuznetsov, V., & Karnaukhov, A. P. (2019). Innovative Small and Medium-Sized Reactors: Design Features and Technology Trends. IAEA Proceedings, CN-164.
International Atomic Energy Agency. (2021, September). Nuclear Energy for a Net Zero World. IAEA. - SMR Regulators’ Forum (International Atomic Energy Agency). (2023, February). Safety, Security and Safeguards: An Integrated Approach – Phase 3 Report. IAEA.
Access the brief here.
