The numbers are clear. Nuclear lifecycle is 11 gCO2-eq/kWh, less than almost anything and on par with wind.
The idea that uranium mining requires tremendous amounts of anything compared to the alternatives is ludicrous simply by the physical fact that there are 938 MW*days of energy in every kilogram of natural uranium. That's 2 million times more energy per mass than any chemical fuel, and that results in a very small mining requirement compared to anything else to power humanity at world-scale.
70 is a a lot closer to the truth. That 11 is a selective figure.
None of these numbers includes the carbon used to bulldoze the East side of Japan, or Belarus. And again, as the first attempt was clumsy, and a minimum.
Which study are you using to suggest 70? That's on the high end on any study, but not the highest.
The IPCC has min, median, and max estimates on these kinds of things. See Table A.III.2 in [1], 12 being the median.
So worst case by any estimate is that nuclear emits 110 gCO2-eq/kg. Solar PV (utility) max is 180. Hydro is an astounding 2200 (twice as bad as coal, due to biogenic methane associated with large reservoirs). By any estimate, nuclear is a very low-carbon energy source, in a whole different class than fossil fuel and biofuels. In other words, it's one of the few low-carbon options we have.
The idea that uranium mining requires tremendous amounts of anything compared to the alternatives is ludicrous simply by the physical fact that there are 938 MW*days of energy in every kilogram of natural uranium. That's 2 million times more energy per mass than any chemical fuel, and that results in a very small mining requirement compared to anything else to power humanity at world-scale.