Climate Change Is Rewriting Europe’s Nuclear Cooling AssumptionsRomania used explosives to clear the way for redirecting Danube water toward Cernavodă as heat and drought cut nuclear output when cooling demand peaked. The most severe documented exposure is in Hungary, where the four-reactor Paks plant normally supplies 45.2% of national generation. Romania’s loss of one 650 MW Cernavodă unit represented about 10.3% of normal national generation on the same annual-equivalent basis. The reduction was 14.6% of French nuclear capacity, equivalent to about 10% of normal national generation given France’s 68.1% nuclear share. Each value multiplies the country’s 2025 nuclear generation share by the proportion of nuclear capacity constrained at that snapshot.