Romania Shuts Down Last Cernavoda Reactor as Danube Drought Cripples Nuclear Cooling

Romania's operator Nuclearelectrica began shutting down the sole remaining working reactor at its Cernavoda nuclear power plant on 13 August 2026, after drought drove Danube river water levels to record lows and eliminated the cooling supply the reactor depends on. The shutdown removes the last unit at Romania's only nuclear station, following the closure of the plant's first reactor in late July for the same reason. Nuclearelectrica said it did not foresee a restart within the next ten days The Guardian.

The two 706-megawatt CANDU pressurized heavy water reactors at Cernavoda together account for roughly 20% of Romania's electricity output. With both now offline, Romania has activated a 330-megawatt lignite-fired plant and is leaning on increased wind and hydro generation to cover the deficit. The government declared a state of energy emergency for the duration of August and has asked companies and households to cut consumption during peak hours. As a last resort, large industrial users will face restrictions in the evening. In early August, the government ordered carmakers Dacia and Ford to pause production in the country until 19 August to help manage the shortfall.

Romania had exhausted interim measures before resorting to the full shutdown. In early August, authorities blew up a rock outcrop to redirect Danube water toward the plant's cooling intake, a step that Nuclearelectrica said could sustain the remaining reactor for nine days Reuters. That window has now closed.

The effects extend beyond Romania's borders. Moldova relies on Romanian power imports to cover up to 60% of its electricity shortages. With those imports unavailable, Moldova faces a choice between purchasing more expensive power from Ukraine or western European suppliers, or imposing rolling blackouts. Moldovan energy expert Sergiu Tofilat told Radio Chisinau that the country should prepare for a worsening situation, including power outages.

The crisis is not confined to Romania. Nearly two-thirds of the Danube has seen flow rates drop to the lowest on record for a July in 34 years, according to analysis by the Copernicus European climate change observatory. The Danube, Europe's second-longest river at approximately 2,850 kilometres from western Germany to the Black Sea, serves as a critical cooling source for multiple nuclear facilities along its course.

Hungary narrowly avoided a complete shutdown of its only nuclear plant at Paks, whose four reactors are also cooled by the Danube. Paks, which typically supplies about a third of Hungary's electricity, has been partially shut down since late July. On 12 August, Prime Minister Péter Magyar ordered the construction of a submerged weir to control flows near the plant. Two 80-metre barges are being stationed at Paks that could be sunk to raise the water level if conditions deteriorate further.

France is experiencing a parallel crisis. More than 20% of EDF's atomic production capacity was offline in the week of 14 August, a deficit AFP calculated from EDF data and attributed to outages linked to drought, extreme heat, and a jellyfish invasion at cooling-water intakes. Thirteen of the 57 reactors in France's nuclear fleet were affected.

The World Weather Attribution group of scientists has linked the European drought to human-induced climate change. The simultaneous loss of nuclear capacity across multiple Danube-dependent and heat-affected facilities reveals a structural vulnerability in the continent's baseload power architecture: river-cooled reactors that were designed and sited under historical flow assumptions that no longer hold.

For Moldova, the immediate stakes are sharpened by the country's heavy import dependency on a single supplier now unable to export. For Romania, the industrial production pauses at Dacia and Ford, both major employers, carry economic costs that will mount the longer both reactors remain offline. And for European energy planners, the convergence of low river flows, extreme heat, and even biological interference at cooling intakes across France and the Danube basin raises hard questions about the resilience of nuclear generation in a warming climate.