Estimating collective doses to transport workers with the RADTRAN III transport risk assessment code

The RADTRAN III transport risk assessment code can be used to calculate collective doses to the public and to transport workers during the transport and handling of radioactive materials. The code includes mode-specific models for calculation of transport-worker doses during transport, at intermediate stops, and during intermodal transfers and storage. Transport workers and other persons who might be occupationally exposed and are considered in RADTRAN III include transport vehicle crew members, flight attendants, rail classification and inspection personnel, loading dock workers, and warehouse personnel. The study reported here relates RADTRAN III transport-worker dose calculations to actual values for a representative package-a truck cask carrying 10-yr-old pressurized water reactor spent fuel. In this example, the package is modeled as a line source for close-in dose calculation. The differences between the conservative RADTRAN III dose calculations based on transport index (TI) values and the doses calculated by accounting for the orientations and distances of workers in the actual radiation field around the cask are discussed separately for the gamma and neutron components