Romania is advancing the refurbishment of Cernavodă Unit 1, one of the country’s key nuclear assets. In July 2026, the European Investment Bank approved an €800 million loan for the project, providing public financing aimed at keeping the reactor in operation for another 30 years.
Unit 1 began commercial operation in 1996 and typically supplies around 10% of Romania’s electricity. Extending its operating life would maintain a source of low-carbon, dispatchable generation as coal capacity is phased out and renewable output becomes more variable. The move is also linked to sustaining technical expertise, workforce and supply chains connected to Romania’s CANDU nuclear fleet.
EIB funding and scope of refurbishment work
The EIB loan is described as a significant part of the overall investment, but not the full project cost. Refurbishment involves replacing or upgrading major reactor systems, implementing extensive safety improvements and preparing for a second operating cycle. The work requires a complex, carefully planned outage, with cost control, scheduling and execution highlighted as critical factors.
The project is positioned as involving less construction risk than building an entirely new nuclear site, reflecting the nature of refurbishment work. Preparations for the second operating cycle are part of the planned scope, alongside safety upgrades. The outage planning is therefore central to maintaining timelines and managing costs during equipment replacement.
Electricity role and system balancing rationale
Romania’s two reactors at Cernavodă normally account for around one-fifth of national electricity generation. Their stable output is described as complementary to rapidly expanding wind and solar capacity. The same operating profile is also linked to reducing exposure to imported fossil fuels while supporting decarbonisation and energy security objectives.
The refurbishment case is therefore tied to maintaining firm generation capacity while renewables expand. It also reflects the need to keep dispatchable low-carbon supply available as variability from wind and solar increases. This approach does not depend on waiting for new nuclear projects to materialise.
Danube water stress affects cooling operations
A vulnerability highlighted by events in August 2026 involved cooling water availability during a Danube emergency. Record-low water levels forced one Cernavodă reactor offline and threatened cooling supply for the remaining unit. Authorities responded by removing a rock obstruction, dredging the riverbed and constructing a temporary dike made from rock-filled barges.
The measures raised local water levels by around four centimetres and extended operation of the remaining unit by at least nine days. The incident is presented as broadening the definition of nuclear resilience beyond reactor safety and fuel security alone. Future nuclear investment planning is expected to account for heat and water stress affecting cooling-system performance.
Regional implications for Southeast European power systems
A prolonged outage at Cernavodă could tighten electricity supply not only in Romania but also across interconnected Southeast European markets. The risk is described as particularly relevant when drought reduces hydropower generation at the same time. In that context, batteries, demand response and stronger interconnections are cited alongside nuclear refurbishment.
The same market framing notes that firm generation remains important but cannot be treated as completely firm under every climate scenario. For other nuclear markets in Southeast Europe, Romania’s experience is described as a benchmark for decisions on extending existing capacity or pursuing replacement projects in Bulgaria, Slovenia and Croatia. Regulators’ confirmation that both technical and climate-related vulnerabilities are addressed is identified as a key condition for refurbishment benefits.
Cernavodă Unit 1 refurbishment is therefore characterised as more than installing new equipment on an ageing reactor. It is framed around adapting critical infrastructure to more challenging operating conditions while preserving low-carbon generation output. The EIB commitment underscores financing support for the effort, while the Danube crisis sets expectations for resilience requirements during future operations.
