Egregoros

@nanook @fluffy

> The Chinese pattern has always been build one, prove it works, built a thousand so I am confident that they will.

That is how scale works, yes. That's not the Chinese method, that's everyone's method.

"It works" and "It works at scale" and "We can build the scale" are all different questions and they did the first one. If they do the rest, sure, that's great. I'm interested in cheap nuclear energy. As far as the likelihood that they do or do not do this, a nuclear power plant is not like building a cell phone. Maybe unforeseen problems occur. Maybe they don't.

Right now, though, no one has built thorium salt reactors at scale. That's it. I understand you would like them to be real and viable and I would like them to be real and viable but that has yet to be demonstrated so I am waiting. I am not building nuclear power plants at present so I have no influence on the outcome.

@nanook @fluffy I have heard you say that you think it is going to be easy. If it were easy, they'd already have a thousand plants. Unless Kirk Sorensen stood up a thousand plants, it's all unproven.

Making one of something is very different from making a hundred of it. I will believe that they can make a hundred when they make a hundred. Right now, it seems possible, it may even seem plausible, but it is not *done*. Telling me that they can is not going to affect my belief in whether or not they will do it, and there is no reason to convince me, since neither of us can affect the outcome.

There is also no reason: if you are reasonably convinced, then I will agree with you in a couple of years. There's no reason to hurry, is there? Do I need to have a positive belief in the practicality of scaling up thorium reactors *before* the thorium reactors are scaled up?

I'm fairly convinced that the reason we don't have cheap power is more or less entirely a political matter.

If you try to build one in a 1st world country, there's so much regulation that it's just not going to happen.

If you try to build one in a non-1st world country, you're gonna get bombed because "muh nuclear proliferation".

China is working on it, but they're probably facing quiet international backlash because once the cat's out of the bag, everyone is going to want one...

It's basically like Free Energy suppression, except it actually happens.

@cjd @p @nanook
>I'm fairly convinced that the reason we don't have cheap power is more or less entirely a political matter.

it's a matter of finance.
as an intern, i ran numbers for an investment firm my first year of grad school.

it's really just not profitable to build nukes. they take a long time to build and they cost a lot.

if it was possible to make cheap power, you could just do it, nobody is stopping you from putting down a power plant on a strip of land, i worked with solar farms a few years ago there is basically no barrier to entry for those guys you just pay the money and wire it into the grid.

> if it was possible to make cheap power, you could just do it

And then men with guns come and take away your house.

You were doing the math on a pressurized water reactor, and all of the safety equipment that is expected when you have hot radioactive stuff under high pressure.

If you use molten fuel (not even a thorium breeder, just plain old boring uranium), you have no pressure to deal with, you could use ceramic pipes, a ceramic Archimedes pump, so basically you need beryllium and lithium fluoride, ceramic clay, u233, high purity graphite, a boiler & steam turbine, and lots and lots of concrete.

None of those things are that costly. They're not *cheap*, but they're not expensive in comparison to being able to crank out like 30kw of power all day and all night.

If it weren't for regulation, there'd be youtubers doing this, I'm sure of it.

@cjd @nanook @p
>if it weren't for regulation
>guys with guns
i can tell you what it looks like on our side: you model it the way you model something like an earthquake, it's just a risk priced into the operational cost.

from what i recall, this risk-adjusted cost was not substantial. this directly contradicts your thesis that "guys with guns" regulation is the barrier.

>if you use thorium
i've long been aware of internet guys talking about thorium reactors. it wasn't something we had data for. the tech is interesting, and i hope it takes off and is everything people promise. i also really like the idea of a fusion reactor.

one thing i will remark is, if thorium is as good as people are saying, why is nobody building more of them? you can just build power plants: it's not any different from building an apartment complex or running a machine shop, anyone can do it.
regulation or not, if it was as incredible as people bill it, people would be building them en masse, you couldn't stop me from building ten thorium reactors, it's literally free money. but that's not what we see happening.

> thorium

There are two different things here, one is molten fuel and the other is thorium breeding.

Molten fuel is a really big deal because you lose the pressure, so then you don't need any pressure vessels, containment, etc. If it's a slow reactor like the MSRE they ran in the 60s, you have a graphite core and hot molten salt with uranium dissolved in it. When the salt passes through the core, the graphite moderates the neutrons which causes reaction and it gets hot, when it's not in the core, it doesn't.

The other really big deal about molten fuel is that it's a liquid, so chemists can do chemistry on it, like for example extracting the waste (and just the waste) and then putting the other 95% good fuel back in to run again. PWRs retire fuel pellets when they're no longer good for reacting, which is when they're about 5% degraded.

The challenge with molten salt is it corrodes things, and that nobody can get permits to build it. There are like 4 or 5 companies trying to build them in the west and it's all just held up on permits.

Thorium is a whole other topic. The thing about thorium is that it's really really abundant, and if you bombard it with neutrons, it will transform into uranium 233. So people have the idea of surrounding the reactor with a layer of thorium to absorb the wasted neutrons and convert it whilst running the normal uranium reaction. But this is not necessary for molten salt, it's just a stretch goal. Uranium is already like $60 a pound which is basically dirt cheap for the amounts you actually need.

The MSRE did not breed thorium, but Alvin Weinberg (administrator of the MSRE and also inventor of everybody's favorite PWR) suggested that it could.

@cjd @nanook @p
>nobody can get permits to build it. There are like 4 or 5 companies trying to build them in the west and it's all just held up on permits.
at the risk of being called SO AMERICAN yet again... if it really was very profitable, permits wouldn't be holding them up. in the united states at least, there is a lot of corruption. you can lobby and get the permits you want. these investments would not be held up on permits if they looked to be an avenue for cheap power.

that's not to say that you can always bribe and lobby, in some places you just will have bad luck, but someone would find a place to build one.

of course, i don't have some specialized knowledge of the state of molten salt reactor lobbying, maybe it really just is a massive barrier, there are industries like that. but there is not a lot that promises of huge bags of money will fail to accomplish, i am somewhat skeptical that the improvement is very substantial if they cannot even successfully bribe bureaucrats.

@cjd @p @fluffy They are two different things but they are best together. The reason, U235, the fissionable isotope of Uranium is only .7% of Uranium, and Thorium is 3-4x more plentiful than Uranium, so energy available if you breed thorium is 4000x+ that available from U235, add U238 and make that 5000 times, add all the actinide waste from existing nuclear reactors and even more.

And it is the actinide waste that in my view is the greatest reason we should build fast spectrum breeders, we can power civilization for 1000 years on the existing nuclear waste because 95+% of the fuels original energy potential is still present in the waste. And doing so converts ALL of the actinides into short-lived fission products with the sole exception of technetium which is the one fission product with a longer than 30 year half-life. Even so this reduced the long term waste to only one isotope, much easier to keep isolated and much lower in total bulk.

There is the issue of neutron economy which is less in a fast spectrum reactor,
but there is a solution that is between thermal and fast spectrum that has all of
the advantages of both and that is to use a beryllium or lead neutron multiplier, this takes one fast neutron and spits out two slower but still faster than thermal and in a range readily usable by even numbered actinides. (the odd numbered actinides can be fissioned by thermal neutrons so they are not difficult).

The other reason I don't favor thermal designs is the moderator is either water or graphite and then you have either hydrogen explosion and corrosion, and water is not really compatible with high temperature salts so that's no good, or graphite, and graphite is flammable and leads to Chernobyl type fire instances. Particularly this happens because graphite captures some neutrons and becomes contaminated with time and occasionally has to be heated to high temperatures to be purged, and this presents a fire hazard if oxygen somehow leaks in.
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@BowsacNoodle @fluffy @cjd @nanook The Soviets did this. I don't know for certain the fate of the project; I've heard shit like "they're all leaky and some of them still work" and I haven't looked into it.

One issue, and you hit this issue with nuclear batteries in probes and satellites because you don't have the ability to get rid of heat the same way you can on earth, is that with a nuclear reaction, you don't get to slow down, you can't, like, shovel more or less coal: there's heat or electricity coming out of the thing, you've gotta figure out what to do with it during off-peak hours. A lot of plants just supplement with gas generators for peak hours and use the nuclear plant for the base level.

@cjd @p @fluffy When you consider Chernobyl, Fukushima, this is questionable. The emphasis is on the wrong things however. One of those is US regulations require radiation to be as low as possible, as low as possible trends towards infinite expense, but there is no indication that exposures to low levels of radiation is hazardous to human health. The cancer rates in Denver are not higher than Seattle. So one thing that would reduce expense considerably is if rules were re-written to allow low but non-zero radiation levels.

@cjd @nanook @fluffy

> I'm fairly convinced that the reason we don't have cheap power is more or less entirely a political matter.

Well, there's logistics, right, like, some metals are hard to get. And as @DemonSixOne pointed out, thorium is a byproduct of coal-mining, right, easier to get than uranium but not quite as easy as the rest.

> get bombed because "muh nuclear proliferation".

Well, on the other hand, please name a third-world country that you think should have fissile material.