Radiological risk assessment of vehicle transport accidents associated with consumer products containing naturally occurring radioactive materials

Abstract

Natural and artificial ionizing radiation can be harmful to human health when they come into contact with people and the environment. Transport of naturally occurring radioactive materials (NORMs) and consumer products containing NORM in the public domain is inevitable owing to their potential applications. This study evaluates the dose and risk to the public from transport accidents of NORM and consumer products. Radiological and physical data were obtained from previous literature. The median and maximum values of radioactivity concentration were applied to consumer products and NORM data, which serve as an input. An external dose rate at 1 m from a transported shipment was calculated using MicroShield® Pro version 12.11 code, which serves as input to RADTRAN 6 code. Based on developed transport accident scenarios, a RADTRAN 6 code was used to estimate collective dose and risk. The sensitivity analysis was conducted by considering the variation of release, aerosol, and respirable fractions of radionuclides at 0.1%, 1%, 10%, and 100% from the transported shipment during an accident, respectively. The results of dose and risk to the general public because of the damage of the shipment container following a fire accident are below the annual regulatory limits of 1 man-Sv recommended by IAEA transport regulation of 2018. The sensitivity results of all NORMs and associated consumer products are also below the regulatory limits. Therefore, radiological safety can be ensured in the event of a transport accident involving the transit of NORM and consumer products containing NORM.