Study on Radionuclide Migration Under Accident Conditions of Mobile Heat Pipe Small Module Reactor

Mobile heat pipe reactor has a wide application prospect in many fields. In the event of a nuclear leak, the reactor will have adverse effects on the environment. So, mastering the circumstances of nuclide migration has great value to enhance the capacity and efficiency of nuclear accident emergency response. This research uses a programming method to describe the diffusion and deposition of nuclides in the atmosphere after a leakage accident. Subsequently, further study the deposition of nuclide diffusion in the unsaturated zone. Through these studies, we can make predictions and evaluate the consequences of accidents. The result shows that there is a certain relationship between the concentration of nuclide diffusion in the atmosphere and the distance downwind direction and there is a maximum value. The maximum diffusion distance of a nuclide is positively correlated with the amount of leakage nuclide when it diffuses over a short distance and near the ground. The deposition conditions of nuclides are different under different conditions. Dry deposition flux can be neglected in short-term calculations. Wet deposition flux is the main source of the diffusion of nuclides into the unsaturated zone. Soil has a good retention effect on radionuclide diffusion and the unsaturated zone can slow the migration velocity. However, rainfall will accelerate the migration of nuclides.