In the present work the creation of decision support system in a radiation accident for a local scale is considered. The main analytical pollutants transport model in the atmosphere is based on Gaussian Plume model. The choice of initial data for modeling (including meteorological data from weather prediction models like GFS and WRF) is considered. The following technical details of GIS creating for a polymodels complex are considered: the use of modular structure, taking into account a surface roughness data, and values interpolation for graphical representation (based on IDW interpolation method). The underlying surface iodine 131 pollution for the maximum design basis accident of a nuclear power plant unit with a VVER 1200 reactor is conducted by created DSS. The results show that radionuclides maximum levels are lower than the level activity in excess of which protective measures should be carried out.