Since 2012, Rosenergoatom and Electricite de France have taken part in preparing Kozloduy Units 5 and 6 for life extension. Now, they are completing a joint project on a comprehensive examination and assessment of residual lifetime of the equipment and buildings of these power units. In the course of this project, a special program was developed and laid as the basis of further actions to prepare Unit 5 for operation beyond its assigned design service life. By date, it has been approved by the Bulgarian regulatory authority.
“The new project is planned to implement within a tight timeframe,” Alexey Sidorov, a specialist from the Department for International Business and Development of Rosenergoatom, explained. The work to implement is has started. The documents of the first stage of the contract are being developed, an active dialogue is held with the customer as to the input data for the calculations, and the work on the subsequent stages is planned,” he said.
In the course of the project implementation the specialized calculation justifications will be made and the studies related to assessment of the technical conditions and justification of residual lifetime of Kozloduy-5 structures, systems and components will be carried out. The leader is Rusatom Service, which bears the major workload under the project. Rosenergoatom has unique experience in operation, upgrading and service life extension of VVER reactors. It is directly involved in development of the quality assurance program, work organization plan, and works and studies methodology. One of Rosenergoatom’s objectives in the project is to be the technical guarantor, which provides references for approaches, methodologies, techniques and standards in use. All documents being developed under the project are subject to concurrence and approval by all members of the Consortium. A special role of EDF in reviewing and agreeing the documents is to take account of practices of the European operator and approaches formulated by the Western European Nuclear Regulators Association.
Rosenergoatom has a great experience in preparing NPP power units for extra service life. One of recent successful projects is the one carried out at Kola NPP in Murmansk Region. The nuclear power plant behind the Polar Circle was granted a license for another 25 years of operation by the regulatory authority in October. Earlier, projects to extend lives of all four existing power units of Kola NPP up to 45 years, as well as the third power unit of Beloyarsk NPP, four power units of Leningrad NPP were successfully completed. To add, the project on restoration of lifetime performance characteristics of the graphite stack of Leningrad-1 was completed.
The contract for Kozloduy NPP will allow Rosenergoatom to use its competences in this field at the international level. “This contract is very important for us,” the specialist from the Department for International Business and Development of Rosenergoatom says. “It is part of the large history of the cooperation with Kozloduy NPP and EDF. We approach implementation of this project with the understanding of to what extend the service life extension of NPP power units is important for our Bulgarian partners,” he says.
Kozloduy NPP in Bulgaria includes six power units. Two units with VVER-1000 reactors are in operation, while four VVER-440s were shut down upon the political demand of the European Union. According to the license conditions, Unit 5 can be operated until November 5, 2017 and Unit 6 until October 2, 2019.
