Loviisa nuclear power plant annual outage to begin – including several major modernization projects

FORTUM CORPORATION PRESS RELEASE 29.7.2026

The annual outage of Fortum’s Loviisa nuclear power plant will begin with Unit 2 on Sunday, 2.8.2026, followed by the servicing of Unit 1. One reactor unit is normally in operation while the other is undergoing maintenance.

Unit 2 will undergo the comprehensive annual maintenance outage carried out every eight years. During this outage, the fuel will be removed from the reactor for inspections of the reactor pressure vessel and a pressure test, a quarter of the fuel will be replaced, and a wide range of other maintenance and servicing tasks will be performed. Unit 1 is scheduled for a shorter annual outage, which includes fuel replacement as well as other maintenance and servicing tasks.

The annual outages will be carried out between 2.8-18.10.2026.

“The Loviisa power plant plays an important role in ensuring the reliability of Finland’s electricity supply. A systematically implemented annual outage will again ensure uninterrupted electricity production for the coming year,” saysSasu Valkamo, Senior Vice President, Loviisa power plant.

In addition to the power plant’s permanent employees, approximately 1,000 workers from contractor companies will participate in the annual outage.

Several major modernization projects will be launched during the annual outage

Several modernization projects aimed at extending the service life of the power plant will also be launched during the annual outage.

“The most significant projects include modernization of the low-pressure turbines, renewal of the turbine automation, and replacement of the main seawater pumps. In total, more than ten major projects will be carried out during the annual outage,” says Sasu Valkamo.

Both units at the Loviisa nuclear power plant have a new operating license valid through the end of 2050. To ensure continued stabile and safe operation, the power plant needs to undergo extensive upgrades in the coming years. Required investments until 2050 are estimated to be up to EUR 1 billion.

Introduction of new fuel type progresses in annual outage

In November 2022, Fortum signed an agreement with the US-based Westinghouse Electric Company for the design, licensing and supply of a new fuel type for the Loviisa power plant. The new fuel type guarantees a reliable Western alternative for fuel deliveries to the Loviisa power plant.
“We have loaded Westinghouse fuel into Unit 2 during the annual outages in 2024 and 2025, and we will continue to do so this year as well. After this annual outage, a large portion of our fuel will be from Western countries,” Valkamo says.

In addition to Westinghouse fuel, another type of Western fuel is also being developed for the Loviisa power plant. In April 2026, Fortum and three other European energy companies signed an agreement with the French company Framatome to develop a fully European nuclear fuel for VVER type nuclear power plants, including Fortum’s Loviisa power plant.

Fortum Corporation
Communications

Further information:
Fortum News Desk, newsdesk@fortum.com, +358 40 198 2843

Loviisa power plant

In 2025, the availability at Fortum’s fully-owned Loviisa nuclear power plant was 89.4%. In 2025, the power plant produced a total of 7.9 terawatt-hours of electricity, which is approximately 10% of Finland’s electricity production. Fortum employs about 800 nuclear sector professionals, 570 of them work at the Loviisa power plant. Additionally, nearly 100 permanent employees of other companies work in the power plant area every day. More information:www.fortum.com/loviisa

Fortum

Fortum is a Nordic energy company. We generate and deliver reliable energy to our customers and the Nordic energy system while at the same time helping industries decarbonise their processes and grow. Our core operations comprise efficient and best-inclass low-carbon power generation, customer services, and heating and cooling. Fortum’s power generation is already 99% from renewable or nuclear sources with one of the lowest specific CO2-emissions in Europe. We are guided by our ambitious SBTi-validated emission reduction targets on our way towards net-zero by 2040. For our ~4,500 employees, we commit to be a safe and inspiring workplace. Fortum's share is listed on Nasdaq Helsinki.fortum.com