Bulgaria’s Nuclear Regulatory Agency (AYaR - Agentsiyata za Yadreno Regulirane) has licensed the use of Westinghouse fuel for unit 5 of the Kozloduy NPP. Loading of the new fuel, which has already been delivered to the site, will begin during the next scheduled repair and maintenance outage, due to begin at the end of April. The first 42 cartridges of the new American fuel arrived at Kozloduy NPP by ship from Sweden, where they were manufactured.
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 in both Kozloduy VVER-1000 reactor units (5&6). 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.
The issued permit contains a number of conditions related to the transition to the new type of nuclear fuel. They include requirements as to make changes to existing instructions and documents defining new fuel operation, and for the periodic provision of additional information as well as analyses of its performance.
More than 75 fuel reports and operational documents modified by the NPP to meet safety requirements and standards were reviewed in the licensing process. Requests for additional information needed to demonstrate compliance with the safety requirements resulted in more than 40 amended documents being presented for review, as well as new reports related to RWFA fuel safety.
Bulgaria's Energy Minister Vladimir Malinov, who visited the plant together with caretaker Premier Dimitar Glavchev at the time of the RWFA fuel delivery, noted that a fuel diversification contract had also been signed with the French company Framatome for unit 6. Glavchev recalled that diversification is a long process, noting that he had personally participated in talks with Westinghouse in 2009-2010.
In March, Bulgaria’s National Assembly (Parliament) ratified the intergovernmental agreement on cooperation in nuclear energy, signed in February between Bulgaria and the US. In January, the Bulgarian government approved a draft agreement with the US on cooperation in the construction of two new nuclear reactors using Westinghouse AP1000 technology at the Kozloduy NPP (units 7&8).
After it was signed in February, Bulgaria’s Parliamentary Energy Commission said South Korea’s Hyundai Engineering & Construction (Hyundai E&C), part of Hyundai Corporation, will be invited to submit a binding offer with a price for the design, construction, supply, installation and commissioning of units 7&8. Of the five candidates interested in building the new nuclear facilities, two Chinese and two American companies did not meet the requirements, he said. Bulgaria plans to launch unit 7 by 2034 and unit 8 in two to three years later. The estimated cost of construction is some $14bn, although some experts have said it could increase to $30bn.
Currently, Kozloduy NPP operates two Soviet-built VVER-1000 reactors (units 5&6). 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. Plans to build a new NPP at Belene comprising two VVER-1000 reactors was cancelled in face of political and financial difficulties after the equipment was manufactured and supplied by Russia. Those reactors, now in storage at Belene, may be transferred to Ukraine for use at the Khmelnitsky NPP pending an agreement on costs.
Image: Bulgaria's Minister of Energy Vladimir Malinov (left) and Prime Minister Dimitar Glavchev visited the Kozloduy site at the time of the RWFA fuel delivery
