Radiation State Practice Exam

To determine the transportation index (TI) for a radioactive source, it is essential to understand how the TI is calculated. The TI is a measure of the radiation level at a distance of one meter from a package. It is defined as the dose rate in millirems (mR) per hour measured at one meter from the surface of the package.

In this case, the source emits 35 mR/hr at a distance of 3 feet. First, it is important to convert the 3 feet to meters, since the TI is measured at one meter. Three feet is approximately 0.91 meters.

The intensity of radiation decreases with distance due to the inverse square law, which means that as you move away from the source, the radiation level decreases as a function of the square of the distance. The TI is derived by calculating the dose rate at one meter based on the 35 mR/hr measurement at 3 feet.

To find the dose rate at one meter, you need to consider that the intensity at one meter will be higher than at 3 feet because of the distance relationship. However, if we were only given 35 mR/hr without requiring specific geometric calculations or given the TI directly, it would be