The 2020 edition of the biennial International Atomic Energy Agency (IAEA) booklet, Advances in Small Modular Reactor Technology Developments provides the latest data and information on SMRs around the world, including detailed descriptions of 72 reactors under development or construction in 18 countries.
Expanding on previous editions, the booklet for the first time contains annexes on waste management and disposal as well as a section on microreactors.
“SMRs’ unique attributes in terms of efficiency, flexibility and economics may position them to play a key role in the clean energy transition,” said Stefano Monti, head of the IAEA’s Nuclear Power Technology Development Section and moderator of a recent webinar marking the release of the publication. “Countries can use the updated booklet as an additional tool for identifying possible technological solutions to the challenges they face on energy, climate change and sustainable development.”
While wider deployment of SMRs is expected to begin over the next decade, two reactor units of KLT-40S design are already in operation in Russia aboard the Akademik Lomonosov floating nuclear power plant. Two other SMR frontrunners in Argentina and China are due to begin operation within the next three years. Argentina, China and Russia presented their progress on SMR technology during the webinar.
Russia is also developing a land based SMR project planned for commissioning in 2027, according to Elena Pashina, marketing director for Rusatom Overseas. “SMR NPPs can provide electricity to remote areas and areas with grid restrictions at a favourable price as compared with alternatives and also satisfy growing energy needs,” she added.
Argentina is developing the 25MWe CAREM SMR, which is intended for small electric grids and may also support seawater desalination, with construction of the prototype nearing completion.
“The CAREM25 prototype is the first step in the development of a competitive SMR, and it will facilitate licensing activities for the commercial modules and local supplier development,” said Dario Delmastro, engineering manager of the CAREM Project at the National Nuclear Energy Agency of Argentina.
China’s HTR-PM, a prototype high-temperature gas cooled SMR located in Shidao Bay, is slated to begin operation in 2021. The reactor is cooled by helium and capable of reaching temperatures as high as 750 degrees Celsius, making it suitable for non-electric applications such as district heating and hydrogen production. The HTR-PM is also designed with inherent safety features that reduce the risk of radioactive releases.
The Advances in SMR Technology Developments booklet 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.
The latest 339-page booklet covers land based and marine based water-cooled reactors, high temperature gas cooled reactors, liquid metal, sodium and gas-cooled fast neutron spectrum reactors, molten salt reactors, and micro modular reactors (MMRs) with electrical power typically up to 10MWe.
“Though significant advancements have been made in various SMR technologies in recent years, some technical issues still attract considerable attention in the industry. These include for example control room staffing and human factor engineering for multi-module SMR plants, defining the source term for multi-module SMR plants with regards to determining the emergency planning zone, developing new codes and standards, and load-following operability aspects”, IAEA notes.
Some potential advantages of SMRs, such as the elimination of public evacuation during an accident or a single operator for multiple modules are under discussion with regulators. Furthermore, although SMRs have lower upfront capital cost per unit, their economic competitiveness is still to be proven as these units are deployed in future.
Advances in Small Modular Reactor Technology Developments: the report
The IAEA's latest report has six parts, focusing on land-based water cooled SMRs, marine-based water-cooled SMRs, high temperature gas cooled reactors, small fast neutron reactors, molten salt SMRs, and micro modular reactors, with capacity below 10MWe.
Part One, on land-based water-cooled SMRs, presents notable water-cooled SMR designs from various configurations of light water reactor (LWR) and heavy water reactor (HWR) technologies for on-land on-the-grid applications. There are 25 water-cooled SMR designs from 12 member states including integral-PWRs, compact-PWRs, loop-PWRs, BWRs, Candu-type designs, and pool-type reactors for district heating. While CAREM is finalising construction for operation by 2023, dozens of designs are being prepared for near-term deployment, including the ACP-100 in China and the NuScale design in the USA.
Part Two, on marine-based water-cooled SMRs, presents six marine-based water-cooled SMRs, some of which have been deployed as nuclear icebreaker ships. The first SMR connected to the grid is from this category, is Russia’s Akademik Lomonosov FNPP, which began operation in May 2020.
Part Three: on high temperature gas cooled SMRs includes details of 11 HTGR-type SMRs, including HTR-PM, which is the next SMR to start operation in 2021 in China and three HTGR test-reactors, two that have been in operation for technology testing purposes in Japan and China for over 20 years.
Part Four, on fast neutron spectrum SMRs,presents eleven designs with different coolant options, including sodium, heavy liquid metal (e.g. lead or lead-bismuth) and helium-gas. “Tangible advances in technology development and deployment on SMRs in this category have been made,” said IAEA.
The BREST-OD-300, a lead-cooled fast neutron reactor is in the process of construction at a site in Seversk, Russian Federation with a scheduled operation by end of 2026. This is a demo-prototype project for future design with large power to enable a closed nuclear fuel cycle.
Part Five, on molten salt SMRs, highlights ten designs from molten salt fuelled and cooled advanced reactor technology (MSRs), which is also one of the six Generation IV reactor designs. “MSRs promise many advantages including enhanced safety due to salt’s inherent property, low-pressure single-phase coolant system that eliminates the need of large containment, a high temperature system that results in high efficiency, and flexible fuel cycle,” said IAEA. Several MSR designs are conducting preliminary licensing activities in Canada, the UK and USA.
Part Six, on MMRs, looks at six designs involving different types of coolant, including HTGRs and designs that use heat pipes for heat transport. Several designs are undertaking licensing activities in Canada and the USA for planned near-term deployment.