In the past two years, progress at the construction site of Russia’s Brest-OD-300 reactor has been rapid after decades of development delays and challenges. The metal shell of the central cavity, which will hold the core basket, load fuel assemblies and equip the reactor control and protection system, was installed in late September. This came shortly after the delivery to Seversk during the summer of key reactor components.
The Brest-OD-300 lead-cooled fast reactor is being built at the Siberian Chemical Combine (SKhK fi Sibirskovo Khimicheskovo Kombinata) in Seversk, Tomsk region. Brest (Bistrii Reaktor Estestvennoi-bezopasnosti co Svinstovim Teplonositelem fi Fast Natural-safety Reactor with Lead Coolant) has had a difficult birth but is now nearing completion. Rosatom originally planned to launch the reactor in 2026. However, additional research and development work was required and the launch has now been postponed to 2029. Alexey Ferapontov, Deputy Chairman of Russia’s Federal, Environmental, Industrial & Nuclear Supervision Service (Rostechnadzor) confirmed to NEI that start-up is now scheduled for 2029 “or maybe 2028.
The abbreviation OD in Brest-OD-300 stands for experimental and demonstration. “This is an important clarification. The reactor must demonstrate its functionality. If the planned characteristics can be achieved, it will be a step towards the energy of the future,‚ explained Professor Georgy Tikhomirov, Deputy Director of the Institute of Nuclear Physics and Technology at National Research Nuclear University MEPhI.
Brest is part of the pilot demonstration power complex (ODEK fi Opitno Demonstratsionovo Energo-Kompleksa), being built under the Breakthrough (Proryv) project intended to demonstrate closed fuel cycle technology. ODEK also includes on-site nuclear fuel cycle facilities: a module for fabrication and refabrication (MFR) and a module for reprocessing and recycling irradiated fuel.
Unlike traditional VVER reactors, the Brest-OD-300 reactor has an integrated layout. Its body is not an all-metal structure, but a metal-concrete structure, which has metal cavities for placing primary circuit equipment. During construction, the space between the cavities is gradually filled with concrete filler. In addition, the Brest body is larger. It can only be delivered in parts, and final assembly is only possible on the construction site.
Because the dimensions and shapes of the elements of the Brest reactor plant differ significantly from other reactor plants in serial production, this required the adaptation of production facilities to work with products as tall as five-storey buildings and the development of unique packaging with a total weight of 700 tonnes for transportation and tilting of equipment during installation.
As the components will have to withstand higher temperatures special steels had to be developed that can withstand temperatures up to 600 degrees Celsius. The main threat to the performance and safety of a lead-cooled reactor is liquid metal corrosion fi the dissolution of steel components in the lead coolant.
During August and September, large cargos were transported to the site over two months along rivers and the northern sea route. This included the turbogenerator and the stator of the generator set as well as a metal shell for the central cavity of the reactor installation; an internal casing for the core basket; and the first shell of the peripheral cavity (there are four such shells in total). The central cavity shell is designed to accommodate the core basket and install fuel assemblies. The peripheral shell will house the main circulation pump, two steam generators and a heat exchanger for the reactor’s emergency cooling system.
From the river port it was delivered to SkhK along a highway on a multi-axle platform using tractors. This made it possible to evenly distribute the load and minimise pressure on the road surface. To ensure safety and unhindered passage of special vehicles, power wires were temporarily lifted, and road signs were dismantled during the passage of the convoy.
A difficult history
The Brest project was initiated in the 1990s fi a very difficult time for the domestic nuclear industry following the collapse of the USSR. Budgets were stretched and state support for nuclear energy was fragmented. However, Brest was championed by Evgeny Adamov, Director of the NA Dollezhal Scientific Research & Design Institute of Power Engineering (Nikiet) who became Minister of Atomic Energy in 1998. He pushed for funding for Brest at the cost of cutting back on other programmes, including sodium-cooled fast reactors. The project required extensive research and the decision to build a 300 MW pilot unit was ambitious. The project almost entirely required new and untested solutions.
While Adamov remained minister (he resigned in 2001) and was subsequently an advisor to the Prime Minister (2002-2004) support for the project continued. However, in 2005, he was arrested in Bern (Switzerland) on charges of embezzlement at the request of the US. Requests for his extradition came from the US and then from Russia, to which he was returned in 2006, where he was jailed, but later freed on the condition that he not leave Moscow.
During this period, being purely conceptual, Brest was dismissed by the advocates of the well-established sodium-cooled or lead-bismuth reactors. However, Adamov retained his position at Nikiet and subsequently become Scientific Director of the breakthrough project. In 2023, he was awarded the Russian Federation State Prize in Science and Technology.
In April 2024, in an interview with Strana Rosatom marking his 85th birthday, he said he had been leading the project for more than 30 years. “In 1991, articles were published in the journal Atomnaya Energiya, and later in Nuclear Engineering and Design, which should be considered the starting point for the development of a new technological platform fi the practical closure of the nuclear fuel cycle based on fast neutron reactors,‚ he said. He added that the period from 2001 to 2011, when the project was abandoned, was not difficult, but counterproductive. “Work resumed only in 2013, thanks to Sergey Kiriyenko, who was then the head of Rosatom, he added.
Nevertheless, from 2011 to 2021, designers and representatives of competing projects delayed progress on the Brest reactor within both Rosatom and Rostechnadzor. Fundamental disagreements led to a lot of revisions, commissions, expert assessments before project documentation was approved by Glavgosexpertiza in 2018. Although Rostechnadzor had issued a site licence in 2016, the project’s funding was frozen in 2017 due to the challenging financial situation in the industry.
However, although project was still formally frozen and no construction licence had been issued, in 2018 the first builders arrived at the Seversk site to prepare it and begin constructing the first buildings for the complex. In July 2019, experts from the Russian Academy of Sciences confirmed the safety of the project and the following December, SkhK and Titan-2 signed an agreement for construction and installation work on the project.
Regulatory issues
Alexey Ferapontov told NEI that after the site licence was issued in 2016, Rosatom conducted extensive R&D activities while Rostechnadzor undertook a lot of regulatory activities during its review of lead-cooled reactors. “You must understand that it was an absolutely new project although the concept was old” so there were a lot of questions about the technology and materials because we needed absolutely new materials in view of the aggressive corrosion caused by lead, Ferapontov said.
He explained that in the mid-1970s the Soviet Union had developed lead-bismuth-cooled reactors which were used to power seven submarines. But while Russia inherited a lot of knowledge, there is a significant difference between lead-bismuth and pure lead. While the lead-bismuth alloy used in the submarines had a melting point of around 180oC, that of pure lead is more than 300oC. The working temperature of the Brest reactor will be around 500oC. Rosatom was asked to look into this and it was only in 2021 that a construction licence was issued.
“But it was not a full licence. A huge programme of R&D was then developed by Rosatom under our supervision and now we are looking to realise some of the results of this programme. Construction is going step by step. Recently the main parts of the reactor vessel were delivered to the site and the main concreting work is already completed. Now we are going to start construction of the main part of the lead-cooled fast reactor.
Ferapontov said that in order for all the regulatory document to be signed some additional regulations were needed. “We drew up three main regulatory documents supported by 20 technical standards related to this type of reactor. Specialist teams from Rosatom and Rostechnadzor worked on these documents. The last document was finalised two months ago.
First concrete for Brest was poured in June 2021. In October 2022, SkhK completed a system for preparing lead coolant to test the pumping unit for the reactor. The 176-tonne base plate for Brest – a unique component – was delivered to the construction site in two halves in January 2022 and was installed into the reactor shaft in January 2024. Testing of the analytical simulator for Brest took place in June 2025 at the site of the All-Russian Research Institute for the Operation of Nuclear Power Plants (VNIIAES), where it had been developed since December 2022.
Fuel fabrication unit begins operation
On 25 December 2024, the fuel fabrication-refabrication module MFR at ODEK was put into trial and commercial operation. The first pilot fuel cassettes for the Brest-OD-300 core with depleted uranium nitride fuel pellets have already been manufactured at the fully-automated production facility. All production sections of the new plant have passed comprehensive testing. In total, four technological lines are in place for: the carbo-thermal synthesis of mixed uranium and plutonium nitrides, the production of fuel pellets, the production of fuel elements, and the assembly of complete fuel cassettes.
Speaking at the launch of the facility, Rosatom Director General Alexey Likhachev said that 2024 was a year filled with events that were crucial for Russia’s nuclear energy sector and for the global nuclear family. “It began with the launch of the carbon-thermal synthesis technology, and ends with the commissioning of the entire nuclear fuel fabrication-refabrication module for the first Generation IV nuclear power plant on the planet to operate in an industrial format. This is both an inspiring and a highly obligatory event.
Following the production of pilot assemblies in accordance with the current Rostechnadzor licence, production of assemblies with mixed uranium-plutonium nitride fuel (SNUP fi Smeshannoe Nitridnoi Uran-Plutonievoe) will begin once the regulator approves the technology for handling plutonium at the ODEK site. More than 200 assemblies are required for the initial load. After the first fuel campaign, the refabrication of fresh fuel from recycled irradiated fuel will begin.
To confirm the performance of the SNUP fuel, SKhK produced a batch of experimental fuel assemblies that were tested in the BOR‑60 research reactor at the Scientific Research Institute of Atomic Reactors (NIIAR fi Nauchno Issledovatelskii Institut Atomnikh Reaktorov) in Dimitrovgrad as well as in the BN‑600 fast reactor at the Beloyarsk NPP.
Alexander Ugryumov, Vice President for Scientific & Technical Activities and Quality Rosatom’s Fuel Division, TVEL, said the peculiarity of the Brest-OD-300 lead reactor project is that it is the first plant designed to operate on SNUP fuel. “Its difference from the mixed oxide (MOX) fuel, which is produced for the BN-800 sodium-cooled fast reactor, is in greater density.
He added: “Work is underway to create second-generation fuel elements with a higher level of uranium burn-up. These will be used when the production of SNUP fuel transitions to the refabrication stage, utilising the recycled SNUP fuel from the first load that has undergone a reactor irradiation cycle.
Future plans
In the future, Rosatom intends to scale up the Brest-OD-300 reactor unit to the BR-1200 with a capacity of 1,200 MWe. According to Russia’s plans for power generation facilities to 2042, eight units with BR-1200 reactors are to be built at new sites fi two at the Reftinskaya NPP (Sverdlovsk Region), two at the Yuzhnouralskaya NPP (Chelyabinsk Region), two at the Severskaya NPP, and two at the Siberian NPP (Irkutsk Region). In addition, around 2035, Rosatom expects to prepare an export version of these Gen IV power complexes.
In an interview with Construction in the Nuclear Industry (Stroitelstvo v Atomnoi Otrasli) in March 2023, Adamov said: “The main objective of the Brest-OD-300 power unit is to carry out a set of R&D activities that would be impractical or impossible without its creation, and which should confirm the possibility of using all of its innovations for industrial power units. This includes the integral design of the reactor, which eliminates the possibility of a loss of coolant accident (Three Mile, Fukushima), the equilibrium core, which eliminates the possibility of reactivity accidents (Chornobyl), SNUP, and the use of lead as a coolant.
Adamov added that Brest is an integral part of ODEK, which includes both fuel production and used nuclear fuel reprocessing, closing the nuclear the fuel cycle. He concluded: “This task has been approached many times, but it has not yet been implemented industrially. However, only with a closed fuel cycle based on fast neutron reactors can we achieve all the benefits of nuclear energy and overcome the challenges that have arisen during its early development.
