Jellyfish Force Shutdown at France’s Gravelines Nuclear Plant, But Datacenters Stay Safe

A large swarm of jellyfish caused four production units at the Gravelines nuclear power plant in northern France to shut down. The plant’s operator, Électricité de France (EDF), said the shutdown happened because jellyfish clogged the filter drums in the pumping stations.

Each production unit at Gravelines can generate 900 megawatts of electricity — enough to power several major datacenters. The affected area was part of the plant’s “non-nuclear” operations, meaning there was no risk to safety, staff, or the environment.

Despite the shutdown, no datacenter outages or power shortages were reported in the nearby region. The city of Lille, about 80 km from Gravelines, is home to OVH’s Roubaix cloud region, one of the largest datacenter hubs in Europe.

EDF confirmed that the incident had no impact on the nuclear core and was purely a mechanical issue caused by the unexpected jellyfish swarm.

The news comes as Big Tech companies — including Google, Microsoft, Amazon, Nvidia, and Meta — invest in nuclear power to run massive datacenters for AI workloads. Some companies are even building facilities directly next to nuclear plants to ensure a steady power supply.

This unusual event may serve as a warning for datacenter planners. Experts suggest that future designs should account for environmental factors like local wildlife, which could unexpectedly disrupt operations.

For now, the Gravelines plant is working to clear the jellyfish and restore full power generation.