Liquid uranium was uranium that had been heated and treated to a stable liquid form. The liquid was used in fission generators as power for small transports and planetary purposes such as lighting. The liquid was the third most efficient fuel device (The first was a Zacklan Blue ZEC) as of 200 ABY.
Only a few planets exported it, those being extremely rich in Uranium. One gram of liquid uranium was capable of producing as much 100,000 kilojoules for three hours. One drawback was that liquid uranium lost its ability to power things after generating a total of 10,000,000 kilojoules per gram.
One gram of Liquid uranium cost 1,000 credits. As a general rule, spacers emptied and refilled their tanks after every 10,000 light-years, as loading energy into nonreactive L.U. resulted in explosion.