(MENAFN) An unusually large swarm of jellyfish has led to the temporary closure of a nuclear power station in northern France, according to the plant’s operator.

The influx of the marine creatures blocked filters in the cooling system at the Gravelines facility, as reported by the energy company managing the site. The “massive and unpredictable presence of jellyfish” caused four of the plant’s power units to automatically shut down. The remaining two units were already offline for maintenance, resulting in a complete halt in operations.

The incident occurred late on Sunday and had “no impact on the safety of the facilities, the safety of personnel, or the environment,” according to the operator, which also confirmed the jellyfish only reached “the non-nuclear part of the facilities.”

“The plant teams are mobilized and are currently carrying out the necessary diagnostics and interventions to be able to restart the production units safely,” the company stated.

The nuclear plant uses cooling water drawn from a channel connected to the North Sea, an area inhabited by various jellyfish species. Officials have not specified which type of jellyfish was responsible for the disruption.

Similar events have been reported globally, where jellyfish have been sucked into cooling systems or blocked intake pipes at both nuclear and conventional power stations. Gravelines is among the largest nuclear complexes in France, a nation that generates about 70% of its electricity from nuclear sources. The facility’s six reactors each have a peak capacity of 900 megawatts, providing enough electricity to supply roughly five million homes.

MENAFN12082025000045017281ID1109915939