Appreciate the effort, but there's some huge errors there. The reactor you mention will fission 1,500 kg of one isotope, U-235 -- out of some ~50,000 kg of nucl

Appreciate the effort, but there's some huge errors there. The reactor you mention will fission 1,500 kg of one isotope, U-235 -- out of some ~50,000 kg of nuclear fuel (3-5% U-235, rest being useless U-238), and 300,000 kg of mined uranium (mostly U-238, most of which is thrown away in enriching from 0.7% to 3-5% U-235 fuel). OTOH, your classroom uranium cost is for natural uranium, 0.7% U-235. So you're underestimating cost by 2 orders of magnitude at least. Here's real numbers from the industry [1]. You use $90/kg. They say on the the order of $3,000 per kg of reactor-grade UO2, which is $60,000-$90,000 per kg of the U-235 isotope. On the flip side, you're greatly overestimating fuel usage (your assumptions are equivalent to about 6 mpg mileage), and you have a unit error where you accidentally multiplied by one thousand (45 kW * 2,500 hours = 112 MWh, not GWh!). So the figure is about 1/3,000x yours: about 5 grams U-235, or 100 grams reactor-grade fuel, or 1 kg of natural uranium. Costing on the order of $300. This doesn't apply to (imaginary) nuclear cars. With reactor-grade fuel, you need hundreds of tons of uranium, and hundreds of tons of moderator, to get a critical reaction. This won't fit into a car. The only way to approach a reactor this small is to use highly enriched fuel -- "weapons-grade", which is not sold at petrol stations. This is how they miniaturize reactors to fit in submarines and space satellites (like [2], not an RTG). If you did try to build a car like this, it be pathologically wasteful. The amount of HEU would need to be several kg or more, to have a critical reaction at all. But because a car uses so little power, you would burn less than 1% of it (several grams) over hundreds of thousands of miles. Extrapolating (using [3]) enrichment costs ($150/SWU from [1]), the fuel cost would be on the order of $300,000. And almost entirely wasted. [1] http://www.world-nuclear.org/info/inf02.html http://www.world-nuclear.org/info/inf02.html [2] http://www.etec.energy.gov/Operations/Major_Operations/SNAP_Overview.html http://www.etec.energy.gov/Operations/Major_Operations/SNAP_... [3] http://www.wise-uranium.org/nfcue.html http://www.wise-uranium.org/nfcue.html