Southeast Europe’s nuclear market entered July 2026 with a split between the near-term commercial value of operating reactors and the uncertain economics of future construction. Existing plants are operating in a system shaped by hot-weather demand, constrained hydropower and higher natural-gas costs. New projects continue to progress politically and technically, but financing, construction risk, supply-chain exposure and long development timelines remain decisive.
Market focus is increasingly on whether reactors are available during periods of highest system stress. In Southeast Europe, nuclear value is measured not only by installed megawatts, but also by reliability and availability and by the ability to reduce reliance on more expensive marginal generation.
July 10 generation snapshot and intraday price dynamics
A regional generation snapshot for July 10 placed nuclear output at 5,579 MW. Hydropower was listed at 4,871 MW and gas-fired generation at 4,521 MW. On the same day, Serbian electricity prices fell to €20/MWh during a solar-rich afternoon before rising to €208.10/MWh in the evening.
Nuclear generation does not track intraday price swings in the way hydro, gas or batteries can. Continuous nuclear output reduces residual demand that flexible resources and imports would otherwise need to cover.
Cernavodă Unit 1 restart and Krško June performance
Romania demonstrated the availability link through the return of Cernavodă Unit 1. The unit reconnected to the national grid on July 5 after completing its planned maintenance program. A July 7 regional market assessment attributed part of an easing in Romanian supply conditions to the restoration of approximately 700 MW of nuclear capacity.
Romania’s day-ahead price settled at €103.81/MWh on July 7, while the country still required approximately 596 MW of net imports. The latest complete monthly result from Krško showed similar strength for operating performance.
The jointly owned Slovenian-Croatian plant produced 495,096 MWh in June, around 1% above plan. Reported availability and capacity factors were 100%, corresponding to average net output of approximately 688 MW shared between the two national systems.
Refurbishment financing for Cernavodă Unit 1
Nuclear’s near-term role in Southeast Europe is tied to reducing the size of ramps that gas, hydropower, batteries and imports must cover. In smaller national power systems, returning or losing a single reactor in the range of 700–1,000 MW can affect import needs, cross-border flows and short-term electricity prices.
Cernavodă Unit 1 refurbishment is currently described as Romania’s most financeable nuclear segment in the region. In July, the European Investment Bank approved an €800 million loan for refurbishment work at Unit 1. The borrowing requires approval from Nuclearelectrica shareholders before it can be contracted.
The EIB financing is set to complement a €540 million preliminary-phase loan signed in September 2025. The broader financing strategy combines company equity with international financial institutions, export-credit agencies and commercial banks.
The project has entered its second development phase covering permits, engineering and construction contracts, equipment procurement and financing. Major refurbishment work including reactor retubing is scheduled for 2027–2030, with Unit 1 expected to resume operation in 2030. Nuclearelectrica estimates refurbished output would provide about 9% of Romania’s annual electricity supply between 2030 and 2060, with a historical capacity factor above 90%.
Doicești SMR conditions after shareholder review
A life-extension project depends on planned outages while replacement supply comes from other resources. Romania expects to cover Unit 1 output during the 2027–2030 works using a combination of Unit 2 availability, renewable generation, imports, gas-fired capacity and storage.
The Doicești small modular reactor decision remains conditional despite being labeled as a final investment decision.
Nuclearelectrica shareholders approved an FID for a planned 462 MW facility at Doicești that would replace part of a former 600 MW thermal-power site. The approval included additional conditions before the project entered a six-month period focused on financial structuring and partnership development.
Bulgaria’s fuel diversification and Kozloduy new-build status
Bulgaria is diversifying nuclear fuel without full independence across its supply chain. Kozloduy Unit 5 returned from annual maintenance on June 15, after receiving Westinghouse fuel assemblies for the third time. Bulgaria began phased transition to alternative fuel for its VVER-1000 reactor fleet in 2024.
Bulgaria granted another sanctions derogation in June , allowing Kozloduy to procure necessary Russian-origin parts and components. The two operating VVER-1000 units provide approximately 34% % of Bulgarian electricity, while much of their installed equipment remains based on Russian design and manufacturing. Unit 6 also experienced two winter outages reportedly linked to difficulties sourcing replacement parts from a Russian supplier.
Bulgaria is also developing two Westinghouse AP1000 units at Kozloduy. The project company recorded meetings in July with Westinghouse, Hyundai Engineering & Construction and US representatives. Indicative targets reported for Units 7 and 8 are 2035 % and 2037 % respectively.
Akkuyu commissioning tests, JEK2 spatial planning, Croatia legal framework
The wider new-build pipeline includes projects at different stages of maturity rather than a single consistent timeline. Türkiye’s Akkuyu Unit 1 is described as closest to commercial operation in the region beyond immediate refurbishments. Construction work on Unit 1 has been completed and cold hydraulic testing began in June.
Akkuyu comprises four VVER-1200 units totaling 4,800 % MW under a Russian build-own-operate model, with Unit 1 targeted to begin supplying Turkey during 2026 % . Testing, regulatory approval, fuel loading and commissioning still separate Akkuyu from sustained commercial operation.
The government in Slovenia initiated preparation of the national spatial plan for a second nuclear plant at Krško under JEK2. The process includes environmental assessments and protected-area evaluations expected to conclude with a government decree in autumn 2028 % . After that step, later investment, technology and financing decisions can proceed.
Croatia published a law on May % 27 establishing an institutional basis for future civilian nuclear policy decisions rather than authorizing an immediate plant. The law sets out frameworks for site selection, technology choice, financing approaches and licensing steps. It also confirms continued Croatian support for the jointly owned Krško plant.
Cooling-water constraints after Danube low-flow event
A separate operational risk highlighted for summer planning is cooling-water availability linked to river flows. At Romania’s entry point on the Danube, flow fell to approximately 1,700 % cubic metres per second compared with a July average around 4,700 % cubic metres per second.
