Flamanville EPR Reaches Full Nuclear Thermal Power

On December 14, 2025, the Flamanville 3 reactor achieved a significant milestone by reaching 100% nuclear thermal power at 11:37 AM. This enabled the generation of 1,669 MW of gross electrical power. The French nuclear safety authority approved the progression beyond the 80% threshold, allowing this ramp-up.

This development allows for full-power testing of the equipment, measurement collection, and system verification. In the upcoming weeks, power levels will fluctuate for continued testing and operations on an internal electrical substation.

EDF and its industrial partners' commitment and expertise have been pivotal in achieving this safe start-up milestone for the reactor.