The Nuclear Energy Agency (NEA) has recently published a 73-page study, which tracks the progress of selected small modular reactor (SMR) designs towards deployment. NEA says the SMR designs are at various stages of development, from fundamental research on new concepts to commercial deployment and operation of mature designs.

NEA notes that the International Panel on Climate Change (IPCC) found, on average, the pathways for the 1.5 degree C scenario would require installed nuclear capacity to reach 1,160 GWe by 2050, up from 394 GWe in 2020. “While the IPCC nuclear target is ambitious for nuclear energy, it is not beyond reach,” according to NEA. “Recent NEA analysis … finds that this target can be achieved through a combination of the long-term operation of existing plants and building large-scale Generation-III new builds and SMRs. It will also include leveraging both power and non-power applications of nuclear energy, including nuclear heat for industry and district heating, nuclear-based hydrogen and synthetic fuels.”

NEA estimates that by 2050 SMRs could reach 375 GWe of installed capacity in an ambitious case, contributing to more than 50% of this capacity gap. The SMR technology pipeline includes a range of technology readiness levels and regulatory readiness levels. Some technologies are already demonstrated (at lab and commercial scales), while others are still in the R&D stage. NEA says timelines for deployment vary based on technology and regulatory readiness levels, with some designs expected to be demonstrated and commercialised before 2030 with others to follow later in the 2030s.

NEA believes less mature SMRs will also play a role in meeting decarbonisation objectives. SMRs and advanced reactors with high levels of technology and licensing readiness will play a central role in getting to net zero by 2050 by supporting decarbonisation efforts that are expected to gain pace in the 2030s and 2040s. SMRs and advanced reactors with lower levels of technology and licensing readiness could be deployed at scale from the 2040s to supply electricity, heat and hydrogen and would contribute to long-term sustainability of nuclear energy after 2050 when associated with advanced nuclear fuel cycles. The report urges policy support for SMRs with high and low levels of technology and licensing readiness.

The NEA SMR Dashboard studies only 21 specific SMRs with respect to six key areas: licensing; siting; financing; supply chain; engagement; and fuel. The 21 reactors include:

  • ARC-100 (ARC Clean Technology, Canada), a 286 MWt fast reactor fuelled by metallic uranium dioxide (UO2);
  • CAREM (CNEA, Argentina), a 100 MWt thermal reactor fuelled by UO2 pellets;
  • APCR50S (CGN, China), a 200 MWt thermal reactor fuelled by UO2 pellets;
  • ACP100 (CNCC, China), a 385 MWt thermal reactor fuelled by UO2 pellets;
  • Nuward (EDF, France), a 540 MWt thermal reactor fuelled by UO2 pellets;
  • BWRX-300 (GE-Hitachi, USA), an 870 MWt thermal reactor fuelled by UO2 pellets;
  • Hermes (Kairos Power, USA), a 35 MWt thermal reactor fuelled by TRISO pebbles;
  • SEALER-55 (Leadcold Reactors, Sweden), a 140 MWt fast reactor fuelled by metallic UO2 pellets;
  • Stable Salt Reactor-Wasteburner (Moltex Energy, Canada), a fast reactor fuelled by molten salt;
  • VOYGR (NuScale Power, USA), a 250 MWt thermal reactor fuelled by UO2;
  • Aurora (Oklo, USA) a 4 MWt fast reactor fuelled by metallic UO2;
  • Rolls Royce SMR (Rolls Royce SMR, UK), a 1,358 MWt thermal reactor fuelled by UO2 pellets;
  • KLT40S (Rosatom, Russia), a 150 MWt thermal reactor fuelled by UO2 pellets;
  • RITM-200N (Rosatom, Russia), a 190 MWt thermal reactor fuelled by UO2 pellets;
  • RITM-200S (Rosatom, Russia), a 198 MWt thermal reactor fuelled by UO2 pellets;
  • Natrium (Terrapower, USA), an 840 MWt fast reactor fuelled by metallic UO2;
  • HTR-PM (INET-CNNC, China), a 500 MWt thermal reactor fuelled by TRISO pebbles;
  • MMR (UltraSafe Nuclear, USA), a 15 MWt thermal reactor fuelled by TRISO prismatic;
  • U-Battery (Urenco, UK), a 10 MWt thermal reactor fuelled by TRISO prismatic;
  • eVinci (Westinghouse, USA), a 13 MWt thermal reactor fuelled by TRISO;
  • XE-100 (X-energy, USA), a 200 MWt thermal reactor fuelled by TRISO-X pebbles.

These include 10 water cooled reactors; four gas-cooled reactors; four fast reactors and two molten salt reactors. NEA also classifies them according to reactor configurations including 17 land-based designs; five multi-module designs; three marine-based designs; and one mobile design.

NEA notes that SMRs can replace fossil fuels for on-grid power generation, diesel generators for off-grid mining and industrial operations, and fossil fuels for cogeneration of heat and power for heavy industries and district heating. They can also enable large-scale water treatment and desalination to produce clean potable water. “These varied market needs have prompted the development of a range of SMR technologies, which vary in technology, sizes, and configuration.” NEA comments: “Policymakers are often overwhelmed with this great variety as they strive to consider which designs might meet their particular needs and in what time frame.”

It says the NEA SMR Dashboard is designed to help navigate this complex area of technology. It adds that future editions will continue to track the progress of these designs and include additional SMR technologies as verifiable information becomes available and is assessed.

However, missing from the array of information on this selection of widely different SMRs is projected deployment dates. Some of these companies have suggested somewhat optimistic dates for operation of their first units. For example, USNC has suggested 2027 for its MMR, while Kairos (Hermes) has suggested 2026. Terrapower (Natrium), Urenco (U Battery) and X-energy (Xe-100) have all suggested 2028, although Terrapower has since indicated a delay of two years due to problems with fuel development. Leadcold initially suggested 2025 for its SEALER-55 but later amended that to 2030. Others scheduled for the early-mid 2030s include EDF’s Nuward, NuScale’s VOYGR, the Rolls Royce SMR and the Westinghouse eVinci. Meanwhile, Russia’s KLT40S and China’s HTR-PM are already in operation.

Much greater detail is available in the International Atomic Energy Agency’s (IAEA’s) most recent edition of its biennial IAEA booklet, Advances in Small Modular Reactor Technology Developments, published in 2022. This provides data on SMRs around the world, including detailed descriptions of 83 reactors under development or construction in 18 countries. The 424 pages provide details of the technologies involved while Annex I summarises the information in a series of tables, including deployment timelines. The first booklet in this series was first published in 2014 and serves as a supplement to the IAEA’s Advanced Reactors Information System (ARIS), an online database with comprehensive information on the latest developments in advanced reactors.

IAEA notes in its introduction to the latest edition: “Several major milestones have been reached in SMR technology deployment. The Akademik Lomonosov floating power unit in the Russian Federation with two-module KLT-40S was connected to the grid in December 2019 and started commercial operation in May 2020. The HTR-PM demonstrator in China was connected to the grid in December 2021 and is expected to reach full power operation by the end of 2022. The CAREM25 in Argentina is under construction and is expected to reach first criticality in 2026. The construction of ACP100 in China started in July 2021 and is targeted to start commercial operation by the end of 2026. The construction of BREST-OD-300 in Russian Federation began in June 2021 and is planned to be completed in 2026. The NuScale Power Module in the United States has received Standard Design Approval from US NRC in September 2020. The NRC has directed to issue a final rule that certifies NuScale’s SMR design for use in the United States.”

All the other designs, including those mentioned by NEA, are either in the pre-conceptual/conceptual or basic/detailed design stages. Those still in the conceptual design stage include U Battery, eVinci, Nuward and Sealer-55.

IAEA notes that the technical description and major technical parameters in the booklet “were provided by the design organisations without validation or verification by the IAEA. All figures, illustrations and tables in technical description of each design were also provided by the design organisations.” A similar caveat is given by NEA.