Rosatom Develops Advanced Uranium-Plutonium Fuels for BN-1200 Fast Neutron Reactor

Rosatom is pushing forward with the research and development of innovative nuclear fuels for the next-generation BN-1200 fast neutron reactor. The corporation is exploring two distinct core fuel designs: oxide MOX (Mixed Oxide) fuel, similar to the fuel used in the BN-800 reactor, and dense nitride MNUP (Mixed Nitride Uranium-Plutonium) fuel, which is designed for the Generation IV BREST-OD-300 reactor. This dual-fuel approach aims to optimize the performance and efficiency of the BN-1200 reactor, set to be the first serially produced fast neutron reactor worldwide.

Fuel Assembly Innovations and Testing Preparations
As part of its efforts to validate both types of fuels, Rosatom has fabricated several experimental fuel assemblies. These include the OS-4 irradiation assembly with MNUP fuel rods, designed to achieve a higher burnup level far beyond standard reactor requirements. The OS-4 assembly incorporates special technical solutions to ensure safe operation during testing in an active reactor. Additionally, Rosatom has created three KETVS-MAK experimental assemblies that feature BN-1200 fuel rods with an axial blanket, a unique feature that separates them from traditional MOX fuels. These rods contain a segment of breeding material within the fuel column, which reduces radiation damage to the cladding while maintaining the required fuel burnup depth. Although the concept has been explored globally, the BN-1200 reactor will be the first to implement it.

Testing to Begin in 2025 with Plans for Full Licensing
The new nitride and oxide fuel assemblies are scheduled for testing at the Beloyarsk NPP’s BN-600 reactor, with the irradiation expected to begin in 2025. The test results will allow Rosatom to validate the fuel performance under maximum design parameters and prepare it for regulatory licensing. These tests are critical in assessing the fuel’s ability to withstand the harsh conditions of fast neutron reactors, ensuring its viability for long-term use in the BN-1200 reactor.

Strategic Importance of the BN-1200 Reactor and Fuel Flexibility
The BN-1200 reactor is a key component of Russia’s next-generation nuclear reactor technology, following the success of the BN-600 and BN-800 reactors. Once operational, the BN-1200 will be a cornerstone in Russia’s nuclear energy infrastructure, leveraging fast neutron technology for greater sustainability and fuel efficiency. The reactor is designed to operate with either MNUP or MOX fuel, allowing for greater flexibility in fuel selection. While Rosatom has extensive experience with MOX fuel, the high-density nitride MNUP fuel offers enhanced neutron-physical advantages, which could play a pivotal role in optimizing reactor performance. Currently, Rosatom is conducting intensive studies to select the most optimal core design based on a thorough evaluation of both fuels.

Expected Timeline and Future Prospects
Construction of the BN-1200 reactor is scheduled to begin in 2027 at the Beloyarsk NPP site, with the reactor expected to become the world’s first serially produced fast neutron reactor. As part of its development, Rosatom continues to innovate in the field of nuclear fuel, testing new materials and reactor configurations to ensure the long-term success of the BN-1200 and subsequent reactors.