Cernavoda Unit 1 restart after scheduled outage
Romania has restored 700 MW of nuclear generation capacity following the return of Cernavoda Unit 1 to commercial operation after a scheduled maintenance outage. The restart follows a period when the unit was taken offline to complete work required under the maintenance programme. Nuclearelectrica said the reconnection strengthens Romania’s electricity supply position and improves system flexibility, particularly when renewable output declines.
The reactor, operated by Nuclearelectrica, was disconnected from the grid on 10 May. The planned maintenance programme lasted approximately two months. Nuclearelectrica reported that the scope covered preventive and corrective maintenance, mandatory safety inspections, equipment testing, and modernization activities on selected plant systems.
Maintenance scope and compliance with safety requirements
According to Nuclearelectrica, all maintenance activities were completed using approved technical procedures. The company said the works complied with nuclear safety standards and environmental protection requirements. Nuclearelectrica added that the successful return of the unit demonstrates the role of nuclear generation as a stable source of low-carbon electricity in Romania’s energy mix.
Nuclearelectrica also stated that bringing Unit 1 back is expected to improve the balance of Romania’s electricity system. The impact is particularly relevant during evening peak hours when solar generation decreases while electricity demand remains elevated. The additional 700 MW of available capacity is expected to reduce reliance on imports and support stability during tighter market conditions.
Operational performance and role in Romania’s nuclear fleet
Cernavoda Unit 1 was commissioned in 1996. Nuclearelectrica said the unit has produced more than 149 million MWh of electricity over its operational lifetime. The company estimates that generation from the reactor has avoided approximately 145 million tonnes of CO₂.
Nuclearelectrica reported that Unit 1 has maintained a capacity factor above 90%. The company operates two 700 MW CANDU reactors at Cernavoda Nuclear Power Plant. It also owns the Nuclear Fuel Factory in Pitesti, which manufactures fuel bundles for CANDU 6 reactors.
Nuclearelectrica said its nuclear assets support security of supply, decarbonisation targets, and electricity-market stability across Southeast Europe.
