It's not that hard...
Do you have the goggle helmet? That's more than enough for radiation.
Also it's all about the RNG God (random number generator, main system of the game)
To get that items it's all about luck, my record was 4 gloves in a row (every chest I opened had that gloves), but it was pure luck.
Ps: depending on your difficulty, there is a way for random loot, it's not a cheat, just simple game mechanics. Save before entering the area, rush to the chests, if something useful is in than use area reload, if not use save before entering the area. That way it's easy to get what you want without cheating, but it can be really boring...
That trick is more useful for random encounter (it's published in wiki, so it won't violate any forum rules to tell that), but also works for ark