The Bulgarian Nuclear Regulatory Agency (BNRA) has reported steady progress in the transition from Russian nuclear fuel to supplies from Westinghouse Electric Company at Unit 5 of the Kozloduy nuclear power plant. This initiative marks a significant step in Bulgaria’s energy strategy, as it aims to enhance energy security and diversify its nuclear fuel sources.
BNRA Chairman Tsanko Bachiyski indicated that the replacement process is adhering to approved technical guidelines. So far, two batches of new fuel assemblies have been successfully inserted into the reactor core, with initial monitoring showing stable and expected performance levels. This reflects a careful approach to maintaining operational integrity during the transition.
A planned shutdown of Unit 5 is scheduled for May 9, during which additional fuel assemblies will be installed as part of a maintenance outage expected to last approximately 40 days. Continuous monitoring will be maintained throughout this period, with the full fuel transition projected for completion by 2027. A comprehensive assessment of long-term performance is anticipated in 2028, underscoring the importance of thorough evaluation in this critical phase.
This diversification effort is particularly noteworthy as Bulgaria becomes the first EU member state to implement such a transition for a VVER-1000 reactor, marking a significant milestone within the European Union. The achievement has been acknowledged in recent reviews conducted under the Convention on Nuclear Safety, highlighting Bulgaria’s commitment to enhancing safety and regulatory compliance in its nuclear operations.
<pSimultaneously, the Kozloduy plant operator has submitted an application to introduce test assemblies of the new fuel into Unit 6. However, this request was returned for revision due to incomplete documentation. The plant has been granted two months to address these issues before the review process can proceed, emphasizing the regulatory body's focus on stringent safety standards.
Bachiyski reiterated that any regulatory approval for test assemblies will hinge on strict adherence to safety protocols. He noted that assessing the performance of these test assemblies in Unit 6 will necessitate several years of operational data, indicating that decisions regarding broader fuel replacements will be made only after sufficient evidence has been gathered. This cautious approach reflects a commitment to ensuring safety and reliability in Bulgaria’s nuclear energy sector.
