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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? 

endolith
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Mad Scientist
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  • 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 Jul 04 '11 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 Jul 06 '11 at 05:30
  • @jwenting: I already answered my own question below. :) – endolith Jul 06 '11 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. http://www.forbes.com/sites/jamesconca/2012/06/10/energys-deathprint-a-price-always-paid/ – David Oct 15 '12 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. – Brian M. Hunt Mar 19 '13 at 17:19
  • "As a general clarification, ounce for ounce, coal ash released from a power plant delivers more radiation than nuclear waste shielded via water or dry cask storage." So coal ash released feely into the atmosphere delivers more radiation than nuclear waste that is suitably stored. Using that sort of comparison cars are more dangerous than beds. I'm not saying coal ash isn't radioactive, but if it was treated with the same respect that nuclear waste is. – Code Gorilla Jul 10 '17 at 12:33
  • @CPerkins - Erm, whoops got that wrong. What I meant was 'Beds are more dangerous than cars, because more people die in their sleep in bed'. – Code Gorilla Jul 10 '17 at 14:43

3 Answers3

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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.

Radiation

Sklivvz
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  • Do you have a source for the total amount of radioactive particles released by coal plants (the ppm value is only a concentration) against some examples of the amount of radioactive elements released in nuclear accidents? And while a nuclear accident may leave large amounts of radioactive elements, do you have a source for how much of that is really realeased and can come into contact with humans? – Mad Scientist Mar 19 '11 at 17:05
  • For the coal plants, the figures are cited in the linked paper. Regarding the exact figures for a nuclear accident, I've looked around, but most figures document how much radiation was released by single nuclear accidents, so it's not handily comparable. On the other hand I stand by my statement. Nuclear plants do not directly emit radiation as byproducts, but that doesn't mean they don't pollute if/when accidents happen. One Chernobyl offsets an awful lot of coal plants... Orders of magnitude different. – Sklivvz Mar 19 '11 at 17:10
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    The radionucleids in coal don't disappear and more than those used in nuclear power. Compare and contrast various nuclear power accidents with events like the [Kingston Fossil Plant coal fly ash slurry spill](http://en.wikipedia.org/wiki/Kingston_Fossil_Plant_coal_fly_ash_slurry_spill). – dmckee --- ex-moderator kitten Mar 19 '11 at 21:44
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    @dmckee: radioactivity doesn't go away, but we are talking about very different quantities, with very different dispersion mechanisms. – Sklivvz Mar 19 '11 at 22:32
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    +1 for appropriately incorporating an xkcd reference (even though Randall made it dead easy) :-) – Patches Mar 20 '11 at 02:28
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    "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 Jul 06 '11 at 05:27
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    @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. – Simon Lehmann Mar 19 '13 at 14:36
  • @SimonLehmann not so. Even the release from the only serious accident, Chernobyl, was relatively low and did not cause long term serious problems (yes, the nearby area to some kilometers had to be evacuated for a few decades, but current thinking is even that was longer than strictly required, people who refused to evacuate have survived there). The total casualties of nuclear power per diem even in the year of Chernobyl are much lower than those of coal power (remember only a few dozen people died in Chernobyl, not the hundreds of thousands environmentalists claim). – jwenting Mar 19 '13 at 14:44
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    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. – Simon Lehmann Mar 19 '13 at 15:00
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    -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 Mar 19 '13 at 18:09
  • @Mark As I've mentioned in my answer, the amount of radioactive material released in a nuclear accident is on the order of kilos/tons (depending on the accident). References are in the image. – Sklivvz Mar 19 '13 at 18:13
  • @Sklivvz - I don't see anything that allows a direct comparison - there are references to ppm, tons, and sieverts. What I don't see is any comparison using the same measurement. How many tons or kilos of radioactive coal ash are released every year? – Mark Mar 19 '13 at 23:46
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    Living within 50 miles of a nuclear reactor 1 day: 0.09 microS; Living within 50 miles of a coal plant 1 day: 0.3 microS; Living in within 30 km of Chernobyl before evacuation: 3-150 milliS (1,000x-50,000x coal) - these are directly comparable. Two are from the image, one from http://en.wikipedia.org/wiki/Chernobyl_disaster_effects#Dose_to_the_general_public_within_30_km_of_the_plant – Sklivvz Mar 20 '13 at 00:04
  • Thank you Sklivvz. If you add the info from Wikipedia to the answer it will be complete. – Mark Mar 20 '13 at 01:38
  • I've done that. – Sklivvz Mar 20 '13 at 01:46
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    The chart shows 50 miles from a plant vs. literally next to the molten Chernobyl core. Not comparable. It's also showing absorbed dosages, not amount of material released. – OrangeDog Jul 18 '15 at 17:01
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    "So it is clear that a single nuclear accident widely offsets any "gains" obtained by using a nuclear plant instead of a coal plant." Read your answer and saw nothing of the sort... if this was truly clear (and not taken on faith) then why would you need to even state this? – NPSF3000 Jul 19 '15 at 03:04
  • @Sklivvz the body of the answer says "within 50 miles of a nuclear reactor 1 day" and "within 50 miles of a coal plant 1 day", but the source/chart says "for a year" rather than "1 day". – DavePhD Jul 20 '15 at 20:42
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    @Mark Not to mention that a full analysis should also include the mining and logistics (and yes, the waste product treatment). Huge amounts of radioactive gasses are released when mining and burning coal; huge amounts of energy are required to move the huge amounts of coal used in thermal power plants. Mining and waste from NPPs aren't negligible either, quite likely (although getting realistic numbers might be tricky, since we're doing little recyclation of the mostly unspent nuclear fuel - there's plenty of space for improvement). It would be interesting to see those addressed as well. – Luaan Sep 23 '15 at 07:21
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    Also, another thing to consider: Even if an accident at a _particular_ plant "offsets" any "gains" -- accidents of this type are very rare compared to the total number and duration of plants operating, compared to continuous emission of all sorts of toxins from coal. So the question is do they offset it _for the entirety_ of nuclear power vs the _entirety_ of coal? An energy generation method that releases very little toxins 99.9% of the time with a few occasional spikes of extreme amounts, can have less total AUC (area under the curve) than a method that releases a modest amount continuously. – The_Sympathizer Jul 10 '17 at 03:17
  • @mike3 that argument doesn't work because a person gets and average of 10µS of radiation because of various causes every day, so both coal plants and nuclear plants are irrelevant, under normal operation, in the grand scheme of things. OTOH coal plants don't irradiate people with tons of radioactive material if they explode. On a more serious level, radiation damage is not linear, so you can't use the "area under the curve" by itself. – Sklivvz Jul 10 '17 at 07:45
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    @Sklivvz : Yes but if you go by an _average_ then the question is whether the _average_ of nuclear operation including the accidents which then _get averaged out over the space and time_ is less or more than the _average_ for coal. While the Chernobyl area is extremely hot, it is also extremely _concentrated_ in a very tiny area of the world, meaning only very few people will ever be in that zone. – The_Sympathizer Jul 10 '17 at 08:14
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    @mike3 Both coal and nuclear plants emit irrelevant quantities of radiation which are literally a rounding error over natural sources. Getting nuked by Chernobyl or Fukushima is not a rounding error. The proportion of the numbers seems to be missed here: the amount of radiation released by a nuclear meltdown is billions of times more than normal and it usually affects millions (within the order of magnitude of natural radiation). – Sklivvz Jul 10 '17 at 09:17
  • @Sklivvz : Yes if you're very near (on a global scale) to it you will be zapped. Sure. But the question is what the effect is on the _world as a whole_ . Does it overall, when averaged out across the entire globe, and also over a lifetime of an _average random person on the globe_ , produce a major enough effect to put nuclear above coal or not, that is, does it cause the final average to be more than 0.3 uSv per year, over that average random person's lifetime, and if so, what is the figure? – The_Sympathizer Jul 10 '17 at 09:21
  • (Don't quote 50 Sv, that's not an average over the globe, that's hot spot right at ground zero which I already said of course will zap you.) – The_Sympathizer Jul 10 '17 at 09:24
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    Keep in mind that all industries have deadly accidents, which will produce extreme, apocalyptic conditions at the point of occurrence by definition. So the question is what is the _global_ threat look like? – The_Sympathizer Jul 10 '17 at 09:25
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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.

endolith
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  • 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 Jul 07 '11 at 05:30
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    @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 Jul 08 '11 at 03:08
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    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 Jul 11 '11 at 06:48
  • What is that "fuel cycle" mentioned in the source you cite? The diagrams I have seen about coal/gas/oil/uranium mining and use for electricity generation don't contain any cycles (except for some use of reprocessed uranium). – Simon Lehmann Mar 19 '13 at 14:46
  • @SimonLehmann: I assume it means that the "490 person-rem/year" is only the pollution from the coal powerplant smokestacks themselves, and not the pollution from mining coal/transporting coal/transporting ash/burying ash/ash running off into fields and contaminating food/etc. (Which would be higher, but probably not enormously higher. I would guess the smokestacks cause the majority of irradiation.) – endolith Mar 19 '13 at 14:59
  • I guess that's what it means. Though my question aimed more at the "cycle" aspect, which I think is misleading. It is actually a "fuel chain" or "fuel path", not a cycle. – Simon Lehmann Mar 19 '13 at 15:03
  • @SimonLehmann: Oh, I see. Nuclear fuel chain is also a "cycle" because of reprocessing, but coal is not. – endolith Mar 19 '13 at 15:53
  • HOW IS THIS A YES ??? The question was if they release MORE - and here it seems they release amounts in the same order of magnitude, but still 2.8 is more than 2.1 ??? So shouldn't it be "No they release about 30% less radiation" ??? – Falco Dec 16 '14 at 17:20
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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 Dec 16 '14 at 20:59
  • How many TWh are 430 Billion kWh? +1 other than that I prefer this answer. Much better and objective!! – Jose Luis Jun 19 '15 at 14:17
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    @joze = 430 Twh – endolith Jun 19 '15 at 14:24
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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.

Peter Mortensen
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KJones
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    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. – Kevin Kostlan May 13 '16 at 19:18