A Comparative Analysis of Advanced Nuclear Fuel and structural Design in Advanced Fission Reactor

The rapid transition toward low-carbon energy systems and increasing global energy demand have renewed interest in advanced nuclear fission technologies, particularly Generation IV reactors and Small Modular Reactors. This study aims to comparatively evaluate advanced nuclear fuels and structural materials based on their thermal, neutronic, mechanical, chemical, irradiation, and safety performance. An analytical review of scientific and technical literature from academic databases and authoritative nuclear organizations was conducted. The literature was qualitatively synthesized according to fuel type, structural material, reactor concept, coolant, and neutron spectrum. The findings indicate that uranium nitride, uranium silicide, and tri-structural isotropic fuels provide important advantages over conventional uranium dioxide fuel, including higher thermal conductivity, greater fuel density, improved high-temperature performance, and enhanced fission-product retention. Among structural materials, iron-chromium-aluminum alloys, silicon carbide composites, and high-entropy alloys demonstrate promising oxidation resistance, thermal stability, mechanical strength, and irradiation tolerance. However, their performance is strongly dependent on reactor type, neutron spectrum, coolant chemistry, operating temperature, and irradiation conditions. The review further shows that integrating advanced fuels and structural materials with passive safety systems and modular reactor architectures can improve safety, thermal efficiency, sustainability, and economic potential. Major challenges remain in irradiation qualification, corrosion, manufacturing, regulatory approval, economic feasibility, and spent-fuel management. Overall, coordinated development of advanced fuels and structural materials represents a promising pathway toward safer, more efficient, sustainable, and economically viable nuclear energy systems.