The Finnish capital Helsinki is taking a decisive leap toward a post-combustion future. Local energy company Helen Oy has identified three potential sites within the city for a small modular reactor (SMR) project — a move that could make Helsinki Europe’s first capital city to deploy an urban nuclear heat reactor.

(Image: Helen)

Three Candidate Sites

The shortlisted areas include:

• Vuosaari (eastern coast) — existing gas power facility

• Salmisaari (west of the city center) — a soon-to-retire coal plant

• Norrberget (western Östersundom) — an undeveloped site

All three are connected to Helsinki’s district heating network, enabling direct integration of nuclear heat. Helen says the selection considered environmental safety, economic feasibility, and social acceptance.

“We’re not building a traditional power plant — we’re creating an energy hub that can live within the city,”

said a Helen spokesperson.

Strong Government Backing

Support from local decision-makers is unusually high. A study by Aula Research for Steady Energy found that around 86% of municipal decision-makers in Finland’s major cities favor the introduction of SMRs — with Helsinki scoring 89% support.

Respondents cited emission reduction, energy security, and stable heating as the top benefits. Finland’s Minister for Climate and Energy Policy has also described SMRs as “an essential tool for decarbonization.”

Public Sentiment: Optimistic but Demanding Transparency

Public attitudes toward nuclear energy in Finland have reached record levels of support. According to an April 2025 national survey, 68% of Finns view nuclear energy positively, while only 9% oppose it.

Local sentiment in Helsinki reflects cautious optimism. On community forums, residents have even welcomed the plan to replace old coal plants with nuclear heat:

“If nuclear heat replaces coal at Salmisaari, I’m all for it,” wrote one local on Reddit.

Still, citizens are calling for transparent risk assessments and continuous public consultation. The City of Helsinki confirmed it will launch a full environmental impact assessment (EIA) with public hearings.

Technology and Energy Strategy

Helen’s SMR plan fits into its broader combustion-free roadmap, which includes:

• Closing all coal-fired plants by 2029,

• Investing in waste-heat recovery and seawater heat pumps,

• Partnering with Finnish startup Steady Energy on nuclear heat development.

The company views SMRs as the “cornerstone” of its next-generation energy mix — offering stable, dispatchable, and weather-independent zero-carbon heat. The pre-development phase runs through 2026, with demonstration operations targeted for early 2030s.

Finland as Europe’s Urban Nuclear Pioneer

Beyond Helsinki, Finnish cities such as Tampere, Loviisa, and Kouvola are exploring similar nuclear-heat initiatives. Yet Helsinki’s project stands out for its urban integration — a model that could redefine how Europe’s cities harness nuclear power.

Helen CEO Olli Sirkka stated:

“Small modular reactors are the key to achieving carbon-free, reliable, and locally produced heat for our citizens.”

If realized, the warmth flowing through Helsinki’s pipes in the near future could come not from burning coal — but from the quiet pulse of a compact nuclear reactor beneath the city.