“Heat- and drought-driven limits on once-through cooling are cited as evidence that riverine nuclear power is incompatible with a warming, water-constrained world. We compile the first global event inventory of weather-linked nuclear curtailments (2003–2022) and a cross-jurisdiction chronology of regulatory-flexibility episodes that relaxed thermal-discharge limits during heatwaves (2003–2024). These records are merged with monthly generation data for six European fleets, and degradation is modeled under elevated intake-water temperatures. Across more than 500 reactor-years, curtailments totaled just 0.6% of affected reactors’ generation, never exceeding 1.3% in any national fleet. In the same fleets, median 2022 capacity factors (90.9%) were an order of magnitude less variable than co-located wind or solar resources. Thermal-hydraulic analysis shows that a 15 °C rise in cooling-water temperature reduces a 1.45 GW PWR’s output by ∼6%, a penalty offset by cooling-water flow or hybrid wet–dry systems. Case studies of tower retrofits, dry-cooling and proactive outage scheduling have already cut French river-fleet curtailment losses from 5.5 TWh in 2003 to 0.5 TWh in 2022 (−91%). Nuclear power’s water challenge is therefore technical and manageable.”

From ScienceDirect.