Four are needed for the quest Earth Mover. They are the primary power source used to fuel the nuclear reactor within the Rockhound bucket-wheel excavator. Due to the amount of power the nuclear reactor consumed, Hornwright Industrial had to ask the Rockhound crew members to lower the power needed to operate and drive the BWE. This was so that the BWE could actually work for more than three minutes; however, this fuel inefficiencies came at the cost of less ore tonnage being excavated and therefore, less overall profits.
Ignition cores are cylindrical devices that bare some resemblance to fusion cores, albeit far more simplistic in design. This may be due to the fact that fusion cores are essentially miniature nuclear reactors, whereas ignition cores are nothing more than a catalyst used to start up the nuclear engine of the Rockhound.
Nuclear material (5)
Ignition core (1)