If there are designated airfields for terrorist threat diversions, then surely the thing to do, if it's desirable to contain the pax, is to erect a compound that is enclosed by a secure wire fence on 3 sides big enough to take a 380, that way the a/c would taxy into it, and the pax could be allowed of the a/c but could only go in one direction making it easy to control them and ensure no one escapes. Also it would ensure that people were in a relative safe zone as most of the explosive force would be to the side of the a/c not rearwards.
This would of course show a lot of planning on the part of the goverment something that seems lacking at the moment.