Is a source of fuel for your ship. I have not yet found another use for it. My issue with it is that the pay off is little for the difficulty in obtaining it. Wood = 1 fuel Coal = 2 fuel Plutonium= 6 fuel Considering how easy, practically effortless, it is to get the other two fuel resources. I think Plutonium should be an infinitely better source of fuel for a space ship then either wood or coal. 1 Plutonium should at LEAST = 100 fuel.
Or, there should be a method for 'enriching' it, like a centrifuge or something. Unrefined plutonium would remain a poor source of fuel, but if you spend time and resources enriching it, you'll get your super fuel.