Nuclearelectrica marks major Cernavodă Unit 1 refurbishment milestone with first continuous concrete pour

Romania’s nuclear modernization push at Cernavodă moved into a more advanced construction phase after Nuclearelectrica completed a major milestone for Unit 1 refurbishment. For investors and power-market watchers, the significance lies in what the company is effectively de-risking: the civil works required to extend the operating life of a reactor that has been central to Romania’s electricity supply for decades.

First continuous concrete pour completed for Unit 1 permanent structures

The operator announced the successful completion of the first continuous concrete pour for permanent structures associated with the Unit 1 refurbishment project. Nuclearelectrica said the operation—described as the largest of its kind at the site since construction of Unit 2—used approximately 3,470 cubic meters of concrete, equivalent to around 380 truck deliveries.

Construction carried out at DIDR-U5 radioactive waste storage facility

The work was performed at the Intermediate Radioactive Waste Storage Facility (DIDR-U5). The company said DIDR-U5 will be important for managing, treating, and temporarily storing radioactive waste generated during refurbishment, and also for future long-term operation of both Unit 1 and Unit 2.

Planned life extension depends on staged refurbishment schedule

Nuclearelectrica CEO Cosmin Ghiță characterized the milestone as a symbolic start to large-scale modernization for the reactor. He said the project is expected to extend Unit 1’s operational life by an additional 30 years after its planned return to service in 2030.

The company also noted that it received construction authorization from Romania’s nuclear regulator for the storage facility in September 2025, allowing civil engineering works connected to the refurbishment program to proceed on schedule.

According to Nuclearelectrica, modernization is being delivered in three main phases. The current stage covers preparation and infrastructure works and is expected to run until the end of 2027. The final phase will include shutting down Unit 1 and carrying out the full refurbishment process.

Return to grid in 2030; reactor performance highlighted

After completion, Nuclearelectrica expects Unit 1 to be reconnected to Romania’s national electricity system in 2030. From there, it said the unit would continue operating for another three decades.

Commissioned in 1996, Unit 1 has supported Romania’s electricity system for nearly 30 years. Nuclearelectrica reported that over its lifetime it has generated more than 149 million MWh while avoiding about 145 million tons of CO₂ emissions. The company also pointed to what it described as strong operational performance, saying Unit 1 has maintained a capacity factor above 90%, placing it among the most efficient nuclear units globally.