Overview

• Reactor 6 resumed operations Wednesday at 07:30 following its automatic shutdown on Monday due to jellyfish clogging fine drum filters in seawater pumps.
• Units 2, 3 and 4 remain offline as crews continue filter cleaning and diagnostics, with sequential restarts slated to begin Thursday.
• Units 1 and 5 were already offline for maintenance when the jellyfish incursion halted the remaining reactors, leaving the site fully nonoperational until this week.
• EDF and grid operator RTE confirm there are no safety, personnel or environmental issues and that national electricity supply is secure thanks to alternative capacity.
• Experts attribute the jellyfish bloom to warmer coastal waters and reduced predators, highlighting the vulnerability of open-circuit cooling designs at coastal nuclear sites and prompting discussions on future resilience measures.