... it appears that there exist within minable depths in the United States rocks with uranium contents equivalent to 1000 barrels or more of oil per metric ton, whose total energy content is probably several hundred times that of all the fossil fuels combined. (climate-resistance.org)
In addition, only about one tenth of the mined uranium ore is converted into fuel in the enrichment process (during which the concentration of uranium 235 is increased considerably), so less than a hundredth of the ore's total energy content is used to generate power in today's plants. (scientificamerican.com)
In the US, the world's second largest coal user, the volume of mined coal is increasing while the total energy content is decreasing. (realclimate.org)