The state-owned Kozloduy plant on the Danube river currently relies on Russian fuel for its two Soviet-built 1,000-megawatt reactors.

Under a 10-year agreement signed Friday, Framatome, a subsidiary of French energy giant EDF, will supply nuclear fuel to Kozloduy's unit 5 reactor from early 2025.

Last week, Kozloduy signed a similar contract with Westinghouse Electric Sweden to deliver nuclear fuel for its other operational reactor, unit 6, from 2024.

With the two agreements in place "we have achieved full diversification of nuclear fuel deliveries" for Bulgaria's only nuclear power plant, interim energy minister Rosen Hristov said at the signing ceremony.

"The aim is security of deliveries and safe operation," he added.

Westinghouse's nuclear fuel has yet to be approved for use by Bulgaria's Nuclear Regulatory Agency.

However, Framatome's fuel is identical with the one currently used in Kozloduy as it is being produced under licence from the nuclear unit of Russia's Rosatom, Tvel.

Bulgaria's current contract with Tvel expires in end-2025.

Kozloduy supplies over a third of the country's electricity and is a major electricity exporter to the rest of the Balkans, prompting the plant to seek to substitute Russian fuel in order to ensure its operation amid the war in Ukraine.