Tractebel has signed a contract with Finland’s Steady Energy, 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 small modular reactor (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. When heat removal through the primary heat exchangers is compromised, water in the intermediate space begins to boil, forming an efficient passive heat transfer route into the reactor pool. 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 is the size of a standard shipping container, and 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. The reactor design is currently being assessed by the Finnish Radiation and Nuclear Safety Authority (STUK). This concept evaluation will speed up the permitting process.
Steady Energy has already concluded agreements for 15 reactors in Finland and is expanding to Sweden and the Baltics. It says construction of the first plant could begin as early as 2029, with district heating operations anticipated to start in the early 2030s.
Tractebel’s experts will review the probabilistic safety assessment and provide engineering support for the reactor design. They will also assess scenarios to establish a severe accident management programme, which is required by national and international legislation despite that the technology itself is inherently simple and safe. Tractebel has been providing state-of-the-art engineering and consultancy services for over 60 years across the full life cycle of nuclear facilities and leads innovation in SMR, which makes it the ideal partner to finalise Steady Energy’s reactor design and licensing process.
Tommi Nyman, CEO of Steady Energy, noted: “We are eager to start working with Tractebel and their internationally recognized nuclear engineers. Combined with our decades of Finnish expertise, we have one of the world’s most capable SMR teams. Heating water to 150 degrees accounts for 10% of global emissions. Our reactor focuses solely on this task, making it possibly the world’s simplest commercial nuclear reactor. This design ensures that SMR-produced heat is cost-competitive compared to other alternatives.”
Denis Dumont, Tractebel’s Chief Nuclear Officer said: “Our engineers are frontrunners in nuclear technology but also energy storage, combined heat and power, and hydrogen production. We are proud to support the development of this groundbreaking technology that unlocks the supply of clean heat to cities and industries.”
