Jellyfish invasion forces French nuclear plant shutdown

Jellyfish Invasion Forces Shutdown at France’s Biggest Nuclear Plant

The nuclear powerhouse in Gravelines, northern France – the continent’s largest – temporarily halted operations after a massive jellyfish swarm clogged cooling pumps.

Impact and Safety

• Four reactor units automatically shut down.
• The incident did not jeopardize safety. EDF confirmed no risk to personnel or the environment.
• Authorities performed thorough inspections to assure a restart in complete safety.

Operational Status

• Gravelines’ remaining two units were already offline for maintenance.
• EDF expects the completed re‑startup by Thursday.
• Other energy stores – including solar power, remain functional.

Plant Capacity and Future Growth

Gravelines hosts six reactors, each capable of 900 MW. The site plans to add two next‑generation units, each 1,600 MW, by 2040.

Historical Jellyfish Incidents

• EDF reports such cases are quite rare. The previous notable effect in the 1990s.
• Sweden experienced a three‑day closure in 2013.
• Japan’s 1999 event caused significant output reduction.

Causes of Jellyfish Proliferation

Overfishing, plastic pollution, and climate change create conditions that support jellyfish thriving and reproducing.