A massive swarm of jellyfish has caused the shutdown of one of France's largest nuclear power plants after clogging the water intake systems used for cooling. The Gravelines plant in northern France saw three reactors automatically shut down late on Sunday, according to operator EDF, after filter drums became packed with the marine creatures.
The entire plant, which can power about five million homes, was taken offline when a fourth reactor shut down shortly after the swarm jammed the system. Two other reactors were already offline for planned summer maintenance. EDF said the event did not affect safety, staff or the environment, and there was no change to electricity exports from France to the UK.
The Gravelines plant draws cooling water from a canal connected to the North Sea, where native jellyfish species are common in warmer summer waters. Jellyfish have a history of disrupting coastal power plants globally, including at EDF's Torness plant in Scotland, which was forced to shut for a week in 2021 and again in 2011 due to jellyfish clogging water intake filters.
Scientists at the University of Bristol have developed an 'early warning tool' to predict sudden jellyfish swarms that could disrupt power plants. Similar incidents have occurred in Sweden, the US, Japan, and the Philippines, where a 1999 jellyfish-related blackout was mistakenly linked to the Y2K bug. In September, a coal-fired power plant in eastern China battled for 10 days to clear over 150 tonnes of jellyfish from its cooling systems.
