Finland’s Steady Energy, a startup company spun out from the VTT Technical Research Centre of Finland in 2023, and TVO Nuclear Services (TVONS), a consulting company wholly owned by Finnish utility Teollisuuden Voima Oyj (TVO) are to collaborate on the development of a nuclear heating plant.
The agreement gives Steady Energy access to TVO’s expertise in the planning and implementation of nuclear power plant projects as well as the operation, maintenance and service life management of the plants. Steady Energy aims to construct several 50 MWt small modular reactors (SMRs) in Finland for the purpose of district heat generation. The company is seeking to construct a heating plant in Finland by 2030 based on its LDR-50 reactor technology.
The LDR-50 district heating SMR has been under development at VTT since 2020. It is designed to operate at around 150°C and below 10 bar (145 psi). The project was part of VTT LaunchPad, a science-based spin-off incubator, where VTT researchers and technology are brought together with business leaders and investors to renew industries. VTT LaunchPad supports incubator teams to develop VTT-owned intellectual property rights into fundable spin-off companies.
The LDR-50 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. The innovation was awarded a patent in 2021.
In baseload operation the reactor is run at full power during the cold season, and cycle length is around two years. After the operating cycle has been completed, the core is reloaded with fresh fuel. When operating at a lower power level, the fuel is consumed more slowly, and the reloading interval is correspondingly extended.
A district heating plant may consist of one or several independent reactor units, enabling the capacity to be scaled up. In addition to the reactor units, the plant includes auxiliary systems and technical buildings. The overall footprint of the heating plant corresponds to a small or medium-sized industrial site. In addition to an above-ground siting option, the reactor units could also be located in an underground rock cavern. Both options are currently being investigated.
TVONS’ Managing Director Ari Leppänen said: “Steady Energy is working on a very interesting project, and we are glad to be involved by offering our expertise in its various areas. This allows us to participate in the clean transition also through small modular reactor projects.”
Steady Energy CEO Tommi Nyman said the collaboration agreement with TVONS is a significant opportunity for Steady Energy. “It will further strengthen our ability to develop and, in time, to construct a small nuclear power plant that is completely based on Finnish design. The agreement also sends a strong message that Steady Energy’s project is important for the development of the entire Finnish nuclear energy industry.”
Image: The LDR-50 reactor design (courtesy of Steady Energy)
