DS2 Nukes in Vacuum

Rob Hofrich and his fellow turkeys--er, sorry Rob, "Virginia
Tech graduates"--have introduced me to playing DS2 (instead of
just reading the rules every few months).    Now that I've
located an opponent, I'll want to simulate Alarish.

The Alarishi are of the opinion that our planets weren't
habitable to start with, so might as well get some use out of
those nukes.  I see what DS2 says about the effects of a nuclear
strike; but isn't a lot of that going to be blast effect?  How
would you change things to represent a nuke strike in vacuum?
(And of course everyone will be in hostile environment suits,
power armor, or vehicles anyway).
--Chris  DeBoe