nuclear-news

Jellyfish Force another French Nuclear Reactor to Shut Down

By Charles Kennedy – Sep 04, 2025,
https://oilprice.com/Latest-Energy-News/World-News/Jellyfish-Force-another-French-Nuclear-Reactor-to-Shut-Down.html

For a second time in three weeks, a swarm of jellyfish has forced the closure of a nuclear reactor in France in another curious incident in which jellyfish entered the filters of the water cooling systems.

The Paluel nuclear power plant in Normandy, northern France, saw its electricity generation nearly halve by 2.4 gigawatts (GW) out of a total 5.2-GW capacity, due to the presence of jellyfish that have entered the filtering system, French operator EDF said on Thursday, as carried by Reuters.

One of four reactors at Paluel was shut down while power output at another reactor was curtailed to prevent further disruption due to the jellyfish swarm.

oday’s incident at Paluel occurred just over three weeks after a jellyfish swarm clogged the cooling system of the Gravelines nuclear power plant near Dunkerque and Calais. As a result, four of six units at one of France’s largest nuclear power plants automatically switched off, while the remaining two units were already shut down for planned maintenance. Gravelines has six reactors, each with a capacity of 900 megawatts (MW).

At the time, France’s EDF said there was “no impact on the safety of the facilities, the safety of personnel, or the environment.”

Reactors at the Gravelines power plant are cooled from a canal linked to the North Sea, where jellyfish are swarming near the coast during hot weather and warm waters.

Global warming can worsen the jellyfish problem in waters cooling reactors close to seas, scientists have warned.

In recent years, heatwaves and too hot waters in rivers have disrupted France’s nuclear power generation, too.

France’s nuclear power generation accounts for around 70% of its electricity mix, and when its reactors are fully operational, it is a net exporter of electricity to other European countries.

But in 2022 and 2023, EDF was forced to curb power generation at some nuclear plants as heatwaves raised the temperatures of rivers. The power plant operator had to limit electricity output because of environmental regulations for using river water for cooling nuclear reactors.

September 7, 2025 - Posted by Christina Macpherson | France, safety