Edith Hejberg
A sudden invasion of jellyfish brought operations at one of France’s largest nuclear power stations to a standstill.
The Gravelines plant, located on the northern coast between Calais and Dunkirk, had to shut down completely after the creatures clogged key intake systems. State-owned operator EDF described the incident as “massive and unpredictable.”
Cooling Water Intake Overwhelmed
The plant’s reactors draw cooling water from a canal linked to the North Sea. Late on Sunday, filter drums at the pumping stations became packed with jellyfish, preventing water from flowing into the system.
Without a steady supply, the reactors automatically shut down to prevent overheating.
Four Reactors Taken Offline
Reactors 2, 3, and 4 stopped automatically as the jellyfish swarmed the intake screens.
Reactor 6 was taken offline shortly afterward as a precaution. The two remaining reactors were already out of service for scheduled maintenance, meaning the entire facility had to halt production.
Seasonal Jellyfish Activity
Several jellyfish species are native to the North Sea and tend to appear in greater numbers during the warmer summer months.
While the creatures are a common sight along beaches in the region, large swarms like this can still catch operators off guard.
No Safety Threat Reported
EDF stressed that the incident posed no danger to staff, the public, or the environment.
The shutdown was a precautionary measure to protect equipment and ensure the plant’s cooling systems were not compromised.
Awaiting Restart
Engineers are working to clear the filter systems and monitor local waters before restarting the reactors.
The timeline for resuming operations has not yet been announced, as the focus remains on preventing a repeat of the jellyfish incursion.
