A computer code designed to calculate potential radiological impact of atmospheric releases of radionuclides from area sources is presented and discussed. The code is written in Fortran IV, requires 48 K storage, and runs about 12 seconds on an IBM 370 system. The code can calculate radionuclide concentrations and individual inhalation doses at up to six specific receptor locations and at up to 192 general locations around an area source. Population doses can also be calculated. The code accounts for area source shape, cloud diffusion, ground and inversion-lid reflections, and radionuclide decay by time of flight. It is dose model independent and requires a dose conversion factor as part of input data to calculate doses proportional to radionuclide concentrations.