Both units of Finland’s Loviisa nuclear power plant have resumed power generation following the completion of extended annual outages, marking a critical step in Fortum’s long-term operational and modernization strategy. While the outages ensured continued safety and reliability, they also underscored the operational complexity of extending plant lifetimes amid fuel diversification efforts and infrastructure renewal.
Unit 2’s annual maintenance, completed on September 18, 2025, ran approximately 12 days behind schedule due to unexpected technical setbacks. A dropped control rod during fuel handling and additional repairs identified during inspection and start-up testing added unplanned work. Unit 1’s outage concluded on October 3, nine days later than planned, following the discovery of boron water leakage onto the reactor deck—an issue that required extensive cleaning and inspection.
According to Sasu Valkamo, Senior Vice President of the Loviisa power plant, the delays reflect both the rigor of nuclear safety standards and the aging complexity of a facility now entering its fifth decade of operation.
The outages also marked continued progress in Loviisa’s transition to Western-supplied nuclear fuel—a strategic shift driven by supply security and geopolitical realignment. In 2022, Fortum signed a deal with Westinghouse Electric Company to design, license, and deliver a new fuel type for the plant, providing a non-Russian alternative for the twin VVER-440 reactors originally designed for Soviet fuel.
The first batch of Westinghouse fuel was loaded into Unit 2 during the 2024 outage. This year’s maintenance extended the use of the new fuel, further reducing Fortum’s dependence on Russian suppliers. As of now, a significant portion of Loviisa’s core inventory originates from Western sources, representing a notable diversification milestone.
While the company has not disclosed the exact share of Westinghouse fuel now in use, this gradual introduction is consistent with the stringent qualification process required for fuel licensing under the Finnish Radiation and Nuclear Safety Authority (STUK). The adaptation underscores how nuclear operators across Europe are rebalancing fuel procurement strategies in response to evolving supply-chain risks.
Loviisa’s outages are part of a broader €1 billion life-extension program aimed at securing safe operation until 2050. Regular annual maintenance, combined with major equipment renewals, plays a central role in sustaining both regulatory compliance and plant performance over the extended operational horizon.
This year’s work included the replacement of Unit 1’s high-pressure preheaters and several valves, renewal of measurement piping, and preparatory work for upcoming modernization phases. The renovation of the employee accommodation village near the plant also reflects Fortum’s focus on long-term operational continuity and workforce sustainability in the small coastal town of Loviisa.
In 2026, the facility will enter an extensive maintenance cycle involving the modernization of low-pressure turbines, renewal of turbine automation systems, and replacement of the main seawater pumps and motors—components essential to the plant’s thermal efficiency and reliability.
The delays at Loviisa highlight a broader issue facing Europe’s aging nuclear fleet: the increasing difficulty of executing large-scale maintenance within tight outage schedules. Many plants commissioned in the 1970s and 1980s face similar challenges balancing refurbishment, fuel transition, and lifetime extension within rigorous safety and environmental frameworks.
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