Analysis of Urban Evacuation Strategies through Large-Scale Empirical Drills and Simulation - Focused on the Emergency Planning Zone of the Kori Nuclear Power Plant Site

This study addresses the critical challenge of establishing reliable radiological disaster evacuation strategies in metropolitan city areas where public transportation infrastructure is well established, specifically focusing on the Kori Nuclear Power Plant Site in Busan. To derive a robust evacuation time estimate (ETE), we employed a novel integrated approach by complementarily analyzing empirical results from three large-scale evacuation drills and quantitative data from VISSIM traffic simulations focusing on the main road network. The drill results confirmed the necessity of complex utilization of multi-modal public transportation (buses, trains, and ships) for non-private vehicle users and highlighted significant time savings when optimizing routes to avoid urban areas. Conversely, the simulation showed that despite sufficient main road capacity, uncontrolled traffic influx from feeder roads quickly causes saturation and leads to a sharp increase in ETE, emphasizing bottleneck mitigation. Based on this integrated evidence, the study proposes core strategies, including staged sequential evacuation, road network simplification, and integrated coordination of multiple transportation modes, to enhance the consistency and feasibility of metropolitan-type public evacuation strategies. This research provides a foundational model for establishing applicable ETE calculation and public evacuation strategies.