Scheduling changes for annual outages at Olkiluoto power plant

6.9.2024

The annual outages carried out at the Olkiluoto nuclear power plant units are designed to ensure uninterrupted electricity production without disruptions. The service outages are planned and scheduled years ahead. Until now, the estimated schedules have been based on the duration of the planned work phases. The scheduling principles have now been modified so that the delays caused by unanticipated failure repairs are also accounted for based on previous experience.

Annual outages are a means to ensure that the Olkiluoto nuclear power plant remains in good condition at all times. Service outages are necessary to carry out refuelling and specific maintenance and service activities. At the same time, annual outages play a key role in the long-term lifecycle management of our plant units.

The outage times of the Olkiluoto power plants have been scheduled up till the year 2027. The scheduling of the annual outages is affected by, among others, the availability of personnel and the refuelling cycle. The objective is to only have one unit undergoing the annual outage at a time.

The new scheduling method increases the announced duration of the annual outages at all plant units. The estimated schedules are based on the actual duration of several previous annual outages. The updated estimates now also account for unanticipated failure repairs.

Next year, annual outages will be carried out in Olkiluoto starting in March and ending in June, like in previous years. The service outage at Olkiluoto 3 will start in March before the expiration of the plant supplier’s warranty period.

In 2026, the Olkiluoto 1 and Olkiluoto 2 units will have their annual outages in late spring because the service outage of Olkiluoto 3 is pushed back till the autumn. In 2027, the annual outages will follow the same schedule as in 2026.

More detailed estimated schedules are provided on TVO’s website at:https://www.tvo.fi/en/index/production/plantunits/annualoutagesandmodernizations.html


For more information, and requests for interviews, please contact:
Johanna Aho, Head of Communications, tel. +358 40 729 0822