Qualla: Olkiluoto Nuclear Power Plant

Olkiluoto Nuclear Power Plant: Introduction

Mon, 17 Aug 2026 00:00:00 GMT

Photo credit Teemu Väisänen, CC BY-SA 4.0. In August 2024, on a low island off Finland's west coast, engineers lowered empty canisters into holes drilled in the floor of a tunnel more than four hundred metres underground and then pulled them back out again. It was a rehearsal. The canisters were copper over a boron-steel insert, each built to hold twelve spent fuel assemblies, and the tunnel was Onkalo, which will be the world's first permanent burial site for high-level nuclear waste. Everything else on Olkiluoto Island operates on a timescale of decades: reactors, licences, outage schedules, electricity prices. The hole in the granite is designed for a hundred thousand years. The two things sit within a few kilometres of one another, which is the whole point.

Image: Teemu Väisänen | CC BY-SA 4.0

Olkiluoto Nuclear Power Plant: The Island's First Business

Mon, 17 Aug 2026 00:00:00 GMT

Photo credit Cryonic07, CC BY-SA 3.0. Teollisuuden Voima, TVO, has been generating power on this shore since Olkiluoto 1 came on line in October 1979, with Olkiluoto 2 following in July 1982. Both are boiling water reactors from ASEA-Atom, the Swedish designer now folded into Westinghouse, with turbines by Stal-Laval...

Image: Cryonic07 | CC BY-SA 3.0

Olkiluoto Nuclear Power Plant: Fourteen Years Late

Mon, 17 Aug 2026 00:00:00 GMT

Photo credit schoella, CC BY 3.0. Then there is unit 3, which became a cautionary tale told across the industry. Finland approved it in February 2005, the first Western European country in fifteen years to order a reactor, and Areva contracted to build the first EPR for a fixed price of three billion euros. Almos...

Image: schoella | CC BY 3.0

Olkiluoto Nuclear Power Plant: First Criticality to Full Power

Mon, 17 Aug 2026 00:00:00 GMT

Photo credit kallerna, Public domain. The endgame was its own drama. First criticality came on 21 December 2021; an unplanned scram on 14 January 2022 pushed grid connection back; electricity finally began flowing at one minute past noon on 12 March 2022. Debris from the steam guide plates turned up in the turbine re...

Image: kallerna | Public domain

Olkiluoto Nuclear Power Plant: The Hundred-Thousand-Year Room

Mon, 17 Aug 2026 00:00:00 GMT

Photo credit kallerna, Public domain. Onkalo belongs to Posiva, a company owned by TVO and Fortum, and excavation began in 2004 after Eurajoki granted a building permit the previous year. The Finnish government issued the construction licence on 12 November 2015. The engineering rests on redundancy rather than clever...

Image: kallerna | Public domain

Olkiluoto Nuclear Power Plant: A Working Plant, Not a Monument

Mon, 17 Aug 2026 00:00:00 GMT

Photo credit kallerna, Public domain. For all the significance layered onto it, Olkiluoto runs like any large industrial site, with the ordinary faults that implies. On 3 June 2024 a turbine tripped unit 3 offline for a night, traced to a pressure measurement failure in the generator's sealing oil and hydrogen coolin...

Image: kallerna | Public domain