UNCERTAINTY IN TRANSPORTATION RISK ASSESSMENT

Transportation risk assessment involves a number of parameters whose values are uncertain. RADTRAN© (hereinafter referred to simply as RADTRAN) is now capable of handling uncertain input parameters with Monte Carlo sampling. Many input parameters in transportation risk assessments are uncertain, so that single-valued parameters can result in an inaccurate representation of risk. Incorporating uncertainty increases the accuracy and precision of the analysis. This paper presents the method of introducing uncertainty and the results of using different distributions for the following RADTRAN inputs: size of exposed populations, particle deposition velocities, fractions of material released from a cask under various accident conditions, fractions of released material that is aerosolized, radionuclide inventory of spent nuclear fuel (since burnup and age may be uncertain), and meteorological parameters.