If you were to stand at a rail road crossing and a train with 10 spent fuel casks would slowly roll past you (at 3 miles per hour) you would receive less than 0.03 mrem of radiation. This amount of radiation is not measurable compared to background radiation levels. This is less than 1/10,000th of the typical annual dose from the background radiation that every person experiences in the US, which is about 360 mrem. This is also less than 1/10th of what a person receives during just 1 hour traveling by plane, which is about 0.5 mrem. Hence the dose rate from rail transport of used nuclear fuel casks, even at close distance, is negligible compared to other radiation sources that are part of everyday life.
