nuclear-news

Jellyfish close down France’s largest nuclear reactor

August 28 2026 , https://www.canberratimes.com.au/story/9339000/jellyfish-close-down-frances-largest-nuclear-reactor/

Reactor units at France’s largest nuclear power station in Gravelines have once again been shut down due to an influx of jellyfish.

A spokeswoman for the French operator EDF said on Thursday more than 200 metric tonnes of jellyfish had appeared since last night.

Two of the six reactor units have been completely shut down as a precautionary measure to “ensure that this situation has no impact whatsoever on the safety of (EDF’s) facilities.”

EDF said the jellyfish are appearing in the area of the filter systems at the seawater pumping station.

Consequently, no reactor units are currently in full operation, as two other units are being run at reduced power, and the remaining two have also been shut down, partly due to a maintenance inspection.

The jellyfish disrupted operations in the middle of the month and in August last year.

The Gravelines nuclear power station has set up monitoring systems to detect and manage large-scale jellyfish gatherings at an early stage, EDF added.

The EDF spokeswoman explained that support for this had been provided, among others, by the organisation France Pêche Durable (France Sustainable Fishing).

Seven boats are operating round the clock near the nuclear power station to catch the jellyfish and then release them further out to sea.

The spokeswoman stated that it was not yet possible to comment on the causes of the phenomenon.

She added that the plant was working with various partners to gain a better understanding of it.

The spokeswoman said the incident posed no risk to the electricity grid.

Gravelines is one of just under 20 nuclear power stations in France.

It is situated on the northern French coast, roughly halfway between Calais and Dunkirk.

August 30, 2026 - Posted by Christina Macpherson | environment, France