On a global scale, nuclear power saves the climate from 2 billion tons of carbon dioxide – every year. This is 40 times as much as Sweden’s total annual carbon emissions. In addition to being fossil-free, nuclear power is also dispatchable, which will become increasingly important as renewable intermittent electricity generation is increased.

A lot has happened within nuclear power in the past decade, and many innovative projects aimed at making nuclear power an important part of the future’s fossil-free energy system are becoming a reality. One such innovation is the Small Modular Reactor, or “SMR.”

How a Small Modular Reactor works

What distinguishes a Small Modular Reactor (SMR) from today's large nuclear power plants is that it could deliver the same stable and fossil-free electricity as today, but more flexibly and without taking up as much space.

Smaller and less expensive – but the same amount of power

What distinguishes an SMR from large present-day nuclear power plants is that it can deliver the same amount of stable and fossil-free electricity as today, but it is more flexible and take up less space. The safety system of an SMR is also different, where a passive safety system entails that in the event of an incident, the reactor will cool itself down, without dependence on any external electricity supply.

The concept is for the various components of an SMR to be prefabricated and transported to site. The sections are then assembled on site – just like a do-it-yourself kit. Since they can be manufactured serially, the cost and time required for building an SMR is much less than for a large-scale nuclear power plant. By linking together several SMRs at locations where there is a need for more electricity, the output can be better adapted to specific needs, which creates a more flexible, stable and dispatchable electricity supply.

An SMR does not need its nuclear fuel to be replenished as frequently as conventional nuclear power plants. Some models of SMR are delivered ready-to-go, with all the fuel it will need in its useful service life, after which, the entire fuel-cell unit is moved to a final repository. This reduces the costs while increasing availability.

Different types of SMRs

Different types of SMRs are being developed. Some are based on the same technology as present-day second- and third-generation conventional nuclear power plants, but on a smaller scale. Other models are known as Breeder reactors, which means that they can convert isotopes that are normally not fissionable into fissionable isotopes, usually from uranium-235 to plutonium-239. This category of reactor is known as a fourth-generation nuclear power plant, or Gen-IV plant, and can extract far higher energy content from the uranium, which also drastically reduces the amount of nuclear waste.

In the SMR models that are currently under development, different types of cooling media are used, such as water, liquid metals such as lead, or gas or molten salt.

Uniper follows the development of SMR

There is considerable international commitment to the potential of SMR technology, and countries such as the US, UK, Canada and Russia are now investing heavily in moving development forward.

In the US, Bill Gates, TerraPower, GEH and X-Energy have received USD 160 million to build to advanced demo reactors, and the company, NuScale, has received federal funding to construct 12 SMRs. In the UK, Role Royce was granted co-financing to build a water-cooled SMR by 2031.

Sweden and Uniper are also part of the development. Together with KTH and Blykalla, Uniper is working to develop an electrical research facility at OKG. The ambition is to be able to test new materials and components for the nuclear power of the future with the aim of continuing to supply industry and society with fossil-free electricity in a stable, cost-effective and climate-smart manner.

Part of the solution for a climate-smart and competitive future

There are many advantages to SMRs. Firstly, the electricity system will continue to need stable and dispatchable power that can complement weather-dependent electricity generation. This is where the flexibility and dispatchability of SMRs have great potential.

Secondly, SMR could play an important role for electricity supply, when Sweden doubles its electricity consumption in the next few decades. All fossil-free energy sources will be needed if we are to satisfy this increase in demand in a climate-smart and efficient manner.

Thirdly, the opportunity to place an SMR exactly where it is needed most, is a major advantage for future climate-smart industry. One or more SMRs could, for example, be built adjacent to a steel plant, a hydrogen gas plant or a battery manufacturer, and thereby directly provide them with stable and fossil-free electricity.

If Sweden is to manage the switch to becoming a climate-neutral society, we need to invest heavily in fossil-free electricity generation, and SMRs have great potential to be one of the solutions. Uniper’s investments in SMR technology are part of our work to create a climate-smart and competitive future.

Find out more

More fossil-free electricity will be required in the future. By 2050, Sweden could need twice as much electricity as today – about 150 TWh more than today. How are we to succeed with this?

Nuclear power plays an important role in stabilizing Sweden’s electricity generation. Uniper takes total responsibility for our participation in Swedish nuclear power.

Although renewable power sources are increasing rapidly, they will not be capable of replacing current production in its entirety. To reduce emissions, we need to utilize nuclear power.

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