Kozloduy is Bulgaria’s only nuclear station located on the very north of the country, on the Danube bank, just several miles away from a town with the same name. The local economy started flourishing after the country’s first and only nuclear station was built here in 1970. Thousands of construction and installation employees worked on the site to bring the station online in 1974. In 1991–2002, the facility featured six reactor units with a combined capacity of 3,760 MW, covering 46% of the country’s power needs. In 2002 and 2006, Bulgaria shut down the first four units of the station to meet the EU admission requirements. At present, the station operates two units (5 and 6) supplying 33% of power consumed in the country.
The 30-year design life of Units 5 and 6 will expire respectively in 2017 and 2019. As this was realized, a decision was made to extend their service life as quickly as possible. The consortium of RosEnergoAtom and EDF selected in the bidding process audited the two units in 2012–2014 and in September 2014 signed a contract for a feasibility study to extend the service life of Kozloduy Unit 5 up to 60 years. The contract was to be performed within only 27 months, which seemed fantastic since a similar procedure would have required far more time in Russia. “In Russia, when it comes to life extension of irreplaceable equipment, preparations begin well in advance. Five years before the service life expiry is a reasonable time,” says Vsevolod Vityazev, Rusatom Service’s manager of the service life extension project at Units 5 and 6.
Combining Russian and European expertise, the consortium of two major nuclear operators – Rosenergoatom (35 reactors) and EDF (58 reactors) – achieved an impressive result as the job was done ahead of the tight schedule. “According to our estimates, the task would require at least 36 months, but we did it in just 25 months instead of the scheduled 27,” says the project manager. “We owe this success to good teamwork and responsible attitude of all the project stakeholders, including Kozloduy staff who were quick to prepare documents containing tens of thousands of pages, as well as EDF and Rosenergoatom representatives who audited the documents and made their comments.”
The consortium experts made a comprehensive assessment of the technical condition and remaining life of the reactor equipment, piping, heat-removal system, pumps, electrical components, steel reinforcement and bearing structures at Kozloduy Unit 5. The Russian party was represented by more than 100 experts from 15 nuclear companies, including OKB Gidropress, AtomTechEnergo, Kurchatov Institute, Prometey Research and Development Institute, OKBM Afrikantov, and others.
In late October, 13 volumes of technical documents made in three languages were handed over to the nuclear facility management during a dedicated ceremony. The documents confirm the feasibility of the life extension project at Kozloduy Unit 5.
Other Projects
Unit 5 life extension is not the only project carried out at the facility with Russia’s involvement. In 2014, Rusatom Service supplied Kozloduy with new generators as part of the power uprate at Unit 6 to 104%. “We have manufactured new equipment for Unit 5. The plans are to deliver it by the end of the year. Basically, Kozloduy is a very good facility. It underwent extensive overhaul in the 2000s, and the both units are in excellent condition, with almost all the equipment modernized. We do not expect any troubles when extending its service life up to 60 years. However, the Bulgarian regulations allow for licenses to be issued for no longer than 10 years,” Mr. Vityazev noted.
The experience we gained during the project is going to be used in the feasibility study for the life extension of Unit 6. This time we will work without the French input, with only two companies involved – Rusatom Service and Bulgaria’s Risk Engineering. The project will run 30 months and end in the summer of 2018. By the end of the year, Russian engineers will check technical condition of the reactor and piping as part of the scheduled maintenance.
Experts Speaking
Kirill Komarov
Rosatom’s First Deputy CEO for Corporate Development and International Business
“This project was of paramount importance for us, and we are very glad to have contributed to Bulgaria’s energy security. When preparing Kozloduy Units 5 and 6 for the life extension, Rosatom has been tasked to assess remaining life of the reactor and other core systems of the nuclear station. It was one of the most crucial stages of the entire project. This year Russia and Bulgaria celebrate the 50th anniversary of their nuclear cooperation. We are proud to say that over all these years Russia has been providing Bulgaria with extensive support in every nuclear-related issue, ranging from construction to fuel supplies and maintenance. Today our cooperation is taking on a new shape. A modern playground is going to be built in the town of Kozloduy with financial support from Rusatom Service. The site has been already selected, with the project design in progress.
Temenuzhka Petkova
Bulgarian Minister of Energy
“The life extension of Units 5 and 6 is vital for the country since the nuclear station in Kozloduy generates 33% of power consumed in the country. It makes our economy competitive and supplies power to our consumers at affordable rates.”
Dariusz Nowak
Kozloduy modernization and life extension project manager
“My job was to do computations for the life extension feasibility study. The task was centered around quantitative assessment of remaining life to determine an exact extension period. No doubt that there were difficulties. Many meetings were held to settle issues, clarify input information and the scope of work.
We spent much time checking draft documents in Russian and commenting on them. Since our comments were many, the contractor had to double their efforts to complete the task on time.”
