Editing Radioactive waste (section)

==== Coal ====
[[Coal]] contains a small amount of radioactive uranium, barium, thorium, and potassium, but, in the case of pure coal, this is significantly less than the average concentration of those elements in the [[Earth's crust]]. The surrounding strata, if shale or mudstone, often contain slightly more than average and this may also be reflected in the ash content of 'dirty' coals.<ref name="ornl" /><ref>[https://web.archive.org/web/20081202150006/http://www.uic.com.au/nip78.htm Cosmic origins of Uranium]. uic.com.au (November 2006)</ref> The more active ash minerals become concentrated in the [[fly ash]] precisely because they do not burn well.<ref name="ornl" /> The radioactivity of fly ash is about the same as black [[shale]] and is less than [[phosphate]] rocks, but is more of a concern because a small amount of the fly ash ends up in the atmosphere where it can be inhaled.<ref>U.S. Geological Survey, [http://geology.cr.usgs.gov/energy/factshts/163-97/FS-163-97.html Radioactive Elements in Coal and Fly Ash: Abundance, Forms, and Environmental Significance] {{webarchive|url=https://web.archive.org/web/20051124173511/http://geology.cr.usgs.gov/energy/factshts/163-97/FS-163-97.html |date=2005-11-24 }}, ''Fact Sheet'' FS-163-1997, October 1997. Retrieved September 2007.</ref> According to U.S. [[National Council on Radiation Protection and Measurements]] (NCRP) reports, population exposure from 1000-MWe power plants amounts to 490 [[person-rem/year]] for coal power plants, 100 times as great as nuclear power plants (4.8 person-rem/year). The exposure from the complete nuclear fuel cycle from mining to waste disposal is 136 person-rem/year; the corresponding value for coal use from mining to waste disposal is "probably unknown".<ref name="ornl" />