Nuclear power plant shuts down due to jellyfish invasion

Perth Now

3 days ago

One of Europe's biggest nuclear power stations was forced to shut down this week after an unexpected invasion - by jellyfish.
The Gravelines nuclear power plant in northern France, located between Dunkirk and Calais, was fully shut down on Monday (12.08.25) after a 'massive and unpredictable' swarm of jellyfish clogged its sea water intake system. The plant, which relies on water from the North Sea to cool its reactors, saw four of its six units automatically shut down just before midnight when filter drums became overwhelmed. A fifth reactor followed hours later.
Each unit at Gravelines produces 900 megawatts of power, making the disruption a significant hit to the region's energy supply. Fortunately, French energy giant EDF confirmed that the incident posed no threat to staff, the environment, or the facility itself.
The jellyfish didn't damage the pumps, but they will need to be removed and the filters cleaned before the reactors can be restarted.
This isn't the first time the Gravelines area has seen jellyfish swarms, with similar events washing up on nearby beaches in recent years. Experts say the increase is likely due to rising sea temperatures caused by global warming, as well as the spread of invasive species.
Derek Wright, a marine biology consultant with the US National Oceanic and Atmospheric Administration, explained: 'Jellyfish breed faster when water is warmer, and because areas like the North Sea are becoming warmer, the reproductive window is getting wider and wider. Jellyfish can also hitch rides on tanker ships, entering ballast tanks in one port and being pumped out halfway across the globe.'
He added: 'Everyone talks about nuclear being clean, but we don't think about the unintended consequences of heat pollution.'