Use of the Hazard Prediction and Assessment Capability (HPAC) at the Savannah River Site

This report provides background information on the implementation of the Hazard Prediction and Assessment Capability (HPAC) software package at the Savannah River Site for atmospheric modeling. Developed by the Defense Threat Reduction Agency (DTRA), HPAC is actually a suite of models that allows for various modes of release of radiological, chemical and biological agents, generates interpolated meteorological data fields based on inputted meteorology, and transports the material using a tested transport and diffusion model. A discussion of meteorological data availability for direct use by HPAC is given, and is important for applications to emergency response. An evaluation of the data input methodology for a release from SRS is examined, as well as an application to the World Trade Center attacks in New York City in September 2001. Benefits of the newer versions of HPAC now in use are then discussed. These include access to more meteorological data sources and improved graphical cap abilities. The HPAC software package is another tool to help the Atmospheric Technologies Group (ATG) provide atmospheric transport and dispersion predictions in the event of hazardous atmospheric releases