site.btaKozloduy Nuclear Power Plant to Launch Annual Maintenance at Unit 5

Unit 5 of the Kozloduy Nuclear Power Plant (K-NPP) will be shut down on May 9 for planned annual maintenance and refuelling, the plant said on Friday. The company added that the necessary repair and preventive maintenance activities on the equipment are due to be carried out by mid-June to ensure the safe and reliable operation of the nuclear unit during the reactor’s next fuel cycle.

For a third time, the reactor will be loaded with RWFA fuel assemblies produced by Westinghouse, continuing the phased transition to new nuclear fuel launched in spring 2024.

The reliable operation of Unit 5 and the analyses carried out confirm the successful implementation of K-NPP’s programme for diversification of the nuclear fuel cycle. Bulgaria is the first country in the European Union to successfully implement in practice the diversification of nuclear fuel for a VVER-1000 reactor, the plant added.

This was identified as an area of good performance in the conclusions of the report from the 10th Review Meeting of the national reports of countries under the Convention on Nuclear Safety, held in Vienna in April 2026.