ARAC [Atmospheric Release Advisory Capability]: Early phase dose assessment for Department of Energy's Federal Radiological Monitoring and Assessment Program

The Atmospheric Release Advisory Capability (ARAC) is a U.S. Government Department of Energy (DOE)-sponsored emergency-response service designed, developed, and established at Lawrence Livermore National Laboratory to provide real-time predictions of the radiation dose levels resulting from the release of airborne radioactive material. Under the auspices of the U.S. Federal Radiological Emergency Response Plan (FRERP), all major U.S. federal agencies now have access to the ARAC service. In the event of a radiological accident that leads to implementation of the FRERP, DOE is responsible for activating the Federal Radiological Monitoring and Assessment Program (FRMAP). ARAC is the modeling or simulation capability that would provide the FRMAP with initial consequence assessments and visual depictions of an accident's impact. From first alert until full staffing and activation of the Federal Radiological Monitoring and Assessment Center (FRMAC), ARAC's calculations would be a primary source of consequence estimation. Once the FRMAC measurement and monitoring systems are activated (18 to 24 h), the ARAC calculations begin the transition to roles such as (a) a reference for measurement data consistency checks, (b) source term derivation (if unknown) from measurements and model simulations, (c) material mass budget reconciliations, and (d) long-range consequence, detectability, and ultimate fate in the environment