“To assess the effects of complex terrain and whimsical weather, planners and environmental engineers use hourly data on wind, temperature, and humidity to simulate the proposed the proposed facility’s operation throughout a more or less typical year. The simulation will treat the region as a huge grid of half-mile-square cells extending ten miles or more outward from the plant—the grid’s resolution and extent depend on terrain as well as the height of the smokestack.—and use one or more air-dispersion models to estimate fallout at each square for every hour of every day throughout the period. In addition to compiling cumulative totals, which are used to make maps of average annual deposition, the simulation will keep track of highest and second-highest concentrations for 1-, 3-, 8-, and 24-hour periods” (108).
“Vulnerability modeling is not foolproof. Emergency managers need to experiment with different models and understand their simplifying assumptions, which usually ignore the influence of terrain on toxic clouds of heavy gasses like chlorine and phosgene. They should also be wary of what the models might not tell them”—such as changes in atmosphere and the effects of terrain and of local winds (107). Some chemicals will react with atmospheric moisture to produce even deadlier chemicals with a greater toxic reach than those initially released.
The center of this Toxic Plume is located approximately 23 miles southeast of St. Cloud, Minnesota. This plume is produced by 1 reactor located at the Monticello Nuclear Power Plant site. The reactor that produces this plume has 579 Mega Watts of radiation generating power. There is a total of 471 tons of Highly Toxic Radioactive spent fuel stored at this Nuclear Power Plant.
For Monticello’s Ground Deposition Modeling please see Off-Site Dose Assessment and Protective Action Recomendations (2003).