Three French nuclear reactors halted by jellyfish

Reuters: Three reactors at the French nuclear power plant Gravelines were shut down due to a jellyfish invasion.

Consensus

Three reactors at the Gravelines nuclear power plant in northern France were stopped due to jellyfish clogging cooling system filters.
The jellyfish entered the cooling systems via seawater drawn from the North Sea.
One reactor was operating at 50% capacity as a precautionary measure.
One reactor was offline for scheduled maintenance.
The sixth reactor remained operational at full capacity.
EDF confirmed the incident did not pose a threat to safety, personnel, or the environment.
The event occurred in August 2026.
This is the second year in a row that jellyfish have caused reactor shutdowns at Gravelines.
EDF has implemented monitoring systems, including cameras in cooling channels, to detect jellyfish early.
EDF has partnered with fishing and maritime rescue organizations to monitor and remove jellyfish before they reach the plant.
Climate change and rising sea temperatures are cited as contributing factors to increased jellyfish populations.
Jellyfish presence is seasonal but increasing in frequency and scale.

EDF has implemented new monitoring and jellyfish removal methods since last year's incident to reduce future impacts. — meduza
Last year, four reactors were automatically shut down at Gravelines, with the last one reconnected only after about 10 days. — fontanka
The incident occurred on August 10, 2026, and was triggered by heat-induced jellyfish proliferation. — vesti
Reactor 2, 3, and 4 were specifically named as the ones shut down. — kommerant
The jellyfish migration has ceased, and reactors are expected to resume operation after equipment cleaning. — interfax