Romania’s Cernavodă nuclear power station has remained fully unavailable after exceptionally low Danube flows disrupted access to cooling water. The outage has removed approximately 1,400 MW of baseload capacity from the national electricity system. Unit 1 entered a controlled shutdown in July, and Unit 2 was later disconnected as severe drought drove river flows to critically low levels. Together, the two CANDU reactors normally account for around 20% of Romanian electricity production.
Cooling-water disruption and reactor status
The loss of both units has reduced available generation and left Romania covering part of the resulting deficit through electricity imports. Additional supply has also come from increased output at gas- and coal-fired plants. The change in sourcing has increased exposure to regional spot prices while European natural gas remains expensive.
Nuclearelectrica has invoked force majeure under its electricity supply contracts. The measure is intended to protect the company from penalties for volumes it cannot physically deliver. It also avoids an obligation to buy replacement power on the day-ahead market at exceptionally high prices.
Contracted nuclear suppliers face replacement-market costs
The commercial impact has shifted to 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. Procurement costs are therefore higher, with potential knock-on effects for future retail pricing.
Government estimates indicate that Cernavodă could remain unavailable until at least the end of September. Restarting operations depends on sustained hydrological improvement sufficient to restore the technical safety margin required by the cooling system. Local assessments suggest a Danube flow of approximately 1,700–1,800 cubic metres per second could allow at least one reactor to return.
Regional balancing impacts across Southeast Europe
Romania is normally an important producer and occasional exporter, so higher import needs can tighten regional power balances. That effect can extend to Bulgaria, Hungary and Serbia, particularly during evening peaks when demand rises. The shutdown therefore alters cross-border supply-demand conditions beyond Romania’s borders.
The incident also highlights how nuclear generation operations intersect with climate-related water constraints. While nuclear output is described as stable and low-carbon, large thermal plants remain dependent on reliable cooling-water availability. Investment in cooling infrastructure, water-management systems and alternative sources of flexibility is therefore part of Romania’s energy-security planning rather than treated as a secondary issue.
