Hey there!

I noted that something is off with the balance between getting Uranium-235 via Kovarex and via Reprocessing.
Considering both cost Uranium-238, I would expect both to have a similar 238-to-235 ratio, possible even higher from reprocessing as it is the more limited method.

But if my math checks out (Considering both the raw Uranium-238 return and the amount you gain from processing the tailings), you get the following numbers:
- Creating 235 via Kovarex converts about 2.5% of 238 to 235 (Losing the rest).
- You input on average 38 U-238 and get 1 extra U-235 from it.
- Creating 235 via reprocessing converts about 0.25% of 238 to 235 (Losing the rest).
- You input on average 2.65 U-238 and get a 0.7% chance of 1 U-235 from it.

With this ratio, I will just throw the burnt fuel cells in the trash as it will waste my U-238 (Which this mod made very precious due to the science pack integration), even before being able to use Kovarex at all.

Maybe I am just missing something here or my calculations are incorrect, but based in this, the balance seems off to me.

It wasn't designed to make sense but to get rid of U238, so several recipes use more U238.
There are several options you can use if the balance feels wrong.
I've never run out of U238 using this mod, even when using 5 per yellow science, sometimes 7.

However, I'm also currently using Schall Uranium mod which also changes the processes significantly.

Hope that helps.