The problem with nuclear is twofold
1. Without CASUC cooling, reactor outputs are not worth the tedious labor to set up a reactor and refuel it every 2.8 hours. If you cannot get 1000 EU/tick out of a single reactor, it simply isn't worth the effort to set up. Massive windmill farms are much easier to spam in large numbers, and they never have to be refueled.
2. Many of the parts involved in reactors are non-stackable items. Especially the complex layouts that are required now with the new reactor modules. This makes it extremely tedious to set up reactors to run, making them essentially non-viable.
As this new feature is broken, please either remove it from the game next release or restore CASUC cooling.