A study on the RIMPUFF module (ARGOS) and simulation of radiation dispersion from a hypothetical floating nuclear power plant accident in the East Sea

In this study, the RIMPUFF module (ARGOS) was used to simulate the Fukushima-Daiichi nuclear power plant accident (FNPPA), thereby assessing the research team’s capability in using the program. The FNPPA simulation results showed good agreement in trend and intensity with the environmental monitoring data and other simulation models. Based on these results, our research team used RIMPUFF to simulate the atmospheric dispersion from the hypothetical accident of a floating nuclear power plant operating in the East Sea (Phu Lam Island, the Paracel Islands, Da Nang Province, Vietnam), through which we analyzed the accident’s impacts on the Vietnamese mainland territory. Depending on weather conditions and specific locations, the impact area of the accident varies. Under conservative conditions, the wind blowed from the East Sea at a speed of 7.5 m/s, the radioactive cloud would reach the mainland territory (Quang Tri and Quang Binh provinces) approximately 15 hours after the accident. Subsequently, the accident created an area of hundreds of square kilometers, with dose rate greater than 1 µSv/h; I-131 and Cs-137 deposition on the ground would exceed 10 kBq/m2 and 2 kBq/m2, respectively. According to the regulation on preparedness and responses to nuclear and radiological emergencies, people in the affected areas must immediately stop consuming local food and milk until the result of sample examination is available. The study results demonstrate the ARGOS usability and its value in supporting decision-making in the nuclear accident emergencies.