Radioactive Dispersive Device (RDD) Bomb Modeling in Cities for Emergency Response Using the QUIC Model

The Quick Urban and Industrial Complex (QUIC) dispersion modeling system was developed as a rapid dispersion analysis tool to examine concentration and deposition patterns from a variety of chemical, biological, and radiological release sources. One of the model's modules produces an approximated three-dimensional wind field around buildings using an empirical diagnostic approach. A second module calculates the contaminant transport and dispersion using an urbanized Lagrangian random-walk dispersion model, incorporating gradient diffusion and non-local mixing to produce building-induced turbulence. QUIC's GUI includes a city builder for creating building domains, a meteorology builder to specify wind profiles, and a source GUI for location(s), geometry, type, and amount of release. Recent code improvements include the ability to release, track, and deposit particles of multiple size distribution, an explosive release accompanied by a buoyant plume, and a post-processing Depositional calculator, which sums deposition on horizontal and vertical surfaces, as a function of particle size bins. Los Alamos National Laboratory and the U.S. Environmental Protection Agency have worked to formulate hypothetical RDD urban releases with the objective of a pre-emptive prediction of contaminant air concentrations, their dispersion, and subsequent surface contaminant deposition, and relate these concentrations to the Protective Action Guides for emergency response and clean-up concentration metrics, with provided examples. We will discuss model development, applications, and direction for further research.