Ydinvoima

ydinvoima is Finnish for nuclear power, electricity produced by nuclear fission in reactor cores using uranium or plutonium as fuel. In Finland, nuclear power provides a large share of the country’s low‑carbon electricity and is considered a cornerstone of energy security.

Finnish nuclear facilities consist of four reactor units operating at two sites: Loviisa and Olkiluoto. Loviisa has two Soviet‑designed pressurized water reactors. Olkiluoto hosts two boiling‑water reactors. A third unit at Olkiluoto, Olkiluoto 3, a European pressurized reactor, has been under construction for many years and has progressed through commissioning in the 2020s, entering service in stages.

Regulation is overseen by the Radiation and Nuclear Safety Authority (STUK), an independent national regulator that issues licenses, conducts safety inspections, and requires environmental impact assessments for new projects. Finland follows international safety standards and maintains emergency planning zones around facilities. The country has not experienced a major nuclear accident; safety culture and continuous inspections are emphasized.

Spent fuel is currently stored on-site, while Finland is developing a deep geological repository at Onkalo near Olkiluoto for permanent disposal of high‑level waste, a project with international interest. The Onkalo facility embodies Finland’s approach to long‑term radioactive waste management.

Economics and policy: Nuclear power has been politically supported as a means to meet climate targets and maintain electricity prices; building new reactors is expensive and requires public acceptance and stable regulation. The Finnish government plans to maintain the nuclear fleet as part of its low‑carbon strategy, with potential future expansions contingent on technology, safety, cost, and regional energy markets.