Yes, there were no noticeable effects on ISO100 and ISO400 black-and-white. Why would Eurostar have different scanners to airports, or have you heard they only have ""checked-baggage" style machines?

If you are worried you could try to find yourself some Delta 3200 and put it in a clear bag with the rest of your film, saying that you "always push your ISO400 film as you will be shooting at a rock-concert". Probably you will not be able to get any sort of hand-check unless the staff open each cassette and check the film within cm by cm - that is a guess, but I have never noticed that the capability for chemical swabs is present. In any case, keep the camera bodies empty for the x-ray as that will reduce the number of stress points!