How am i supposed to get this? I got loads of 237 by recyclicing LEN Fuel, but i can't seem to find out how i get 236 which i Need to craft Neptunium fuels. Also, the only recipes i can see for getting Neptunium 236 is recyclicing LEN or HEN fuel which both Need 236 to craft in the first place oO

Found it. Thorium is the way to go.

Yeh - Thorium and HEU-233 fuels are the best sources of Np-236. Depleted HEU-233 is particularly Np-236 rich :)