Ambient and personal dose assessment of a container inspection site using a mobile X-ray system.

Ambient monitor and phantom studies of absorbed and effective doses by TLDs were carried out in a non-intrusive inspection station for containers, Terminal I, of Taichung harbor, Taiwan. The doses from the X-ray scan in the control room and driver waiting room, located outside of the radiation control area, were quite small and could not be distinguished from the natural background radiation. The doses in the driver cab and the inspector cab of the X-ray scan car were also within background radiation levels. The protection wall, a 40-cm thick concrete barrier, can effectively attenuate the intensity of the primary X-ray scan. The possible effective dose of a person in the container or trailer is about 3.15 ± 0.23 μSv/scan and 2.31 ± 0.38 μSv/scan. This dose is below the annual background dose. If someone was to be scanned by the X-ray, the effective dose would be at an acceptable level.