Small Modular Reactors (SMR)

SMRs are highly efficient, small-scale nuclear power stations. With a capacity of between 10 and 300 MW, the most advanced models are pressurised water reactors that use uranium as fuel, just like today’s traditional nuclear power stations. Thanks to their compact size and standardised design, they can be built much more quickly and at a lower cost than a conventional nuclear power station. Meanwhile, engineers around the world are already working on SMRs capable of recycling nuclear waste from our existing nuclear power stations and using it as fuel.

Each design is different and has its own advantages, but what all SMRs have in common is their size, which is a fraction of that of a conventional nuclear power station, enabling the deployment of safe, decentralised and adaptable energy generation.

The small size of SMRs makes them easier to transport, which greatly expands the possibilities and makes access to electricity easier. SMRs are smaller, more flexible and more affordable, meaning they can be used on smaller electricity grids or built in hard-to-reach locations where large reactors would be impractical. As they require less space and fewer resources, SMRs minimise the impact on natural habitats and biodiversity.

As SMRs are small in size, their design can be standardised and their production optimised in a factory setting to enable mass production. This means they can be produced much more quickly and at a significantly lower cost than a conventional power station, which involves a massive construction project spanning several years. This reduction in costs makes them, amongst other things, an excellent option for emerging and developing countries.

By combining several SMRs, it is possible to create a network of fully modulatable mini-power stations. Indeed, when several SMRs are combined, some can be switched on or off, thereby allowing electricity generation to be modulated much more quickly and easily than with a conventional power station. This makes it possible, for example, to easily increase generation to support renewable energy sources when there is no wind or sunshine, and to reduce SMR output when weather conditions are favourable for renewable energy.

SMRs will also enable us to decentralise electricity generation. Indeed, it will be possible, for example, to deploy these small power stations according to local needs. For instance, to supply and make a small, remote town, an industrial estate or even a scientific research facility completely self-sufficient.

In order to reduce the size of these reactors, all SMR designs rely on passive nuclear safety systems. These intelligent systems use gravity or the natural circulation of the coolant to ensure safety; they require no external power source and can therefore operate with very little human intervention.

Furthermore, these systems often ensure that the fuel remains operational for longer, meaning that refuelling is required much less frequently (every 3 to 10 years depending on the model, compared with every 1 to 2 years for large power stations), which further reduces the need for human intervention. Some SMRs are designed to operate for up to 30 years without refuelling.

Beyond electricity generation, SMRs can help us take further steps towards decarbonising our societies.

Two of the human activities that currently produce the most CO₂ are heating and transport. SMRs can be used to produce heat (for our homes and industry, for example via district heating networks) and hydrogen (which would serve as a clean fuel), and various designs already incorporate these applications.

Some real-life examples:

• The Polish chemicals manufacturer Ciech is considering using nuclear technologies to replace the coal used to generate electricity and industrial heat at its plants.
• A Canadian innovation organisation has launched a new study on the role of nuclear energy in supporting a hydrogen economy.
• For Rolls-Royce’s SMRs in the UK, applications such as hydrogen production are also being considered as possibilities, alongside the supply of grid-connected electricity.

A large number of major companies in the nuclear sector are working on the development of SMRs, mainly in the United States, China, Russia and Canada. In Europe, it is primarily the United Kingdom and France that are taking an interest.

Of the fifty or so projects currently underway worldwide, a few have already been built, such as the HTR-PM in China, or are even already operational, such as the two reactors on board the Akademik Lomonosov in Russia, a floating nuclear power station. Other small reactors are under construction in Russia, China, the United States, Canada, the United Kingdom and France. In Belgium, Tractebel and SCK CEN are at the forefront of SMR research.

In Russia

Russia is the most advanced country in the field of SMRs. Indeed, marine SMRs are already in operation: on board icebreakers, where they serve as propulsion systems, and on board the Akademik Lomonosov, to improve access to electricity in a remote and hard-to-reach area.

Other projects, this time on land, are also underway. The most notable is that of a lead-cooled fast neutron reactor. Construction of a commercial industrial closed-cycle demonstrator began on 8 June 2021 in Seversk. This means that the fuel is constantly reused by the reactor, which recycles it itself. The circular economy in practice: “The nuclear industry’s resource base will become virtually inexhaustible thanks to the infinite reprocessing of nuclear fuel,” said Alexey Likhachov. This also means that virtually no nuclear waste remains. The BREST-OD-300 reactor is scheduled to come online in 2026.

In the United States

Through its ARDP (Advanced Reactor Demonstration Programme), the US Department of Energy is driving various SMR technologies towards the stage of actual demonstration by the end of the decade. Several projects are therefore at the licensing stage, and the NuScale pressurised water reactor has received regulatory approval.

Under a recent agreement, NuScale and Nuclearelectrica, Romania’s national nuclear company, will take the necessary steps to build a first NuScale plant comprising six modules in Romania as early as 2027/2028.

The US Secretary of Energy, Jennifer Granholm, recently stated that the government is “very optimistic” about the construction of new nuclear reactors, including SMRs. The US government recognises the benefits of the SMR project, having awarded $80 million to TerraPower (the energy company founded by Microsoft’s Bill Gates) to enable it to build a demonstration reactor in Wyoming, on the site of a coal-fired power station that is due to be decommissioned shortly.

In Canada

Canada is exploring several avenues for SMR development in parallel.

The CANDU SMR, a 300MW project expected to come on stream by 2028. Built using tried-and-tested technology to enable rapid deployment, this reactor features simplified systems, fewer components and a modular design. The design objectives are low-cost, low-carbon energy with a high capacity factor in a compact footprint.

Advanced fourth-generation SMRs by 2030. Several SMR models are being considered for deployment at the existing Darlington nuclear power station (Ontario): the BWRX-300 (GE Hitachi Nuclear Energy), the Integrated Molten Salt Reactor (Terrestrial Energy) and the Xe-100 high-temperature gas-cooled reactor (X-energy). The potential for SMR deployment is also being investigated at the Point Lepreau nuclear site (in the province of New Brunswick). The aim is to establish a supply chain for SMRs in the province and to deploy SMRs. One of the designs under consideration is the SSR-W 300 (Moltex Energy), a molten salt reactor that uses nuclear waste as fuel (Stable Salt Reactor – Wasteburner).

Micro-SMRs (or MMRs) are being considered to replace the use of diesel in remote communities, notably with a first 5MW reactor scheduled to come online in 2026.

In China

China, which is investing heavily in nuclear power in order to reduce its carbon footprint (including, notably, a large-scale nuclear fusion project), began construction of its very first SMR in 2021. With a capacity of 125 megawatts, it is expected to supply electricity to 526,000 households, but the reactor can also be used for heating, steam generation and seawater desalination.

By 2030, the first thorium-fuelled reactor – also known as a molten salt reactor – could be fully operational and ready for commercial deployment in China.

Other versatile projects, combining electricity and heat generation, are expected within 3 to 7 years.

In the United Kingdom

In the United Kingdom, SMRs form part of the ‘10-point green programme ’. A British SMR consortium, led by Rolls-Royce, has announced the design of a 470 MW SMR.

The aim is to complete the first unit in the early 2030s and to build up to 10 by 2035. Rolls-Royce has secured the necessary investment from the government and investors to take the project forward.

In France

On 12 October 2021, President Macron unveiled his ambitious plans for the reindustrialisation of France during a speech entitled “France 2030”. A key element of this project is the investment of one billion euros in research and development into small modular reactors (SMRs).

France has named its own SMR project “Nuward”. This small 2 x 170 MW reactor is the result of a collaboration between the French Atomic Energy Commission (CEA), EDF, Naval Group and TechnicAtome.

Elsewhere

Russia, the United States, the United Kingdom, Canada, France and China are the major countries to have launched SMR projects. But there are many others: Argentina, Estonia, Finland, Poland, the Czech Republic, Bulgaria, Romania, … The list is long and growing by the day, further demonstrating the interest in this new technology, which promises to solve many energy challenges. Even countries that used to ban – or still ban – the construction of new power stations, such as the Netherlands and Australia, are reconsidering their stance.

SMR in Belgium: small nuclear reactors, big opportunities

In Belgium, Tractebel and SCK CEN are taking the lead in developing this innovation.

The SCK CEN nuclear research centre will receive an additional research budget of 100 million euros (spread over four years), earmarked for research into small modular reactors (SMRs). They will investigate innovative SMRs based on various criteria, including nuclear waste management and passive safety. This research will be carried out in close collaboration with (inter)national partners.

Tractebel: Belgian expertise supporting innovative SMR projects

With over 150 years’ experience, Tractebel is regarded as one of the world’s leading experts in the field of consultancy and engineering. Their aim is to help shape the world of tomorrow. For over 60 years, Tractebel has been developing reliable and innovative bespoke core technologies. As the design engineer for Belgium’s seven nuclear power stations, Tractebel felt it was only natural for the company to be involved in the development of SMRs. Tractebel has a unique pool of engineers with multidisciplinary skills, all of whom are specialists in their respective fields. They form an indispensable link between the basic concept and the actual construction of an SMR. Tractebel’s engineers develop the concept for industrial application and/or assess the financial and technical feasibility of the project, taking into account criteria such as safety, operability and feasibility. Tractebel supports inventors, manufacturers and operators in their projects to develop innovative SMRs, from the feasibility study through to obtaining the necessary licences from the relevant authorities and final commissioning.

Tractebel published its vision for SMRs at the end of 2020. In early 2022, it opened a new office in Canada. There, the nuclear engineering office aims to be a dynamic player in accelerating the deployment of SMRs and building bridges to the European market. Finally, in May 2022, it signed a contract to contribute to the development of the French SMR project, ‘NUWARD’. In collaboration with Laborelec, the experts will carry out studies aimed at finalising the conceptual design of the European Union’s first SMR.