ZiO-Podolsk (part of Rosatom’s Mechanical Engineering Division) has manufactured and delivered the first of two steam generators for the Multipurpose Fast-Neutron Research Reactor (MBIR – Mnogotselevoi Bistrii Issledovatelskii Reaktor) under construction at the Research Institute of Atomic Reactors (NIIAR – Nauchno Issledovatelskii Institut Atomnikh Reaktorov) in Dimitrovgrad, Ulyanovsk Oblast.
The 150 MWt multi-purpose sodium-cooled fast neutron MBIR 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. Comprehensive commissioning and initial physical start-ups remain targeted for 2027–2028.
The steam generators for the MBIR are highly specialised engineering units. MBIR operates on a complex three-circuit heat transfer scheme. Sodium coolant is used in the first (primary) and second circuits to manage extreme core temperatures.
The steam generators act as the bridge between the second (sodium) circuit and the third (steam-water) circuit, transferring thermal energy from the liquid sodium to water, turning it into high-pressure steam to drive a steam turbine and generate electricity.
The thermal-hydraulic dynamics of MBIR’s reverse steam generators required unique experimental verification to ensure safety under extreme operating loads. The equipment consists of three parallel modules each more than nine metres long and weighing nine tonnes.
The equipment is similar in design to the steam generator of the BOR-60 reactor plant, which has been operating at NIIAR since 1969. BOR-60, a sodium-cooled fast reactor, is one of the most in-demand domestic installations for testing the fuel cycle, sodium coolant technology, as well as a wide range of design and engineering solutions for fast neutron reactors.
“The BOR-60 steam generator has proven itself to be a reliable and technologically advanced device, said Svyatoslav Novikov, Deputy Head of Technology and Chief Engineer at NIIAR’s Directorate of Facilities Construction. “It is a reverse steam generators – the sodium coolant flows inside the heat exchange tubes, and feed water supply and superheated steam extraction are carried out from the inter-tube space. The positive operational experience was one of the key reasons for choosing a similar steam generator design for the new MBIR reactor.”
With the reactor vessel already installed, the introduction of these primary heat exchangers brings the facility a step closer to final system loops integration. SO far this year, as well as the two
This year, as well as the steam generator, deliveries to the site have included two heat exchangers and a breathing tank for the intermediate circuit of the reactor; heat exchangers and capacitive equipment for washing used fuel assemblies from sodium; four condensate pumps; three low-pressure heaters for the steam turbine unit; as well as auxiliary heat exchange equipment for the turbine. By the end of the year, a steam turbine, another steam generator, and storage equipment for the turbine unit are expected to be delivered according to schedule.
Research time needed at MBIR will be several times less in comparison with the currently operating installations It will feature three independent loop channels capable of testing alternative coolants (such as lead, lead-bismuth, or helium) alongside its main sodium setup. This makes it a primary testing bed for validating Generation IV reactor designs. MBIR will use mixed-oxide (mox) fuel and serve as the main research hub for testing closed nuclear fuel cycle technologies.
The facility is designed around an International Research Centre (MTsI – Mezhdunarodnovo Tsentra Isledovanii) Consortium. Its participants have the opportunity, as a matter of priority, to conduct experiments necessary to advance their civil national nuclear programmes. Partners that have joined the consortium to reserve reactor capacity for global material science, physics experiments, and medical isotope production include:
- Rosatom State Corporation (Russia)
- Joint Institute for Nuclear Research (JINR)
- Nuclear Physics Institute of the Academy of Sciences of Uzbekistan
- Shanghai ZDAN International Co (China)
- Arab Atomic Energy Agency (AAEA)
- Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP)
- Vietnam Atomic Energy Institute (Vinatom)
While these organisations have legally signed on as main participants, the broader platform and its Advisory Board involve researchers, enterprises, and observers from over 20 countries. The International Atomic Energy Agency (IAEA) and the African Commission on Nuclear Energy (AFCONE) participate in advisory capacities.
