SMRs are smaller, both in terms of power output and physical size, than conventional gigawatt-scale nuclear reactors. Typically, SMRs are nuclear reactors with power output less than 300 megawatts electric (MWe), with some as small as 1-10 MWe.
SMRs are designed for modular manufacturing, factor production, portability and scalable deployment.
SMRs use nuclear fission reactions to create heat that can be used directly, or to generate electricity. Some SMRs are based on currently deployed technologies, while others are based on so-called “Generation IV” and advanced reactor concepts.
Pathways to net zero call for installed nuclear capacity to triple by 2050.
Considering the magnitude of global emissions reduction targets, both long-term operation of existing nuclear power plants as well as new builds of Generation III gigawatt-scale reactors have important roles to play. In addition, a wave of innovation in small modular reactors (SMRs) could unlock even further emissions reductions by reaching into hard-to-abate parts of the economy, providing off-grid options, and options for sites that do not require (or cannot support) gigawatt-scale power generation.
The 2021 NEA report Small Modular Reactors: Challenges and Opportunities offers an overview of recent progress with the development and deployment of SMRs. The report discusses the key economic drivers of this innovative nuclear technology and highlights market opportunities for SMRs to support decarbonisation strategies, complement variable renewables as well as facilitate access to nuclear energy in new sectors and regions. The report also emphasises the need to review regulatory and legal frameworks and suggests grouping SMRs into different categories to support these policy changes. Finally, the report stresses the role of government support and international collaboration to enable large-scale SMR deployment.
SMRs bring a number of unique design features that support both the safety case and economics of these innovative reactors. This includes integral designs that contribute to a robust inherent safety case, low core inventories to reduce the need for emergency planning zones, improved modularisation and manufacturability that would transform nuclear new builds delivery models, and enhanced flexibility for nuclear energy to further support variable renewables integration in the electricity mix.
Cost competitiveness of SMRs will depend on several factors. Modularisation is planned to drive new delivery models, with factory production expected to drive down unit costs through economies of series. The price of carbon and regulatory costs will also be key drivers of the economics of SMRs.
While the pace of SMRs deployment is still subject to a number of uncertainties, it is clear from existing market outlook studies (e.g. NEA, Canada’s SMR Roadmap, National Nuclear Laboratory, McKinsey & Company) that these reactors could see a rapidly increasing rate of construction in net zero pathways, with several SMR designs expected to be commercially deployed within 5 to 10 years to contribute to near-term and medium-term emissions reductions.
Up to 2035, the NEA estimates that the global SMR market could reach 21 gigawatts (NEA, 2016). Afterwards, a rapid increase in build rate can be envisaged with construction between 50 and 150 gigawatts per year considered by McKinsey & Company (2018). Assuming a build rate that reaches 75 gigawatts per year by 2050, up to 375 gigawatts of installed capacity would be built over the next three decades.
This would translate into 15 gigatonnes of cumulative CO2 emissions avoided.
Read more about the potential of SMRs to contribute to climate change mitigation efforts in the NEA's latest publication Meeting Climate Change Targets: The Role of Nuclear Energy.
The mission of the NEA is to assist its member countries in maintaining and further developing, through international co-operation, the scientific, technological and legal bases required for a safe, environmentally sound and economical use of nuclear energy for peaceful purposes. It strives to provide authoritative assessments and to forge common understandings on key issues as input to government decisions on nuclear energy policy and to broader OECD analyses in areas such as energy and the sustainable development of low-carbon economies.
The NEA SMR Strategy is the Agency’s cross-cutting approach to carry out its mission and deliver on member countries’ priorities related to SMRs. The NEA SMR Strategy creates an analytical framework for understanding and analysing the conditions for successful development and deployment of SMRs across various power and non-power markets. It facilitates gap analysis and work planning across the Agency, to ensure the current and future NEA programmes of work directly support priorities of member countries related to SMRs, and supports dialogue and co-operation with member countries as well as partners and stakeholders.
SMRs are included in the Strategic Plan of the Nuclear Energy Agency 2023-2028, which situates SMRs and nuclear energy more generally within a broader strategic context of priorities on net zero and security of energy supply. NEA member countries have included SMRs across the NEA Strategic Programme Areas: Nuclear safety technology and regulation; Human aspects of nuclear safety; Nuclear science; Development and innovation in the civil use of nuclear energy; Radiological protection of people and the environment; Radioactive waste and spent fuel management; and Nuclear decommissioning and legacy management.
Beyond technical feasibility, the NEA SMR Strategy connects the technology push of the landscape with the market pull for innovative nuclear concepts, addressing the full set of conditions for success. The Strategy is built around three themes: Technologies; Enabling conditions; and Applications and markets.
The first SMR concepts are being demonstrated today, with commercial deployment expected in the next five to ten years.
Under the first theme, activities focus on technology development from research to commercialisation. This includes research infrastructure, research and development, and laboratory studies that directly contribute to the safety assessment for new nuclear technologies. This theme considers SMRs - including Generation IV reactors - of various sizes, temperatures, fuel cycles, and technology readiness levels. Various reactor concepts are considered: water-cooled; gas-cooled; fast spectrum; molten salt, and micro reactors. Various reactor configurations are also considered: land-based; marine-based; mobile; and multi-module variations.
NEA activities under this theme support research, development, demonstration, and safety assessments to accelerate innovation and commercialisation. Activities under this theme by the NEA, in collaboration with partners, create a basis for authoritative safety and technology assessments of SMR and Generation IV reactor technology readiness and development readiness more broadly.
There are several essential conditions to connect supply and demand.
The second theme considers conditions for success beyond technical feasibility. Enabling conditions are the measures that bridge the supply side with the demand side of the SMR market, ensuring that technologies can be successfully deployed for a range of applications. Technologies must be a good fit to connect with the specific market applications.
This theme considers enabling frameworks, such as policy frameworks, regulatory readiness, legal aspects and safety as well as security and non-proliferation frameworks. Governments and international organisations have a role to play in creating the enabling frameworks, including policies, regulatory readiness and legal aspects. Safe and secure SMR fuel supply chains are essential, as is a responsible plan for the management of the back-end of the fuel cycle. Similarly, supply chains more broadly and infrastructure, as well as human resources, a pipeline of talent, public engagement and trust are essential enablers of SMR and Generation IV innovation. Equally importantly, costs must be competitive and a mix of public and private financing are required to enable demonstration and deployment of nuclear innovation.
Strategic partnerships will be key to successful technology development, as the centre of gravity for nuclear technology development has shifted toward the private sector. Collaborations with national laboratories and research institutions will continue to be key for successful research, development, and demonstration, as well as safety assessments and access to critical research infrastructure.
SMRs are positioned to open up new markets and applications for deep decarbonisation.
The third theme is focused on developing a clear understanding of the demand side of the SMR market.
Markets are signalling the need for innovative technologies to address energy and climate challenges, including in hard-to-abate industrial sectors. A key market around the world for SMRs and Generation IV reactors is on-grid to replace coal power generation. Beyond on-grid power generation, however, several other markets are signalling interest in SMRs and Generation IV reactors: off-grid heat and power to replace diesel generators in remote regions including for mining operations; high temperature heat to replace fossil cogeneration in heavy industries such as chemicals processing and potash production for the fertilizer industry; and marine propulsion to replace bunker fuel for merchant shipping.
These markets represent emerging – and often disruptive – applications of nuclear energy technologies. Near-term policy and investment decisions will play a key role in shaping overall market outcomes. Public policy and private sector decision makers alike are looking for authoritative assessments to understand and map market demand, in terms of power requirements, temperature ranges, as well as other operational and technical requirements for specific applications. This includes: technological and market challenges associated with sector coupling; logistical and regulatory challenges related to mobility and transportability of nuclear modules and reactors; end user decision making criteria and timelines; as well as an understanding of the competitive landscape in each specific market.
The NEA is well positioned to play a central role in connecting with prospective end users and customers to understand their future requirements, evaluate overall market potential, and facilitate sector coupling.
Through the activities of its Standing Technical Committees and Technical Secretariat for NEA-serviced bodies (Generation IV International Forum, International Framework for Nuclear Energy Cooperation), the Agency is advancing many activities across the three themes of the NEA SMR Strategy.
Click here to view the NEA Standing Technical Committees.
The Agency also collaborates with key partners on SMR initiatives, including the Generation IV International Forum and the International Framework for Nuclear Energy Cooperation.
More about Generation IV International Forum
More about International Framework for Nuclear Energy Cooperation
This page will be updated periodically as the NEA SMR Strategy is implemented.