Abstract: The purpose of this article is to use SLAB model and HGSYSTEM/UF₆ model, to build the near source field evaluation model after UF₆ leakage accidents. And based on the data of three UF₆ release experiments carried by the French Bordeaux National Experimental Base, it tested the model preliminarily. It turned out that the model can simulate atmospheric diffusion and migration in the near source field after UF₆ leakage very well (P/O=1.0—2.4), the simulation results errors are acceptable.It also aims to provide theory basis for the later large model program development, and offer help for more precision simulation of contaminants transfer after UF₆ leakage accidents.

Key words: UF₆, leakage accident, heavy gas diffusion, shallow model