The objective of the NordRisk II project has been to derive practical means for assessing the risks from long-range atmospheric dispersion of radioac-tive materials. An atlas over different atmospheric dispersion and deposi-tion scenarios has been developed using historical numerical weather pre-diction (NWP) model data. The NWP model data covers three years span-ning the climate variability associated with the North Atlantic Oscillation, and the atlas considers radioactive releases from 16 release sites in and near the Nordic countries. A statistical analysis of the long-range disper-sion and deposition patterns is undertaken to quantify the mean dispersion and deposition as well as the variability. Preliminary analyses show that the large-scale atmospheric dispersion and deposition is near-isotropic, irrespective of the release site and detailed climatology, and allows for a simple parameterization of the global dispersion and deposition patterns. The atlas and the underlying data are made available in a format compati-ble with the ARGOS decision support system, and have been imple-mented in ARGOS.