Ultronium Rod

Ultronium is an extremely rare, ultra-radioactive isotope. You cannot obtain or craft it directly - only as a side product. It is one of the key ingredients in creating a Neutronium Rod. While Ultronium Rods can be used as fuel, it is extremely unpractical.

At least 40 Ultronium Rods are required in order to craft an Atom Smasher. You will need to refine an approximate of 450 Solarium Stars, more than 3000 Neptunium Rods or Thorium Rods, or 600 Raw Nocxium to get that amount.