Record Danube lows force Hungary's only nuclear plant offline as heatwave peaks

Hungary's Paks nuclear power plant, the country's sole reactor, will shut down entirely for the first time as record-low Danube water levels prevent the facility's cooling system from drawing water. The plant's suction nozzles cannot reach the river at its current depth, according to BBC reporting.

The shutdown arrives as temperatures across the region are forecast to reach 37 degrees Celsius and persist for a week, driving peak electricity demand precisely when supply is collapsing. Prime Minister Péter Magyar warned on Monday that Hungary's energy supply could become critical from that day forward due to the combined effect of the plant closure and the heatwave.

Magyar asked Hungarians to limit activities requiring significant energy consumption between 17:00 and 22:00, including charging electric cars and using air conditioning, according to BBC reporting. If voluntary restraint proves insufficient, Magyar said a rotational shutdown regime was possible, under which the government would compile a list of electricity and water consumers whose consumption could be limited.

The Danube's collapse extends across the continent. Romania's National Institute of Hydrology reported the average Danube flow entering the country in July is 4,700 cubic metres per second. On Wednesday, the actual flow had fallen to 1,600 cubic metres per second, less than a third of the July average, with forecasts showing further decline to 1,500 cubic metres per second by Tuesday. In Romania, one of the two 706-megawatt reactors at Cernavoda power plant has already shut down, with state-owned company Nuclearelectrica trying to avoid closing the second reactor on Thursday. The Cernavoda plant provides about 20 percent of Romania's power, per BBC reporting.

Serbian hydrologist Dejan Vladikovic told Serbian television that the Danube had fallen to levels not seen for 50 to 60 years. Vladikovic attributed the collapse not only to current high temperatures but also to low rainfall during spring. Climatologists do not expect improvement until mid-September, according to Vladikovic.

The immediate human toll is mounting across the region. Border police evacuated 186 river cruise passengers from the Viking Ullur ship when it ran aground near Vidin, on the Bulgaria-Romania border, according to BBC reporting. Passengers had been running low on food and water because the cruise ship was unable to dock, and rescue vessels were unable to get close enough due to shallow depths. Shipping has ground to a halt in Bulgaria. Ivan Zhekov, head of river supervision at Bulgaria's maritime administration, said: "I have never heard of such low levels over the years. There has certainly not been a similar situation since 1990."

Europe is warming twice as fast as the global average, according to the Copernicus climate service, per BBC reporting. The Danube runs 2,857 kilometers through 19 countries.