ATMOSPHERIC RELEASE ADVISORY CAPABILITY - REAL-TIME MODELING OF AIRBORNE HAZARDOUS MATERIALS

The Atmospheric Release Advisory Capability (ARAC) at Lawrence Livermo re National Laboratory is a centralized federal project for assessing atmospheric releases of hazardous materials in real time. Since ARAC b egan making assessments in 1974, the project has responded to over 60 domestic and international incidents. ARAC can model radiological acci dents in the United States within 30 to 90 min, using its operationall y robust, three-dimensional atmospheric transport and dispersion model s, extensive geophysical and dose-factor databases, meteorological dat a acquisition systems, and experienced staff . Although it was origina lly conceived and developed as an emergency response and assessment se rvice for providing dose-assessment calculations after nuclear acciden ts, it has proven to be an extremely adaptable system, capable of bein g modified to respond also to nonradiological hazardous releases. In 1 991, ARAC responded to three major events: the oil fires in Kuwait, th e eruption of Mt. Pinatubo in the Philippines, and an herbicide spill into the upper Sacramento River in California. Modeling the atmospheri c effects of these events added significantly to the range of problems that ARAC can address and demonstrated that the system can be adapted to assess and respond to concurrent, multiple, unrelated events at di fferent locations.