The Danube River has fallen to record-low levels, forcing Hungary's only nuclear power plant to slash electricity production and raising the prospect of the country's first complete reactor shutdown caused by drought.

The situation has exposed the growing vulnerability of Europe's energy infrastructure to prolonged heatwaves and shrinking rivers, with experts warning that similar disruptions could become more frequent as climate change intensifies.

At the Paks Nuclear Power Plant, about 100 kilometers south of Budapest, all four reactors have reduced output to less than half of their normal capacity because the Danube no longer provides enough cooling water.

The plant, commissioned in the 1980s, normally generates nearly half of Hungary's electricity, making it the country's single most important source of power.

Hungarian authorities say a complete shutdown may become unavoidable if water levels continue falling.

The Danube gauge at Paks measured minus 123 centimeters on Friday, already well below previous records. Hydrological forecasts indicate the river could fall to between minus 131 and minus 154 centimeters within days, threatening the operation of the cooling water intake system.

Hungarian nuclear regulators stress that the reductions are precautionary measures designed to comply with environmental regulations on cooling-water temperatures rather than nuclear safety concerns.

The consequences extend far beyond electricity generation.

Shipping traffic on parts of the Hungarian Danube has virtually stopped as cargo vessels struggle to navigate increasingly shallow waters.

Several barges have become stranded on exposed sandbanks, disrupting freight transport along one of Europe's busiest inland waterways.

Similar problems are affecting other sections of the Danube and major rivers across the continent.

Prime Minister Péter Magyar has warned that Hungary could face rotating power cuts if the situation deteriorates further. He called on major industrial electricity consumers, including automotive manufacturers, battery producers and other energy-intensive companies, to reduce consumption, particularly during the evening peak between 5pm and 10pm. 

Government institutions are also implementing energy-saving measures while Hungary increases electricity imports to compensate for falling domestic production.

Energy analysts say the simultaneous impact on nuclear generation, river transport and agriculture illustrates how prolonged drought can trigger cascading economic consequences. 

As another week of extreme heat approaches, the Danube has become a visible reminder that Europe's climate challenges are increasingly becoming energy security challenges as well.