Rosatom has developed the first batch of nuclear fuel assemblies for the MBIR multi-purpose fast reactor, successfully passing factory acceptance testing

At the site of the Fuel Technology Division of the “State Scientific Center—Research Institute of Atomic Reactors” (NIIAR, Dimitrovgrad), under the Scientific Division of Rosatom, the first batch of 3 pilot nuclear fuel assemblies (Fuel assemblies / ТВС) for the multi-purpose sodium-cooled fast neutron research reactor (MBIR) successfully completed comprehensive factory acceptance tests. The professional acceptance committee conducted a thorough review of the maturity and completeness of the fuel production process line for this batch as well as all technical performance parameters of the trial-manufactured assemblies, and completed high-precision geometric dimension and quality re-verification measurements item by item.

This acceptance review brought together the expertise of multiple core research and manufacturing institutions in the Russian nuclear industry, including the Dollezhal Research and Development Institute of Power Engineering (NIKIET), the Institute of Physics and Power Engineering (IPPE), and the Machine-Building Plant Joint Stock Company (MSZ, Elemash).

Sergey Kiverov, Deputy Director for Construction Projects at NIIAR, stated that after rigorous evaluation by the joint expert committee, all three trial fuel assemblies from the first batch met all stringent technical specification indicators and were formally approved for in-core service qualification for commercial irradiation testing in the initial core loading of the MBIR fast neutron research reactor. The manufacturing process for MBIR fuel elements is extremely complex, covering multiple highly challenging processes including fuel pellet fabrication, high-precision hermetic cladding sealing, laser welding, and precision final assembly of assembly structural components.

Elena Fokeeva, Deputy Head of the Fuel Technology Division and Chief Process Engineer at NIIAR, emphasized that the dedicated experimental design and trial-manufacturing research and development (R&D) tasks for MBIR fast neutron fuel assemblies have been successfully completed, and the full production line of the institute's internal fuel manufacturing complex has been formally recognized as having fully mastered the large-scale manufacturing technology for this type of advanced fuel assembly. According to the established engineering schedule, the technical team plans to complete delivery of all supporting components for the fuel elements (Fuel elements) by the end of this year, and simultaneously deliver the full set of structural components required for the final assembly of the first batch of fuel assemblies.

The MBIR reactor, located at the NIIAR site in Dimitrovgrad, is a core strategic project of Russia's nuclear industry long-term experimental research infrastructure and is regarded as a key experimental platform supporting Russia's leading position in frontier reactor technologies for the next half century. With its extremely high fast neutron flux density, MBIR will provide unique research support for deepening the “thermal reactor—fast reactor” two-component nuclear energy system (Two-component nuclear energy system) and closing the nuclear fuel cycle (Closing the nuclear fuel cycle), significantly accelerating the engineering validation and safe commercial deployment of fourth-generation advanced nuclear power units.