Atomic rivers. The (Un)sustainability of nuclear power in an age of climate change

The sustainability of nuclear energy amidst climate change and environmental regulations poses critical challenges, particularly in European contexts where major rivers like the Rhine, the Danube, and the Rhône are experiencing declining water levels and rising temperatures. We scrutinise the operational difficulties nuclear power plants encounter, arising from insufficient cooling water and environmental mandates that prevent the discharge of overly warm cooling water into rivers. These conditions have led to partial or full shutdowns of nuclear facilities across France, Germany, Switzerland, Belgium, Spain, Romania, and other countries, emphasising the tension between nuclear energy as a low-carbon solution and its environmental impacts. We explore the concept of sustainability in the context of riverine nuclear energy from three angles: technical challenges posed by water scarcity, regulatory constraints on cooling water temperatures, and the ecological impacts of thermal discharges on riverine ecosystems. Our analysis reveals an emerging contradiction between ensuring electricity supply and adhering to environmental protection, highlighting the need for a reevaluation of nuclear energy's role in a future sustainable energy landscape. • The sustainability of riverine nuclear power plants is questionable. • Extreme weather, like heatwaves combined with water scarcity, threatens nuclear reliability. • Energy companies seeking exemptions from temperature limits, prioritise energy security over water. • Aquatic life is sensitive to temperature changes, and cooling water adds warming, worsened by climate change.