The jellyfish blocked the pumps that take in cooling water from the English Channel to the reactors in Gravelines, a nuclear power plant with six reactors on France's north coast. Two of the reactors were already shut down for maintenance, so the acute shutdown of the other four means that the entire plant is down.
French energy giant EDF explains the sudden shutdown of four reactors with "the massive and unforeseen presence of jellyfish in the filter drums of the pump stations".
France is one of Europe's most nuclear power-dependent countries. Previously, reactors have also been affected during the summer by the water being so hot in the country's rivers that it is not suitable for cooling, which has led to unplanned shutdowns during heatwaves. That problem is feared to worsen with climate change.
