This device provides "recharge" of a fusion cores. Operating principle based on nuclear reaction. It is using nuclear material to reestablish energy potential of nuclear element. This is my entry to the Nvidia contest. In the category "Data" I assume.
Button must be placed close enough to be detected, you can even place it right on the hull. To link button with refueler you need to interact with refueler by accessing it's storage.
I will introduce explanatory video today.
Located in workbenches section.
How to use:
You have to put 2 nuclear material scraps and your core into container(object storage).  Charged core will be will be thrown out of lower window.(2 scraps for each core)
Refueler should be powered to work. It's takes 2 energy points.