As a response to the disaster at the Fukushima nuclear power plant I've heard the claim that fossil-fuel power plants using coal release more radiation than a nuclear power plant. I searched for some information and found an article supporting this statement in the Scientific American called Coal Ash Is More Radioactive than Nuclear Waste.

This is a topic with huge political and economic interests which makes accurate and reliable information hard to find. I'm now wondering if that comparison of coal ash and nuclear waste is accurate, and also if it is misleading, how it compares to the real-world radiation release.

How much radiation is released by coal and nuclear power plants in regular operation? How do the numbers compare if you include different types of nuclear accidents? 

  • I would like to know the amount of radioactive waste produced by coal and nuclear plants for a given amount of energy generation (tons per GWh, for instance). Based on some numbers I've read, they seem similar: “a typical nuclear reactor will generate 20 to 30 tons of high-level nuclear waste annually." "For the year 1982, assuming coal contains uranium and thorium concentrations of 1.3 ppm and 3.2 ppm, respectively, each typical plant released 5.2 tons of uranium (containing 74 pounds of uranium-235) and 12.8 tons of thorium that year." But how much is a "typical" plant?
    – endolith
    Commented Jul 4, 2011 at 17:58
  • interesting question, endolith. And of course there's the little problem that a "typical" nuclear plant most likely has a far higher electrical output than does a "typical" coal fired plant. You have to therefore take the numbers per KWh produced to get any real comparison.
    – jwenting
    Commented Jul 6, 2011 at 5:30
  • @jwenting: I already answered my own question below. :)
    – endolith
    Commented Jul 6, 2011 at 21:28
  • While not directly related to which releases more radiation, another interesting statistic is deaths / kilowatt-hour. Looking at this statistic,per unit of energy generated, coal causes over 1000 times as many deaths as nuclear or wind and over 100x hydro. forbes.com/sites/jamesconca/2012/06/10/…
    – David
    Commented Oct 15, 2012 at 18:52
  • Purely anecdotal, but when I worked at the health-physics department of a nuclear power plant for Atomic Energy Canada in the 1990's, it was commonly accepted among and regularly repeated by my peers that coal power plants released magnitudes more radioactive material than nuclear power plants. It was a point of aggravation for my peers at the time, as the coal plants were relatively unregulated yet the nuclear power plants had significant regulatory requirements. Commented Mar 19, 2013 at 17:19

3 Answers 3


The answer to your first question is already in the article you linked. It contains the following referenced quote:

In fact, the fly ash emitted by a power plant—a by-product from burning coal for electricity—carries into the surrounding environment 100 times more radiation than a nuclear power plant producing the same amount of energy.

The paper referenced in the article is here: http://www.sciencemag.org/content/202/4372/1045.short

Radiation doses from airborne effluents of model coal-fired and nuclear power plants (1000 megawatts electric) are compared. Assuming a 1 percent ash release to the atmosphere (Environmental Protection Agency regulation) and 1 part per million of uranium and 2 parts per million of thorium in the coal (approximately the U.S. average), population doses from the coal plant are typically higher than those from pressurized-water or boiling-water reactors that meet government regulations. Higher radionuclide contents and ash releases are common and would result in increased doses from the coal plant.

The paper itself states that this result is only valid not considering nuclear accidents and nuclear waste, nor it considers non-radiological effects:

The study does not assess the impact of non-radiological pollutants or the total radiological impacts of a coal versus a nuclear economy.

Regarding your second question, it can be answered easily:

  • The paper itself speaks about Uranium and Thorium being released by normal operation in less than 10 parts per million - very very low doses
  • A bad nuclear accident leaves kilograms or tons of radioactive elements exposed or emitted
  • Typically nuclear waste is composed of tons of material

So it is clear that a single nuclear accident widely offsets any "gains" obtained by using a nuclear plant instead of a coal plant.

Furthermore, the average radiation we all get by "living" makes the normal power plant emissions irrelevant:

  • Living within 50 miles (~80 km) of a nuclear reactor (1 year): 0.09 µS;
  • Living within 50 miles (~80 km) of a coal plant (1 year): 0.3 µS;
  • Daily average radiation: 10 µS;
  • Living in within 30 km of Chernobyl before evacuation (10 days): 3-150 mS

The first three are data from the image below, the third comes from from Reconstruction of the inhalation dose in the 30-km zone after the Chernobyl accident

Thanks to Borror0 for the great find. To put things in perspective see the following infograph. At the top left, in blue, you can see the radiations absorbed by living next to a (nuclear|coal) plant. In yellow, the radiation doses of Chernobyl - many orders of magnitude higher.


  • 6
    +1 for appropriately incorporating an xkcd reference (even though Randall made it dead easy) :-)
    – Patches
    Commented Mar 20, 2011 at 2:28
  • 24
    "So it is clear that a single nuclear accident widely offsets any "gains" obtained by using a nuclear plant instead of a coal plant." That's a value statement. Taking into consideration everything else (chemical pollutants, the far higher accident rate in non-nuclear plants, etc.) and the equation changes dramatically, and highly in favour of nuclear.
    – jwenting
    Commented Jul 6, 2011 at 5:27
  • 6
    @jwenting I think your statement is more of a value statement than what Sklivvz said. During normal operation, a nuclear plant releases less radiation/radioactive material than a coal plant (actually, you should take waste into account... which "we" still don't know what to do with it), but one severe accident releases more than what you have saved before. Now, saying this is tolerable or not would be a value statement. Commented Mar 19, 2013 at 14:36
  • 5
    I think this would be material for another question here on Skeptics: "only a few dozen people died in Chernobyl, not the hundreds of thousands environmentalists claim" (but I think focusing on death alone is kind of silly). I hear/read all those claims about how safe even the most severe accidents have been, but I have yet to find more than just assertions that this is actually true. But I digress, the point is that this question and answer is not about the effects of the radiation release. It asks how the numbers compare during normal operation and taking accidents into account. Commented Mar 19, 2013 at 15:00
  • 17
    -1 for the statement "So it is clear that a single nuclear accident widely offsets any "gains" obtained by using a nuclear plant instead of a coal plant". There is nothing cited to support this claim. It may or may not be true, but should be answerable - how much radiation was released at Three Mile Island, Chernobyl, and Fukushima vs total radiation from coal combustion ( each year, or in the same time period perhaps).
    – Mark
    Commented Mar 19, 2013 at 18:09

Yes, people are exposed to more radiation from coal power plants than from nuclear power plants:

Dosage comparison from Wikipedia:

According to U.S. NCRP reports [source says 92 and 95], population exposure from 1000-MWe power plants amounts to

  • 490 person-rem/year for coal power plants and
  • 4.8 person-rem/year for nuclear plants during normal operation, the latter being
  • 136 person-rem/year for the complete nuclear fuel cycle.

So coal power plants are irradiating you 4 to 100 times as much as nuclear plants. (The complete fuel chain dose for coal is not known.)

And to answer my own question, coal power plants and nuclear plants produce similar amounts of radioactive waste:

  • US nuclear

  • France nuclear

  • US coal

    • "The actual average generated power from coal in 2006 was 227.1 GW" (WP)
    • "In 2006, the U.S. consumed 1,026,636,000 short tons (931,349,000 metric tons)" of coal (WP)
    • "Using these data, the releases of radioactive materials per typical plant can be calculated for any year" ... "assuming coal contains uranium and thorium concentrations of 1.3 ppm and 3.2 ppm, respectively" ...
    • they produce 1210 tons of uranium and 2980 tons of thorium ash each year. Combined and divided by energy produced
    • = 2.1 metric tons of radioactive waste per TWh

So, for a given amount of energy, the tiny fraction of uranium/thorium in the ash created by coal power plants is similar in mass to the total amount of radioactive waste produced by nuclear plants, which is mostly uranium. I don't know how much of this is stored in ash ponds vs dumped into the atmosphere, but it's certainly not held to the same standards as nuclear power plant waste.

  • and don't forget that the smoke that comes out of the smokestacks of those coal fired plants (there's some even after filtering) contains ash (which is somewhat radioactive as noted) that isn't part of the amount of waste mentioned here.
    – jwenting
    Commented Jul 7, 2011 at 5:30
  • 2
    @jwenting: This is the ash. I'm just not sure how much is released in smoke and how much is stored in ponds. Another answer says there's a EPA regulation that only 1% can be released as smoke?
    – endolith
    Commented Jul 8, 2011 at 3:08
  • 1
    It's the stored ash only (at least if the figures are based on similar data to what I've seen during graduation work), the stuff removed from the burners and piled onto ash heaps and dumped into holes and covered over. And do the math, even 1% of that much is a lot...
    – jwenting
    Commented Jul 11, 2011 at 6:48
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    The answer has 2 parts, separated by the horizontal line. The first is about exposure to radiation, for which the answer is "Yes, 4 to 100 times as much". The second part of the answer is incidental, about total amount of radioactive waste.
    – endolith
    Commented Dec 16, 2014 at 20:59
  • 1
    @joze = 430 Twh
    – endolith
    Commented Jun 19, 2015 at 14:24

Although the concentration of uranium and thorium in coal is extremely low, a typical 1000 MW coal fired plant burns about 4 million tons of coal every year. This results in an unregulated release to the environment of 5.2 tons of uranium along with 12.8 tons of thorium from a single coal plant each year. This does not include the large amounts of radium, radon, polonium and potassium-40 that is also released from coal plants. Please refer to the Oak Ridge National Laboratory article Coal Combustion: Nuclear Resource or Danger by Alex Gabbard for more information on this subject.

Nuclear power plants are owned by electric utilities which also run coal fired plants, and it is not in their best interest to point out the fact that radiological releases from coal plants exceed those from nuclear plants.

  • 1
    Potassium-40 release is a non-issue because the body regulates potassium and the isotope composition is almost the same everywhere. But the other stuff IS a problem. The ashes toxicity is a far greater problem still. Commented May 13, 2016 at 19:18

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