EDF Shuts Three Reactors and Downgrades Eight as France Faces Intense Heatwave

Overview

• EDF told AFP on Sunday that three reactors are fully stopped — Golfech n°2 on the Garonne, Bugey n°3 on the Rhône, and Chooz n°2 on the Meuse — because river water used for cooling is nearing regulatory limits.
• The operator also said eight reactors have been throttled at reduced power, including units at Saint-Alban, Blayais, Bugey, Chooz and Tricastin to keep thermal discharges within site-specific limits set to protect aquatic life.
• A 2006 regulation caps permissible river temperature after plant discharges and the nuclear safety authority sets site limits that can force power cuts; those rules are the immediate cause of the stoppages and reductions.
• The government published a temporary derogation allowing Bugey reactors n°4 and n°5 to maintain minimum output through July 20 to help grid stability, subject to EDF’s proposed 1°C Rhône warming limit and extra environmental monitoring.
• France’s 57 reactors produce about 70% of the country’s electricity and sit on rivers or the sea for cooling, a concentration that makes the fleet repeatedly vulnerable to heatwaves and could press grid operators to seek more temporary exceptions in coming heat events.