Romania’s Cernavoda nuclear power plant will keep Unit 2 connected to the grid after a technical assessment concluded the reactor could continue operating safely despite exceptionally low Danube levels. The decision follows conditions affecting river levels used for cooling and related operations.
Nuclearelectrica had previously indicated that Unit 2 might be shut down after Unit 1 was disconnected under the same drought conditions. The revised outcome keeps a substantial block of low-carbon generation available as Hungary faces its own nuclear constraints and regional electricity demand remains high.
Enhanced monitoring for drought-related operating conditions
Both Cernavoda units are under enhanced monitoring. Operating parameters, cooling-water conditions and nuclear-safety margins are assessed continuously under procedures designed for severe drought.
Unit 2 will remain online while the relevant criteria are met, but it could be disconnected at short notice if the Danube level falls further.
Implications for Romania’s power balance and supply mix
The decision is intended to reduce immediate pressure on Romania’s power balance. If both reactors were lost, the system would need to rely more heavily on gas-fired plants, renewable output, battery storage and imports.
Interim Prime Minister Ilie Bolojan previously asked households and large industrial consumers to reduce electricity use during the evening peak in preparation for a possible loss of both reactors. The request reflected the difficulty of replacing nuclear output during hours when solar generation declines and regional import availability is limited.
Regional flows involving Hungary and Bulgaria
Romania’s system includes hydro, gas, coal, wind and rapidly expanding solar capacity. Combined availability remains weather-dependent, while imported electricity may become more expensive if Hungary is simultaneously seeking additional volumes.
Keeping Unit 2 online supports not only Romania but also the broader SEE market. Romanian exports toward Hungary have increased sharply as reduced generation at Paks expands the Hungarian deficit, while Romania has been importing larger volumes from Bulgaria, creating a northbound regional supply chain.
Conditional nature of the operational decision
The operational decision remains conditional rather than permanent. Cernavoda’s safety procedures take precedence over market requirements.
A further deterioration in Danube conditions would trigger a controlled shutdown regardless of price effects. The situation also highlights hydrological risk for nuclear generation across central and south-eastern Europe, where low river levels can constrain key baseload assets beyond hydroelectricity.
