Don't worry about the effects of x-ray on Delta 3200. I frequently pass it through as many as 10 or 12 machines on any one trip and have never experienced any fogging. I have even taken the same film on two different trips still without problem. One word of warning, don't put your film in baggage going into the hold for the machines checking that are very powerful and almost certainly will cause fogging. If you are still concerned about the machines checking the hand baggage a polite request to have the attendant inspect the film by hand usually works.
Have a good trip