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Coal plants emit more radioactive waste than nuclear plants (2007) (scientificamerican.com)
332 points by ChuckMcM on June 1, 2017 | hide | past | web | favorite | 100 comments



And as has been pointed out to me offline the article compares 'radioactivity release' of an operating nuclear plant to an operating coal plant. Clearly a properly designed nuclear plant emits no radioactivity at all.

On the plus side I offer the following report from the USGS in 2016 : https://pubs.usgs.gov/fs/1997/fs163-97/FS-163-97.html which talks about the levels of uranium and thorium in fly ash (0 - 4 ppm).


And for the curious (and since I was wondering about the potential for mining fly ash for uranium), according to Wikipedia, in 2008 the US coal plants generated 131 million tons of fly ash per year[1], so at 4ppm that is 4 tons of uranium per million tons of fly ash, or ~500 tons of uranium per year. According to this site[2] a 1000Mw nuclear plant produces roughly 27 tonnes of 'spent fuel' per year. (be careful of the metric tonnes vs imperial tons variations in sources). Since the EPA in the US requires coal plants to recover and dispose fly ash it could, in theory, be post processed as a source of uranium but also according to Wikipedia it gets used in lots of places.

[1] https://en.wikipedia.org/wiki/Fly_ash#Present_production_rat...

[2] http://www.world-nuclear.org/information-library/nuclear-fue...


Building on your "lots of places" comment:

I've got memories of an experiment we did in undergraduate physics labs, which involved a directional array of Geiger tubes. Pointing them at the view through the window gave a low count, but pointing them at the concrete structure of the building gave an elevated count. My understanding at the time was that it was due to naturally occurring uranium and thorium in the raw materials of the concrete.

Given that fly ash is a common component of concrete [1], I wonder how much of the elevated radiation from concrete can be put down to the concentrating effects of coal combustion that you mentioned in one of your comments?

[1] http://www.cementaustralia.com.au/wps/wcm/connect/website/bu...


I just did a guesstimate:

Combustion concentrates radioactivity by a factor of 5x to 10x [1]. Fly ash can replace 25-50% of cement [2]. A typical concrete is 16% cement (1 part cement, 2 parts sand and 3 parts gravel) [3].

Hence a concrete might be 4%-8% fly ash. If the ratio of fly ash is 'A', the concentrating caused by combustion is 'C' and the background radiation of other concrete ingredients is uniformly taken to be 'B', then the radiation count of concrete without fly ash will be:

B

and the radiation count of concrete with fly ash will be

A.C.B + (1-A).B

Plugging in values for A (0.04 to 0.08) and C (5 to 10), we find that fly ash increases the radiation from concrete by a factor of 20% to 70%. That strikes me as a significant proportion of the radiation from concrete.

[1] https://phys.org/news/2015-09-radioactive-contaminants-coal-...

[2] http://www.theconcreteproducer.com/how-to/concrete-productio...

[3] http://www.cementaustralia.com.au/wps/wcm/connect/website/pa...


But how radioactive is concrete compared to a similar volume of bananas? I would like to know this, but I'm on my phone at the moment. :)


An interesting question!

Typical banana dose: 0.1 μSv per banana [1].

Typical concrete building dose: 100μSv per year [2]

ie. 1 year in a concrete building = eating 3 bananas a day.

I'm not claiming that fly ash laden concrete is going to kill anyone, but I think it's interesting that (given my assumptions) the concentrating effects of coal combustion are causing a decent proportion of concrete's radioactivity (even if the total is still negligible).

[1] https://en.wikipedia.org/wiki/Banana_equivalent_dose

[2] https://www.euronuclear.org/info/encyclopedia/r/radiation-ex...


My understanding is that more than direct exposure to radioactive materials in fly ash, the real risk is Radon. As Thorium and Uranium decay they will produce Radon, which can accumulate especially in low-lying areas with poor ventilation (e.g. basements, which tend to rely on concrete as a key building material). Since Radon can be inhaled, it has the potential to cause far more harm than anything "baked into" the concrete itself.


> I'm not claiming that fly ash laden concrete is going to kill anyone...

That's the thing though, these low 'safe' levels of radiation do actually kill people. Every now and then somewhere, someone will be hit by a radioactive emission from Fly Ash that happens to hit one of their chromosomes and trigger cancer.

If Fly Ash increases cancer cases in a year by x% then we can be pretty sure that x% of cancer patients were victims of Fly Ash, it's just that x is actually fairly small and we just don't know which ones they are. But they still have cancer.


You should probably compare the U content of fly ash with the rocks around you for some context.

The average U content of the upper continental crust is between 2 and 3 ppm. Individual rocks will range lower and higher than that. If fly ash is only 4 ppm U, you have more to worry about from living on granitic rocks, or near a swamp than you do from fly ash.

More context: if you live on the Chattanooga shale it has an average U content of 30-120 ppm. The extensive Alum Shale (runs the length of Sweden) has U contents of 100-300 ppm. Granites will have low-mid 10s of ppm U and Th.

The report [1] linked in a comment above makes the comment Fly ash is commonly used as an additive to concrete building products, but the radioactivity of typical fly ash is not significantly different from that of more conventional concrete additives or other build-ing materials such as granite or red brick. One extreme calculation that assumed high proportions of fly-ash-rich concrete in a residence suggested a dose enhancement, compared to normal concrete, of 3 percent of the natural environmental radiation.

[1] https://pubs.usgs.gov/fs/1997/fs163-97/FS-163-97.html


If you can absolutely correlate the cancer to the presence of fly ash then yes. But that is going to be rather hard. How do you normalize for other equally chromosome-destroying environmental factors? Maybe drinking two cans of Coke a year less gives you exactly the same level of risk than someone living in a fly-ash free building?


If you use a decent (high resolution γ-ray) detector, you'll find that the background (from UK concrete, at least) is dominated by the ⁴⁰K decay line, whose energy might be ingrained in ex-γ-ray spectroscopists years later. Geiger counters may indicate radiation, but not what radiation.


marble counters emit radiation (radon) due to the break down of iridium that occurs naturally. your actually supposed to test your marble counters for excessive radon release. It comes to no surprise that concrete would have an elevated count - anything with any kind of stone probably would.


Iridium in nature has two stable isotopes and is not radioactive. The longest half-life of the radioactive isotopes of Iridium is 241 years and quickly disappears over geologic timescales. Potassium is what will make stone counters radioactive as Potassium 40 has a half-life of 1.25 billion years and will release beta particles but not radon. Radon is a radioactive gas created in the decay chains of Uranium and Thorium. Stone used for counter tops will have some Uranium and Thorium, but usually at very low levels.


The iridium content of marble is going to be in ppt or more likely ppq abundances.

I see no decay chain leading to Radon. https://en.wikipedia.org/wiki/Isotopes_of_iridium


I believe this is the stuff they put on the roads in PA during the winter. Other places put down sand or gravel when it snows; PA put down ash. It was gross.


I think it's important to compare the actualities instead of idealizations.

Airplanes and cars aren't designed with a certain death rate in mind, but it's good to compare the actual bad outcomes.

It's true that coal plants are "designed" to emit a characteristic amount of radioactive material, but they also don't suffer from catastrophic or significant accidental releases so it's appropriate to compare actual historical outcomes. The failure rate of nuclear power is an important part of the consideration. (and it still ends up on top)


> also don't suffer from catastrophic or significant accidental releases

We've had a countable number of catastrophes and are getting better at building safer reactors (G IV reactors are modulated by physics).

Regardless, Chernobyl is estimated to be currently claiming 4000 lives per year worldwide[1], while coal power plants are claiming 7500 lives per year in America alone.[2] Nuclear meltdowns are very scary events. Merely running a coal power plant is a far scarier.

[1]: http://www.who.int/mediacentre/news/releases/2005/pr38/en/ [2]: http://www.catf.us/fossil/problems/power_plants/


Your source for [1] says that up to 4000 people may die, in total, not per year.


> don't suffer from catastrophic or significant accidental releases

In 2008, 1.1 billion gallons of coal fly ash slurry was released from Kingston Fossil Plant in Tennessee.

https://en.wikipedia.org/wiki/Kingston_Fossil_Plant_coal_fly...


> Airplanes and cars aren't designed with a certain death rate in mind.

Not entirely true. The NHTSA can promulgate safety regulations, but if the cost of implementing exceeds the societal cost of not implementing then the regulations don't need to be followed.


The ridiculous thing about all of this is plain topsoil has between 0-4ppm of uranium and thorium. Means fly ash is roughly as radioactive as dirt. However pointedly in modern coal fired plants fly ash it scrubbed[1].

Deal with Uranium and thorium is normal geological processes aren't very efficient at concentrating either. Which means commercially exploitable ores are rare and the element remains widely distributed.

[1] It's a bit more tricky since part of the radioactivity from uranium and thorium is due to decay products, some of which probably escape out the stacks. (See radon).


Well, here in Australia we are lucky - we've got Clean Coal™! /s

http://www.abc.net.au/news/2017-05-30/clean-energy-funding-c...


Does the articles calculation include the nuclear waste that needs to be taken care of after it has served its purpose of producing energy? Or is this article only counting the radioactive emissions during power production?


Everything is naturally radiactive to some degree, so it will emit some radiation, but ideally at or lower than background levels.


Can we focus on renewables and stop trying to sell people hazardous waste that can last for millenia? You do realize that you can't actually guarantee what will happen in 10, 20... 50 years time. Earthquakes, Tsunamis, tornados, terrorist attacks, wars, neglect, malfunction, human error... How can you guarantee that a certain place is safe to store millions of tons of radioactive waste for thousands of years if we can't even guarantee what will happen tomorrow? We need to stop this nuclear madness!


Well, damming rivers turned out to be a bad idea in cases so (Washington State)[https://relay.nationalgeographic.com/proxy/distribution/publ...] is undoing them. Wind turbines require surmounting large technical hurdles with storing energy. Solar takes a lot of resources/space. Heck, in 50 years we might be in a dust bowl and solar doesn't even work.

Why would you suggest we prevent using all appropriate options at our disposal? Why not push for using a different type of fuel instead?

I didn't grow up during the nuclear scare times. Fukushima wasn't great, but it wasn't so horrific either. If it gets us off coal and natural gas then I'm down.


Fukushima isn't over, we don't know what it will have done in the next 50 years yet.


Estimates of excess deaths due to nuclear, counting chernobyl, are the lowest of any energy technology. This isn't even counting the part where no new nuclear reactor could possibly be as unsafe as Chernobyl or Fukushima in the same way that no modern car could be as unsafe as as a car from the 1960s: https://www.youtube.com/watch?v=fPF4fBGNK0U


There are fates worse than death.


Don't go there, unless you want to talk about the lives of coal miners.


My grandfather's dad died in the coal mines. They dropped his body off on the sidewalk infron of the house. His mother married two more times and the other husbands also died in the mine. My grandfather then worked from age 7 to 21 in the mines. He died at 88 from Black Lung induced Lung Cancer.

Yeah coal mining sucks.


>This isn't even counting the part where no new nuclear reactor could possibly be as unsafe as Chernobyl or Fukushima

That's what they say after every accident too. "This time, with the new designs, it's different".


A dangerous plant design like Chernobyl would have been illegal to build in any western country, so not sure why you think it is relevant to any other country. Accidents from hydroelectric plants have killed orders of magnitude more people than even the largest estimates of deaths from Fukushima (or even Chernobyl) - are you also opposed to hydroelectric power?



Lying about diesel emissions is also illegal. Whoops!


Um. This isn't something where you can just run your reactor in different configurations at test time and run time. The technology has come a long way since the 1960s and the math and science have advanced transformatively. Building an unsafely non-compliant nuclear plant would be like building a diesel car and then trying to tell the regulators that it's electric. You can do some fudging, sure, but things like the sign of the void coefficient are effectively impossible to lie about.


>Um. This isn't something where you can just run your reactor in different configurations at test time and run time.

No, but lying and having experts being, ahem flexible, about the expected safety is very easy, and par for the course when selling multi-billion dollar projects...

It's also very easy to ignore "black swan" event cases, and the potential impact to millions of lives, just because you think you've covered everything there is to cover.


Chernobyl was just about the worst possible outcome of a nuclear disaster: The majority of the radiological material was swept up in a cloud of graphite dust and lofted into the upper atmosphere by a fire that burned, uncontrolled, for over a week. Fukushima happened in one of the most densely populated areas on Earth. And yet, even counting those, Nuclear is still the safest energy source we have. We can talk about black swans and fudging the estimates, and I'll admit that your line of argument would be stronger if we were talking about the very first reactors to be built, when they were still just blueprints.

But that's not the case. We have real-world evidence that we can use to calibrate our expectations against reality. The fact is that, even if you count Chernobyl and Fukushima, our existing reactors are safer than fossil fuels. And I think that you would have an exceedingly difficult time arguing that newly-built reactors would be less safe than existing reactors.


And it is different. Cars still crash, but for any given crash speed ťhe survivability of any given class of car is two orders or magnitude better than its 1950s counterpart.


Which "new designs" have failed catastrophically?


The recipe for the catastrophe is design + time, so it's not like "new designs have fewer failures" offers much comfort. Of course they would.

Plus, previous installations had fewer potential non-design-related issues, such as terrorism, which (in today's nihilistic "more possible damage, including innocents and even myself" way) wasn't as much a thing in the 60s and 70s.


If you want to talk risk-of-terrorism, look at dams, not nuke plants. https://en.wikipedia.org/wiki/Banqiao_Dam


At least damns damage only the area relatively near them. The implications of a nuclear catastrophe can impact thousands of miles around, including major cities.


Dams are built on large rivers. Inundations resulting from dam failures tend to follow the path of the river. Cities are also built near large rivers. The Banqiao Dam failure displaced fifteen times as many people as the Chernobyl and Fukushima Daiichi disasters combined. The impending failure of the Mosul Dam is projected to do the same.


... very likely less than coal power plants will have done.


Agreed, I'm not pro-nuclear in opposition to coal. But good point.


>Why would you suggest we prevent using all appropriate options at our disposal?

He already answered that: because not all options are appropriate.


>Can we focus on renewables and stop trying to sell people hazardous waste that can last for millenia?

No one I know is opposed to renewable energy, but advocates really do everybody a disservice when they try to argue that an intermittent power source without storage is a reasonable replacement for base load power. This comic illustrates the problem: http://www.smbc-comics.com/comic/capacity

>... How can you guarantee that a certain place is safe to store millions of tons of radioactive waste for thousands of years if we can't even guarantee what will happen tomorrow?

Millions of tons? Where are you getting that number from? Right now nuclear waste can and should be recycled which would reduce the amount of waste: https://en.wikipedia.org/wiki/Radioactive_waste

Soon it will be possible to use most of the waste as fuel:

"...Fast reactors can "burn" long lasting nuclear transuranic waste (TRU) waste components (actinides: reactor-grade plutonium and minor actinides), turning liabilities into assets. Another major waste component, fission products (FP), would stabilize at a lower level of radioactivity than the original natural uranium ore it was attained from in two to four centuries, rather than tens of thousands of years"

http://en.wikipedia.org/wiki/Integral_fast_reactor

The worry people have about nuclear waste is greatly overblown. The amounts generated are manageable and in a relatively short amount of time we can use most of this "waste" to generate electricity.

>...We need to stop this nuclear madness!

NASA has estimated that using nuclear power has saved an estimated 1.8 million lives that would have been lost if the power has been replaced by fossil fuels: https://climate.nasa.gov/news/903/coal-and-gas-are-far-more-...

As someone in a previous discussion pointed out, the historical record for deaths from nuclear power have been very low:

Energy Source Mortality Rate (deaths/trillionkWhr)

Coal – U.S. 10,000 (32% U.S. electricity)

Natural Gas 4,000 (22% global electricity)

Solar (rooftop) 440 (< 1% global electricity)

Wind 150 (2% global electricity)

Nuclear – U.S. 0.1 (19% U.S. electricity)


>> Can we focus on renewables and stop trying to sell people hazardous waste that can last for millenia?

> No one I know is opposed to renewable energy, but advocates really do everybody a disservice when they try to argue that an intermittent power source without storage is a reasonable replacement for base load power. This comic illustrates the problem: http://www.smbc-comics.com/comic/capacity

The comic is a bit disingenious as it implies that all renewables are intermittent.

But many renewable energy sources are base load as well, e.g. hydro or wind. Yes, they have variations, but so does the load -- from the perspective of power grid management there's nothing new.

In fact this is part of the problem: renewables and nuclear (or coal) are competing for base load. If we build a nuclear plant, we need to run it for 50 years for the investment to make sense. This means that it will economically and politically impede the installation of e.g. wind power for 50 years.


Wind most certainly isn't base load. It's highly weather dependent. Occasionally, Ireland's wind infrastructure produces the country's entire electricity demand, and they actually have to start shutting down wind turbines. Also occasionally the whole system only produces a couple of hundred megawatts for a period of about a week.

There are some locations with very reliable constant wind (though usually only for part of the year) but that's not the norm. Offshore wind does better, but is still far from base load.


> Wind most certainly isn't base load.

The German government's scientific service, for one, disagrees with you.


Do you have a link to an article on this? My impression was that Germany was trying to move away from base load as a concept entirely, using unreliable renewables plus highly responsive fossil plants instead.


Here's the link: http://www.tab-beim-bundestag.de/de/untersuchungen/u140.html

It being a German government publication it's in German unfortunately.

As far as I can tell from skimming it your impression is correct.

So I apparently misremembered the article, and my claim about base load a few posts above may be incorrect after all. Sorry, rsynnott.


They moved away from Nuclear. However, now they import power from France, etc. Which has Nuclear and fossil fuel plants.


In 2016, Germany was a net exporter of electrical energy: https://de.statista.com/statistik/daten/studie/153533/umfrag...

However you're right that Germany was a net importer from (among others) France: https://de.statista.com/statistik/daten/studie/180862/umfrag...

Which is surprising as I remember reading that France has tremendous difficulties satisfying their electricity demand, especially in winter (lots of electric heating apparently).


>...The comic is a bit disingenious as it implies that all renewables are intermittent.

No, I don't think it does that.

>...But many renewable energy sources are base load as well, e.g. hydro or wind.

As user rsynnott said "Wind most certainly isn't base load." While hydro is base load power, only a few countries like China are considering building more hydro plants. We aren't going to be able to use hydro as a means to get off of burning fossil fuels.


"The budget for Hanford alone is about $2.3 billion in the current fiscal year, about $1.5 billion of that going to the management and treatment of approximately 56 million gallons of radioactive liquid waste stored in underground storage tanks." https://www.washingtonpost.com/news/post-nation/wp/2017/05/0...

Ultimately, however, the core problem may be that such new reactors don't eliminate the nuclear waste that has piled up so much as transmute it. Even with a fleet of such fast reactors, nations would nonetheless require an ultimate home for radioactive waste, one reason that a 2010 M.I.T. report on spent nuclear fuel dismissed such fast reactors. Or, as Cochran puts it: "If you want to get rid of milk, don't feed it to cows."

https://www.scientificamerican.com/article/fast-reactors-to-...

"Do the math! 1.1 additional GT out of 36 GT emitted is only a 3% difference. This 3% value is not a typographical error. Worldwide, all those nukes made only a 3% dent in yearly CO2 production. Put another way, each of the 438 individual nuclear plants contribute less than seven thousandths of one percent to CO2 reduction[18]. That’s hardly enough to justify claims that keeping your old local nuke running is necessary to prevent the sea from rising."

http://www.fairewinds.org/demystify//demystifying-nuclear-po...


>The budget for Hanford alone is about $2.3 billion in...

Hanford was started in the Manhattan project to produce plutonium and during the cold war produced plutonium for tens of thousands of nuclear warheads. All of these government weapons plants were quickly started with inadequate policies for handling the material.

>...Ultimately, however, the core problem may be that such new reactors don't eliminate the nuclear waste that has piled up so much as transmute it.

A 4th gen design like the IFR would allow you to end with a much smaller volume of waste that would only be dangerous for a few centuries.

In terms of natural gas, the numbers given are probably out of date - CO2 emissions from a natural gas plant are lower than a coal plant, but that doesn't account for the methane emissions that come with fracking and distributing the methane.

>...Back in August, a NOAA-led study measured a stunning 6% to 12% methane leakage over one of the country’s largest gas fields — which would gut the climate benefits of switching from coal to gas. We’ve known for a long time that methane is a far more potent greenhouse gas than carbon dioxide (CO2), which is released when any hydrocarbon, like natural gas, is burned. But the IPCC’s latest report, released Monday (big PDF here), reports that methane is 34 times stronger a heat-trapping gas than CO2 over a 100-year time scale, so its global-warming potential (GWP) is 34. That is a nearly 40% increase from the IPCC’s previous estimate of 25. ...The IPCC reports that, over a 20-year time frame, methane has a global warming potential of 86 compared to CO2, up from its previous estimate of 72. Given that we are approaching real, irreversible tipping points in the climate system, climate studies should, at the very least, include analyses that use this 20-year time horizon. Finally, it bears repeating that natural gas from even the best fracked wells is still a climate-destroying fossil fuel. If we are to avoid catastrophic warming, our natural gas consumption has to peak sometime in the next 10 to 15 years, according to studies by both the Center for American Progress and the Union of Concerned Scientists.

https://thinkprogress.org/more-bad-news-for-fracking-ipcc-wa...

As we use more and more natural gas, we can expect more and more methane disasters like the leak from Aliso Canyon in CA which was the largest methane leak in US history. This released over 100,000 tons of methane into the atmosphere and required 11,000 residents to be evacuated.

http://www.bbc.com/news/science-environment-35659947


It is slightly disingenuous. Although it might be true that a coal plant emits more radioactive material overall, the concern with nuclear plants is the radioactive emission in the event of an accident, not the emissions during regular operation. Just wanted to bring up an important distinction. I personally still support nuclear energy.


It's also almost certainly wrong in practice, given that the 2007 data in the article wouldn't include the Fukushima meltdown.


Even accounting for Fukushima and Chernobyl, coal has emitted more radiation per MWh.


No one can deny when fission goes wrong, it goes really wrong. Statistics are often ineffective influencing emotions.


When Naki was evacuated on ground of radiation levels that was orders of magnitude lower that that found naturally at Guarapari beach not a single person died. One year later the suicide count due to the emotional trauma caused by forced eviction exceeded 1000.


But coal and oil, working correctly, are destroying the planet.


To clarify, I'm pro nuclear. I mean it is very hard to fight irrational fears with logic. Like how flying is safer than driving per miles, yet many people are more afraid of planes than cars.


An interesting discussion about how burning coal concentrates trace amounts of uranium and thorium in coal and leaves it in fly ash (the remaining particulates).

It makes me wonder how much of each element you could extract by "mining" fly ash dump sites.


People have already looked into extracting rare earth elements from fly ash.

>Average total REE content (defined as the sum of the lanthanides, yttrium, and scandium) for ashes derived from Appalachian sources was 591 mg kg–1 and significantly greater than in ashes from Illinois and Powder River basin coals (403 and 337 mg kg–1, respectively). The fraction of critical REEs (Nd, Eu, Tb, Dy, Y, and Er) in the fly ashes was 34–38% of the total and considerably higher than in conventional ores (typically less than 15%).

http://pubs.acs.org/doi/abs/10.1021/acs.est.6b00085


It's amazing they just dump that stuff as if it's garbage.


Awesome, thanks for that link!


I think that the Scientific American article somewhat distorts the original article by paraphrasing it. Let's go back to the source. You can view the original Science article via sci-hub.cc if you want to see all the numbers or if you suspect that I've made mistakes with my own commentary.

http://science.sciencemag.org/content/202/4372/1045

DOI: 10.1126/science.202.4372.1045

First look at tables 2 and 3. The raw radionuclide release from the reactors, measured in curies, are far greater than those from the coal plant. Both reactor types release thousands of curies of xenon isotopes and hundreds of curies of krypton isotopes. The PWR also releases thousands of curies in the form of tritium. The coal plant releases less than 2 curies of all radionuclides combined.

Next look at table 4. The maximum whole body dose commitment, e.g. the dose that somebody might be exposed to if they lived 500 meters from the sources, just beyond the plant boundary, is highest for the boiling water reactor (4.6 mrem/year), then coal (1.9), then the pressurized water reactor (1.8).

But if you look at table 5, average population dose within an 88.5 km radius, you see that the population dose commitment over the whole region is lower for both pressurized and boiling water reactors (given the assumption that 100% of the food people eat is grown in the same region).

Table 6, "Population dose commitments from the airborne releases of model 1000-MWe power plants as a function of food intake", is the most interesting table in the article. It shows what parameter is most key to which power source produces greater population exposures: percentage of food eaten that is grown within the same region as the population. At 50% or more local food consumption, which is assumed in table 5, coal always exposes the regional population to a higher radionuclide dose than nuclear reactors. If people were eating 30% or less locally grown food -- which admittedly does not seem likely -- then the region's population could be exposed to more radiation from a nuclear plant than from an equivalent coal plant.

Why do nuclear reactors initially emit so much more than coal plants, measured in curies of radionuclides, yet generally expose human populations in the region to less of a body burden? Why does the relative population exposure ordering of nuclear power and coal change depending on how much locally grown food those populations consume?

The answers lie in the chemical and biological behaviors of the different radionuclides that respectively dominate emissions from reactors and from coal plants. "Radium-226 and radium-224 are the major contributors to the whole-body and most organ doses from the coal-fired plant. Assuming that the deposited radionuclides could enter the food chain, ingestion is the main exposure pathway for the population dose commitments from this plant (93 to 96 percent for the whole body and most organ doses, 83 percent for the bone dose, and 62 percent for the lung dose). ... Carbon-14 is the main contributor to the whole-body and most of the organ doses from both nuclear plants. Ingestion is the major exposure pathway."

Radium is chemically similar to calcium, so it is taken up by plants via the same pathways that take up calcium. It gets stored in the bones of exposed humans. Carbon of course is a major part of human and plant dry mass and also gets stored in organisms. These key isotopes are chemically available to plants and processed as nutrients in the bodies of both plants and humans.

Those thousands of curies of noble gases initially released by the nuclear plant? They matter orders of magnitude less when it comes to human exposure. Those gases can't chemically react with anything and diffuse throughout the whole volume of the atmosphere. Plants don't concentrate them and the human body can't store them.

The much less significant exposure route, "immersion," basically means exposure to radionuclides in the air all around you. Under most assumptions the immersion route will deliver a lower exposure to a regional population than ingestion via food. But if people in the exposed region are eating 30% or less locally-grown food, then the immersion route can become dominant and can lead to higher population exposure from nuclear power than from coal power.

The Scientific American article does not touch on any of these interesting points. It paraphrases the original in a way that actually introduces mistakes. It does not explain why some reasonable assumptions lead to lower population radionuclide exposure from nuclear power than from coal power. The broad summaries remain similar but the mistakes and simplifications lend the Scientific American article an unfortunate air of "here's a nice simple conclusion to bash your friends with the next time they fret about radiation from nuclear power."


Interesting points. Keep in mind though, this article is from 1978. Technology and law regulation for reducing dangerous concentrations of gases from flue gases at coal power plants improved since then. I don't know for nuclear. I recently was leading electrical works for new DeNOx (SCR) plant at one coal power plant. Since my country entered EU, the allowable safety margins improved forcing the power plant owners to either invest in purification plants or shutdown by 1st jan 2018.


Yes, it would be interesting to compare a modern nuclear reactor and a modern coal plant using the same evaluation criteria. Regulators have changed how both operate since the 1970s, even if the facilities were originally constructed earlier.

Maybe I should have phrased my original objection more strongly: the headline of this HN piece, the original headline in Scientific American, and many commenters writing here are unambiguously wrong about certain points. Coal ash is not more radioactive than waste from nuclear reactors. Ordinary commercial reactors, operating normally, emit far more curies of radioactive material than is present in the fly ash emitted from coal plants. The effective exposure of populations to radioactivity is however lower for reactors than for coal plants due to the differing chemical/biological characteristics of the different radionuclides emitted. That's pretty interesting! But that key point which produces the counterintuitive lower-effective-exposure result is completely lost in the SA article. Over the past decade I have mostly seen this Scientific American article used as a club to bash people who "just don't understand" nuclear power. It's a sad triumph of tribal affinity over comprehension.

Coal is certainly far worse than nuclear power when you broaden the criteria beyond radionuclide release. Most of the world's coal plants are still operating without state-of-the-art pollution controls for mercury, acid gases, and particulates. Even with modern emissions controls for acute pollution hazards, coal emits a lot of CO2 for each MWh generated. But the overall superior environmental and human health profile of nuclear power should not tempt people to spread falsehoods in its defense.


Comparing the momentary release of coal combustion with the 10,000 year waste management issues of nuclear in the way only "science" journalism can.


If you believe in nuclear power so much, please keep the nuclear waste in your state where it's created instead of sending it elsewhere


I'm fine with that as long as people opposing nuclear power keep the radioactive ashes from coal powerplants needed to replace the nuclear baseload in their states. As well as all the other toxic wastes. Not mentioning the side-effects, including global warming, starvation, migrations, and wars caused by that.

Instead so far they seem to push the externalities to others by either using coal and spewing it all into air, or not using coal, but buying balancing power from elsewhere, where they do use nuclear power or coal power :).

I think we can agree both of these alternatives are morally dishonest.


If you believe in "green" power so much, start using it for everything in your daily life.

Also, stop importing energy from other states, while essentially banning energy development in your own (cough... Calfornia).


Over having a coal plant spew out shit all day long? Gladly. Too bad everyone else is being irrationally NIMBY like yourself.


Same for neodymium processing for wind turbine production.


The title is extremely misleading. The article says that the amount of radiation released into the environment by a coal power plant is more than the amount of radiation released by a comparable nuclear plant. This is because coal ash is radioactive, and although it's (obviously) far less radioactive than radioactive waste, there's no effort to contain its radioactivity, so it results in more radiation exposure to people living around the plant.


"Coal plants emit more radioactive waste than nuclear plants" is a better translation here.


Or "than nuclear plants emit during normal operations". I would have liked to see a comparison about how much radioactivity is released per kWh by a coal plant versus a nuclear plant, if you divide Chernobyl and Fukushima by the total amount of nuclear energy produced in the same timespan.


To get a better average you'd need to compute the total radioactive emissions of all nuclear plants divided by their operating time and compute per GWh versus coal plants on the same scale.

Chernobyl and Fukushima are two exceptional events. There are hundreds of reactors out there both civilian and military that have never had catastrophic faults.


Ok, we've changed the title above to that. Thanks!


This isn't very useful information. I'm sure Chernobyl and Fukushima have released more radioactivity than every coal fired plant that has ever been or ever will be.


There are a lot of coal plants that constantly emit a lot of waste into the atmosphere. Nuclear events are, thankfully, quite rare and have been largely contained.

Plus, as bad as radioactive incidents can be, they don't affect the climate. Once the radiation dies down or is mitigated through clean-up efforts there will be no lasting impact on the world. In other words, with the right insurance policy you can recover from a disaster.

Hiroshima and Nagasakia were both deliberately targeted by nuclear weapons and are still inhabited. Cleaning up the mess can be expensive, but it's not impossible.

Cleaning up the mess made by a coal plant is basically impossible, the effects are too far reaching.


https://www.theguardian.com/world/2017/mar/09/fukushima-nucl...

Seriously? "Expensive but not impossible"?


There's a huge difference between cleaning up the surrounding landscape and dealing with the broken reactors themselves. Eventually we'll figure out how to fix those. Nothing an X-Prize contest or two can't help address if things get truly desperate.

I'd take a contaminated room any day over a whole planet slowly cooking itself to death.


>Nothing an X-Prize contest or two can't help address if things get truly desperate.

Yeah, because technology advances magically if you will it enough...


We have a number of commercial space-flight companies now and a dozen self-driving car platforms that work quite well. Neither of these really existed before their respective X-Prize type challenges.


The difference is that there was a focused effort to cleanup after those disasters. Coal plants dump tons of ash into the environment on a daily basis with only lax regulation. Coal ash is intentionally not regulated as toxic waste due to politics rather as simply solid waste.

Thus it builds up in our ground water and atmosphere with no warnings and little community notification.


...So, if I told you the number of deaths per year due to car assembly accidents, you'd call it not useful, because car crashes cause way more deaths?

To be clear, my suggestion would be to google "category error".


More people have died from design failures, mishandling, and, in fact, normal operations of non-nuclear power generation facilities than nuclear plants, including the Chernobyl and Fukushima disasters. If a gas pipeline explodes what is the conclusion? If a dam breaches and kills thousands, what is the conclusion? If a coal plant kills thousands even when it's working correctly, what is the conclusion?


You think that you are sure, but you are wrong. The numbers are found a few posts above.


I think if you add up all the coal power stations and add up all the nuclear power stations, nuclear power stations emit millions of times more radiation than coal fired power stations.. just look at fukashima

Not to mention the waste fuel containing stuff that never existed before being produced in a nuclear power station


> I think if you add up all the coal power stations and add up all the nuclear power stations, nuclear power stations emit millions of times more radiation than coal fired power stations.. just look at fukashima

No. Coal spews out constant radioactivity. Nuclear emits nothing during normal operation. Even counting Nuclear disasters, emitted radiation and deaths per kW/h are lower for Nuclear. It is the safest per kW/h, period.

> Not to mention the waste fuel containing stuff that never existed before being produced in a nuclear power station

Which is much easier to contain then fly ash.


That's nice.

Now let's talk about costs. Not idealized costs, but actual, non-hidden costs of building, maintaining, and decommissioning nuclear power plants (oh and storing the waste in effective perpetuity).

What's that you think decommissioning would be too expensive and want to keep running the plant extra long with upgrades? Oooops, that's how you get Fukushima.

http://www.nytimes.com/2011/03/22/world/asia/22nuclear.html


>oh and storing the waste in effective perpetuity

The only reason we aren't upcycling the 'waste' is because of an order issued by Jimmy Carter to prohibit the proliferation of Plutonium; we could be using it as fuel in other reactors.


You get Fukushima by building backup generators right next to the ocean on an island prone to being hit by tsunamis.


Building next to the ocean is fine. Japan has a lot of experience in protecting their shorelines. The seawall that covers over 40% of their coastline is very impressive. However, as the 2011 tsunami demonstrated, all defenses eventually fail. While some blame lies with TEPCO avoiding recommendations to upgrade the seawall, it's hard to defend against the insane[1] power of over 4m of moving water.

This is why the real lesson is to build defenses in depth, with enough variety to protect against common mode failure. Fukushima Daini - only 12km away from Fukushima Daiichi - suffered similarly from the earthquake and tsunami, but a single surviving pump (and the skill and effort of the staff) was enough to prevent Daini from suffering the same fate as it's sister powerplant.

Good engineering asks questions like, "Are we safe when (not "if"!) the entire bank of backup generators fail?", or "Can a single event cause catastrophic failure?"

[1] https://www.youtube.com/watch?v=5IKIazZc-a8


It was my understanding that TEPCO was warned against the exact event that happened, and didn't upgrade their backup generator infastructure accordingly. Things only got bad when they ran out of power. Which seems ironic that they couldn't use their own generated power to prevent a meltdown, but that was because the reactors was shut down I assume.




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