Jellyfish shut down French nuclear reactors

Four French nuclear reactors shut down after a swarm of jellyfish entered a cooling system at the Gravelines nuclear power plant, French firm EDF said Monday.

“These shutdowns are the result of the massive and unforeseeable presence of jellyfish in the filter drums of the pumping stations, located in the non-nuclear part of the installations,” an EDF spokesperson told POLITICO.

EDF is conducting diagnostics and necessary interventions to safely restart the plant, according to the spokesperson.

Three reactors automatically stopped working late Sunday, and a fourth shut down early Monday. There are six reactors total at the plant, but the other two are undergoing maintenance.

EDF is France's main electricity generation and distribution company, through nuclear, hydropower, renewables, and thermal power plants. The company said that the incident does not pose a safety threat to the plant, its workers, or the environment.

Water pumped from a canal connected to the North Sea cools off the plant. There has been an increase in jellyfish at beaches in the area in recent years because of increasing sea temperatures, changes in salinity, and overfishing, which reduces jellyfish predators.