Gravelines is one of the largest nuclear power plants in France. Six blocks with a capacity of 900 MW each (5.4 GW in total) is cooled with water collected from the canal connected to the North Sea. In recent years, more and more jellyfish has been observed on the beaches between Dunkirka and Calais, which scientists are associated with water warming and the introduction of invasive species into the ecosystem.
Experts pay attention to two factors. First, a higher water temperature extends the reproductive period for jellyfish, increasing the likelihood of sudden, mass blooms. Secondly, These organisms can “travel” along with global trade – They go to the tanks of ballast ships, and then be pumped out in completely different waters.
According to the adviser for biology, Derek Wright from Noaa Fisheries, this combination of warm waters and maritime transport promotes the expansion of newcomers, including the Asian variety of moon jellyfish, whose first observations in the North Sea were recorded in 2020.
Jellyfish blocked filtering systems
The operator's message shows that Reactors 2, 3 and 4 turned off automatically just before midnight, when the filtration drums of the pumping station began to fill with the remains of Meduz. A few hours later, reactor 6 was also disconnected.
These jellyfish do not pose a threat to people, because they do not have venomous pans, but in a large number they can paralyze the port infrastructure and, as it turns out – energy. Cases of short -term restrictions on the power plant work due to blocking of jellyfish filters have already been recorded in China, Japan or India.
The incident in Gravelines reminds that although nuclear energy does not emit greenhouse gases during energy production, it is elements of its technological cycle – such as consumption and removal of cooling water – they interact with rapidly changing sea ecosystems. In warmer seas there is a risk that similar “biological traffic jams” will appear more oftenforcing expensive stops and additional security.
EDF did not provide immediate commentary, and the production in Gravelines will remain suspended until the animals from the shots are removed and the patency of cooling systems. For the French network, it is an incident that is possible to absorb, but for engineers – another signal that the adaptation of infrastructure to the realities of the warming sea becomes an urgent need.
