kilemall
SOC-14 5K
I would think that given the armor rating of the hull, along with a need for some sort of insulation to help regulate the ship's internal temperature, that those alone would be sufficient for quite a bit of radiation and to deal with micrometeorites on a short-term basis. I could see this combo reducing say 500 rem (deadly) to .5 rem on its own--equivalent of 12" of lead plate. That would be sufficient in most cases to give the crew time to fix the problem before they all were glowing in the dark...
I deal with armor by resolving incoming solar flares and the like as PA ‘hits’. My version of HG has more hits stop than mitigation, but either will do.
Micrometeorites are more like missiles, although I would tend to valuate agility more and PDs less.