Danube drought keeps Romania’s Cernavodă nuclear plant offline as cooling water runs short

CERNAVODĂ — Romania’s only nuclear power station has been forced offline by a record Danube drought, removing roughly one-fifth of the country’s electricity supply during a summer of extreme heat. State operator Nuclearelectrica shut down Unit 1 in late July and carried out a controlled shutdown of Unit 2 in mid-August, after Danube flows fell to around a third of the typical July average.

Romania’s Energy Ministry said Danube flow had fallen to 1,630 cubic metres per second — about a third of a typical July average, according to the National Institute of Hydrology and Water Management. Plant director Romeo Urjan told AFP he did not foresee a restart within the next ten days. It is the first complete shutdown of the Cernavodă plant due to drought since 2003.

FAKTA

• Nuclearelectrica shut Unit 1 at Cernavodă in late July 2026 due to severe drought; a controlled shutdown of Unit 2 began on 13 August 2026 (sources: AP/SRN News).
• Danube flow fell to 1,630 cubic metres per second — about a third of the typical July average — cutting off reliable cooling water for the plant’s two 700 MW reactors.
• The Cernavodă plant normally provides roughly 20% of Romania’s electricity; it is the country’s only nuclear facility.
• The last time both units shut down together for drought was in 2003, ending 23 years of continuous full-capacity operation.
• Romania budgeted more than €2 million for emergency works: underwater demolition of a rock formation and sinking four rock-filled barges to redirect the Danube’s flow toward the plant.
• The energy ministry declared a state of alert; carmakers Dacia and Ford paused production to help with the power deficit, and large industrial users faced possible evening consumption limits.
• Record-low levels also forced Hungary to cut generation at its 2 GW Paks nuclear plant by nearly 90%; roughly half of southeastern Europe’s nuclear capacity was offline at the peak, according to regional reporting (source: Ports Europe).

Why the Danube drought stopped the reactors

Nuclear reactors need large volumes of river water to cool their systems. When river levels drop too low, plants cannot draw enough water safely and must power down. “The decision to carry out a controlled shutdown of Unit 2 was determined by the continued significant decrease in the level of the Danube River,” Nuclearelectrica said in a statement to the Bucharest Stock Exchange. The company added that maintaining both units in a safe shutdown state had no impact on nuclear safety, personnel, the environment or the population.

Emergency works to redirect the river

Romania had tried to avert a full shutdown. It budgeted more than €2 million to divert the Danube’s flow, including underwater explosives detonated by the military to blast a submerged rock formation and four rock-filled barges sunk near the Bala Canal to create an underwater barrier redirecting water toward the plant. But the river kept receding, and levels fell below what the plant needs to operate.

The energy ministry said alternative sources — wind power and imported electricity — should be enough to maintain supply, while repeating its appeal for responsible consumption. As a last resort, large industrial consumers would face evening restrictions. More on the drought’s European impact on the main Watan News site.

A regional energy shock

The shutdown rippled across southeastern Europe. Hungary was forced to cut generation at its 2 GW Paks nuclear plant by nearly 90 percent and requested voluntary industrial demand reductions, while record-low Danube levels disrupted river transport across the corridor, according to regional reporting. The Danube — Europe’s second-longest river at 2,850 kilometres through 10 countries — saw nearly two-thirds of its flow points record their lowest July levels in 34 years, according to EU Copernicus monitoring data.

FAQ

Why does low river water force a nuclear shutdown?

Reactors use large amounts of river water to cool their systems. When water levels fall below the suction intakes of the cooling pumps, the plant cannot draw water safely and must power down to maintain safety margins.

How important is Cernavodă for Romania’s electricity?

The plant normally supplies about 20 percent of Romania’s electricity from its two 700 MW reactors, so its full shutdown removed a major source of low-carbon baseload power during a heatwave-driven demand peak.