Okiluoto Nuclear Power Plant

Olkiluoto is Finland’s largest nuclear power complex, featuring two operating boiling-water reactors (Units 1 & 2, ~890 MW each) and a flagship European Pressurized Reactor (Unit 3, ~1,600 MW). Units 1 and 2 commenced operations in 1979 and 1982, respectively, and have since been upgraded to enhance output and efficiency. Unit 3—Europe’s first EPR—achieved commercial operation in 2023 after an extended construction period beginning in 2005. Together, the three reactors supply over 3 GW to the Finnish grid, producing around 14 TWh annually.

Engineering highlights include large-scale reactor pressure vessels, advanced safety systems, redundant cooling circuits harnessing Baltic Sea water, and modern digital instrumentation. Unit 3 in particular showcases third-generation design, including a double containment structure, enhanced seismic resilience, and passive safety systems. The plant integrates with Finland’s national grid and neighboring Sweden via interconnectors. Olkiluoto’s broader site includes the adjacent Onkalo facility—the world’s first permanent geological repository for nuclear waste. The combined complex offers a comprehensive case study in nuclear power development, construction, and lifecycle management.

The Olkiluoto Visitor Centre is open daily from 10:00 to 20:00 and offers free self-guided access to interactive exhibits on nuclear energy, fuel cycles, and environmental monitoring. The "Electricity from Uranium" exhibition, developed jointly with Finland’s Heureka science centre, includes multimedia displays, control-console mockups, and an outdoor nature trail along the coastline at Olkiluoto.

Guided group tours of the actual power plant and Onkalo repository are available by appointment for adult groups (min. 10 people), lasting approximately 3 to 3.5 hours. Tours are conducted in Finnish and English and include passage to the reactor vantage areas and controlled-access zones; planning approval and identity verification are required in advance. Tours are typically scheduled on weekdays and must be reserved at least two weeks prior. Photography is only allowed inside the Visitor Centre. Group tours may carry a fee, while basic visits to the exhibition area are free. Boat access is also available to the Visitor Centre via seaside moorings, with a 4‑hour free berthing limit.