here is my tip: go for radiation damage and if its tier 1 only upgrade damage. once all of your uranium shards becomes tier 2, upgrade the range of all of them to 25, and DO NOT make it a tier 3 build if you have less than 5 plutonium rods, cause if you tier 3 without backup rods then the enemies will overwhelm you and you will die. then just upgrade it and you should be good