I have been stupid enough to ship my unexposed Tmax 400 in checked in baggage during flight, not thinking about the powerful xray scanners. I dont have time to check the harm before I will be travelling again. Considering these 120 films are packed in foil when unexposed, are they somehow safe? Or is it almost 100% sure they are affected by the xrays? Is the foil any help at all?
I don't think it's 100% sure, I think at some airports, not all bags even get scanned. If I were you, if it's not much film, I'd probably throw it away, if it is a lot of film, then I'd find a way to shoot one roll and get it processed and see if it's affected.
Depends on which airports you go through. Some are fine, but some will completely destroy the film and that little layer of foil is irrelevant.
You will need to develop one roll (don't bother exposing it) to see what the rest are like. Don't bin it! Just buy and use different film in the interim, test it when you have time and if it's still good then use it.
Even if the film is damaged by the x-rays, I'd keep it to use as "seasoning" for newly-prepared developers which may be too hot and need to have the edge taken off.
I've done it a few times and it was fine. Foil won't protect from anything. The xray operator will just increase the power to penetrate it if he was curious what they were. As polygot says, just test one and see. Even bad film is useful for testing "stuff" so don't throw them away.
Even if the film is damaged by the x-rays, I'd keep it to use as "seasoning" for newly-prepared developers which may be too hot and need to have the edge taken off.