Kozloduy Nuclear Power Plant

Kozloduy Nuclear Power Plant is a major nuclear power facility located on the Danube River near the town of Kozloduy in northwestern Bulgaria. It is the only nuclear power plant in the country and a cornerstone of the national energy system, providing a significant portion of Bulgaria's electricity. The plant's operational history spans the Cold War era under the Comecon framework to its current role within the European Union.

History

Construction of the facility began in 1969 with significant technical cooperation from the Soviet Union. The first reactor, a VVER-440 model, was connected to the grid in 1974, marking the start of nuclear power generation in the Balkans. During the 1980s, the complex expanded with the addition of larger VVER-1000 units. Following the political changes of 1989, the plant's future became a key issue in Bulgaria's negotiations for accession to the European Union. Under pressure from the European Commission, the government of Simeon Saxe-Coburg-Gotha agreed to close the older Soviet-designed units as a precondition for membership.

Reactors and operations

The site originally housed six reactors. Units 1 to 4 were first-generation VVER-440/V-230 models, while Units 5 and 6 are more modern VVER-1000/V-320 units. Following the decommissioning of the first four units between 2002 and 2006, only the two VVER-1000 reactors remain operational. These are designated as Unit 5, commissioned in 1987, and Unit 6, commissioned in 1991. Both units underwent major modernization programs supervised by companies like Westinghouse Electric Company and Framatome. The plant is operated by Kozloduy NPP EAD, a subsidiary of the state-owned Bulgarian Energy Holding.

Safety and upgrades

Safety concerns, particularly from Western European countries regarding the design of the older VVER-440 models, were a driving force behind the closure agreements. Since the early 2000s, extensive safety upgrades have been implemented on the operational units under the oversight of the International Atomic Energy Agency and in line with European Union regulations. Key projects included the installation of new digital control systems, improvements to emergency core cooling, and seismic reinforcement. These modernization efforts were often financed through support mechanisms like the Kozloduy International Decommissioning Support Fund, managed by the European Bank for Reconstruction and Development.

Economic and environmental impact

The facility is critically important to the national economy, consistently generating over one-third of Bulgaria's electricity and allowing for significant exports to neighboring countries such as Serbia, North Macedonia, and Greece. Its operation supports energy security and price stability within the region. Environmentally, nuclear power from Kozloduy avoids millions of tons of carbon dioxide emissions annually compared to fossil fuel alternatives, aiding Bulgaria in meeting its climate targets under the Paris Agreement. The plant is also a major employer in the Vratsa Province region.

Decommissioning and waste management

The shutdown of Units 1–4 initiated one of the largest decommissioning projects in Eastern Europe. Activities are managed by the state-owned Kozloduy NPP-Decommissioning, with significant financial and technical assistance from the European Union and the European Bank for Reconstruction and Development. Spent nuclear fuel from the operational reactors is stored on-site in a wet storage facility, with plans for a centralized dry storage installation. The long-term strategy for high-level waste involves eventual deep geological disposal, with ongoing research coordinated with institutions like the Bulgarian Academy of Sciences. The safe management of radioactive waste remains a key commitment under the Joint Convention on the Safety of Spent Fuel Management.

Category:Nuclear power stations in Bulgaria Category:Buildings and structures in Vratsa Province Category:Energy infrastructure completed in 1974