site.btaNuclear Regulatory Agency: Transition from Russian to US Nuclear Fuel at Kozloduy NPP Unit 5 will Take 4 Years

The transition from Russian nuclear fuel to US Westinghouse fuel will start in May with the refuelling of 43 cartridges in the reactor core of Kozloduy Unit 5 and will last for 4 years, said Bulgarian Nuclear Regulatory Agency (BNRA) Chairman Tsanko Bachiyski at a briefing in the building of the Agency on Tuesday.

Kozloduy NPP Executive Director Valentin Nikolov pointed out that the process of preparation for the switch to Westinghouse fuel began in 2019 with the signing of the contract with the company. During this time, several stages have been passed, and the necessary documents required by BNRA have been secured.

"Thanks to specialists who worked on this process, everything is already on schedule," Nikolov pointed out. According to him, the production process of the nuclear fuel assembly was also controlled throughout the period.

The BNRA Chairman specified that on April 22, as a result of positive opinions of the Agency's inspectors, a permit was issued for a phased transition of Unit 5 from Russian to American fuel. Bachiyski explained that the licensing process lasted for 9 months and was completed in full compliance with BNRA 's internal programme.

Nikolov added that after the Westinghouse fuel arrived at the plant site, the containers were inspected, and that the nuclear power plant will start to reduce its power on May 4 in preparation for the planned annual maintenance on May 7.

Kozloduy NPP has a stockpile of Russian nuclear fuel for unit 6 until 2029. After the first delivery of Framatome's fuel for unit 6, the plant will operate with both types of fuel, Nikolov explained, adding that the French nuclear fuel is expected to arrive at the end of 2025, but because of the negotiations with the French company it may be delayed a little. However, he pointed out that this would not be a problem for the plant because it has fuel reserves until 2029.

Bulgaria is in delay on the adoption of a nuclear fuel storage strategy, the Kozloduy NPP Executive Director said. He specified that this strategy should be comprehensive and not just for a specific period. Until recently, spent nuclear fuel was shipped to Russia, but in view of the war in Ukraine, these contracts have changed and therefore the strategy has been revised several times. It is almost ready at the Ministry of Energy and the Energy Ministry is expected to submit it to the Council of Ministers for approval. "So far the fuel is stored according to all the regulations and there is no problem, but if no measures are taken and no strategy is adopted, we will have some problem, but at the moment there is none," Valentin Nikolov said.