Finland's Helen has launched the first phase of its nuclear programme, aimed at constructing a small nuclear power plant for producing heat for Helsinki city. Meanwhile, Finnish small modular reactor developer Steady Energy has submitted documentation about its design to the country's nuclear regulator for pre-licensing review.

LDR-50 district heating SMR (Image: Steady Energy)

During the initial phase of its nuclear programme, Helen will negotiate with potential partner shareholders, evaluate plant suppliers and determine potential plant sites. The first phase of the programme is due to be completed in 2026.

The company said its decision to start exploring the potential of nuclear energy stems from its goal of carbon-neutral energy production during the 2030s. "Achieving this requires a steady, reliable and electricity-independent heat source that can be located near the district heating network," it said.

Helen - which currently produces heat, electricity and cooling in power plants and heating plants in different parts of Helsinki - said its nuclear energy programme will evaluates small modular reactors (SMRs) based on proven solutions, which can be used to produce just heat or both electricity and heat.

"Our goal of non-combustion requires determined measures to harness all clean forms of production as part of our energy system," said Helen CEO Olli Sirkka. "We have therefore decided to proceed with the nuclear energy programme systematically and as quickly as possible, realising that this is a multi-year project. Eventually, if everything falls into place, we will have our first SMR providing heat for Helsinki no later than in the early 2030s."

He added: "We have never had any doubt about the need to mitigate climate change. In practice, this means including all clean forms of production in our energy palette. It is good to acknowledge, however, that everything is not in our own hands and that the transition requires accomplishments also from decision-makers and technology developers. I am expecting the ongoing reforms of the Nuclear Energy Act and official regulations to pave the way for the incorporation of nuclear power into Helsinki's heat production."

In October last year, Helen became the first energy company to engage in cooperation with Steady Energy by signing a letter of intent aimed at enabling an investment in a small-scale nuclear power plant for the production of district heating. Valid until 2027, the agreement includes promoting the reform of the Finnish Nuclear Energy Act, applying for a siting licence and a technological permit, and fixing the contract price of the plant. It would also enable Helen to procure up to ten reactor units with an output of 50 MW from Steady Energy.

In November 2022, Helen announced a joint study with Finnish utility Fortum - operator of the Loviisa nuclear power plant - to explore possible collaboration in new nuclear power, especially SMRs. The companies formed a study group to explore possible synergy benefits for the two firms.

Pre-licensing assessments

Finland's Radiation and Nuclear Safety Authority (STUK) said Steady Energy submitted to it at the end of August material concerning its SMR for assessment.

It also noted that Fortum asked STUK earlier this year for "preliminary estimates of the special characteristics of a few plant alternatives" as it investigates the prerequisites for the construction of new nuclear power plants in Finland and Sweden.

"The assessments requested by the companies give STUK the opportunity to familiarise itself with new types of plant alternatives and assess their safety," the regulator said. "At the same time, STUK gains practical experience of how safety assessments will be carried out once the renewal of nuclear energy legislation enters into force. The assessments tell the companies whether their plans meet the safety requirements set for the plants."

It stressed the companies have not submitted any licence applications for plants, and its investigations are not related to the licence processes. However, it said the Nuclear Energy Act gives STUK the opportunity to carry out preliminary safety assessments unrelated to licence processes.

Steady Energy - which was spun out in early 2023 from the VTT Technical Research Centre of Finland - aims to build the world's first district heating plant featuring its LDR-50 SMR by 2030.

The LDR-50 district heating SMR - with a thermal output of 50 MW - has been in 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".

The LDR-50 reactor module is made of 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 company said. The system does not rely on electricity or any mechanical moving parts, which could fail and prevent the cooling function.

In December 2023, Steady Energy signed a letter of intent with municipal energy company Kuopion Energia that included an option for the construction of up to five district heating reactors starting in 2030.

In July, Steady Energy signed a one-year pre-planning agreement with Kuopion Energia aimed at constructing a small nuclear power plant to start producing district heat in the city of Kuopio - the regional capital of North Savo in eastern Finland - in the early 2030s. As part of the agreement, Kuopion Energia started an environmental impact assessment for potential plant locations.