Radioactive releases from nuclear facilities may contribute to radiation exposure through external or internal pathways: external exposures by direct radiation from plumes or deposited radionuclides; or internal exposures from inhalation or ingestion of radioactive material. The Radiological Safety Analysis Computer (RSAC) Program Version 7.0 (RSAC-7) calculates the consequences of a release of radionuclides to the atmosphere. RSAC 7.2 is the current release and RSAC-7 is the version. Using a personal computer, a user can generate a fission product inventory; calculate inventory decay and ingrowth; the inventory during transport through processes, facilities, and the environment; model the downwind dispersion of the activity; and calculate doses to downwind individuals.
A fission product inventory can be calculated from reactor operating history and can be used to simulate a nuclear criticality accident. Radionuclide inventories can also be directly input into RSAC-7 if desired. Source term modeling allows for complete progeny ingrowth and decay during all accident phases. RSAC-7 release scenario modeling allows fractionation of the inventory by chemical group or element. RSAC-7 also models the effects of high-efficiency particulate air (HEPA) filters or other cleanup systems. RSAC-7's meteorological capabilities include Gaussian plume diffusion for Pasquill-Gifford, Hilsmeier-Gifford, and Markee models. RSAC-7 possesses the unique ability to model Class F fumigation conditions. Optionally, users can supply plume standard deviations (σs) or atmospheric diffusion (χ/Qs) to the code as input data. RSAC-7 also includes corrections for deposition (wet and dry) plume rise (jet and buoyant), resuspension, and release in a room and building wake. Doses are calculated through inhalation, immersion, ground surface, and ingestion pathways, and cloud gamma dose from semi-infinite plume model and finite plume model.
RSAC 7 calculates internal dose using the dose conversion factors and methodology from both ICRP 26/30 and ICRP 60/68/72. In addition to the calculation of lifetime dose, RSAC 7 calculates the acute 24 hour dose from radiological sabotage events.
RSAC 7 is an excellent tool to evaluate accident conditions in emergency response scenarios and to evaluate of safety basis accident conditions.