What is the concentration of U and Th in the flyash. Are these statements generalized observation or based on solid data.

Coal contains Ra-226 and natural uranium in concentration varying with the area where it is mined. Burning the coal leaves an ash which concentrates the natural radioactivity in the areas where the ash is deposited. This is now addressed by various studies as well as by regulation dealing with NORM (the acronym for Naturally Occurring Radioactive Material). It has been observed since quite long that some anthropic activities tend to redistribute the natural radioactivity - and we do not speak only about the ash from coal burning plants, but also about the phosphogypsum resulting from the production of phosphatic fertilisers.

It is not true that these wastes are more radioactive than the waste from a nuclear power plant, but it is true that they are less regulated. As a result, the NORM pollution resulting from these activities is much higher than the pollution resulting from the nuclear waste from an NPP.

You can find several technical documents on this on the publications page at www.iaea.org

Nuclear waste are not only NORMs am interested to know if anyone has actually measured these concentrations before making this general statement that Fly ash is more radioactive than nuclear power plant waste?

Saif, as I said before, the ash is not more radioactive than the waste of the NPPs, but in fact even less radioactive than the low level waste from the NPP. The difference comes from the fact that the nuclear waste is highly regulated and will never end up in the environment, while the coal ash is stacked usually in the environment and much less regulated as a waste. As a result, the ash is much more polluting than the nuclear waste simply because in many cases it is freely released in opened stacks, not because it is more radioactive.

I got your point Radu and agree that the fly ash is not well regulared and NPP waste are issue that are taken care of at the highest level. But just interested to know what the levels are and I have strong reservation on the statement by the author of this question "the waste produced by coal plants is actually more radioactive than that generated by their nuclear counterparts. 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".

Here's a link to an old story in Scientific American on the subject, the clear communication of the issues can be as much of a story as the subject itself (look at the amount of comments the article generated)

http://www.scientificamerican.com/article.cfm?id=coal-ash-is-more-radioactive-than-nuclear-waste

Thank Rory it is an interesting article. However am not very convinced with this specific statement that thermal plants generate 100 times more radiation. The attached article also carries a editorial remark which also puts a concern.

Exactly

The first remark on the paper posted by Rory is that it must be the source of inspiration for Sabitri, she appears to have quoted from it. Then, I agree with Saif, the statement that the ash is more radioactive is simply wrong, for the reasons we all stated above. In fact, from the measurements we have made here, in Romania, the ash and the phosphogypsum stacks contain Ra-226 in levels situated between tenths of mBq/kg to a few hundreds of Bq/kg (especially for phosphogypsum stacks, the ash is usually in the range of up to some tens of Bq/kg). This is less than the radioactivity of low level nuclear waste. Probably the author of the article means that the pollution produced is much higher, which is not difficult - the waste from NPPs produces virtually no pollutions because all the cycle of nuclear fuel is so highly regulated. In this case, even the ash from a home stove would be more polluting - if you compare any positive amount to zero, than this is the result. The problem is that even the journalists from a high standard scientific journal seem to misunderstand the problem and this can generate public hysteria.

Thanks Radu for understanding my concern and point of view.

dear Nahak,

please, read here:

http://www.weenergies.com/environmental/ccp_handbook_appendixb.pdf

On the more general point of Technologically Enhanced Naturally Occuring Radioactive Materials (TENORM) a relevant review paper would be that of Vearrier et al (Clinical Toxicology v47 (2009), 393-406 http://informahealthcare.com/doi/abs/10.1080/15563650902997849) which summarises TENORM exposures to workers and the general population related to several industries. Though, the authors omit coal-powered stations and associated fly ash and other wastes, with just a very brief mention. Which is, IMO, a significant and regrettable omission from the paper.

My understanding on the issue is that combustion fuel driven power plants use millions of tons of fuel per year. Even a 0.00001 percent composition of radioactive elements in this massive amount of fuel results in a release of radiation that adds up to amounts of tons per year - that are spread as ash across our globe. The levels are quite low - and the comment "more radioactive" is misleading.

On the other side, nuclear power stations are intended to provide full containment of the small mass of nuclear fuel that is used per year in power stations. The amount of radiation released in the air from nuclear power plants is miniscule.

But to the point of your question: the amount of trace uranium in the fossil fuels that we burn for power is greater than the amount of uranium required to operate equally powered nuclear plants; this is the motivation behind the "more radioactive" comment.

Americans living near coal-fired power plants are exposed to higher radiation doses than those living near nuclear power plants that meet government regulations

http://web.ornl.gov/info/ornlreview/rev26-34/text/colmain.html

See also:

http://www.iisc.ernet.in/currsci/dec102006/1508.pdf

http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&ved=0CDUQFjAB&url=http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F224861996_Natural_radionuclides_from_coal_fired_thermal_power_plants__estimation_of_atmospheric_release_and_inhalation_risk%2Ffile%2F9fcfd5003d7a196f89.pdf&ei=kVWpUvqPCIr8ygOkx4GICw&usg=AFQjCNG3yofCEnrZFZfBwCu8lSV0R8waBg

http://www.uswag.org/usgsradash.pdf

I agree, the statement "the waste produced by coal plants is actually more radioactive than that generated by their nuclear counterparts" is very misleading.

On the other hand, it is right that certain amount of radioactivity can be introduced into environment with the fly ash. When we studied 226Ra content in river sediments, we found slightly increased values at sites near coal power plants. But much more significant contamination was detected at sites influenced by (former) uranium mining (for nuclear fuel)....http://dx.doi.org/10.1016/j.limno.2005.05.004

Sorry; the question is really not correct and generate a confusion. The ash of what coal and nuclear waste of what composition?

Therefore the adequate answer will depend completely on the correct and concrete question.

HI sabitri,

I am not so sure if fly ash of a power producing coal plant and the nuclear isotope output of a power producing nuke plant are comparable.

But you asked for it.

One human error and you got the Tsjernobyl explosion, wit a lot more nuke output than fifty coal plants (or more). One earth quake of more than 8 on Richters scale followed by a Tsunami with waves higher than 10 meters combined with a nuke plant (actually five nuke plants of which two with mixed fuel) and you get even more nuclear rubbish under which Plutonium in the environment (Fukushima ring a bell?).

We did not have to wait very long for these nuclear incidents to happen. I am not even counting the Irish Sea which is contaminated with radiaoactive isotopes from the Sellafield nuclear waste processing plant, WITHOUT producing energy. How about that?

Somthing to think about no?

Cheers,

Frank

Thank you for all who have given the answers of my questions...i appreciate the answers but i need more for my research work. Thank you

coal ash is more radioactive than coal. Effect of concentration. CO2 is released into the atmosphere. The heavy part is the coal ash with radionuclides of the uranium and thorium series. You can not generalize. depends on coal ash and radioactive waste. ash can be more radioactive than a contaminated glove, but it sure is less radioactive than a burnt fuel

I still don't agree with the statement that waste produced from coal fired plant is more radioactive than nuclear power plant. I guess the scientists should be more responsible in giving such conclusions.

It may be true that the amount of radioactivity released from coal fired power stations is greater than the amount of radioactivity released from nuclear power plants under normal conditions. It may be, I've not looked up the numbers but it wouldn't surprise me.

BUT. And, it's a big series of 'buts' that by not including the statement is misleading and irresponsible.

1) The nuclear power cycle is more than operating power plants. There is significant amounts of radioactivity released into the environment from uranium mining, fuel production, used fuel storage and reprocessing. This radioactivity will almost certainly be more than released in coal plant operation, even if you add in radon gas produced in coal mines.

2) Nuclear power plants occasionally, though rarely, operate under something other than "normal conditions". Even relatively small incidents can liberate radioactive material into the plant if not the wider environment; any leak of primary coolant, accidents handling spent fuel. Many such products, including some inert gases, 14C as CO2, 3H in H2O, and would be very difficult to contain in a reactor building if they egt outside the primary systems. And, of course, we know of the consequences of the major accidents including Chernobyl and Fukushima. Add that to the equation and the emissions from coal plants become comparatively small.

3) The vast majority of radioactive waste from nuclear power will (hopefully!) never see the wider environment, being safely and securely stored. Add that waste to the equation and in comparison the emissions from coal plants look almost infinitesimal.

Not that any of that lets the coal power station operators off the hook. Emissions from the stack in the form of gases, aerosols and fine particles can be readily inhaled by people living and working downwind and may be a significant contribution to their received dose with potential health consequences (including from non-radioactive biological effects of heavy metals, particulates etc). In situations where the source of coal, design of the plant, proximity of members of the public etc result in members of the public receiving a significant dose enhancement amd potential negative health impact then action should be taken to attempt to mitigate those effects as much as practically possible.

Forgive me if I treme see your review, the majority agreement or express some sort of agreement the answer 1

1- It is not true that these wastes are more radioactive than the waste from a nuclear power plant

Radu Vasilache, Costante Invernizzi, John Kelley, Frank Veroustraete, Saif Uddin

2- It is true that these wastes are more radioactive than the waste from a nuclear power plant

Alan Cresswell, Florian Glodeanu, Eva Juranova, Wagner de Souza Pereira

3- It is not sure that these wastes are more radioactive than the waste from a nuclear power plant

Evgueni Shumilin

If I am a producer of nuclear energy and the people of nearby mainfeste their inconvenience, may be I can tell that other industries or coal plant gives more radioactivity than a reactor or I'm a decision maker or I want substituted coal by nuclear generating or downright intention to promote nuclear energy.

I agree with the majority

I say: depend of coal and waste. I say the coal ash is more radioactivity than the coal. is true. But There are different waste with different activity concentration. in some case, is possible that activity concentration the coal ash is bigger than the low activity concentration waste. But is not correct put my name in the secon group Benamar El Amine.

I agree with Saif Uddin, is necessary more responsability for this kind of affimation. Is not possible make generalization.

This may be also interesting: Coal ash is NOT more radioactive than nuclear waste - http://www.cejournal.net/?p=410

Benamar El Amine,

Just to clarify my position (as I'd put myself in 1 rather than 2).

Coal fired power stations may (and I emphasise, may) release more radioactivity into the environment than routine operation of nuclear power stations. However, taking the full fuel cycle into account including mining and reprocessing, and considering how much radioactivity has been released from non-routine operation of power stations (ie: accidents), then quite clearly nuclear power releases more radioactivity into the environment. That doesn't even consider the nuclear waste stored, hopefully securely, that should never be released into the environment.

Really the question should be formulated in another way. It is wrong to say that something is more or less radioactive than another one. Radioactivity is a yes/no property and as such a material is or not radioactive. It is the same as pregnancy: a women cannot be more or less pregnant, she simply is pregnant or not. Thus one should say that a radioactive material has higher or lower activity. Be carefull about this.This is not a semantic aspect. Science must be expressed correctly.

Coal typically contains 5 to 30% inert mineral material that remains as ash after burning. The ash content of lignite (brown) coals is lower than that of black coal. Fine ash is collected by the electrostatic precipitators, fabric filters and flue gas scrubbers. The heavier, more refractory mineral matter settles at the bottom of the boiler as bottom ash or slag. Most of the waste from a typical coal fired power station is generated as fly ash. Current management practice for the disposal of fly ash is to slurry the ash and transfer it to a settling pond after which the ash is disposed of in a landfill, usually at the site of the power station. Approximately 30% of bottom and fly ash is sold for industrial uses such as cement-extender in concrete, for road making or other applications, such as mine site rehabilitation.

Coal contains traces of naturally occurring radioactivity from uranium and thorium series and potassium-40, either associated with elements in the coal itself, such as sulphides, or within the minerals that are part of the coal formation. The radionuclide content of coal is generally below the average radioactivity levels in soils and depends on the type of coal and the location of the mine. The radionuclide concentrations in the ash material are generally enhanced compared to the original coal used. In addition, the various radionuclides are partitioned between the various forms of ash. For example, the more volatile radionuclides, such as polonium-210 and lead-210, tend to accumulate in the fly ash and smaller particles in the stack emissions. In contrast, the more refractory elements, such as uranium and thorium, accumulate in the bottom ash and slag. For example the bottom fly ash contains less TENORM than stack-fly ash as shown below:

Radionuclide content in ash (Bq/kg)

Type of ash Pb-210 U/Ra-226 Th-series K-40

Stack fly ash 130-200 80-150 100-200 500-800

Bottom Ash 5-10 80-120 100-120 500-700

The radioactivity in coal fly ash is a result of enhanced naturally occurring radioactive elements. It is low level long lived radioactive elements. However, waste from nuclear power station will contains high level radioactive waste from the used nuclear fuel. It is strictly regulated and internationally observed.

Thanks to all

Well Question is that from where the radioactivity is coming from?

Is the radioactivity is more than that of the crustal values?

Coal has inorganic material of crustal origin and organic mostly from Plant biomass. On burning lots of elements contained in the organic fraction tends to settle loosely on the ash particles by volatilization-condensation mechanism.

So the question is how much radioactivity is sponsored by crustal matter and how much by the organic part.

If it is also contributed by the organic, it is really a concern because of leachability problems.

Moreover, if coal ash is more radioactive, there should be an evidence of higher radioactive elements in the ground water and soil around ash ponds.

Hi!

My advice is is to read the Annex B of UNSCEAR (United Nations Scientific Commette on the Effects of Atomic Radiation) 2008, Exposures of the public and workers from various sources of radiation available at http://www.unscear.org/docs/reports/2008/09-86753_Report_2008_Annex_B.pdf

This is the background information everyone should have/give within a structured and up-to-date framework. Lot of references

Among the several radiation sources described there are those concerning "Enhanced sources of natural radioactivity" which include coal among many others. Many tables and infos on industrial cycles + abundant bibliography are provided.

I add that major concern could be attributed to natural radionuclides according to their chemical properties and consequent fractionation while burning. In particular the most volatile and possibly more hazardous radionuclides such as 210Pb and 210Po which may enrich in some fractions of the abatement systems and/or eventually escape the mitigation stages and stacks.

Obviously the comparison with NPP's should be addressed with the due attention since the topic cannot be liquidated in simple terms.

No doubt coal is radioactive. but it is not straighaway possible to tell coal ash is more radioactive than nuclear power plant. coal contains u-238 and its radioactivie daughters and Th-232 and its radioactive daughters which are in equilibrium. But when the coal is burnt equilibrium is disturbed. Moreover more radioactive nuclides is formed in the form of ash. the most hazardous among them are Po-210, Pb-210 and Ra-226.

Just to consider an other point of view, to be added to the elements of the debate so far vividly and really satisfactory developed.

I wish to introduce a different way to tackle the discussion, taking into account to be cautious to search for and effectively find an ideologic answer. I imagine whether I want to stress a position I can use some arguments and discard others. In this case, since I'm not so expert in fly ashes, i prefer to avoid details, and let us consider the general following topics (questions?): Is the total balance of radioactivity really increased or not, and is the actual dose equivalent to population in the whole process really increased in CPP vs NPP. This could be an answer to the side normal "risk". (not the potential). So without worrying about cost and benefits, we can introduce a very restrict way of judgement.

I've just looked at the 'thread' regarding this question and the comments. I'd like to make a few comments on other participant’s responses, in addition to adding some additional information that will hopefully be helpful.

Firstly, one responder commented that materials are either radioactive or they are not, a yes/no scenario; a woman isn't a little pregnant, she's either pregnant or not! This is not a proper perspective to take in regards to radioactivity. In nature radioactivity is ubiquitous - occurring in all natural materials (rocks, minerals, soils, waters, etc). Man goes to great lengths to manufacture materials (i.e., radiation detectors and shields) with the minimal amounts of radionuclides such as 238U, 235U, 232Th (and their decay series) and 40K, for example. Consequently, the amount of radioactivity, normalized to sample mass, i.e., the specific activity of the radionuclides in question, IS important and is used as a significant criterion in classifying such material from a health physics perspective, and for safe disposal purposes. The recent comments of Radu Vasilache are, I believe, most germane to the question.

My input would be the following - as a consequence of the aqueous geochemistry of uranium, quadravalent uranium (U4+) which is generally insoluble becomes soluble in an aqueous environment when oxidized to the hexavalent state (U6+) (n.b., unlike Th which remains in the insoluble quadravalent state). When such oxidizing waters, with very low levels of dissolved U), come into contact with a reducing, anoxic environment, (such as a swamp or bog with decaying organic matter...i.e., possible precursors to coal formation) the uranium in solution is reduced to the insoluble U4+ state, comes out of solution and becomes associated with the organic-rich material. Hence the very strong correlation with U and black shales in the sedimentary environment/record. Consequently, when coals are burned in a coal-fired power station U and many of its daughter products typically become enriched in the flyash. While the volume (and mass) of flyash, etc from such processes worldwide greatly exceeds the 'nuclear waste' from nuclear power plants the specific activity of the flyash is significantly less than that of nuclear reactor used fuel. As commented previously the difference is that the latter is highly regulated while the former is not and is generally more 'available' to the environment.

The ash has very little activity as compared to nuclear waste. See the publication: T.P. Barton, P.L. Ziemer in Health Physics, 50 (1986), p. 581

The fly ash contains long half-time naturally occurring radionuclides, whose radioactivity are lower than wastes from NPP. Maybe, it refers to the total radioactivity in wastes because the amount of fly ash is much lager.

I suggested that the type of materials and the environment may determines this. Also fly ash is known to be more radioactive as a material. The nuclear waste is saved carefully and protected and shielded to decrease it's radiation to the environment so this reason may reduces the amount of radiation emitted by it.

The question is not accurate, because radioactive waste material, for example from the use or reprocessing of nuclear fuel. and the radioactivity of this materials is more than that produced from coal used in electric power. however, for why the the fly ash has higher activity concentrations for radioactive materials such as 226Ra, 232Th and 40K, than other materials?. As you know, the natural radioactive substances are found everywhere in nature in rocks, soil, water and plants, as well as in the human body and the concentration of these substances vary from one material to another.For plants, the concentration of radioactive material above the natural range of 1 to several Bq per kilogram. And of course when they are burning these materials from which the coal originate, the carbon reacts with the oxygen and the carbon dioxide and carbon monoxide are composed, and the radioactive materials and heavy metals remaining in the ash and thus the concentrations of these substances will be high because, for example, if a ton of coal after burned become kilograms of ash, and thus radioactive material in a ton of coal will be concentrated in 1kg of ash, and so will be the concentration of radioactive materials in the ash high.

For the same amount of power generated by Thermal system and by NPP, the fly ash content is much more than NPP waste, and as U, Th and 40-K are available with fly ash it generates more radioactivity.

the coal ashes are not more radioactive than NPP, the problem is these ashes stick with ares ole and can inhale easily which produce more damage than NPP.

While this technical discussion is very good, I would just add the fact that naturally occurring radioisotopes in coal ash are cosmogenic and have been radioactive for billions of years.  They will continue to remain radioactive for billions of years.  NPP byproduct material isotopes have much shorter half-lives and thus burning U-238/235 in reactors actually lowers the overall environmental levels of radioactivity when looked at from a geologic perspective.  It is also interesting to note that at the time when life is currently thought to have begun on Earth (~ 3.6 billion years ago), terrestrial levels of radioactivity were about 7 times higher than now.  On top of that, cosmic sources of radiation were probably much higher due to the primitive atmosphere,.  Consequently, life has always been exposed to radiation and as long as we keep it at the low end of the scale we shouldn't be spending billions of dollars every time we find some coal ash disposed properly.  There are a lot of regulations out there that are the result of radiophobia, not true radiological risk.  It is important to keep this in perspective and spouting "coal ash is more radioactive" or "NPP's are more radioactive" really misses the reality of the situation.

Coals may include radioactive materials but not all of them, because they are sedimentary material and bounds to contain any material brought to the depositional environment. When you talk about a certain nuclear waste and compare coal ash, you absolutely make a mistake. Coal is not so miserable material to make it be afraid of. I am sorry but I will call this comment as just "bullshit".  

I  understand that a large number of publications on 'Toxicity of coal/fly ash including geno-toxicity ' in accessible in standard Journals. Just type google search for 'Recent publications in coal and fly ash from TPP' and the answer to the same is evident. Due to the same,  most of the countries are looking for other types of sources for energy generation and add to their overall Energy mix/inventory. The immense R&D on unconventional hydrocarbons and renewal energy is a clear indication that in the next decade their would be an enhance focus on the latter and slowly the component of coal (TPP)  to the energy mix of most of the countries would decrease. This would also decrease the carbon footprint, effect of acid rain, large land requirement for fly ash ponds (specially in more populous countries like India and China), heavy metal hyper-accumulation around TPP's, ground water contamination due to fly ash leachates etc.

A few of our colleagues within the Research-Gate already mentioned that the radioactivity in coal ash per MWh is not more than that of a nuclear power plant, but it is distributed over the environment, while the effluents of a NPP are well contained and taken care off. Now a days the coal PP are usually scrabing most of the fly ash out of the smoke within the chimney, thus reducing the concentration in air. These effluents (the caught fly ash) are eventually used as raw material in other products, like concrete and cement, and similar. Limits for the use of these effluents need to be established by the national authorities.

Some of the previously given replies explain in a good manner the question. However, I think the question is not posed precisely enough. You cannot just ask for a unit of radioactivity, you need to know the circumstances. One example of a crazy question would be, is the ocean more radioactive than the landmasses? You need to know, if you mean a "concentration" - radioactivity referenced to a volume or a mass, or do you mean just the inventory in total. Of course the radioactivity in coal ash contains more radioactivity, because there is much more coal ash available than radioactive wastes in total, and in addition to that, this is mainly very long-lived K-40, uranium and thorium isotopes and their decay products. In coal ash most of the radioactive NORM products will be fixed to the ash particlies, which means you might have an extremely high specific or mass activity (given in Bq/g) of these radioactive substances but on a relative low mass amount on a specific site.

This might not be the case for radioactive wastes, which contain also "short-lived" fission products and not only long-lived radionuclides. They will decay after - let us say some hundreds of years, while the NORM products on the coal ash and fly ash will stay for "ever". But these will later be diluted with other particles e.g. in the soil, where the ash will be deposited and thus, the "radioactivity" be diluted and result in much lower specific or mass activity given in Bq/g. I think the answer cannot be provided in a simple way, because the question needs to be more specified.

@Hartmut,

thanks for the clear comment.

I agree with the reason given for the enrichment of radionuclides (U, Th and K ) when a coal with normal radioactivity (equivalent to crustal abundance) is burnt in the Thermal Power Plants. However studies indicate that the concentration of radionuclides specially uranium gets further enhanced with increasing organic content and the ash content of coal. Typically ash content of about 15%  (or a bit higher) are utilized in the TPP's however of late high ash content coals greater than 30% are also being used.  Apart from this, the nature of  radioactivity in coals differs from seam to seam and depending on its specification lithology (location dependent). A large amount of coal which have high radioactivity i.e. much more than few hundred parts  per million, are often being used without in-situ measurement of  its ambient radioactivity and even ash content, before being used as feed coal. In a number of countries feed coals from different coal seams/lithology, is mixed to address this problem, but that may not be appropriate. In addition with the recent advancement of  ESP's and other methods being used to trap the fly ash from escaping (as best as possible) in the atmosphere makes the bottom ash,. stored in fly ash ponds become more enriched in contaminants, specially uranium, thorium as well as mercury, selenium, arsenic, lead,. chromium to name a few.

The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) released the new report on 8 February 2017, which is freely downloadable from

http://www.unscear.org/docs/publications/2016/UNSCEAR_2016_Report.pdf

This "UNSCEAR 2016" report discusses radiation dose from various electricity-generating technologies, including the coal cycle and nuclear fuel cycle.

It was found that the coal cycle contributed more than half of the total radiation dose to the global public from electricity generation, and that the nuclear fuel cycle contributed less than a fifth of this. This estimate was made as of 2010 when 40% and 13% of energy were produced by the coal cycle and the nuclear fuel cycle, respectively.

The report further evaluated radiation exposure per unit of electricity generated (again, using the data as of 2010), and concluded that in the short term, the values for the two main electricity generation technologies (coal and nuclear) are about the same. In the longer term such as hundreds of years, accumulation of very small doses from long-lived radionuclides result in larger collective doses from the nuclear fuel cycle.

Following

This is a missunderstand of the data

I assume you are referring to the observation of 10 times radioactive waste around coal plants than around nuclear plants.

Three points to make:

1. Both are 20 to 70 times smaller radiation levels than background radiation experienced by an average person in one year.

2. The smaller amount of nuclear waste reflects the more stringent safety requirements required from a nuclear station.

3. If all the fuel were to be released from a nuclear station it would be far more in quantity and more hazardous than the total amount of radioactive fly ash that could ever be emitted from a coal station.