I believe you can find these items in loot. Running POI's and finding the rare alien container will have these things, not always, but enough that you'll be able to use them. I think these are in the more advanced POI's like level 3 and above? I could be mistaken, but I know I've found them this way.

One thing to remember is that most of the time before these guys will sell you anything you usually have to do some fetch quest first.

Check the empyriopedia.

You can salvage an entire reactor from mid sized zirax ships if you are into combat, obviously don't target generators.

Grabber 님이 먼저 게시:

You can salvage an entire reactor from mid sized zirax ships if you are into combat, obviously don't target generators.

which ships have reactors instead of generators?

Imerats have a reactor

I found one in derelict freighter level 3 exploration site, but hasten to add that I'd visited loads of level 3 exploration sites before finding one, so very rare spawn too, should find radiation shielding there no problem.