Romania’s Cernavodă nuclear power station has remained fully unavailable after exceptionally low Danube flows disrupted the plant’s access to cooling water, removing approximately 1,400 MW of baseload capacity from the national electricity system.
Unit 1 entered a controlled shutdown in July, while Unit 2 was subsequently disconnected as severe drought pushed river flows to critically low levels. Together, the two CANDU reactors normally account for around 20% of Romanian electricity production.
The simultaneous loss of both units has forced Romania to cover part of the deficit through electricity imports and increased production from gas- and coal-fired plants. This has raised exposure to regional spot prices at a time when European natural gas is also expensive.
Nuclearelectrica has invoked force majeure under its electricity supply contracts. The measure protects the company from penalties for volumes it cannot physically deliver and avoids an obligation to purchase replacement power on the day-ahead market at exceptionally high prices.
The commercial exposure has instead shifted towards suppliers that contracted nuclear electricity, including Electrica Furnizare, PPC Energie and Engie. These companies must source replacement volumes from the wholesale market to meet customer obligations, increasing procurement costs and potentially affecting future retail pricing.
Government estimates indicate that Cernavodă could remain unavailable until at least the end of September. Restarting operations depends on a sustained hydrological improvement capable of restoring the technical safety margin required by the cooling system. Local assessments indicate that a Danube flow of approximately 1,700–1,800 cubic metres per second could permit at least one reactor to return.
The disruption has wider regional consequences because Romania is normally an important producer and occasional exporter. Its increased import demand can tighten balances in Bulgaria, Hungary and Serbia, particularly during evening peaks.
The shutdown also exposes the operational relationship between nuclear generation and climate-related water constraints. Nuclear power provides stable, low-carbon output, but large thermal plants remain dependent on reliable cooling-water availability. Investment in cooling infrastructure, water-management systems and alternative sources of flexibility is therefore becoming part of Romania’s energy-security calculation rather than a secondary environmental issue.
