Bulgaria - World Nuclear Outlook Report
Current operations
Bulgaria has two VVER-1000 reactors in operation, Kozloduy 5&6. Together, the two units generate around one-third of Bulgaria’s electricity.
The two VVER-1000 units at Kozloduy began operating in 1987 and 1991. A programme of work was carried out between 2014 and 2019 to allow for 60 years of operation, and to uprate both reactors to 104% of their original capacities. The operating licences have initially been extended by ten years, to 2027 and 2029.
Table Bu.1 Nuclear capacity status (as of 1 October 2026)
| Operable reactors | Operable reactors net capacity (MWe) | Operable reactors gross capacity (MWe) | Reactors under construction | Reactors under construction gross capacity (MWe) | Cumulative carbon dioxide emissions avoided 1970-2025 (c.f. coal) (MtCO2) |
|---|---|---|---|---|---|
| 2 | 2006 | 2080 | 0 | - | 644 |
Nuclear policy and outlook
Additional units have been under consideration at Kozloduy and at Belene since the 1980s. In March 2024 the Bulgarian parliament ratified an agreement with the USA on coordination regarding construction of Westinghouse AP1000s as Kozloduy 7&8.
In February 2024 the Bulgarian parliament gave the go-ahead for talks to take place with Hyundai E&C, as the sole shortlisted constructor for engineering, construction, delivery and commissioning of the new units at Kozloduy. In July 2025 Bulgaria's Ministry of Energy and the US's Citi bank agreed a partnership to secure funding for the construction of the two AP1000 units.
In December 2025 Kozloduy NPP-New Build EAD and a consortium comprising Laurentis Energy Partners, its subsidiary Canadian Nuclear Partners SA (CNPSA) and BWXT Canada, signed an owner’s engineer contract to advance the two new AP1000 units. In April 2026 Minister of Energy Traycho Traykov said Bulgaria wanted the new Kozloduy reactors to be built at fixed prices. The current aim is for the first AP1000 to be operational in 2035, and the second unit two years later.
Bulgaria has also been considering deploying SMRs. A grant agreement was signed by the US Trade and Development Agency with state-owned Bulgaria Energy Holding (BEH) in December 2024 for a technical analysis of US-sourced small modular reactor (SMR) design options to support Bulgaria's planned deployment of one or more SMR nuclear plants.
Table Bu.2 Contributions to total capacity projection in 2050 (gross)
| 60 year operation (MWe) | 80 year operation (MWe) | Currently under construction capacity (MWe) | Planned capacity (MWe) | Proposed capacity (MWe) | Potential capacity (MWe) | Government capacity target (MWe) | Additional capacity* required to meet government target (MWe) | Total capacity (MWe) |
|---|---|---|---|---|---|---|---|---|
| 1040 | 1040 | - | 2500 | - | - | 4000 | - | 4580 |
| *Capacity additional to operable, under construction, planned, proposed and potential capacities required to meet the government target. | ||||||||
Readiness Assessment
Bulgaria has a strong institutional foundation for both long-term operation and new build. Its regulator and operating organizations are highly experienced, while the project company is adding new build expertise.
| Country Category | Restarter |
|---|---|
| Policy Framework Readiness | Moderate-High Bulgaria has strong policy readiness. Its nuclear objective is supported by formal decisions covering both long-term operation (LTO) and new build. There are still several investment, contracting and financing decisions needed for the Kozloduy project to proceed. |
| Institutional and Infrastructure Readiness | High Bulgaria has a good institutional foundation for both LTO and new build. Its regulator and operating organizations have relevant experience, while the Kozloduy project company is adding new build expertise. This readiness can be maintained by ensuring its regulatory, owner, engineering and construction workforce grow to manage the two AP1000 projects alongside continued LTO and decommissioning responsibilities. |
| Programme & Project Development | Moderate-High For Kozloduy, the site and technology have been selected, and financing preparation and supply chain mobilization are substantive, with decisive construction commitments being the next step. |
| Target Achievability | Moderate-High Bulgaria has made good progress regarding the deployment of new capacity at Kozloduy. Moving promptly to construction will help ensure the project remains on track. |
