Jellyfish invasion halts French nuclear plant operations

An unexpected jellyfish invasion has brought one of the largest nuclear power plants in France to standstill as the swarms entered the water pumping systems that used to cool reactors.

According to French Nuclear company Electricite de France (EDF), three reactors at the Gravelines nuclear facility were shut down on Sunday, August 11 after the filter drums of water intake systems filled with “massive and unpredictable” marine invertebrates.

However, the unexpected shutting down of the operations did not jeopardise the safety of the power plant, staff, and the environment. Even the electricity exports from France to the UK did not affect.

Being the largest plant in northern France, the facility is capable of powering 5 million homes and the cooling mechanism of these reactors is linked to a canal connected to the North Sea.

The North Sea is also a home to several native marine species.

According to scientists, the increased warmer waters of the ocean and proliferation of invasive species have led to an increase in jellyfish population in Gravelines.

Derek Wright, marine biology consultant with United States National Oceanic and Atmospheric Administration said, “Jellyfish reproduce faster in warmer water, and because areas like the North Seas are turning warmer, the reproductive window is getting wider and wider.”

This is not the first incident of its kind as jellyfish have a long history of jamming coastal power plants.

For example, the Torness nuclear plant in Scotland was forced to shut down for a week in 2021 after jellyfish invaded seaweed filters.

To tackle this operational hindrance and economic cost, scientists at the University of Bristol developed an early warning tool to predict the sudden invasion of jellyfish swarms.