Cernavodă Unit 2 could go offline Thursday as the falling Danube disrupts electricity supplies Romania’s only operating nuclear reactor may be shut down on…
Cernavodă Unit 2 could go offline Thursday as the falling Danube disrupts electricity supplies
Romania’s only operating nuclear reactor may be shut down on Thursday morning as severe hydrological drought pushes the Danube below the level needed to maintain reliable cooling-water supplies. The warning places new pressure on Romania’s electricity system after the plant’s other reactor was taken offline in July.
State-owned operator Nuclearelectrica said a controlled shutdown of Cernavodă Unit 2 was possible on 13 August, depending on river forecasts, operating parameters and the continued decline in the Danube’s water level.
The company’s latest notice, dated 11 August, did not say that the closure had begun. Nuclearelectrica said it would issue another statement if a shutdown became imminent.
Safety decision, supply consequences
The possible closure is a precaution intended to keep the reactor within its nuclear-safety margins. There is no indication of a radiological incident or malfunction at the facility.
Yet its effect on electricity supplies could be substantial. Cernavodă’s two reactors normally provide about one-fifth of Romania’s electricity generation. Unit 1 has been in a controlled shutdown since 28 July because of the exceptionally low river level, leaving Unit 2 as the plant’s sole source of power.
Nuclearelectrica has also obtained force-majeure certificates covering electricity supply contracts. The company said the drought had prevented it from fully meeting contractual obligations from its own production since 27 July. The certificates do not remove electricity from the grid by themselves, but they formally recognise that the hydrological emergency has disrupted the producer’s ability to deliver contracted volumes.
Romania declared an energy-sector state of alert on 31 July. Authorities have asked residents and public institutions to reduce consumption voluntarily during evening peaks, when solar generation falls and demand can remain high.
Emergency works bought limited time
Romanian authorities have dredged sections of the river and submerged four rock-filled barges near the Bala Canal to redirect more water towards Cernavodă. The intervention helped raise the local level temporarily, allowing Unit 2 to continue operating.
However, the benefit was never expected to be permanent. Earlier this month, the Danube’s flow into Romania fell to about 1,400 cubic metres per second, less than one-third of the seasonal norm, according to reporting on the emergency works.
The renewed shutdown warning indicates that those measures may have delayed rather than removed the risk. Restarting either reactor will depend on water conditions and confirmation that operating requirements can be met safely.
A regional grid problem
Romania can compensate through gas-fired generation, renewable energy, storage and imports. But neighbouring electricity systems are also confronting drought, heat and reduced hydroelectric or nuclear output. That makes cross-border capacity especially important during evening demand peaks.
The situation reinforces the case behind the EU’s proposed overhaul of European power networks. Stronger interconnections and faster access to flexible generation can prevent a national production loss from becoming a wider supply emergency.
Authorities must also distribute the burden of conservation fairly. Hospitals, care facilities and people who rely on electrically powered medical equipment cannot reduce demand as easily as other consumers. Clear public information, targeted assistance and protection against sudden price increases will therefore matter alongside technical grid management.
What to know about the Cernavodă shutdown warning
Romania’s state-owned nuclear operator, Nuclearelectrica, warned on 11 August 2026 that Cernavodă Unit 2 could be shut down on the morning of 13 August. Falling Danube water levels are threatening the cooling-water supply required for safe operation. Unit 1 has already been offline since 28 July, although authorities have reported no nuclear accident or radiological danger.
Key facts
- Plant: Cernavodă Nuclear Power Plant, Romania
- Operator: SN Nuclearelectrica SA
- Reactor affected: Cernavodă Unit 2
- Possible shutdown: Morning of 13 August 2026
- Immediate cause: Exceptionally low Danube water levels during severe hydrological drought
- Current status: A shutdown remains possible but had not been confirmed when the warning was issued
- Safety status: No radiological incident or reactor malfunction has been reported
- National importance: Cernavodă’s two reactors normally provide about 20% of Romania’s electricity generation
Has Cernavodă Unit 2 already been shut down?
No. Nuclearelectrica warned that a controlled shutdown could occur on 13 August 2026, but said a further announcement would be issued if the closure became imminent.
Why could the reactor be taken offline?
The Danube has fallen to an exceptionally low level. Cernavodă relies on river water for essential cooling processes, and the reactor must be stopped if safe operating requirements cannot be maintained.
Does the warning indicate a nuclear accident?
No. The proposed shutdown is a preventive safety measure. Authorities and the operator have reported no radiological release or nuclear emergency.
Could the shutdown affect other European countries?
The immediate impact would fall on Romania, but reduced production could increase its need for electricity imports. This matters regionally because drought and heat are also constraining power generation elsewhere in Central and Eastern Europe.
For now, Unit 2 remains under close monitoring. The next decision will turn on updated Danube forecasts and overnight operating data, leaving Romania facing a narrow margin between continued generation and the first complete drought-related shutdown of its nuclear plant.
