Lawrence Livermore National Laboratory

The National Atmospheric Release Advisory Center (NARAC) provides tools and expertise to simulate and map the spread and impacts of hazardous materials accidentally or intentionally released into the atmosphere. NARAC plume predictions are used to inform decisions on actions to protect the public and the environment.

NARAC's operations center and expert staff are available on a 24/7 basis to respond to emergencies anywhere in the world. Since its foundation in 1979, the center has responded to hundreds of alerts, accidents, and disasters; supported thousands of exercises; and conducted numerous studies related to emergency response preparedness.

Standard technical and briefing products have been developed with interagency consensus for radiological/nuclear, chemical, and biological releases that are focused on protective actions that need to be considered. NARAC plume products proved predictions of:

  • Airborne plumes
  • Ground contamination areas
  • Affected populations, including potential casualties and fatalities
  • Areas where health effect and protective-action-guide levels for sheltering, evacuation, or relocation may be exceeded
  • Blast damage

During a response, NARAC expert staff develop additional customized products and work closely with monitoring and sampling teams to conduct source term estimation and refine model predictions based on field measurement data and other information.

NARAC personnel have expertise in a variety of disciplines, including atmospheric dispersion, meteorology, numerical modeling, computer science, software engineering, geographical information systems, computer graphics, hazardous material (radiological, chemical, biological) properties, chemistry, and health physics. NARAC's expert analysts provide quality-assured, detailed plume model analyses, refine modeling predictions based on field data, perform emergency preparedness studies, train users, and assist in NARAC plot interpretation. Research staff members conduct scientific studies and develop new modeling tools.

NARAC's state-of-the-science system includes an advanced suite of modeling and analysis tools and supporting databases. NARAC computer systems collect and store global meteorological data and numerical weather prediction model results, as well as geographical (terrain, land-use, building heights and footprints, maps) and population data. These data are used in a sophisticated 3D atmospheric flow and dispersion modeling system that can be utilized for any location in the world. NARAC tools include Web-based modeling and information sharing capabilities and the standalone PC-based modeling software packages HotSpot and EPIcode.

NARAC's software system and computer hardware allow authorized users to perform fully automated, initial 3D model simulations in 5 to 15 minutes. Quality-assured refined products based on field data are provided by NARAC expert staff in 30 to 60 minutes, depending on the quantity and quality of the provided data.