Realistic Reactors is a great mod, but seems geared towards vanilla and not Space Age. You can unlock an upgrade to its reactors... before you're even able to build them since Efficiency 2 is locked behind space science. This mod tweaks Realistic Reactors Reborn's recipe to use vanilla reactor recipe so you can enjoy the threat of it exploding in your face before you go to space.
Small changes concerning balance, gameplay, or graphics.
Realistic Reactors is a great mod. Love it! However, it has a problem in Space Age: you can't have the threat of a game ending explosion in your base before you go to space. [Insert disappointment here]
This small mod sets the Realistic Reactor recipe to the vanilla one, and removes Efficiency 2 as a tech requirement.