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).
[1] https://en.wikipedia.org/wiki/Fly_ash#Present_production_rat...
[2] http://www.world-nuclear.org/information-library/nuclear-fue...
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...
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...
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...
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.
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.
I see no decay chain leading to Radon. https://en.wikipedia.org/wiki/Isotopes_of_iridium
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)
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.
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...
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/
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).
http://www.abc.net.au/news/2017-05-30/clean-energy-funding-c...