Will this take me back to the future in my DeLorean?
A: No. Your DeLorean uses a standard GE General Purpose Waste Disposal FUSION Reactor. U238 is not a fusible material, and thus will just clog up the intake, rendering your reactor useless. I recommend ordinary H20 for the reactor, and place the canister of U238 in your pocket, where it will best serve the interests of the human race by improving the gene pool.