Steady Energy pours first concrete for non-nuclear LDR-50 SMR pilot in Helsinki

Steady Energy marked a construction milestone in mid‑February 2026 when crews poured the first concrete for a full‑scale, non‑nuclear pilot of its LDR‑50 district‑heating small modular reactor inside the turbine hall of the decommissioned Salmisaari B coal power plant in central Helsinki. The pilot will use electric resistors rather than nuclear fuel, is budgeted at about €20 million, and is intended to deliver roughly 6 MW of heat to Helen’s district heating network when completed.

The LDR‑50 concept being tested traces back to VTT Technical Research Centre of Finland, where the design has been developed since 2020. The commercial LDR‑50 is specified as a 50 MW thermal unit designed to operate at about 150°C and at pressures below 10 bar (145 psi), with a physical footprint described as “the size of a shipping container.” Steady Energy says commercial units will be built underground and that the reactor’s operating conditions “are less demanding compared with those of traditional reactors, simplifying the technical solutions needed to meet the high safety standards of the nuclear industry.”

Steady Energy has stressed that the Helsinki pilot is non‑nuclear: the heat source inside the pilot capsule will be an electric heating element used to verify operational and safety systems and to build supply chains before any fuelled units are deployed. NucNet reported the non‑nuclear plant will demonstrate that safety features operate as designed, while company messaging says the pilot’s purpose is to validate processes and supply‑chain arrangements ahead of commercialization.

Funding and industrial partnerships underpin the project. Steady Energy’s timeline records a completed €32 million funding round on July 1, 2025 and an earlier €22 million raise on March 10, 2025. Energy group Fortum invested €2.1 million and entered an agreement to provide exclusive operation and maintenance services in Finland and Sweden, and state‑owned Finnish Industry Investment is listed among the company’s backers. Neimagazine reports the pilot budget as €20 million and cites a company estimate of about €100 million for a final fuelled commercial unit.

The site and ceremony were framed as symbolic reuse of coal infrastructure. The pilot sits in the Salmisaari B turbine hall owned by Helen, and Finland’s Minister of Climate and the Environment Sari Multala attended the public event, saying, “This pilot project advances Finland’s strategic objective of becoming a clean‑energy superpower. Affordable cost and stable production, together with world‑leading technological expertise, form the foundation of our competitiveness.” Steady Energy CEO Tommi Nyman called the pour “a major milestone” and said the project moves the company “one step closer to the first Finnish small nuclear heating facility.”

Steady Energy’s public timeline lists a February 16, 2026 post titled “Construction of Steady Energy’s Small Nuclear Heating Pilot Plant Begins in Helsinki,” while media reports placed the pour and ceremony across mid‑February 2026. The company says the pilot will pave the way for planned projects in Finland and for deals underway or planned in Poland, Sweden and South Korea, including a Dec. 5, 2025 agreement with Korea District Heating Corp. Regulators gave the LDR‑50 a first preliminary assessment on June 17, 2025 noting the concept can be developed to meet Finnish nuclear safety requirements; further technical and commissioning timelines remain to be confirmed.