Jellyfish Intrude on French Nuclear Power Operations Again

Sat Sep 13 2025 10:46:59 GMT+0300 (Eastern European Summer Time)

For the second time in a month, jellyfish have caused significant operational disruptions at France's Paluel nuclear power plant, affecting energy production.

A swarm of jellyfish has once again disrupted operations at the Paluel nuclear power plant in Normandy, leading to a significant reduction in energy output. This incident marks the second occurrence within a month, as jellyfish have challenged nuclear facilities across France. Efforts are underway to restore full operation at Paluel amidst these aquatic intrusions.

A swarm of jellyfish has caused major disruption at one of France's largest nuclear power plants, for the second time in a month.

The jellyfish entered the filters of the pumping station at the Paluel nuclear plant, affecting energy outputs severely.

According to France's national energy firm EDF, the incident resulted in a 2.4 gigawatt reduction in plant output, with crews actively working to restore it to full operation.

In August, another significant disruption occurred at the Gravelines plant when a 'massive and unpredictable' swarm of jellyfish forced a temporary halt in operations.

The latest event has almost halved Paluel's normal output of 5.2 gigawatts, as one reactor was shut down, and another was reduced as a protective measure.

Since nuclear energy accounts for about 70% of France's energy consumption, these disruptions raise concerns about the reliability and resilience of energy supply.

Paluel is one of the largest nuclear power plants in the country, with each of its four reactors producing over 1,300 megawatts of power. EDF reported taking precautionary measures promptly after the jellyfish were detected in the filters at around 21:00 local time.

The company emphasized that their teams are undertaking necessary diagnostic checks and interventions to restore full functionality to the affected reactors.