I thought mine was fine since I was only using 6 single sticks of uranium and a ton of heat vents and regardless of the fact mine said it had zero heat for some reason it decided to explode. Either by glitch or reasons that I don't understand I cannot ever trust that they wont blow up my base lol.
Totally worth it if you have the resources, I refuse to have anything other then a mark I reaction system
(I'm trying to remember what the reactor classes all are)
I really need someone to tell me what the best reactor is that can run a full cycle