Aug. 11 is quickly becoming jellyfish invasion day at the Gravelines nuclear power plant in northern France.

Despite spending hundreds of thousands of euros to protect the plant from a jellyfish swarm like the one that saw reactors shuttered on Aug. 11, 2025, French utility provider EDF on Tuesday was again forced to bring the parts of the facility offline due to the presence of “several dozen tons” of jellyfish blocking pumping systems.

“On-site teams are fully mobilized to ensure the safety of the facilities and to reconnect the reactors to the national power grid,” EDF said in a statement.