There are some great benefits to a nuclear-powered car. It would rarely need to be refueled -- perhaps every three to five years [Source: Stanford University]. Highly enriched uranium is so potent that just one pound can power a submarine or aircraft carrier. Even smaller amounts could conceivably power a car. Assuming the car is adequately shielded (a subject we'll discuss later), the car would put out almost no emissions. And forget turning the ignition: Your nuclear-powered car would be always on -- although that means it would likely need batteries to store the energy constantly being produced by the miniplant.
Perhaps the main thing standing in the way of creating a nuclear-powered car is this: The power source is radioactive, so this vehicle would require lots of shielding. Without proper shielding, the radioactivity of the power source could kill people in and near the car, putting a damper on any commute.
Nuclear power plants and nuclear-powered aircraft carriers and subs all employ heavy shielding. Nuclear power plants generally have three layers of shielding in addition to the containment structure, which is made of concrete several feet thick and houses the reactor. U.S. law requires most reactors to have these layers of shielding and containment. Government-operated reactors are an exception, though the exact amount of shielding used on aircraft carriers and submarines remains classified.
With all of this shielding needed to protect against radioactivity, expect your nuclear-powered car to be extremely heavy. Reproducing the shielding of a nuclear reactor on an appropriate scale may make the car practically immobile. The shielding must also be resistant to earthquakes and other trauma and must be airtight so that air laden with radioactive molecules can't escape.
When someone mentions a nuclear-powered car, the danger of radioactivity likely comes to mind. Having radioactive material readily available is a security and public health concern. While not all fuel used in nuclear reactors can be immediately used in a nuclear bomb, even uranium that's not highly enriched could be used in a dirty bomb or other harmful radiological device. Our nuclear-powered car would have to be immune from such tampering. Then there's also the question of what happens in a car accident. Would the shielding stay intact, even in a catastrophic collision?
Finally, energy companies, car manufacturers and the government would need to collaborate to establish the infrastructure and a standardized process to dispose of spent fuel, which would be highly radioactive for hundreds of years. Other problems associated with nuclear power include the startup costs and time (up to 10 years) for new plants. Then there is the fear of accidents and the need to safely dismantle old plants and dispose of spent fuel and waste. The rekindled interest in nuclear energy has also driven up the price of uranium. The logistics and costs of such an endeavor may prove prohibitive.
With all of these challenges in mind, nuclear-powered cars likely remain far out of reach, at least made of today's technology. But for lots more information on other uses of nuclear technology and the future of automobiles, explore the links on the next page.