This study is conducted based on the hypothesis of an accident from Fengcheng NPP with an incident level of 7, equivalent to the Fukushima accident. A modeling system has been established with different failure scenarios based on the Delft3D model. The research results will provide more insights into the extent and scope of the incident and the impact of meteorological conditions and dynamics on the propagation and distribution of radiation when an incident occurs. | Vietnam Journal of Marine Science and Technology 2023 23 1 39 55 Vietnam Academy of Science and Technology Vietnam Journal of Marine Science and Technology journal homepage jmst Research for forecasting the effect of various meteorological-dynamic conditions on the possible spreading of Cs-137 radioactive substances in case a level 7 incident occurs from Fengcheng nuclear power plant China Nguyen Minh Hai1 Vu Duy Vinh1 Nguyen Trong Ngo2 Tran Quang Thien2 1 Institute of Marine Resources and Environment VAST Vietnam 2 Dalat Nuclear Research Institute Lam Dong Vietnam Received 31 December 2021 Accepted 30 June 2022 ABSTRACT Because its location is quite close to the Vietnamese border the future operation of the Fengcheng Fengcheng Nuclear Power Plant NPP can raise many concerns about the impact on the marine environment in case a serious incident occurs. Based on the Delft3D modeling toolkit calculation scenarios to simulate the spreading of Cs-137 radioactive emission when a level 7 incident occurs at Fengcheng NPP have been set up according to different dynamic meteorological conditions presented at the time of incidents during the Northeast monsoon transitional monsoon or Southwest monsoon to assess predict the possibility of radioactive emission and to spread and their affecting the waters of Vietnam. The simulation results show that when a level 7 incident occurs from Fengcheng NPP the area of influence might be the entire East Sea after 3 6 months. The Gulf of Tonkin area would be contaminated with high radiation levels 300 350 Bq m3 after about one month. The radiation would then gradually decrease to less than 150 Bq m3 after one year and below 30 Bq m3 after two years. The impacts of various dynamical and meteorological conditions on the ability to spread and disperse radioactive substances when an incident occurs are only evident in the early stages up to 3 months after the incident . After this time the contaminated area would cover .
