Nuclear power plants are thermal plants.
Thermal plants need cooling.
"A nuclear plant in northern France was temporarily shut down on Monday after a swarm of jellyfish clogged pumps used to cool the reactors, energy group EDF said.
The beaches around Gravelines, between the major cities of Dunkirk and Calais, have seen an increase in jellyfish in recent years due to warming waters and the introduction of invasive species."