Helen Assesses the Environmental Impacts of Building an SMR Plant

Helen aims to achieve net-zero emissions and phase out combustion-based energy production by 2040. To support these goals, the company is planning the construction of an SMR facility consisting of one or more reactors in Helsinki.

“We are exploring the potential of nuclear energy to meet the needs of a growing and vibrant city. Low-emission, weather-independent nuclear power can help mitigate energy price volatility and ensure energy availability under all circumstances,” says Pekka Tolonen, CEO of Helen Nuclear Power Ltd, summarising the project's objectives.

The potential locations for the SMR plant are the power plant sites at Salmisaari and Vuosaari, as well as Norrberget in Östersundom. The Environmental Impact Assessment (EIA) procedure will evaluate five possible implementation alternatives depending on the selected plant technology and location. The assessment covers both a heat-only plant and a combined heat and power plant. In addition, the so-called zero alternative, under which the project would not be implemented, will also be assessed.

The heat-only plant option will be evaluated at all three locations. The impacts of a combined heat and power plant will be assessed only at Vuosaari and Norrberget. Due to electricity generation requirements, a CHP plant would require additional infrastructure, including cooling water arrangements and electricity transmission connections. Because of limited space, a CHP plant cannot be accommodated at Salmisaari.

“Helen wanted to initiate the Environmental Impact Assessment process as early as possible so that the project's impacts and feasibility can be thoroughly evaluated before further planning proceeds. The EIA provides essential information for decision-making and permitting processes regarding the project's impacts on the environment and local residents,” says Melina Laine, Nuclear Siting Manager.

The Environmental Impact Assessment will proceed in two phases. The EIA programme describes which impacts will be studied and how the assessment will be carried out. The results of the studies will be compiled into an EIA report, to be published in 2028. Opinions and statements will be collected on both the EIA programme and the EIA report. Acting as the coordinating authority, the Ministry of Economic Affairs and Employment of Finland will issue a reasoned conclusion on the EIA report.

AFRY serves as the project's EIA consultant and also supports Helen's nuclear energy programme in studies related to potential plant sites and technical solutions. Helen aims to make a decision on the potential plant location in 2028.

SMRs Would Strengthen Energy Self-Sufficiency in Helsinki and Finland

Helen has significantly reduced its emissions by phasing out coal and has simultaneously invested in wind and solar power, the utilisation of waste heat and ambient heat through heat pumps, the electrification of heating, and flexible energy solutions.

As Finland's energy system undergoes transformation, electricity generation has increasingly shifted away from Helsinki to other parts of the country, while local generation capacity in Helsinki has declined. In recent years, Helen has electrified heat production, increasing electricity consumption and the need for power transmission into Helsinki.

“Finland is electrifying rapidly, while some existing stable forms of energy production will be phased out in the coming decades. We need solutions that strengthen security of supply and bring generation closer to consumption. An SMR plant would enhance not only Helsinki’s but also Finland’s energy self-sufficiency while reducing pressure on the electricity transmission network,” says Tolonen.

According to Helen's estimates, Helsinki's electricity capacity demand could nearly double by 2030 compared to 2024 levels, and further growth is expected beyond that. Helen has calculated that it will require approximately 400–500 megawatts of additional district heating production capacity. This demand could be met by an SMR facility while enabling the company to phase out combustion-based energy production.

“With small modular nuclear reactors, we can address key challenges in the energy system and ensure stable, low-emission energy production far into the future, throughout the 21st century,” Tolonen says.

The Environmental Impact Assessment will examine the maximum output levels of the facilities. The heat-only plant option would have a thermal output of 600 megawatts (reactor output 630 megawatts), while the CHP plant option would have a thermal output of 700 megawatts and an electrical output of 500 megawatts (reactor output 1,400 megawatts). The final characteristics of the plant will be refined as planning progresses and may ultimately be smaller in scale.

The SMR plant concepts under consideration are significantly smaller than many large nuclear power plants built in recent decades, which partly enables their location close to residential areas and the district heating network. For comparison, Olkiluoto 3 has a reactor output of 4,300 megawatts and an electrical output of 1,600 megawatts.

Helen is currently evaluating approximately half a dozen Western reactor vendors, with several candidates representing both the heat-only and combined heat and power plant concepts.

Read More:

EIA Programme: YVA-ohjelma | tem.fi
Interactive Map Service: Karttapalvelu | helen.fi