Jellyfish force partial shutdown of French nuclear plant

A massive influx of jellyfish forced the partial shutdown of a French nuclear reactor. Two of the six units at the Gravelines nuclear power station were taken offline on Wednesday and Thursday after jellyfish entered the seawater filtration system used for cooling, Électricité de France (EDF) reported. A third unit has remained shut since 10 August for the same reason, while a fourth unit was closed for inspection. Gravelines, one of France’s largest nuclear plants situated between Dunkirk and Calais in the Hauts‑de‑France region, had previously been closed in August due to jellyfish in its filters. EDF stated that units three, four and six are currently offline. Unit 3 had only been reconnected to the grid on 18 August following the earlier jellyfish influx this month, the company said, and units 1 and 2 are operating at reduced power as a precaution. Each of Gravelines’ six units generates 900 megawatts of electricity, and the station draws cooling water from a canal linked to the North Sea. Several jellyfish species native to the area appear near the shore when water temperatures rise. Experts note that jellyfish activity peaks in warmer months, as hot winds boost plankton levels at the surface and draw the organisms upward. To mitigate the problem, authorities have instituted measures including a partnership with local fishermen who capture and relocate the jellyfish farther offshore, according to the French outlet Ici. Similar incidents have occurred elsewhere, such as at Scotland’s Torness plant in 2011 and Sweden’s Oskarshamn facility in 2013, though such events remain uncommon.