Hmmm...tossing nukes around on planets. BAAAAAAD idea. Only so much real estate out there...and the last time a planet got fusion bombed, well...remember what happened to Earth in reprisal.
On a more practical note: Hex scale is 200m. Even a artillery combat tac nuke will wipe out (blast, heat, and shock wave) a radius of 25 hexes (5 km) minimum (My ROTC instructor was a Nuclear Ord. Officer for reference. ) Ortillery is even more impressive in AoE due to simple kinetic energy, hence most such weapons are likely to be energy based if a so-called surgical strike is desired. If I were to model the actual effects in the rules scale...no unit above ground would have a prayer of surviving the strike...which is the primary reason that this was specifically not included.
If you REALLY want to go play on irradiated environments, then as Rifleman said. Infantry (other than PA) is out.
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OFFICIAL CONTENT
Type M- Irradiated
Class 31: Lock-on range is limited to 15 maximum. Infantry cannot survive.
Class 32: Lock-on range is limited to 9 maximum. Treat as Class 26 (Desert) for possible equipment failure due to radiation damage. Infantry cannot survive. Vehicles without Hostile Environment Modifications cannot survive.