Why not use uranium in cars?

Answer 1

We don't need to use uranium in cars. Why would we? Uranium as a nuclear fuel requires a big machine to extract its power. We call that machine a thermonuclear reactor. They don't come in a version that will permit us to build one into a car. We can build a nuclear weapon into a suitcase, but that's not the same thing. Uranium is extremely dense. We don't need to make any parts or subassemblies out of this stuff for automotive applications. It's way too heavy and doesn't give us anything we can't get from other, lighter materials.