5 ms·

So a typical nuclear reactor in a car is a terrible and unworkable idea. But what about an EV powered by nuclear batteries? Could that be economical or safe? Y

• duskwuff 5y ago
  "Nuclear batteries" aren't, strictly speaking, batteries. They're RTGs, and they have very low (and constant) power output relative to other energy sources.
  • moftz 5y ago
    It would take days to fully charge an EV from a typical RTG and there's no way an RTG could put out enough power to even keep an EV rolling on a flat highway at highway speeds. They are good for remote, unmanned stations but not much else.
    • jandrese 5y ago
      An RTG powered electric car may not be able to drive cross country at highway speed, but most cars spend the vast majority of their time parked. Having a RTG constantly top off the battery of an electric car would probably work quite well, assuming you worked out the many, many issues surrounding the RTG itself first.
      • stickfigure 5y ago
        A "large" RTG puts out a few hundred watts of electrical. A very efficient electric car might consume 25 kWh/100 miles, so about 250 watt-hours per mile. If your car sits parked 6 days per week, it might work. Also: RTGs are typically 3-7% efficient, so your trunk will put out thousands of watts of waste heat continuously. Hope you live in a cold climate.
        • jandrese 5y ago
          So if you're charging at a rate of 2 miles per hour you can drive 48 miles a day on average, which is a fair bit more than most cars do. Even a 1 mile per hour charge rate would be enough for some people, although at that point you'll probably supplement with solar panels or something. One advantage over solar charging is that this won't be affected by the weather and works all night long. The excess waste heat is a problem, but it is way down the list of problems with running a RTG.
          • stickfigure 5y ago
            That still sounds incredibly optimistic. The most modern RTG: https://en.wikipedia.org/wiki/Multi-mission_radioisotope_thermoelectric_generator https://en.wikipedia.org/wiki/Multi-mission_radioisotope_the... Puts out 125W electrical, 2KW thermal, and costs $109M each (!) Most cars could support 600w of solar panels. Even in bad weather you'd still come out ahead.
            • duskwuff 5y ago
              The price is almost meaningless. We don't have enough refined plutonium available to build more than three MMRTGs right now.
              • eloff 5y ago
                You wouldn't use a plutonium based RTG in civilian use for obvious reasons.
        • eloff 5y ago
          > Also: RTGs are typically 3-7% efficient, so your trunk will put out thousands of watts of waste heat continuously. Hope you live in a cold climate. Ouch. It might be possible to harness some of that with e.g. Thermal to electric circuits to improve the efficiency.
          • duskwuff 5y ago
      • moftz 5y ago
        The work required for moving the RTG up a slight hill might just negate the energy you gain from it. An RTG is not really meant to move itself very fast. Consider the Mars rovers, they move extremely slow but benefit from the stable, long term power supply.
• coolspot 5y ago
  Any fission material in a consumer vehicle is unacceptable due to drastic consequences of a crash.
  • eloff 5y ago
    That's not how nuclear batteries work. The one I linked is radioactive carbon 14 formed into diamonds. That'd be fine in a crash.
    • duskwuff 5y ago
      It also has power density on the order of 1 µW/cm^3 (= 1 W/m^3), which is incredibly low. An entire truckload of those batteries wouldn't even be able to power the truck's headlights.
      • eloff 5y ago
        That's a good point.