Tom Reynolds had just delivered his truckload of materials to the port of Savannah, Georgia when Homeland Security detected his nuclear payload. The port of Savannah is now safe from any harm Tom might bring to it.
As it turns out, the prior day he had a "nuclear stress test" done on his heart. Most of us know Tom has had some heart issues the past few years. The residual atomic radiation from the stress test set off an alarm as Reynolds was departing the port facility. He was detained for questioning.
Several Geiger counter readings later and a confirmation of the heart stress test with the hospital - and verification that the hospital and the Doctor are real people, was enough to allow Tom to be released without further incident.
Homeland Security personnel thanked Tom for his cooperation. The world is safer today, especially in Savannah.