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