Guess, it is old bug that didnt mentioned because there was no chanse for him to occure.
It seems that nuke doesnt affect the very board of the map - cells, items and being. Except player, who takes proper damage whereever he is on the map.
You can meet this bug if you enter Phobos Lab with Trigun, move 1 step down to the row where small medpacks lie, then activate Trigun's holy arm. If you survive nukage, you'll see almost clear level - those two medpacks survives nuke, and under your feet there will'be .. an armed nuke cell!
(http://s001.radikal.ru/i193/1307/62/17892bbf913d.png)