Jellyfish force French nuclear plant shutdown

A swarm of the marine creatures clogged the cooling system of a nuclear site in northern France

A “massive” swarm of jellyfish prompted the Gravelines nuclear power plant to automatically switch off, the energy group EDF that operates the facility said on Monday.

The swarm of marine creatures clogged the filters of the cooling systems of the plant, the operator said. The “massive and unpredictable presence of jellyfish” prompted four power units of the facility to automatically shut off. The incident put the entire facility offline, as two other units were already inoperable due to maintenance. 

The incident, which occurred late on Sunday, had “no impact on the safety of the facilities, the safety of personnel, or the environment,” the EDF said, adding that the gelatinous creatures made it only to “the non-nuclear part of the facilities.” 

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“The plant teams are mobilized and are currently carrying out the necessary diagnostics and interventions to be able to restart the production units safely,” the energy group added. 

The nuclear site draws cooling water from a channel linking it to the North Sea, which is home to several jellyfish species. The plant operator did not elaborate on the exact type of jellyfish involved in the incident. 

Jellyfish have a long history of disrupting the the work of coastal power plants, repeatedly getting sucked into cooling systems or clogging up intake pipes of nuclear and conventional energy facilities worldwide. 

The Gravelines power plant is one of the largest nuclear sites in France, the country that gets 70% of its electricity from nuclear installations. Six units of the facility have a peak production of 900 megawatts each, making the station alone capable of powering an estimated 5 million homes.