Western Europe's biggest nuclear power station, Gravelines, was forced to shut down on Monday after millions of jellyfish swarmed into its cooling system, according to operator EDF.
Emergency shutdown at Gravelines
The plant, located near Dunkirk and just 30 miles from Britain, took emergency measures as jellyfish clogged filter drums at the seawater pumping stations used to cool the reactors. Reactors two, three and four were taken offline, while output from reactor one was halved. Only reactor six was operating at full power on Tuesday; reactor five had already been offline for scheduled maintenance.
EDF issued a statement saying: “This situation has no impact on the safety of the facilities, the safety of our personnel, or the environment.”
Impact on power supply
Gravelines has six reactors and generates 5,400 megawatts, supplying around 70 per cent of the electricity for the Hauts-de-France region each year.
The jellyfish invasion comes exactly a year after a similar event took the plant offline for two days. An invasive species, the Asian Moon Jellyfish, has been proliferating in the English Channel and North Sea since 2020. The species, native to the Pacific, is thought to have been introduced via ballast water from supertankers.
Response and recovery efforts
Nuclear plants in China, Japan and India, which also rely on seawater for cooling, have faced similar disruptions. After last year's incident, Gravelines installed cameras to monitor seawater intake and filters, plus a warning system for approaching swarms.
Fishing boats were sent out on Saturday with trawler nets to reduce jellyfish numbers, which helped limit the latest invasion, according to an engineer. Vacuum trucks are now removing jellyfish trapped inside the plant, and since no new jellies are arriving, the plant is expected to resume operations soon.
