Stopped the operation of the nuclear power plant in France due to jellyfish

• Four reactors of Gravelines were stopped due to jellyfish
• The entire plant suspended operations for technical maintenance
• Increase in jellyfish is related to warming waters

The Gravelines nuclear power plant in northern France suspended its operations due to jellyfish clogging the cooling system. The operator of the plant, EDF, reported this on September 11, 2025.

The incident occurred over the weekend when four reactors automatically shut down after the cooling system filters became clogged with "massive and unprecedented" jellyfish. Reactor 6 was also stopped for several hours. The entire plant temporarily halted production, as the other two reactors were already undergoing planned technical maintenance.

The Gravelines nuclear power plant is one of the largest in the country and uses water from a canal that connects to the North Sea. Each of the six reactors generates 900 megawatts of electricity, which totals 5.4 gigawatts.

The warm waters of the North Sea contribute to the increasing jellyfish population, which is becoming more prevalent. This phenomenon is linked to global warming and the invasion of new species, such as the Asian jellyfish, which was first spotted in the North Sea in 2020.

EDF representatives stated that the incident did not impact the safety of the facility, personnel, or the surrounding environment. Investigations show that jellyfish do not pose a safety risk, as their stings do not cause harm.

Tags: Energy