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Comment by w0mbat | Hacker News Reader

Coal is an environmental disaster. Burning it releases CO2, sulphur that causes acid rain, and surprising amounts of radioactive uranium and thorium.

In fact, coal power plants cause more radioactive contamination than nuclear power plants, and coal ash is more radioactive than nuclear waste, says Scientific American.

https://www.scientificamerican.com/article/coal-ash-is-more-...

Leave the coal in the ground.

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> coal ash is more radioactive than nuclear waste, says Scientific American.

This isn't true in any reasonable sense, and SA retract the claim in a footnote. But nuclear plants produce so much less waste than coal plants that overall, they release less radiation joule for joule.

> This isn't true in any reasonable sense,

> overall, they release less radiation joule for joule.

How is that not a "reasonable sense"? Less radiation joule per joule seems to me like a reasonable measure as "less radioactive overall"

Saying that coal ash is "more radioactive than nuclear waste" is too ambiguous. There are many kinds of nuclear waste with varying degrees of radioactivity. I assume there are also variations in the degree of radioactivity in coal ash. It might be meaningful to say that a particular kind of coal ash is more radioactive than a particular kind of nuclear waste, but without that context it's a meaningless comparison.

At the point where it's already waste, you don't really care about the energy that was produced from it, possibly years or thousands of years ago.

If one power plant creates 1000t of waste, and another creates 10000t of waste while providing the same amount of electricity, I think we can reasonably say that the second generates 10x more waste.

"Well, if you pick just one ton of waste from either plant it's the same waste!" is technically true, but it's neither here nor there.

(Of course in case of nuclear vs. coal it's a bit more complicated because the waste products are not the same, but I still think we can reasonably compare waste per energy.)

If the 1000t is radioactive at 5Bq/Kg and the 10000t is radioactive at 2Bq/Kg, it's at best confusing to say the second plant's waste is "more radioactive".

If bill gates venture into power pans out there won’t be nuclear waste at all it seems.

There are already plants that can do what he's proposing, like the CANDU reactor. It looks like they've taken some ideas directly from that reactor, so it looks pretty conspicuous that they never mention it.

Wait, what, no!

CANDU is a thermal water moderated reactor, albeit moderated with heavy water rather than light water, allowing it to use natural uranium instead of enriched (as Canada didn't have enrichment capability and didn't want to depend on other nations). And it's a pressure tube design, meaning the high pressure water is kept in a bunch of tubes rather than having one big pressure vessel like most light water reactors (again, because Canada didn't have heavy forges required to produce traditional reactor vessels).

What Bill Gates funded is a company called Terrapower that is making a sodium cooled fast breeder. Very different from CANDU. Fast breeders are a pretty cool concept, but they and the reprocessing technology for closing the fuel cycle isn't as mature as light water reactors.

I wasn't saying that they're the same, I was saying that they solve many of the issues that they were talking about with nuclear power (ie: need to use enriched uranium, no waste etc.). Candu reactors currently produce "waste", but they were designed not to since Canada thought they had little uranium to work with. Once it was found it was abundant in Canada, they stopped the reprocessing step, and just used newly mined uranium.

I don't know much about this stuff. Just watched that doco on Netflix, inside bills brain. It was the first I had heard of Nuclear power using depleted uranium, and that America apparently has enough depleted uranium to power the US for ~140 years or something.

I don't know why this isn't being pushed harder if it's safer and cleans up some of this waste.

Yeah, I watched the whole thing too. They leave out so much stuff, like that Paul Allen left the company because Bill & Steve Ballmer tried to dilute his shares when he had cancer, or that they actually bought DOS (the doco makes it look like they were working their ass off to build it).

CANDU reactors are Canadian, they use heavy water. They've been around for 50 years, people don't use them because they can't be used to make nuclear weapons. All the reators in Canada are these style.

We just need to find a way, way cheaper source of heavy water.

Sure there will. What do you think will happen to all the maintenance items and discarded scrap?

Surely you usually do care, because usually the discussion is about the best way to generate a given amount of energy.

The coal is as radioactive as the ash, thus these power plants are not creating any new radioactive waste.

Does that apply also to nuclear fuel? The byproducts of fission with uranium is less radioactive, or has a shorter half life, if I recall.

Short half lives are what make something radioactive. It's not 1:1 but basically take the amount of material / half life > how much radiation is being released.

Uranium 238 is extremely stable with a half life of 4.468 billion years, and the more active uranium 235 still has a half life of 0.7 billion years. Which is why they survived geologic timescales from earths formation.

Strontium-90 by comparison is produced in a nuclear reactor and has a half life of 28.8 years making it vastly more nasty. Further, while nuclear waste is incredibly nasty stuff, high neutron fluxes also turn the walls etc radioactive though to a less extreme extent.

I don't think so either ... and SA should never had put that in print. Anyway, there's no argument, just numbers. The measure of 'more radioactive than' is Bq/kg. (Total radiation? who releases those numbers? where's the transparency?)

According to the following article (and a couple I'm not citing), coal fly ash counts are on the order of 250-1000 Bq/kg. https://link.springer.com/article/10.1007/s10967-006-6966-1

Specifically, concentrated (fly ash) measures:

"263 to 950 Bq·kg−1 for 238U, from 142 to 605 Bq·kg−1 for 226Ra, from 133 to 428 Bq·kg−1 for 210Pb, from 27 to 68 Bq·kg−1 for 228Ra and from 204 to 382 Bq·kg−1 for 40K"

Anyone who cares to is welcome to cite the Bq/kg numbers for waste from nuclear plants. Go ahead, pick some. I think you'll find they are higher. And most coal doesn't contain any Pu.

We are not discussing nuclear waste here. It is highly concentrated and disposed of in the end of the fuel cycle. What you should be comparing with is the radioactivity that is released in the environment during the operation of the plant. That is mostly Tritium and isotopes of Xenon, definitely no heavy metals. Tritium is a very low energy beta emitter and is mostly harmless. Xenon is a noble gas and a beta emitter, so again not very harmful.

The WHO guidelines on alpha emitters (all elements you cite that are contained in fly ash) is 1 Bq/l in drinking water. So depending on how and where this ash goes to, you can definitely cause some significant damage with it.

For context, that seems to make coal ash about as radioactive as granite based on these figures for the latter: https://www.sciencedirect.com/science/article/pii/S168785071...

I think the real valid point is that nuclear waste is stored in a safe location, while coal waste is stored in the atmosphere and thus partially in our lungs.

> while coal waste is stored in the atmosphere and thus partially in our lungs

can't argue with that

> nuclear waste is stored in a safe location

so, that's part of the reason many people i know are still very suspicious about nuclear power even though they know _intellectually_ that it's (supposed to be) safer than some of the alternatives.

nuclear waste used to be dumped into the ocean, because back then we thought that would be safe. now it's stored in places that are deemed (earthquake-) safe until an earthquake (or a tsunami) hits. next we outsource the storage to private companies as those are cheaper and act suprised when we learn that they were skimping on manpower, maintenance and safety protocols when trying to cut costs and containers are leaking into the ground water.

it's the same as nuclear power plants. they're always perfectly secure until something unforseen happens or they've been secure for so long people get neglient.

But nuclear plants produce so much less waste than coal plants that overall, they release less radiation joule for joule.

Even that isn't quite accurate. Reactors release more radiation, but mostly in the form of elements that don't bioconcentrate into the food supply, so that the effective exposure of the human population is lower.

I wrote a long comment a couple of years ago discussing the original article that Scientific American paraphrased for this report:

https://news.ycombinator.com/item?id=14466887

Joule for Joule radioactivity seems like the only reasonable sense. Who cares if it's one drop of death or a pool full of lightly toxic waste? You could easily just dilute the drop to arrive at a similar but less toxic pool (if you wanted to, for some reason).

> coal ash is more radioactive than nuclear waste, says Scientific American.

Coal is definitely bad, however, coal power producing more radioactive waste than nuclear power is a meme that deserve to die.

Here's where the meme originated. Somewhere towards the end of the SA article there's this paragraph:

"The result: estimated radiation doses ingested by people living near the coal plants were equal to or higher than doses for people living around the nuclear facilities. At one extreme, the scientists estimated fly ash radiation in individuals' bones at around 18 millirems (thousandths of a rem, a unit for measuring doses of ionizing radiation) a year. Doses for the two nuclear plants, by contrast, ranged from between three and six millirems for the same period."

Well, guess what: people living near nuclear power plants have a very reasonable expectation to see zero radioactive releases from those plants, and this expectation is generally met (with a few notable exception that we all know about, like Fukushima). That does not mean nuclear power plants don't produce radioactive waste. They do, and that waste is stored and shielded. After the shielding, the amount of radiation released is zero. Yes, zero.

Let's look at the actual numbers now: 18 millirems/year from coal ash, vs 3-6 in the neighborhood of the nuclear power plants. But how much is normal natural radiation? Per [1] it is about 300 millirems/year. So both 3-6 and 18 are negligible levels compared to the normal radiation background.

How does this all compare to Chernobyl? Per [2] the radiation in the vicinity of the famous Elephant Foot is about 8500 Roentgens/hour. Which corresponds to about 75 billion millirems/year.

So, whenever someone mentions again the fact that coal produces more radioactivity than nuclear, keep these two numbers in mind: 18 units for coal and 75 billion for Chrnobyl. Oh, and the natural background is 300 units.

[1] http://news.mit.edu/1994/safe-0105

[2]https://en.wikipedia.org/wiki/Elephant%27s_Foot_(Chernobyl)#...

Not sure if you noticed before spending all that time into apples to oranges comparisons: SA article was about ingested sources of radiation.

Elephant Foot and natural background radiation are outside of your body. Coal ash gets inside. There is profound difference in effect - skin and outer layers of body cannot shield the rest.

Also, the Elephant Foot is rather easy to avoid; just don't go standing next to it. Avoiding fossil fuel pollution, OTOH, is something most humans can't realistically do.

Unless it had melted through the floor and made its way to ground water.

Then we get back to discussion that inhaling radioactive particles is harmful.

> Elephant Foot and natural background radiation are outside of your body

Have you heard of Carbon-14 dating? Of course you did. All things containing carbon that we interact with contain a bit of C14 ( * ) . Including the things we eat. Yes, we ingest every single day, and we inhale every single second radioactive things. If you eat one banana a day you get a yearly dose of 2.6 millirems [1]. That one comes from Potasium-40, but it's the same idea.

So the dose SA was talking about, 18 millirems/year, was equivalent to 7 bananas a day.

Here's a more scientific study than the SA articles [2].

"The radiation hazard from airborne emissions of coal-fired power plants was evaluated in a series of studies conducted from 1975–1985. These studies concluded that the maximum radiation dose to an individual living within 1 km of a modern power plant is equivalent to a minor, perhaps 1 to 5 percent, increase above the radiation from the natural environment. For the average citizen, the radiation dose from coal burning is considerably less."

( * ) Fun fact: fossil fuels contain essentially no C14 (the half-life of C14 of about 6000 years is many times smaller than the age of the fossil fuels). This is used in testing alcoholic beverages. Natural alcohol (obtained via fermentation) has the usual ratio of C14/C12 and emits a recognizable radiation spectrum. Alcohol industrially produced from petroleum is much cheaper. It does not have C14, so this is how you can detect if an unscrupulous producer uses synthetic ethyl alcohol (which is a dangerous because it has traces of methanol and benzene).

[1] https://newatlas.com/radiation-explained-food-sources-danger...

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

So I'll break news to you: C14 and K40 do not accumulate in your body up same way like radium/uranium/heavy metals do.

"Even at low levels, these isotopes represent health hazards as they can accumulate in the human body (eg, in lungs), gradually enter the blood circulation, and deposit in bones and teeth to remain for life."

http://www.ncmedicaljournal.com/content/79/5/289.full

So there are three things that you really miss: doses are essentially permament (due to half-life), cumulative and localized in small areas of body.

And you miss problem of coal ash waste which needs to be stored and there is plenty of it.

Are there people living next to the elephants foot thinking the power plant is a good thing?

Don't forget the Mercury. Coal is the reason why we have to be careful eating tuna.

> Leave the coal in the ground.

More actionable: conserve power.

Whether using coal or other: dress to avoid heating and a/c, carpool, fly less, turn things off when not using, buy less stuff, avoid packaged food, etc.

You'll probably end up simplifying your life, living closer to nature, saving money, connecting with people more, and generally liking life more.

You're employing a fallacy that corporations are only too happy to indulge, shifting the blame to consumers. Whereas the vast majority of power consumption (and pollution) is caused by big industries.

Suggesting ways to pollute less and improve their lives and environment != blame

That's a stretch. I enjoy creature comforts. Hot high flow showers, A/C, a muscle car. My life is better with these features. It's not practical to advocate abstaining from these things.

What you're really saying is that you don't pay the external costs of these things, and you don't care that anyone else has to either - people in poorer countries who will be affected by new and dangerous weather, or even your own children.

You can say you life is good with these features, but how can you say it's better? How did you compare?

Here's another question. Is practicality the adequate criteria to judge the ethical implication of some behaviour?

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