Bulgaria’s Kozloduy Nuclear Power Plant (NPP) has announced its decision to terminate the contract with Russia for the supply of nuclear fuel, according to plant executive director Valentin Nikolov. The contract was due to end in 2025. He added that Russian fuel already delivered will now serve as a reserve.

He made the comments during a ceremony marking the loading of the last of the initial 43 cassettes containing nuclear fuel from US-based Westinghouse at Kozloduy NPP’s unit 5. The unit, which was closed for scheduled maintenance, is due to resume operations on 9 June. Nikolov emphasised that the price of American fuel is comparable to the Russian fuel. Simultaneously, negotiations are underway with the French company Framatome for the supply of nuclear fuel for Kozloduy unit 6. The last loading of unit 6 with Russian fuel will take place in the autumn. In October-November 2025, the reactor will operate in part with French fuel, which is a prototype of the current Russian TVSA.

Currently, Kozloduy NPP operates two Soviet-built VVER-1000 reactors (units 5&6), which provide about 34% of Bulgaria’s electricity Bulgaria was obliged to close four older VVER-440 units as a condition for accession to the European Union, even though the units had undergone significant safety upgrades. Kozloduy 5&6 were due to be decommissioned in 2027 and 2029 but have undergone refurbishment and life extension programmes to enable extension of operation from 30 to 60 years. Unit 5 was connected to the grid in 1987 and unit 6 in 1991.

In April, Bulgaria’s Nuclear Regulatory Agency (AYaR – Agentsiyata za Yadreno Regulirane) licensed the use of the Westinghouse fuel for unit 5, the first 43 cartridges of which had already been delivered to the site. A 10-year contract with Westinghouse Electric Sweden AB for fuel supply for unit 5 was signed at the end of 2022. The new American fuel arrived at Kozloduy NPP by ship from Sweden.

The permit is for a step-by-step transition to the new Robust Westinghouse Fuel Assembly RWFA fuel from the Russian TVEL fuel which is currently used. An earlier permit was issued in January for storage of the fuel at the site. The process of partial refuelling and parallel operation of both fuels will continue for four years. Only a quarter of fresh nuclear fuel will be replaced during the coming four fuel campaigns.

“Today we are present at a historic moment… since, in the 50-year history of the Kozloduy NPP, the plant will operate with an alternative fuel for the first time,” commented Vladimir Malinov, Acting Minister of Energy at the ceremony.

Kenneth Merten, the Ambassador of the United States in Bulgaria said: “Nuclear fuel diversification in Bulgaria is a first step towards diversification. The step was taken by several governments. I congratulate you on your vision. I believe that Bulgaria will become an energy hub after diversifying its fuel sources.”

Caretaker Prime Minister Dimitar Glavchev said this was the first stage of a real diversification of the nuclear fuel process. “This it is truly the beginning of the separation of Bulgaria from the almost complete dependence on Russia…. And without politicising, I will say that it is always good to have a choice. Diversification provides us with exactly that – a choice that gives better opportunities with 100% safety and security.” He noted that the first discussions with Westinghouse took place 2009-2010.

“Kozloduy NPP celebrates its 50th anniversary in 2024 and it is a pleasure for us to contribute to the diversification of nuclear fuel supplies for this valuable customer of ours with this first charge”, said Tariq Choho, President of the Nuclear Fuel Department at Westinghouse.