Danube drought forces nuclear plant shutdowns in Hungary and Romania

Hungary's Paks plant nears complete shutdown

The Paks nuclear power plant, about 100 kilometres south of Budapest on the Danube, has been driven toward its first full shutdown in its 44 years of service as river levels fell to record lows. Unit 3 was taken offline on 29 July and Unit 1 on 1 August, reducing the four-reactor plant to roughly a quarter of its 2,000 MW capacity. On 2 August at 01:30, the turbine generator of Unit 4 was disconnected, leaving only Unit 2 running at about 50 percent, or roughly 240 megawatts. As of 6 August, the plant was operating at around 12 percent of capacity. A complete shutdown would be the first in the plant's history.

The Danube gauge at Paks told the story: the previous record of minus 98 centimetres was set in 2018, but the level had already fallen to minus 124 centimetres earlier in the week, 26 centimetres below that minimum. By 16:00 on 1 August it measured about minus 131 centimetres, and about minus 133 centimetres on 2 August. The last operating unit must be stopped at minus 134 centimetres, and forecasts put the level below minus 144 centimetres.

Romania races to keep Cernavoda running

Romania's Cernavoda nuclear plant, which accounts for about 20 percent of national electricity generation, shut down one reactor last week. The second reactor remained in operation, but plant director Romeo Urjan said on Thursday that without intervention it would likely need to be shut down in five to six days. Romania's military blasted rock from the riverbed near the Bala Canal and loaded four barges with the material; once submerged, the barges will form an underwater barrier redirecting water down the main channel toward Cernavoda, about 60 kilometres downstream. Urjan said the impact of the submerged barges could take about a day to reach the plant.

If the installed barges bring surplus water... instead of five to six days, we will talk about nine to 10 days of operation from today onward.

The Danube's flow in Romania fell to 1,400 cubic metres per second, less than a third of the typical August level. Acting Prime Minister Ilie Bolojan announced a nationwide state of alert in the energy sector on 31 July and appealed to citizens to voluntarily limit electricity use during peak evening hours.

Energy conservation and regional impact

Hungary switched off decorative lighting on Budapest's parliament, Buda Castle and Chain Bridge. Prime Minister Peter Magyar announced extraordinary measures and the government brought in a new decree reordering electricity restrictions, allowing grid operator MAVIR to order mandatory reductions from large consumers after prior warning, with households last in the chain. Audi Győr, oil company MOL and other firms scaled back production. Bucharest dimmed street lighting by a third and switched off landmark buildings at night.

In Serbia, cooling water for the Kostolac coal-fired plants became harder to draw, forcing some units to run at reduced power. Davor Maljokovic, director of electricity production at the Djerdap hydro plant, said production continued without interruption at reduced capacity. Mining and energy minister Dubravka Djedovic Handanovic described the situation at Kostolac as stable.

Drought grips the Danube basin

Successive heatwaves since May pushed the Danube to its lowest level in 30 years in Romania and Slovakia, and the lowest ever recorded in Hungary. Temperatures reached 43 degrees Celsius in Budapest on 5 August and exceeded 40 degrees across the region on 6 August. Ships could not navigate with full cargo, ferry services between Bulgaria and Romania were suspended in two areas, and a cruise ship with nearly 200 passengers was evacuated in Bulgaria after running aground. A report by World Weather Attribution found that the severe drought had become more extreme due to human-caused climate change.