Is there a theoretical lower limit to how small a nuclear reactor can be made, perhaps due to a minimum amount of nuclear material being needed to sustain a reaction?
Can one be made small enough to fit in a modern (electric) car, and last long enough so that one wouldn’t need to replace the fuel (be it uranium rods or whatever) in a human lifetime?
It’s my understanding that several space probes were nuclear powered, could these same type of power supplies be theoretically used to power vehicles on Earth?
I’m just wondering if this is theoretically possible, I don’t care about cost or safety or nuclear waste issues.
Theoretically, maybe. The radioisotope thermal generators that spy satellites and deep space probes use are usually based upon the breakdown of highly enriched nuclear materials. The materials decay and generate heat, which in turn is converted to electricity.
There are several problems with this. They are dirty, and some if not all rely upon concentrated fissile material, although I see the modern plants based on Pu-238 have been converted to a “more stable pressed oxide,” whatever that means.
Some can generate a significant amount of power, up to a thousand watts. I think some Soviet satellites created even more power than that.
Someone else will have to go into steam-turbines and the like.
I’m pretty sure some company in Japan produced a reactor about the size of a refridgerator. I don’t have a site or anything, just something I read in the paper a couple of months ago.
You’ll have to set a defining line. The smallest electricity-generating use of Plutonium that I know of is a pacemaker. Such pacemakers ideally would last 20+ years without a recharge, but they aren’t very common because of the expense as well as the problem of disposal after the patient’s death.
If you want to narrow your search to a reactor capable of suppling 110volt (or 220volt) AC energy to a household or small office building… tricky.
One thing that occurs to me is that the nuclear power source for a car would not have to put out enough power to drive the car directly; it would be charging the battery constantly, even at night.
I would think that the reactor core could be as small as one likes, but the hitch would be in the sheilding (safety contianment), and especially in the actual means that the nuclear reaction is transformed into electricity. Steam turbines, cooling devices, generators, etc. would be the problem as I see it.
Seems to me another major problem would be significant quantities of fissionable material in public hands. It would make it much easier for your unsavory terrorist types to get into mischeif.