I believe that spending caps is the way to repair it.
I don't have a Handy, I haven't been lucky enough to get one. I'm also certainly not spending money on the game in this state myself. Every random molerat attack ends up costing me half my reserves of stims as well as killing 2-3 people if I'm lucky. If I'm not it could cost me more. I had 11 armed vault dwellers level 20+ die to a single molerat attack this morning and I've just recovered.