Multiphysics Coupling Mechanisms and Damage Assessment of Plate-Type Fuel Elements Under Nuclear Accident Conditions: A Comprehensive Review

Plate-type fuel elements are critical components in advanced nuclear reactors, prized for their high power density and efficient heat transfer. However, understanding their damage mechanisms and safety under accident conditions remains a significant challenge for next-generation nuclear systems. This review systematically examines the damage behavior and assessment methodologies for plate-type fuel elements under Reactivity Insertion Accidents (RIA), Loss of Flow Accidents (LOFA), and Loss of Coolant Accidents (LOCA). It highlights the synergistic effects of multiphysics factors—such as irradiation swelling, oxidative corrosion, thermal-mechanical stress, and coolant boiling—on failure modes like blistering, cracking, and cladding rupture. Recent advances in numerical modeling (e.g., finite element analysis, CFD, multiphysics coupling tools) and experimental techniques are critically evaluated. Key limitations persist, including insufficient cross-scale modeling, lack of validation under extreme multi-fault conditions, and scarce experimental data on irradiated fuel behavior. Future work should focus on developing integrated multiphysics frameworks, constructing extreme-condition experimental platforms, and incorporating AI-assisted safety assessment tools to advance inherently safe and intelligent nuclear energy systems.