Regulator completes preliminary assessment of Steady Energy's SMR concept

Friday, 20 June 2025

The Finnish Radiation and Nuclear Safety Authority says the draft concept assessment for Steady Energy's proposed LDR-50 plant found that "nuclear and radiation safety, security arrangements, emergency arrangements and nuclear material safeguards solutions are such that they can be designed to meet safety requirements".

Regulator completes preliminary assessment of Steady Energy's SMR concept
A multiple LDR-50 unit plant (Image: Steady Energy)

Concept assessment is a procedure proposed in the new Nuclear Energy Act in which the Radiation and Nuclear Safety Authority (STUK) assesses whether the power plant could meet safety requirements in general terms. It is separate to the construction permit process for the nuclear power plant.

STUK said it used the draft concept as a basis for its assessment. It also said of Steady Energy, which had requested the assessment, that "although it is not yet a complete plant supplier for a nuclear power plant, it has the potential to develop into one".

Project Manager for STUK, Minna Tuomainen, said the process was useful for the authority: "We were able to get to know the plant at an early stage, for which a permit may be applied for in Finland later." It would also help inform the development of the legislation regarding concept assessments, she said.

Tommi Nyman, CEO of Steady Energy, welcomed the authority's verdict and said they would continue to work closely in future, adding: "The result of the concept assessment supports our view of the development schedule of the LDR-50 nuclear power plant and confirms our previous view of the implementation schedule of the LDR-50 plants in Finland."

Juho Vierimaa, Head of Licensing and Quality, said: "We hoped for and received invaluable information from the evaluation to support our work. In addition, the assessment reinforces our belief that we are on the right path in terms of both technology and organisational development."

Steady Energy said that in accordance with the recommendations of the assessment it will demonstrate the operation of key safety features in a full-size pilot plant built inside a former coal-fired power plant in Salmisaari, Helsinki. Construction is scheduled to start in late 2025, with a budget of EUR15-20 million (USD17-23 million), funded by capital investments already raised by Steady Energy.

The pilot plant will serve as a full-scale, operational model of the Finnish-designed 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 the Helen district heating network with an output of about 6 MW when completed.

Following Finland's regulator's assessment an international assessment from regulators is also about to begin, building on STUK's work as they assess the reactor and "seek to find ways in which authorities in different countries could benefit from each other's work".

Steady Energy was spun out of Finland's VTT Technical Research Centre in 2023. The LDR-50 SMR, with a thermal output of 50 MW, is designed to operate at around 150°C. Unlike most SMRs being developed around the world, it is not designed to generate electricity - or electricity and heat. Instead, it is designed to only produce heat and is focused on district heating, as well as industrial steam production and desalination projects.

The company has already signed agreements for 15 reactors in Finland, with its reactor design currently being assessed by STUK. The aim is for construction of the first plant - to be the clean energy source for a district heating scheme - to begin in 2029.

Listen to a World Nuclear News podcast interview with Tommi Nyman in September 2024:

 

 

Article researched and written by WNN's Alex Hunt

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