There are some really huge explosions in the game. For example, the scene at the end, where you blow up a certain object... there's a series of very large explosions. Plenty big enough for your "nuke".

Or... you could make the missile object have a death Fuse that triggered all sorts of pyrotechnics when it went off- for example, it could spit small "shrapnel" objects from the centerpoint, with lines of smoke chasing them, or have a series of explosions erupt at various invisible Hardpoints whilst playing various sound effects.

This is something I haven't seen anybody do ... yet... but there's no reason why it cannot be done.

modify scales?Alcander says he's getting some real progress with ALEs including changing scale. ALE files - git em done