Helsinki studies a nuclear plant with small reactors: Helen assesses three sites

Helen, the City of Helsinki's energy company, published on 3 November the environmental impact assessment (EIA) programme for a possible nuclear plant in the Finnish capital, Yle reports. According to Helen, the assessment covers only small modular reactors (SMRs) and five implementation options, depending on technology and site, plus the option of not carrying out the project.

What is being assessed. The options include a plant producing only heat for district heating and a combined heat and power plant that also produces electricity. The candidate sites are the Salmisaari and Vuosaari industrial areas and the Norrberget area in Östersundom, where forest would have to be cleared, Yle notes. The main impact being assessed is the warming of seawater: a combined heat and power plant would release part of the reactor heat into the sea, a heat-only plant would not.

The timetable. According to Yle, Helen aims to choose the plant model and the site by the end of 2027, and the plant would be ready in just over a decade. The timetable published by Helen foresees the assessment report in 2027 and the reasoned conclusion of the Ministry of Economic Affairs and Employment in 2028. “The coming year will be more significant than all the previous years combined,” Pekka Tolonen, CEO of Helen Ydinvoima, the nuclear subsidiary that started operating in February 2026, told Yle.

Background. Helen's nuclear programme began in 2024 and aims to end combustion-based energy production by 2040. The city's coal-fired plants have closed, and electricity is now produced only from natural gas at Vuosaari and, to a small extent, from solar panels, according to Yle. Peaks in electricity demand are expected to double within a few years.

What comes next. The city says a plant could operate at the earliest in the mid-2030s and that the project needs the environmental assessment, zoning plans approved by the city and the approval of the radiation and nuclear safety authority STUK. In November, Helen is holding four public meetings, at the Oodi library and in Vuosaari, Ruoholahti and Östersundom.

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