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Fact-check: Five claims about thorium made by Andrew Yang

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Re: Fact-check: Five claims about thorium made by Andrew Yang

#11

Post by acidburnNSA »

HorstG wrote: post #4
Glyptodon wrote: post #3

Several things in this FAQ are frequently contradicted, which I'm not sure what to make of.

They are not wrong, but also not right in all scenarios. Truth very much depends on the reactor design. Thorium is often associated with Gen4 reactors which are responsible for the claims of superior safety. Not much, but some of the safety benefit comes from thorium. Similar for the claim of less waste: Some reactors have better neutron economy, burning their own waste down to more shortlived and therefore "better"…

> But the fuel cost of thorium is an order of magnitude below uranium due to no enrichment

This turns out not to be true in practice. Uranium-238 is fertile just like Thorium-232. To run a reactor off either of these fertile fuels requires breeder reactor technology, which involves chemical separations and exotic fluids. In practice, this has always been more expensive, even though the U-238 or Th-232 is not enriched. It turns out that breeder reactor infrastructure outweighs the cost reduction in not having to enrich.

In fact, this is the primary reason that we don't have any breeder reactors today: it's simply cheaper to mine and enrich uranium than to reprocess. There are political reasons as well, but the primary reason is this economics.

Re: Fact-check: Five claims about thorium made by Andrew Yang

#12

Post by djohnston »

im not sure it's useful to hold yang accountable for such technical minutae. i generally believe that nuclear has an important role to play in our mitigation of climate change, but that our bias to remember flash-point events like chernobyl and fukushima will overshadow the far more deadly and ubiquitous proliferation of CO2 and methane that lacks the same "pizazz"

Re: Fact-check: Five claims about thorium made by Andrew Yang

#13

Post by acidburnNSA »

sjwright wrote: post #10
erentz wrote: post #5

Yang is to be credited for stating he is open to all possible solutions to the climate crisis, and rightly pointing out that with a crisis of this magnitude no solutions should be taken off the table at this point. Something other candidates are reluctant to do when it comes to the topic of nuclear energy. He shouldn’t be expected to be an expert in the nuances of the technology or fuels. This should always be left t…

Exactly. The takeaway should be that Yang is approaching this issue from a position of technical merit and not on an irrational emotional basis like most others. This is to his credit. Properly technocratic leadership is rare in the USA and it's beyond time for them to experiment with it. In my opinion the analysis linked to from HN is laughably flawed. It's not exactly wrong, but it's so terse and reductive that it…

Technically the big gamma emitter is Tl-208 which is in the decay chain of U-232.

Careful about downplaying the U-233 weapons potential. Phenomenal nuclear weapons can be derived from Thorium. Here's a good declassified hint from 1966: https://www.osti.gov/biblio/79078

Re: Fact-check: Five claims about thorium made by Andrew Yang

#14

Post by acidburnNSA »

djohnston wrote: post #12

im not sure it's useful to hold yang accountable for such technical minutae. i generally believe that nuclear has an important role to play in our mitigation of climate change, but that our bias to remember flash-point events like chernobyl and fukushima will overshadow the far more deadly and ubiquitous proliferation of CO2 and methane that lacks the same "pizazz"

I just wish he would switch from promoting Thorium to promoting technology development in nuclear. But believe me when I say I'll take what I can get!

Heh. I've been whining that HBO hasn't made a miniseries about the 4 million outdoor air pollution deaths every year or the other 4 million indoor air pollution deaths per year.

Re: Fact-check: Five claims about thorium made by Andrew Yang

#15

Post by acidburnNSA »

DennisP wrote: post #9

> similar radioactivity at 100 years to uranium-plutonium fuel cycles, and actually has higher waste radioactivity at 100,000 years At 100 years your radioactivity is still dominated by fission products, which are the same in either reactor. At 100,000 years the radioactivity is minuscule with any reactor. But what you don't have with thorium or fast uranium reactors is a lot of transuranic waste, like plutonium. Tha…

A few points:

* Uranium-Plutonium fuel in a closed cycle can burn all the transuranics and have very low radiotoxicity waste as well.

* Molten salt fuels are 10x less dense than typical solid fuels, implying an increase in waste volume. They're also water soluble and frequently liquid. This complicates waste disposal and transport. Not terribly, but still.

A good summary reference on radiotoxicity vs. reprocessing is: https://www.iaea.org/publications/8359/assessment-of-partiti...

Re: Fact-check: Five claims about thorium made by Andrew Yang

#16

Post by sjwright »

djohnston wrote: post #12

im not sure it's useful to hold yang accountable for such technical minutae. i generally believe that nuclear has an important role to play in our mitigation of climate change, but that our bias to remember flash-point events like chernobyl and fukushima will overshadow the far more deadly and ubiquitous proliferation of CO2 and methane that lacks the same "pizazz"

And it's important to remember that the Fukushima nuclear disaster has caused one confirmed death so far. I'm not saying that it wasn't a horrific disaster, but it's like comparing one dramatic aeroplane accident to the totality of road vehicle deaths worldwide—one plane is newsworthy; whereas the vehicle death toll is normalised and ignored.

Worldwide, around 50 to 500 people die in planes each year.

Worldwide, over 1 million people die in cars each year.

Re: Fact-check: Five claims about thorium made by Andrew Yang

#17

Post by HorstG »

acidburnNSA wrote: post #8
HorstG wrote: post #2

It is useless to make claims about a particular fuel without looking at a concrete reactor design. Leftover isotopes for example are very dependent on neutron flux and neutron energy as well as general breeding properties of the reactor. This in turn decides the waste to be dealt with, proliferation risk and possible reuse of leftover fuels from previous generation reactors (which the submission didn't even discuss).…

Its easy to make bombs from U-233. In fact it is better than plutonium in some rare circumstances. Check out the discussion and cool declassified letter from the Livermore bomb letters here: https://whatisnuclear.com/thorium-myths.html#myth3

Yes, making the bombs themselves seems to be easy. The difficulty comes from U232-contamination which decays into strong gamma emitters, making handling difficult. However, there seem to be paths for the production of pure U233 from chemically separated Pa233, which one might be doing anyways in a thorium reactor. That would mean a significantly higher proliferation risk, because one would get pure bomb fuel form the normal operations of the reactor. However, I don't know enough about how easy or likely that would be to judge.

But in all, you are right, I think. And maybe even more than right.

Re: Fact-check: Five claims about thorium made by Andrew Yang

#18

Post by sjwright »

acidburnNSA wrote: post #14
djohnston wrote: post #12

im not sure it's useful to hold yang accountable for such technical minutae. i generally believe that nuclear has an important role to play in our mitigation of climate change, but that our bias to remember flash-point events like chernobyl and fukushima will overshadow the far more deadly and ubiquitous proliferation of CO2 and methane that lacks the same "pizazz"

I just wish he would switch from promoting Thorium to promoting technology development in nuclear. But believe me when I say I'll take what I can get! Heh. I've been whining that HBO hasn't made a miniseries about the 4 million outdoor air pollution deaths every year or the other 4 million indoor air pollution deaths per year.

I agree with you in principle, but let him focus on thorium during the election process. It's his way of letting us know he's on the correct side of the broader issue without freaking out the hippies.

Re: Fact-check: Five claims about thorium made by Andrew Yang

#19

Post by paulchen »

The fact that we are discussing thorium here and in many other places suddenly, proves the successful mission accomplished by Andrew Yang. Federal bureaucrats and their aides are forced to do their homework to seriously consider the option and answer intelligently.
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