Romania is unlikely to restart either reactor at the Cernavodă nuclear plant for at least another 10 days, extending the loss of around 1.3-1.4 GW of baseload generation and keeping the country dependent on imports during the evening peak.
Nuclearelectrica technical director Emil Macovei said Danube conditions remained insufficient to support the restart of even one unit.
Unit 1 has been offline since July 28 and Unit 2 since Aug. 13.
Earlier expectations had focused on a reassessment around Sept. 10.
The latest hydrological outlook pushes a meaningful nuclear recovery beyond mid-September.
That matters because Cernavodă normally supplies a large block of Romania’s low-marginal-cost baseload generation.
Its absence has materially changed the country’s power balance.
Romania has relied more heavily on coal, gas, hydro, renewables and cross-border imports since the reactors went offline.
The effect is strongest during evening hours after solar production declines.
Recent day-ahead markets have repeatedly shown prices above €250/MWh during the evening peak across Romania and neighbouring markets.
The prolonged outage increases that exposure.
It also puts more pressure on Hungary and Bulgaria, which are among Romania’s main potential import sources.
This means Cernavodă availability has become a regional rather than purely domestic trading factor.
The extended shutdown comes after low Danube levels affected nuclear generation elsewhere in the region.
Hungary’s Paks plant and Bulgaria’s Kozloduy also faced hydrological restrictions during August.
Kozloduy has since restored part of the lost output, but Romania remains the most severe case.
The situation highlights a growing climate-risk problem for large thermal and nuclear plants that depend on river water for cooling.
Nuclear generation is normally treated as firm supply.
But prolonged drought can reduce that firmness precisely when hydro output may also be weak.
That creates correlated hydrological risk across several technologies.
Romania has already been forced to consider emergency measures, including water-management interventions and temporary support for thermal generation.
The longer the nuclear outage continues, the more important those measures become.
The impact also extends into forward power prices.
Traders will price in uncertainty over restart timing, hydrology and the availability of flexible thermal generation.
Even a partial restart would materially improve Romania’s position.
But until there is enough water to operate safely, the system remains exposed.
The key risk is not only the lost 1.3-1.4 GW of nuclear capacity.
It is the fact that the missing generation is concentrated in the part of the supply stack that normally provides stable, low-cost power around the clock.
That leaves Romania unusually dependent on imports and expensive flexibility during evening scarcity hours.
