A new real-time modeling capability for predicting radionuclide resuspension at contaminated sites is being developed. Resuspension has been shown to contribute to dose and interfere with clean-up efforts at a number of contaminated sites worldwide. Several resuspension models are being implemented to provide a range of modeling options, depending on the scenario of interest and the extent of supporting data available for model parameterization. These models will be integrated within the Department of Energy (DOE) National Atmospheric Release Advisory Center (NARAC) emergency response modeling system at Lawrence Livermore National Laboratory. NARAC provides both real-time operational predictions and detailed assessments of events involving atmospheric releases of hazardous material. The NARAC modeling system contains coupled meteorological data assimilation and dispersion models, initial versions of which were described by Sugiyama and Chan (10th Joint Conference on the Applications of Air Pollution Meteorology, Phoenix, AZ, January, 11-16, 1998 Am. Met. Soc., Boston, MA. 285-289) and Nasstrom et al. (Eleventh Joint Conference on the Applications of Air Pollution Meteorology, Long Beach, CA, Jan. 9-14, 2000. American Meteorological Society, Boston, MA, 84-89), as well as an in-house version of the Naval Research Laboratory's mesoscale weather forecast model COAMPS (Hodur, R. M. 1997, Mon. Wea. Rev. 125, 1414-1430). The most elementary resuspension model to be implemented in the NARAC modeling system utilizes the resuspension factor with the assumption of a power-law concentration profile with height, which enables rapid estimation of resuspension emission rates immediately after an event. More sophisticated models utilize concentration measurements, surface details, and site-disturbance parameterization to refine and correct the initial estimations. Preliminary comparisons of these models are presented.

This work was performed under the auspices of the U.S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48.