Jellyfish invasion shuts down reactors at France’s nuclear giant

A massive influx of jellyfish has forced the partial shutdown of France’s Gravelines nuclear power plant in the country’s north, disrupting operations at several of its six reactors, BBC reports.

Two reactor units were shut down on August 26-27 after jellyfish entered the seawater filtration system used to cool the plant, operator Électricité de France (EDF) said.

A third unit has been offline since August 10 because of the same problem, while a fourth is currently shut down for inspection. EDF said units three, four and six are now offline, while units one and two are operating at reduced power as a precaution.

Gravelines, one of France’s largest nuclear power stations, is located between Dunkirk and Calais in the Hauts-de-France region. Its six reactors each have a capacity of 900 megawatts, with the facility relying on a canal connected to the North Sea for cooling.

The incident is not unprecedented. Gravelines was also forced to halt operations last August after jellyfish clogged its filtration systems. Unit three had only returned to the grid on August 18 following an earlier wave of jellyfish this month before being affected again.

Several jellyfish species are native to the area and become particularly active during warmer months. Experts say rising temperatures can increase plankton levels near the surface, attracting larger numbers of jellyfish to coastal waters.

EDF has introduced measures to reduce the risk of jellyfish entering the cooling system. The company is working with local fishermen who capture jellyfish and release them farther offshore.

Similar incidents have occurred at other nuclear facilities. Scotland’s Torness nuclear plant experienced a jellyfish-related disruption in 2011, while Sweden’s Oskarshamn plant faced a comparable problem in 2013.

Such incidents remain relatively rare, but the Gravelines shutdown highlights the vulnerability of coastal nuclear facilities to unusual marine conditions and extreme weather.

By Vafa Guliyeva