Jellyfish have shut down three reactors at the Gravelines nuclear power plant again.

On August 12, 2026, a large group of seals disrupted operations at the nuclear power plant in Gravelines, France, prompting the utility company EDF to shut down three of its six reactors. The incident occurred after the seals entered the intake system of the facility, which draws seawater for cooling purposes. According to EDF, the safety of the plant was not compromised, though the event highlighted the vulnerability of coastal energy infrastructure to environmental changes. The seals, which had previously caused similar disruptions earlier in the year, again surprised operators despite prior preparations. Two reactors automatically shut down on Monday due to the influx of marine life, in accordance with the plant’s safety protocols. Operators took preventive action by manually shutting down a third reactor and reducing the output of another by half. One reactor was already offline due to planned maintenance, while the sixth remained connected to the electrical grid. Gravelines, located along the coast of the North Sea in the department of Nord, is one of the largest nuclear power plants in Western Europe. It plays a crucial role in meeting regional electricity demand and contributes significantly to France's energy production. The plant operates six pressurized water reactors, each capable of generating substantial amounts of electricity. The shutdowns temporarily reduced the plant’s overall capacity, though EDF stated there were no adverse effects on personnel or the surrounding environment. The incident has sparked discussions among local authorities and environmental groups regarding the need for enhanced measures to protect critical infrastructure from wildlife interactions. While EDF emphasized that the seals did not pose a direct threat to the plant’s operational integrity, they acknowledged the importance of monitoring such occurrences more closely. The utility company has since initiated a review of existing protocols to better manage potential future incidents involving marine life. Operators at Gravelines have confirmed that the seals entered the intake system through a section of the facility designed to filter debris and foreign objects. However, the animals managed to bypass these safeguards, leading to automatic shutdowns as a precautionary measure. The affected reactors were restarted within hours following the resolution of the situation, restoring normal operations. EDF has not yet announced any long-term modifications to the facility’s design or security systems, though internal assessments are ongoing. Environmental experts have noted that rising sea temperatures and shifting migration patterns could increase the likelihood of such encounters in the future. They suggest that greater investment in adaptive technologies and real-time monitoring systems might help mitigate risks associated with wildlife interference. Meanwhile, local communities remain concerned about the broader implications of climate change on both ecological balance and industrial operations. As the plant continues to operate under heightened vigilance, officials are working to ensure that such disruptions do not recur without adequate preparation.