The Multi-purpose Fast Neutron Research Reactor (MBIR)


The Multi-purpose Fast Neutron Research Reactor (MBIR)


Research reactors have contributed substantially to the development of nuclear science and technology for the last half-century.

But today we are at the point where most of the discoveries achievable with existing research reactors have already been made. New innovations and discoveries need newer tools and more powerful research facilities based on high flux reactors with well-equipped laboratories for post-irradiation experiments and extended research options.


But the world reactor fleet is inevitably aging. There are less than 250 operating research reactors in the world. The vast majority of them are operated for about 50 years, approaching their decommissioning within the next couple of decades.

Major European research reactors will be close to their 60th anniversary by 2020.

But there should be a surplus capacity to catch up with the requirements of tomorrow and beyond.

Out of the new construction, the fast neutron projects are MBIR – currently under construction – and MYRRA which is still at a design stage and will be a valuable addendum to the world research potential in a longer term horizon but will need test facilities of the fast spectrum before passing on to the construction stage. Commercial fast reactors – BNs including – may also be used for a range of research but they are neither intended not adapted therefor so research programs will have to adapt to the reactors’ work schedule not the other way round as it is with a research reactor.

Thermal research reactors may be an alternative for some time but it is the same level of research as the past 2-3 decades and efficient for the existing reactor types but with limited capabilities for innovative technological cases which are thus left with 3D modeling option – an exhibitive exercise but hardly enough for moving up to a practical application.

So without new high flux research reactors providing the fast neutron spectrum within a couple of decades nuclear science and material testing may face a shortage of tools.

The purpose of the MBIR construction is the creation of a high-flux fast neutron research reactor with unique consumer properties for the following tasks: carrying out reactor and post-reactor studies, generating electricity and heat, developing new technologies for the production of radioisotopes and modified materials.

MBIR research reactor facility

MBIR is a research facility with a multipurpose fast neutron reactor and metal coolant (sodium). The facility will be equipped with a wide range of experimental devices providing for a variety of research options.

MBIR reactor is a loop type facility with three cooling circuits.

The facility will be equipped with the following in-core elements:

  • 14 cells for material testing assemblies
  • 3 instrumented channels
  • up to 3 Independent loops for different coolants
  • Outside the core there may be up to 6 horizontal and up to 14 vertical experimental channels (nay be used also for silicon doping, isotope pellets irradiation and NAA.
 Fabrication of vessel for MBIR

The AEM-technology Company (a part of Atomenergomash JSC, the mechanical engineering division of Rosatom) had started to fabricate a vessel for the Multi-Purpose Fast Neutron Research Reactor (the MBIR) during 2017. The MBIR is being deployed on a SSC RIAR JSC site in Dimitrovgrad, Ulyanovsk Oblast.

Machining of the first large workpiece of the MBIR, a conical adapter for the reactor vessel bottom, was taking place at the production facility of Atommash. Simultaneously with the turning and boring operations, the first welding on an upper shell ring was being performed. The finished 83-ton reactor vessel is 12 meters long and 4 meters in diameter. Fourteen more workpieces with a total weight of 360 tons was planned for production at the Volgodonsk Branch, including vessel components and support structures. The AEM-technology Company is the main MBIR equipment supplier. Some pieces are fabricated at the Petrozavodskmash Branch.

The Multi-purpose Fast Neutron Research Reactor (the MBIR) will be the most powerful operating research reactor in the world. The new sodium-cooled reactor will have a thermal capacity of 150 MW. The MBIR’s unique tech specs will allow to solve quite a few research problems in order to create new, competitive and safe nuclear energy facilities, including fast reactors. Therewith, the research periods at MBIR will be shorter compared to the operating reactors.

 Welding milestone with fast neutron reactor

Source: Rosatom

AEM-Technology has announced the completion of key welding work on MBIR – the multipurpose sodium-cooled fast neutron research reactor during 2018 that is to be installed at the site of the Research Institute of Atomic Reactors (NIIAR) at Dmitrovgrad, which is in Russia’s Ulyanovsk region. AEM-Technology is part of Atomenergomash, a subsidiary of Russian state nuclear corporation Rosatom.

The MBIR project is to be open to foreign collaboration, in connection with the International Atomic Energy Agency’s International Project on Innovative Nuclear Reactors and Fuel Cycles. MBIR will replace the BOR-60 experimental fast reactor that has been in operation at NIIAR’s site since 1969.

The basket and the high-pressure chamber have been welded, AEM-Technology said, adding that the length of the welded seam exceeded 6 metres and had a wall thickness of 22 mm. The basket, which will be installed inside the building of the research reactor, will divide the incoming and outgoing coolant flows. It will weigh 45 tonnes, be more than 5m long and have a diameter of 3m.

Yulia Chizhova, executive director of JSC AEM-Technology, said the MBIR project is unique and thus “tests the company’s skills and ability to meet technological challenges quickly”.

Atommash performed a Test Assembly

The Volgodonsk Branch of JSC”AEM-technology” (a part of the Rosatom engineering division – Atomenergomash) has performed the first stage of the test assembly of the world’s multifunctional fast research reactor MBIR during 2019.

The test assembly has been performed in a caisson with a depth of 20 meters. During the procedure, the reactor pressure vessel was installed on a special support using a crane, after which the height of the assembly unit exceeded 10 meters, diameter – 4 meters with a reactor pressure vessel weight of 60 tons. The cradle has been installed inside the reactor pressure vessel. It is designed to separate the coolant flows entering and leaving MBIR, organize the cooling of the reactor pressure vessel and the internals, and also location of the additional parts. The weight of the cradle is 25 tons, the length exceeds 5 meters, and the diameter is 3 meters. In some areas, specialists needed to ensure a uniform gap between the vessel and the reactor cradle of 70 mm.

The test assembly has been attended by a special representative of the State Corporation Rosatom for international and scientific projects Vyacheslav Pershukov. “Unique equipment is a unique enterprise. “Atommash, of course, has enough competencies,” he said. The task is rather complicated for the whole Rosatom, including due to the large scope of international orders. To the best of its uniqueness, MBIR is not a priority for us from the point of view of commerce, but it is so from the point of view of reputation.”

“MBIR is a unique complex project, in the implementation of which several enterprises of the division take part: “Atommash”, “Petrozavodskmash”, and also the foundry “Petrozavodskmash”, which participated in the manufacture of large-sized castings. Non-standard equipment always requires new tools and technical solutions that have been developed and used by our specialists,”-said Andrey Nikipelov, Director General of JSC “Atomenergomash”.

In particular, due to the small metal thickness of the MBIR vessel (from 25 to 50 mm with a diameter of 4 meters – for comparison: the thickness of the VVER-1200 reactor pressure vessel is 300 mm) there are risks of changing equipment geometry during processing. For exact observance of parameters throughout the entire production of the reactor, a special purpose tooling was used.

The next steps in the manufacture of a research reactor will be hydraulic test, the assembly of a protective casing, after which the second stage of the test assembly will be completed with all the internals.

“This is an interesting project for us, an opportunity to find new effective decisions,” said Igor Kotov, Director General of JSC “AEM-Technology”. – You can say a new chapter in history of nuclear energy is being written today on our site. MBIR is a fundamentally new product, and all operations performed by the “AEM-technology” team are performed for the first time. ”

“Atomenergomash” is the main equipment supplier of the MBIR reactor facility. On the basis of the Volgodonsk Branch of JSC “AEM-technology”, 14 products will be manufactured for a multifunctional research reactor with a total weight of over 360 tons including internals and supporting structures.

The multifunctional fast research reactor (MBIR) will be the most powerful of the existing, constructed and designed research reactors in the world. The thermal capacity of the liquid sodium coolant reactor will be 150 MW. The unique technical characteristics of MBIR will allow solving a wide range of research tasks in support of the creation of new competitive and safe nuclear power plants, including fast neutron reactors for closing the nuclear fuel cycle. At the same time, the research time at MBIR, as compared with currently operating reactors, will be reduced several times.



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