site.btaKozloduy NPP Unit 5 Annual Maintenance Completed

The scheduled annual maintenance of Unit 5 at the Kozloduy Nuclear Power Plant (NPP) was completed on Monday, the plant’s management said in a press release. Following an inspection and a positive assessment by the Nuclear Regulatory Agency, the unit was reconnected to the national power grid at 11:49 a.m.

During the outage, which began on May 9, 2026, all planned repair and maintenance activities on systems and equipment were successfully completed. Measures aimed at ensuring the unit’s long-term operation and maintaining a high level of safety were also implemented. RWFA-type fuel assemblies manufactured by Westinghouse were loaded into the reactor for the third time.

The phased transition to new nuclear fuel began in spring 2024, and Bulgaria is the first country in the European Union to successfully implement a nuclear fuel diversification programme for VVER-1000 reactors. The Kozloduy NPP said this achievement was highly regarded by international nuclear energy organizations, the press release reads.

The unit is being brought back online in stages in line with technical regulations.