Danube at record low forces first-ever shutdown of Hungary's Paks nuclear plant, Romania and France also curb output

Nuclear shutdowns along the Danube

Hungary's Paks nuclear plant, which normally supplies about half of the country's electricity, will cease all generation by Monday at the latest. Prime Minister Péter Magyar said the four Soviet-era reactors, with a combined capacity of roughly 2,000 MW, can no longer draw cooling water from the Danube because the river has fallen 121 cm below its previous record low at that location. The plant has been reducing output stepwise: block 1 was cut by 254 MW on Monday evening, block 3 by 237 MW on Tuesday and then temporarily shut down on Wednesday, and block 2 was reduced to 50% on Thursday. It is the first full stoppage in the plant's 42-year history.

The energy supply could become critical from Monday.

In Romania, the Cernavoda plant on the Danube shut down one of its two 706 MW reactors earlier this week to prevent damage to the cooling system. The second reactor was still operating as of Thursday, with state-owned operator Nuclearelectrica reporting stable parameters overnight. Together the two units normally produce about 20% of Romania's power. The average July flow where the Danube enters Romania is 4,700 cubic metres per second; on Wednesday it was down to 1,600, and the national hydrology institute forecasts a further drop to 1,500 by Tuesday.

France and Austria also curb generation

France's Golfech nuclear plant, on the Garonne river about 100 km north of Toulouse, took one of its two reactors offline on Wednesday evening. Operator EDF had already shut the unit twice this summer, from 23 June to 3 July and again from 9 to 27 July, to avoid raising the river water temperature further. In Austria, many of the more than 4,000 small hydropower plants on Danube tributaries in Upper Austria have cut output by up to 50% or stopped entirely. Florian Seidl, spokesman for Verbund, Austria's largest hydropower operator, linked the low water to declining snowmelt.

We should actually be working off the water from the snowmelt now, but because of global warming less and less snow falls.

Hungary prepares for supply strain

Magyar asked households and businesses to curb electricity use during the peak hours of 17:00 to 22:00, including charging electric vehicles and running air conditioning. He said a rotational shutdown regime for large industrial consumers was possible if voluntary savings and imports proved insufficient. Environment Minister Laszlo Gajdos said water management services had been placed on alert and that four pontoons with pumps and two floating cranes had been deployed near Paks in case water levels drop further. Hungary has cross-border import capacity of 3,600–3,800 MW, which Magyar said should prevent a supply collapse even with Paks offline.

Heat and fire across the continent

The heatwave pushing temperatures to around 37°C for a week in Hungary is part of a broader pattern. Europe is warming twice as fast as the global average, according to the Copernicus climate service, intensifying summer heatwaves and pressure on water resources. The Danube, which runs 2,857 km through 19 countries, has seen record low levels in several nations including Serbia and Romania, disrupting shipping and tourist cruises. In southern England, a wildfire near a nuclear plant burned about 100 hectares, forcing evacuations of residents and a holiday park and causing local power outages.