Abstract
Accident Tolerant Fuel (ATF) is a next-generation fuel technology developed to enhance the fundamental safety of light water reactors. Compared to existing standard fuel technologies, ATF technology can provide the same or better performance during normal operation, transient conditions, and accident scenarios of nuclear power plants, enhancing the ability of fuel elements to withstand severe accidents while reducing the cost of generating electricity over the licensed life of the plants. This paper introduces the definition, characteristics and thermal-hydraulic research objectives of ATF technology, systematically reviews the thermal-hydraulic research results of different ATF technologies in various aspects from the perspectives of near-term concepts (UO(2)-based composite fuels, coated Zr-based claddings, FeCrAl claddings) and long-term concepts (high-uranium-density UN fuels, FCM fuels, extruded metal fuels, SiC/SiC claddings), respectively. Mainly includes: improving fuel thermal conductivity, lowering fuel operating temperatures and stored energy, reducing fuel-cladding interactions, improving cladding-coolant reactions, reducing the production of flammable gases (e.g., hydrogen) and enhancing the retention of radioactive fission products. Finally, this paper points out the current shortcomings and challenges in the field of ATF thermal-hydraulic research and outlooks the potential future directions.