Excessively Warm Rivers Force France to Halt Three Nuclear Reactors
The heatwave is not only putting hospitals, transport, and tourist areas in France under pressure. High temperatures are also disrupting one of the backbones of the country’s energy system: nuclear power plants.
State-owned electricity company Électricité de France, or EDF, temporarily halted three nuclear reactors on Sunday (12/7/2026). Eight other reactors were operating at reduced power because the temperature of the rivers used in the cooling systems continued to rise.
The three units shut down were reactor number two at Golfech, in the Tarn-et-Garonne department; reactor number three at Bugey, in the Ain department; and reactor number two at Chooz, in the Ardennes department. The three are located on the banks of the Garonne, Rhône, and Meuse rivers respectively.
“Due to weather conditions and to comply with regulations on cooling water discharge, while protecting the environment,” EDF told AFP, as reported by Le Monde on Sunday, 12 July 2026.
The shutdowns were not caused by reactor damage, radioactive leaks, or a nuclear safety emergency. Production was reduced so that water returned to the rivers after being used in the cooling process does not raise water temperatures beyond established environmental limits.
In addition to the three halted reactors, EDF carried out what it calls power adaptations on several other units. Reactors number one and two at Saint-Alban, number one and three at Blayais, number four and five at Bugey, and number one at Chooz continued to operate but at lower production levels. Reactor number three at Tricastin also reduced production on Sunday before returning to normal operation in the afternoon.
Thus, the figure of eight reactors operating with limited power represents the number of units undergoing adjustments at some point during the day. After Tricastin 3 returned to normal operating levels, seven reactors remained under power restrictions.
France operates 57 nuclear reactors. These plants generate around 68 to 70 per cent of the country’s electricity, meaning disruptions to several units at once can affect export capacity and regional electricity prices, even if domestic supply is not immediately threatened.