Hardspace: Shipbreaker

Confirmed that successfully salvaging a reactor after having finished the campaign (before the title update was released) doesn't trigger the achievement.

Recommencing the campaign from scratch (deleting your existing profile) fixes this issue. The first reactor I dragged out of a Mackeral on my second campaign run triggered the achievement.

If you're going to do a couple of extra achievements (no spoilers here) within the story, you will need to restart the campaign anyway.

After your first few ships some ships will have a reactor. There will be a tutorial offered as a shift to guide you through salvaging a reactor. Basically all you need to do is follow the tutorial. But if you're having trouble it could help to do the following: clear a direct line of sight from the reactor to the barge by removing walls in the way, then tether the reactor to the barge, press with the grapple tool on it until it detaches and let it go, the tether will shoot it right away to the barge safely. This makes it go very fast and prevents risk of shock damage (which is a different achievement) or reactor meltdown.