Steady Energy and Alva-yhtiöt, the City of Jyväskylä’s water and energy group, have signed a letter of intent (LOI) to study the suitability of small-scale nuclear power as a source of district heating for the city. Finnish company Steady Energy could supply Jyväskylä between two and six LDR-50 reactors, which would produce 100–300 MW of heat underground.
Steady Energy is a startup company spun out from the VTT Technical Research Centre of Finland in 2023 to provide engineering services to develop Steady Energy’s LDR-50 SMR. The LDR-50 district heating SMR has been under development at VTT since 2020.
The 50 MW LDR-50 is a simplified pressurised light water reactor specifically designed to operate at around 150°C and below 10 bar (145 psi). The reactor module comprises two nested pressure vessels, with their intermediate space partially filled with water. The system does not rely on electricity or any mechanical moving parts, which could fail and prevent the cooling function. It was awarded a patent in 2021. The LDR-50, the size of a standard shipping container, is designed to be built underground for added safety and to free valuable real estate for key urban areas. It is optimised for district heating, industrial steam production, and desalination projects.
Under the LOI, the companies are launching a year long preliminary study. It will assess the feasibility of small nuclear heating plants in Jyväskylä from the perspectives of regulation, residents’ views, potential sites, land-use planning, technology and costs, among other factors. After this phase, the companies may proceed to a concrete technical and commercial pre-planning.
“We want to carefully assess whether small-scale nuclear power can be a suitable solution for Jyväskylä’s future heat production. At this stage, we are not making an investment decision, but we are investigating the prerequisites and gathering as much information as possible to support our final decision,” said Alva Production Director Alex Schreckenbach.
“Jyväskylä is the fourth city in Finland where SMR heat is being seriously considered to replace combustion-based energy sources. Finnish energy companies, such as Alva, are at the global forefront in the development of sustainable heating solutions,” noted Steady Energy CEO Tommi Nyman.
In addition to Jyväskylä, SMR heating projects are underway in Helsinki, Kuopio and Kerava. Steady Energy is currently building a full-sized test facility of its LDR-50 reactor in a decommissioned coal-fired in Helsinki city centre. The purpose of the test facility is to demonstrate the key safety features of the LDR-50 reactor and accelerate its licensing process with the Finnish regulator.
