Romania has shut down both reactors at its Cernavoda nuclear power plant after the Danube River fell to record-low levels due to severe drought, removing roughly one-fifth of the country’s electricity generation capacity from the grid.
State-owned Nuclearelectrica announced the controlled shutdown of Unit 2 on Wednesday after Unit 1 was taken offline earlier in the week. Both reactors, each rated at 706 megawatts, use Danube water for cooling systems that cannot function at the river’s current historically low flow rate. The dual shutdown marks only the second time in 23 years that Cernavoda has been forced offline entirely because of Danube water levels, according to Dumitru Chisalita, president of the Smart Energy Association.
Unprecedented Water Levels
The Danube’s flow rate at Romania’s border has dropped to around 1,500 cubic metres per second, close to the record low of 1,400 cubic metres per second recorded in 1985. The current flow is roughly one-third of the long-term July average of 4,750 cubic metres per second, according to the National Administration Apele Romane.
Forecasts from the National Institute of Hydrology and Water Management offer little near-term relief. The hydrology institute’s latest projections show the Danube flow rate remaining at current depressed levels through early August, raising the prospect that both reactors could remain offline for one to two weeks if the drought persists. Nuclearelectrica said in a filing to the Bucharest Stock Exchange that “the operation of Units 1 and 2 is carried out based on strict monitoring of operating parameters and safety margins, as well as on procedures specific to drought conditions.”
Interim Prime Minister Ilie Bolojan urged households and large industrial consumers to voluntarily reduce electricity consumption during evening peak hours as authorities prepare to rely more heavily on gas-fired generation and cross-border imports. “At the moment there are no problems with imports, but such problems could arise in the coming period,” Bolojan warned in a televised address. He added that Romania was exploring all available options to maintain grid stability during the crisis.
Regional Crisis Across the Danube Basin
The Cernavoda shutdown is part of a broader regional energy crisis driven by drought conditions gripping the entire Danube basin. Hungary’s Paks nuclear power plant, the country’s only nuclear facility, has also been forced to reduce output and could shut down entirely. Prime Minister Peter Magyar warned that Hungary’s energy supply could become “critical” from early August due to the combination of Paks restrictions and a sustained heatwave bringing temperatures above 37 degrees Celsius for an extended period.
Bulgaria’s Kozloduy nuclear power plant has already cut capacity by 12% due to the same Danube water level crisis, marking the first such reduction in the plant’s 52-year history. Serbia has similarly reduced output at the Djerdap 1 hydropower plant to approximately one-third of its normal capacity, further tightening regional electricity supply.
Unlike nuclear plants in Slovakia and the Czech Republic, which rely on natural or artificial lakes for cooling water, the facilities at Cernavoda, Kozloduy and Paks depend directly on river water from the Danube. This structural vulnerability leaves them uniquely exposed to drought-related restrictions that lake-cooled plants do not face.
Supply Concerns and Industrial Impact
The simultaneous offline status of multiple nuclear and hydroelectric facilities across southeastern Europe has tightened electricity supply across the region and pushed wholesale power prices higher. Romanian authorities are monitoring the situation closely, with the government preparing contingency measures should the drought extend beyond current forecasts.
Romanian car factories had to temporarily halt production during the previous shutdown episode in late July, highlighting the industrial economic cost of nuclear curtailments. The automotive sector, one of Romania’s largest employers, is particularly sensitive to electricity price spikes and supply interruptions. Industry groups have called on the government to prioritise industrial supply during the crisis.
Nuclearelectrica said it will reconnect the reactors as soon as operating conditions allow, but acknowledged that the timeline depends entirely on hydrological developments beyond its control. The company said it continues to monitor water levels and weather forecasts on a daily basis.
The drought’s impact extends well beyond energy generation. The Danube, one of Europe’s busiest commercial waterways carrying goods between Central Europe and the Black Sea, has seen significant disruptions to cargo shipping and river cruise operations as low water levels make navigation difficult or impossible in several stretches. Transport authorities in multiple countries have imposed draft restrictions on vessels, slowing deliveries and increasing costs for exporters.
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