Innovative Liquid Metal Nuclear Fuel Assembly from Russia Pushes the Limits of Advanced Reactors Technology
Rosatom, Russia's state nuclear corporation, has manufactured a new type of nuclear fuel assembly, OS-5, designed for fourth-generation fast neutron reactors. This development is a significant step towards the goal of improving the operational reliability and economic profile of nuclear fuel.
The OS-5 assembly will be used in the BN-600 reactor at the Beloyarsk Nuclear Power Plant in the Sverdlovsk region, pending approval from the Russian regulator Rostekhnadzor. The BREST-OD-300, the central facility of a Pilot Demonstration Energy Complex that includes on-site fuel fabrication, re-fabrication, and reprocessing facilities, will be the recipient of this innovative fuel.
The OS-5 assembly is unique in its design, incorporating a liquid metal sublayer and using mixed nitride uranium-plutonium (SNUPP) fuel. This design is expected to result in lower fuel operating temperatures while coolant parameters are maintained, leading to a reduction in thermal expansion of the uranium-plutonium fuel pellet.
Burnup, a measure of fuel efficiency, indicates how much energy is extracted from the fuel. Higher burnup values lead to longer fuel cycles and reduced waste per unit of energy generated. The goal is to gradually increase the burnup depth of the OS-5 fuel to an average value of 12%.
Upon approval, the OS-5 assembly is scheduled for pilot industrial operation in the BN-600 reactor at the Beloyarsk nuclear power plant. The long-term plan is to develop a larger, commercial-scale 1200 MWe version known as the BN-1200M, should the 300 MWe demonstration unit prove successful.
The Proryv project aims to establish the technologies for a closed nuclear fuel cycle, where used nuclear fuel is reprocessed to reduce the volume and long-term radiotoxicity of the final nuclear waste. The mitigation of thermal expansion in the OS-5 assembly is a key aspect of this project, contributing to its overall goal of improving the safety and sustainability of nuclear energy.
