Small Modular Reactors

Energy supply is one of the decisive political, economic and ecological challenges facing the planet in the 21st century. Satisfying global energy demand and meeting international targets for combating climate change require the development of low-carbon energies. With this in mind, nuclear power is a key asset in the energy mix of the future.

By 2022, nuclear power supply will be concentrated on high-power plants (between 1,000 MWe and 1,700 MWe per generating unit), and is likely to remain so to meet most of the needs of the major industrialized and emerging countries.

However, for some time now, a number of reactor-designing countries have been convinced of the need to offer the market nuclear power plants with lower power ratings. This has led to the development of innovative small modular reactors, typically below an equivalent of 300 MWe per reactor, called SMR for Small Modular Reactor.

The target market is complementary to that for power reactors. It concerns countries constrained by the size of their electricity grid, their geography or their economy, but also countries keen to introduce maneuverable reactors into an energy mix where intermittent renewable energy sources (wind, solar) are increasingly present.

In addition to the supply of electricity, other functionalities are also open to such an offer, such as the production of heat for industrial processes, cogeneration or the production of fresh water by desalination of sea water, or the production of hydrogen, for example.

However, the competitiveness of today's nuclear power plants is based on a size effect, with ever higher unit power levels. A paradigm shift is therefore required to offer a competitive product for power levels 5 to 10 times lower. It is based on the choice of power plants comprising several low-power reactors, enabling innovative designs and construction methods compared to current reactors: compact, modular for advanced factory production, standardized and mass-produced, thus reducing construction times and risks on site. The measures adopted to guarantee safety and security are made easier and simpler thanks to their low unit power, enabling the use of passive cooling systems, for example.

SMRs therefore open up new prospects for nuclear power and decarbonized electricity generation worldwide.

By 2022, the enthusiasm for SMRs is reflected in the large number of projects at various stages of study (the IAEA lists more than 70) and a number of projects already underway.

Finally, the IAEA inventory of SMR projects includes very low-power reactors (typically under 10 MWe) designed to supply military bases or isolated...