Finland’s supreme administrative court halts enforcement of market court rulings in Olkiluoto 3 grid protection dispute

Finland’s Supreme Administrative Court has suspended enforcement of two 2025 Market Court decisions concerning cost responsibility for the Olkiluoto 3 nuclear plant’s system protection measures, state broadcaster Yle reports.

The interim ruling means the existing agreement between nuclear operator Teollisuuden Voima and grid company Fingrid will remain in force while the Supreme Administrative Court reviews the case. The dispute centers on which party should bear the costs of technical arrangements allowing OL3 to generate electricity beyond the grid’s 1,300-megawatt capacity limit—up to the plant’s 1,600-megawatt maximum.

In its decision, the court emphasized the need to ensure “clear and unambiguous” grid protection arrangements during proceedings to maintain operational continuity. Teollisuuden Voima confirmed the suspension in a statement, noting the court had deemed the pause justified to avoid disruption.

Fingrid defines the system protection as a technical solution enabling OL3’s output to exceed standard grid constraints without compromising stability.