The first concrete for the pilot was poured on 12 February in the Salmisaari B turbine hall in a ceremony attended by Finland’s Minister of Climate and the Environment Sari Multala.
The pilot plant will serve as a full-scale, operational model of the LDR-50 reactor design. Unlike the actual power plant, the pilot unit will use an electric element to produce heat inside the reactor capsule instead of nuclear fuel. The main purpose is to test operational features and to establish the necessary supply chains with various manufacturers to construct actual plants. It will be used to produce heat for energy firm Helen’s district heating network with an output of about 6 MW when completed. The pilot plant is being built with a budget of EUR15-20 million (USD17-23 million), funded by capital investments already raised by Steady Energy.
Steady Energy CEO Tommi Nyman said: “The first concrete is a major milestone for all the professionals involved in developing Steady Energy’s small nuclear heating plant. We are one step closer to the first Finnish small nuclear heating facility.”
Steady Energy – which was spun out in May 2023 from the VTT Technical Research Centre of Finland – said this will be the first instance of physically testing a reactor module at full scale, beyond simulation environments, before actual construction.
“This pilot project advances Finland’s strategic objective of becoming a clean‑energy superpower,” added Minister Multala, who spoke at the ceremony. “Affordable cost and stable production, together with world‑leading technological expertise, form the foundation of our competitiveness.”
Steady Energy and Helen signed an agreement to lease the decommissioned Salmisaari B power plant building as a space for Steady Energy’s small modular reactor (SMR) pilot plant. The lease runs until 2028.
“The reactor module fits entirely inside the turbine hall and will not be visible in the cityscape,” Steady Energy noted.
Helen ended coal usage in energy production last year with the closure of the Salmisaari coal power plant, reducing Helsinki’s carbon emissions by about 30%. The company aims to achieve carbon neutrality by 2030 and entirely combustion-free energy production by 2040.
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A multiple LDR-50 unit plant (Image: Steady Energy)
The LDR-50 district heating SMR – with a thermal output of 50 MW – has been under development at VTT since 2020. Designed to operate at around 150°C and below 10 bar (145 psi), Steady Energy says its “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”. It noted that its reactors are affordable enough for municipal utilities to invest in independently. The LDR‑50 is the size of a shipping container, and the actual facilities will be constructed underground.
Steady Energy said it has several projects under way in Finland, and new projects are also planned in Poland, Sweden and South Korea.
Last week, Steady Energy announced in a LinkedIn post that it had signed a memorandum of understanding with Fermi Energia to advance the deployment of its LDR-50 heat-only reactor concept in Germany. “Germany has a significant need to decarbonise its heating sector, one of the largest sources of emissions in Europe,” it said. “Replacing fossil-based heat production with reliable, zero-combustion nuclear heat presents a major opportunity.”
