The Nuclear Reactor uses Uranium to produce Nuclear Power, Which is required for Lightning towers to operate.
- Keep these the same level as your Uranium Mines, they have a 1:1 ratio when the same level.
- It is best to put these close to your mines to decrease supply line distance.
- If you ever don't have full ammo at night upgrade these as soon as possible.
- When you receive a new Nuclear Reactor, upgrade it to the level of the others as soon as possible.
- These have a high upgrade priority, keep them one level above your Lightning towers.
- at base level 5, should be 3rd thing you place behind crystal mines/uranium mines.
Characteristics at different levels
 original reference