The SMRs are, by interntional definition, nuclear reactors with up to 300MW electrical output capacity.

"Small" means that the power (and also the dimensions) are significantly smaller compared to the reactors (1000+ MW) mostly in use today. Reactors from different manufacturers vary from a few megawatts up to 300 MW, some even slightly larger.


The "M" stands for modular. It means thatthe reactor is transported to site as modules or as a single unit. This simplifies and shortens the building process, making the plant cheaper to build.

Large NPP in Finland
SMR power plant
  • Standardized components
  • Factory-built reactors
  • Shorter construction time
  • Less materials used
  • Less nuclear fuel used

Väikesed moodulreaktorid on lähituleviku tehnoloogia tuumaenergia kasutamiseks. Väikese moodulreaktoriga  elektrijaamad on küll tööpõhimõttelt tuumajaamad, kuid nii ehituselt, ohutuselt kui ökonoomikalt väga erinevad 20. sajandi suurtest ja ülikeerukatest tuumajaamadest. Väikese moodulreaktoriga jaamad on kümneid kordi väiksemad – need võtavad vähem ruumi, kuid annavad ikkagi palju CO2-vaba puhast elektrienergiat ilmast ja aastaajast sõltumata.

Therea are over 50 SMR designs in development around the World. Fermi Energia is assessing those technologies in order to choose the best option to be built in Estonia - after it has been built and tested in countries already using nuclear power - UK, US, or Canada.

Fermi Energia on alates 2019. aastast analüüsinud mitut potentsiaalsemat reaktoritehnoloogiat, mille on välja sõelunud feasibility study (pdf) in Estonian languageAn important selection criterion is that the reactor model in question must first have been built and proven in practice in the US, Canada or the UK, where there are competent inspection authorities.

Valikus olnud tehnoloogiad

300 MW electrical capacity a modular reactor, the design of which is based on the same company's 1520 MWe ESBWR boiling water reactor that passed the NRC licensing process in the US in 2014.

The reactor does not have circulation pumps, but instead uses a convection cooling system to cool the residual heat of the nuclear fuel. This system is very safe and in the event of an emergency it will operate for 7 days without human intervention and without external power, after which it will be necessary to add water to the cooling pool, using station pumps or even a fire engine pump. The station will benefit from proven technologies and design solutions, ensuring the use of known delivery and training systems. In addition, the construction size of the plant is half per 1 MW and the safety structure requires ten times less concrete than an ESBWR.

GE/H website

The development of the reactor started in the early 2000s, in 2017 the licensing process began at the US nuclear regulator NRC..

The first plant based on this technology will consist of twelve modules with a thermal capacity of 200 MW and a gross electrical capacity of 60 MW, i.e. a total electrical capacity of 720 MW gross / 685 MW net (a plant with 6 modules would be suitable for Estonian conditions). The reactors will use classical pressurised water reactor technology, but instead of pumps, cooling water will circulate naturally through the reactor core and steam generators.

Nuscale website

In addition to manufacturing cars and jet engines for airplanes, Rolls-Royce is also known as a manufacturer of steam turbines and reactors. Rolls-Royce has more than 60 years of experience with submarine reactors of British Navy. The pressurized water reactor they are developing is slightly more powerful - with an electrical capacity of 470 MW.

UK SMR uses passive safety systems, the design life is 60 years, and the developer estimates that it will take 4 years to build the station.

Approximately 90% of the production and assembly operations are carried out in factory conditions, which ensures higher quality and avoids delays compared to the construction of the reactor at the construction site of the nuclear power plant. 

Vaata lähemalt Rolls-Royce SMR website kodulehelt.


Tehnoloogiavaliku võitja

Fermi Energia valis 2023. aasta algul kolme pakkumise esitanu vahel Eestisse arendamiseks sobivaimaks GE Hitachi väikese moodulreaktori BWRX-300, mille esmaehitust alustati Kanadas, Toronto külje all asuvas Darlingtoni tuumajaamas. Kanada kogemustele tuginedes saame planeerida ka Eesti jaama ehitust.