Europe's Nuclear Reactors Stumble as Heatwaves Drain Vital Waterways

Nuclear facilities convert roughly one-third of reactor heat into electricity, relying on large volumes of river or sea water to dissipate the remainder. When drought conditions shrink these water bodies, waste heat causes temperatures to climb rapidly, hitting legal limits designed to protect aquatic life. In Romania, the state-owned Nuclearelectrica disconnected its only operating reactor at Cernavoda after dredging and underwater explosions failed to secure sufficient flow from the Danube. Similarly, Hungary’s Paks plant—which typically covers 40 percent of national demand—was forced to run only one of its four turbine units during the peak of the water crisis.

France, which generates over two-thirds of its electricity via nuclear energy, faced even broader disruptions. Beyond the heat-induced shutdowns, the Gravelines plant was forced to halt three reactors after a massive influx of jellyfish triggered automatic safety protocols. A report from Triodos bank estimates these compounding climate impacts could shave 1 percent off the European Union’s GDP, with France potentially seeing a 1.4 percentage-point reduction. As governments weigh long-term fixes—including coastal site relocation and cooling system upgrades—the region remains squeezed by the dual pressure of climate-driven infrastructure vulnerabilities and broader energy shortages stemming from Middle Eastern geopolitical instability.