France Cuts Nuclear Output by Record 6.3 Gigawatts as River Temperatures Hit Limits

France cut nuclear output across eight reactors by 6.3 gigawatts on July 13—its largest single-day reduction this summer. River temperatures neared regulatory discharge caps, which limit how much heat plants can return to waterways. This is the third major curtailment since June, driven by record Atlantic sea surface temperatures sustaining drought. For a nation generating two-thirds of its electricity from nuclear, summer thermal constraints are becoming structural risk.