A Multistage Model for Vehicle Routing Planning in a Dynamic Nuclear Radiation Dose Field

Nuclear safety technology arouses the concern of nuclear power works when historical nuclear accidents have proven irreversible environmental damage and bodily injury. Significantly, nuclear evacuation technology is one of the critical parts to guarantee public lives, exacerbated by the spatial and temporal uncertainties associated with unfixed routes, radiation distribution, and crowdedness in traffic. At present, large-scale nuclear evacuation falls into three challenges: 1) round-trip, 2) unfixed routes, and 3) dynamic radiation field. This article proposes a multistage vehicle planning model for evacuation time and individual dose optimizations under real-world constraints such as vehicle limits, evacuee demand, and number of evacuation times. The critical contributions include three stages: 1) optimizing the number of vehicles and vehicle schemes for round-trip, guaranteeing the evacuation of all personnel efficiently; 2) the next pick-up point is selected to minimum distance and dose for unfixed routes; and 3) vehicle routing is conducted of emergency response, featuring a dynamic programming by nondominant sorting genetic algorithm II with minimum time and individual dose. Therefore, the proposed model can provide recommended schedules, consisting of the number of vehicles, associated arrival, departure trips, and the exposure dose. With the actual data of the nuclear power plant in China, the case demonstrates the model's efficiency by comparing it with conventional solutions.