The physical launch of Russia’s multi-purpose fast neutron research reactor MBIR (Mnogotselevoi Bistrii Issledovatelskii Reaktor) under construction at the Scientific Research Institute of Atomic Reactors (NIIAR) in Dimitrovgrad, Ulyanovsk region, is officially scheduled for launch in 2027. In 2028 it will begin supplying electricity to the site and a pilot programme is planned.

The 150MWt multi-purpose sodium-cooled fast neutron reactor will be the world’s largest facility of its kind. It is expected to provide the nuclear industry with a modern and technologically advanced research infrastructure for the coming 50 years. Its unique technical characteristics will make it possible to solve a wide range of research problems to support the development of new competitive and safe NPPs, including fast reactors based on closing the nuclear fuel cycle. Research time needed at the new reactor will be several times less in comparison with currently available installations.

Work started in September 2015. The entire reactor complex – comprising 16 hectares – will consist of 53 facilities and 220,000 cubic metres of concrete will be used on its construction. Two thousand people and about 100 units of construction equipment are involved in the construction, including heavy caterpillar cranes with a carrying capacity of 1,350 tonnes. In 2023, the reactor vessel was installed and the reactor building dome was lifted into place.

“The pace of construction of this facility is simply amazing, said Vladimir Troyanov, Scientific Director at the AI Leipunsky Institute of Physics & Power Engineering (IPPE – part of Rosatom) in Obninsk. “The reactor complex, many auxiliary buildings have almost been erected. The pace of construction today is such that at the end of 2026 a physical launch will be possible."

Rosatom is constructing MBIR as part of the second federal project. “Creation of a modern experimental benchmarking base for the development of dual-component nuclear energy technologies with a closed nuclear fuel cycle”. The project is being implemented within the framework of the programme “Development of equipment, technologies & scientific research in the field of nuclear energy use in the Russian Federation for the period up to 2024" (RTTN – Razvitiye Tekniki Teknologii i Nauchnikh).

The RTTN programme was developed together with the Kurchatov Institute Research Centre, the Russian Academy of Sciences, and the Ministry of Science & Higher Education. It includes the development of new advanced technologies and materials, samples of new equipment, technical re-equipment, construction of unique complexes and infrastructure facilities in the field of nuclear energy and control of thermonuclear fusion reactions, as well as low-power nuclear plants. In 2022 it was extended until 2030.

MBIR will replace the BOR-60 experimental fast reactor that has been in operation at NIIAR since 1969 and has been widely used for research by scientists worldwide. BOR-60 is due to close in 2025. The density of neutron flux in the MBIR will be twice that of the BOR-60 MBIR will be used for materials testing for Generation IV fast neutron reactors. It will be capable of testing lead, lead-bismuth and gas coolants and will enable reactor and post-reactor experiments, perfecting technologies for the production of isotopes and modified materials.

The MBIR reactor will have three full-time cooling circuits: two sodium and one steam-water. The steam turbine circuit will be equipped with a steam turbine unit. This will not only allow innovative research, but also provide electricity and heat to NIIAR and the residents of Dimitrovgrad.

MBIR will include several loop experimental installations with special devices, within which it will be possible to create conditions different from those of the MBIR core. They will make it possible to simulate the conditions of radiation, implemented in various types of reactors with various neutron spectra, coolants and fuel compositions. MBIR will provide the ability to test a wide range of technologies needed to create new generation reactors. It will be possible to test both device diagrams, control methods and operating modes of reactors, including emergency handling, and types of fuel, coolants and structural materials.

Some of MBIR’s in vitro and irradiation channels will be used for production. Vertical channels will be used for neutron alloying of silicon, including large ingots for the electronic industry. Horizontal channels will offer neutron beams enabling research laboratories to solve applied and fundamental problems. MBIR will provide testing capabilities for any industry that uses nuclear technology. These can be fundamental neutron-physical studies, experiments on space programmes, medical, material science and many other applied tests.

MBIR will be the basis of an international research centre (ICC MBIR). Partner countries interested in the development and implementation of fast neutron reactors and the closure of the nuclear fuel cycle will be involved in its work. Scientists from all over the world will be invited to conduct their research programmes at the site.

The involvement of a wide number of participants representing various scientific and technical schools will create a synergistic effect for all project partners. According to Rosatom, the opening of such an international research centre will contribute to the promotion of future nuclear energy technologies in the world market and the formation of a broad international collaboration for the development of nuclear science and technology. The estimated life of MBIR is 50 years.

Image: Artist's impression of how the MBIR research complex will look (courtesy of Rosatom)