Construction of Finnish modular reactor prototype for district heating to begin next year

Finland’s small modular reactor LDR-50, designed for district heating, is set to reach an important milestone next year. Steady Energy will begin construction of a prototype at one of three shortlisted sites. Unlike the actual unit, it will be powered by electricity rather than nuclear fuel. Construction of the actual small reactor, with a thermal output of 50 MW, is planned for 2028, with completion scheduled for 2030.

Finnish company Steady Energy said it will begin construction next year on the first prototype of its modular reactor designed for district heating. A functional prototype of the LDR-50 unit will be built at one of three sites in Finland, with the capital Helsinki among the candidates.

The pilot project will not use nuclear fuel to produce heat. Instead, it will generate heat inside the reactor using electricity. Apart from this difference, however, it is intended to be an exact replica, allowing the operator to test the supply chain and the unit’s operating characteristics.

"Final assessments of potential sites are now under way, and we expect a decision by the end of the summer. Detailed planning and a tendering process will then begin. After the testing phase, the facility will be used for training and research," Steady Energy said.

Steady Energy estimates that construction of the prototype, with a thermal output of 50 MW, will cost around EUR 15-20 million (approximately CZK 370-495 million). Last summer, the company announced that it had secured EUR 2 million in funding (approximately CZK 50 million) to continue and develop the project.

A suitable solution for urban areas too

The LDR-50 project was launched in 2020 by VTT Technical Research Centre of Finland. In developing the reactor, Steady Energy is drawing, among other things, on the expertise of Finnish nuclear power plant operator TVO. The company is targeting deployment of the reactors in district heating from 2030. It has already agreed with energy companies Kuopion Energia and Helen to build up to 15 reactors.

"Although Finland has made great progress in generating energy from green sources, our cities are still heated with fossil fuels and biomass. Replacing heating plants with a small, zero-emission nuclear plant that can be installed underground would eliminate endless convoys of fuel trucks and drastically reduce local air pollution," said Steady Energy CEO Tommi Nyman.

The company says its solution is ideal for urban district heating because it takes up less space. Thanks to its passive safety design, the LDR-50 does not rely on an external power supply or any moving mechanical parts that could fail. In normal operation, it can run for around two years without refuelling.