credit_guy 23 minutes ago

Before anybody gets too excited, it's better to understand what exactly happened.

China ran an experimental reactor that achieved some conversion of thorium into uranium. More precisely, the conversion ratio was 0.1 [1]. This means that for each new fissile atom generated from thorium (i.e. uranium-233) 10 atoms have been burned from the original fissile inventory.

Now, conversion happens in every nuclear reactor. Some new fissile material (generally Pu-239) is generated out of "fertile material" (generally U-238). And, surprisingly, that conversion ratio is quite high: 0.6 for pressurized light water reactors and 0.8 for pressurized heavy water reactors [2].

What China has achieved therefore is well below what is business as usual in regular reactors. The only novelty is that the breeding used thorium, rather than uranium.

Is this useless? No, it is not. In principle increasing the conversion ratio from 0.1 to something higher than 1.0 should be doable. But then, going from 0.8 in heavy water reactors to more than 1.0 should be even easier. Why don't people do it already? Because the investment needed to do all the research is quite significant, and the profits that can be derived from that are quite uncertain and overall the risk adjusted return on investment is not justified. If you are a state, you can ignore that. If China continues the research in thorium breeding, and eventually an economically profitable thorium breeder reactor comes out of that, the entire world will benefit. But the best case scenario is that this would be three decades in the future.

[1] https://www.world-nuclear-news.org/articles/chinese-msr-achi...

[2] https://en.wikipedia.org/wiki/Breeder_reactor#Conversion_rat...

HPsquared 2 hours ago

The notable thing here is that it's a molten salt reactor design, where the fuel is dissolved in a molten salt (FLiBe). This allows online continuous processing of the fuel, unlike with solid fuel rods sealed inside a pressure vessel.

This unlocks a lot of options for the fuel cycle, including the use of thorium.

This work builds on a previous molten salt reactor experiment at Oak Ridge, decades ago. There's a whole lore about MSRs.

  • JumpCrisscross an hour ago

    > notable thing here is that it's a molten salt reactor design

    Notable, but not unique. The unique bit is it burns thorium.

    • AtlasBarfed an hour ago

      It breeds thorium to fissionable uranium from a starting fissionable uranium starter fuel. It doesn't directly use thorium for fuel.

      What people need to understand about the cycle efficiency is that when you mine uranium, the fissionable part of uranium (U-235) is only 1% of that uranium, the rest is nonfissionable U-238.

      Thorium is about twice as abundant as Uranium (all isotopes). The MSR uses Thorium to create U-233, a fissionable but not naturally occurring Uranium isotope.

      So the "unlimited energy aspect" is that about 200-300x more breedable Thorium exists than fissionable U-235.

      A MSR nation could also try to breed U-238 into plutonium, which would provide another 100x more breeding stock, although LFTR never talked about U-238 breeding. IIRC the plutonium may be difficult to handle because of gamma rays, but I don't recall exactly.

      While I don't have confidence that even LFTR/MSR reactors can get economical enough to challenge gas peakers, it may be possible to make truly price-competitive MSR electricity with the right modular design. I wish the Chinese the best of luck, because if they do it will spur the rest of the world to adopt this about-as-clean-and-safe-as-it-gets nuclear design.

      • JumpCrisscross 28 minutes ago

        > Thorium is about twice as abundant as Uranium

        China has thorium, and while less than others [1], it’s better than they do with uranium [2].

        > it may be possible to make truly price-competitive MSR electricity with the right modular design

        Yes. But probably not in the near term with thorium. This isn’t designed to be cheaper. It’s designed to be more available to China than being dependent on Russian deposits.

        [1] https://www.nature.com/articles/492031a

        [2] https://www-pub.iaea.org/MTCD/Publications/PDF/Pub1800.pdf

      • rhoads 36 minutes ago

        That's what you learn playing factorio

  • bilsbie an hour ago

    What absorbs the neutrons then?

    • lazide an hour ago

      The thorium cycle is generally neutron negative.

      • JumpCrisscross an hour ago

        > thorium cycle is generally neutron negative

        Source for the fuel cycle?

        Thorium 232 -> 233 is neutron negative. But after that you get all kinds of nonsense.

        • lazide a minute ago

          Thorium 232 is the thorium in the cycle yes. And all kinds of nonsense is correct for the daughter products. But in general, to actually use do anything with thorium you need excess neutrons.

perihelions 4 minutes ago

This post is just an excerpt—it's the first 4 paragraphs of a 29-paragraph article,

https://archive.is/DQpXM ("China reaches energy independence milestone by ‘breeding’ uranium from thorium"–SCMP)

T-A 2 hours ago
  • cubefox 35 minutes ago

    > Now, the research team is conducting systematic studies on the key scientific issues related to adding thorium, and aims to completethe construction of a 100-megawatt TMSR demonstration project, and begin operation by 2035.

    For comparison: A commercial nuclear power plant is 1 gigawatt, a 10x difference. I assume this would be the next step.

_trampeltier 2 hours ago

This came up several times the last few weeks, but never stayed on the front for long. Also no comments.

I guess soon the west has to copy chinas tech.

  • pfdietz an hour ago

    Breeding is a technology looking for a business case.

    It's more expensive than just using fresh uranium in current market conditions. It's a way from keeping future uranium shortages from making nuclear power more expensive; it's not a way to make nuclear cheaper than it currently is.

    • NewJazz an hour ago

      Emphasis on current market conditions. Relations with uranium mining countries and environmental opposition to uranium mining could shift conditions.

      • SirHumphrey 31 minutes ago

        The truth is that nuclear power is not that financially attractive at the present and would the price of uranium rise enough that breeders would become economically viable most countries would just stop bothering with nuclear power altogether.

        • cpursley 24 minutes ago

          > The truth is that nuclear power is not that financially attractive

          Let me fix that for you: "The truth is that nuclear power is not that financially attractive in the bureaucratic high cost litigious Anglo-sphere". And that's pretty much all infrastructure these days, unfortunately.

          • dalyons 16 minutes ago

            They’re not financially attractive in other parts of the world either. China, a zero litigation single party state, is building some but a tiny % compared to their renewable buildout

    • dmix an hour ago

      It also apparently provides a way to make reactors that don’t depend as much on water so they don’t all have to be near the coast.

      This would allow Western China to also develop reactors to help underpin their renewable and coal energy.

      > The interest in MSR technology and Thorium breeding did not disappear however. China's nuclear power production relies heavily on imported uranium,[10] a strategic vulnerability in the event of i.e. economic sanctions. Additionally, the relative lack of water available for cooling PWRs west of the Hu line is a limiting factor for siting them there.

      https://en.wikipedia.org/wiki/TMSR-LF1?wprov=sfti1#History

      • JumpCrisscross an hour ago

        > also apparently provides a way to make reactors that don’t depend as much on water so they don’t all have to be near the coast

        Non-water microreactors broadly fall into two categories: ones using a different moderator, most commonly sodium, a sodium salt or helium; and those using heat pipes. Most microreactor designs don’t use water.

      • littlestymaar 27 minutes ago

        Nuclear plants don't need more water than a coal plant of the same power, they both use the same steam turbine with water as cold source.

    • adrian_b an hour ago

      They highlight less the advantages from breeding, than other advantages of the molten salt design, like not needing a lot of cooling water, which allows this reactor to operate in the Gobi desert, the possibility of replacing the fuel without halting the reactor and various safety features.

      • littlestymaar 24 minutes ago

        Nuclear reactors don't need a particularly big amount of cooling water.

        The thermodynamic cycle needs a cold source though, and it's most commonly water. This doesn't depend on the reactor design and this is equally as true of coal plants.

        As long as you are making electricity out of a thermodynamic cycle, you need a heat source (be it a flame or a nuclear reaction) and a cold source.

    • lunar-whitey an hour ago

      There is no business case for basic research, but if you stop basic research long enough you will have no business. The United States and its allies seem to have completely forgotten this.

      • HPsquared an hour ago

        It makes sense for big monopolies like Bell, or the CCP. The investment can be justified if the ones investing are confident they will be able to capture the value and not some competitor.

        • lunar-whitey an hour ago

          Bell Labs also served to maintain positive perceptions of the monopoly. Unix was famously developed despite the knowledge that AT&T would not be able to offer it as an independent product.

    • littlestymaar 29 minutes ago

      > in current market conditions.

      That is, as long as we don't build more nuclear power plants.

      If you want to increase nuclear power adoption, then you're not going to stay in “current market conditions” for long.

    • inglor_cz 35 minutes ago

      Reducing the energy sector to pure business would probably work in the 1990s, but not now, when countries are afraid of strategic dependence on potentially hostile suppliers.

      Uranium isn't as ubiquitous as, say, natural gas, and stockpiling it comes with a big heap of physical problems. I can definitely see countries spending on more expensive technology if it comes with more energy security.

inshard 6 minutes ago

Thorium is abundant in Sri Lanka’s mineral sands. Mined with dredgers at shallow depths 10-100m off the western coast.

jonplackett 2 hours ago

I think I read recently that this was a US idea that was abandoned that China took up and made it work. Is that accurate?

  • lunar-whitey an hour ago

    No country has seriously invested in the thorium fuel cycle because it cannot be used to create weapons. Unfortunately, the technology also began to look most promising as an energy source around the same time the Three Mile Island nuclear accident effectively ended all interest in nuclear energy in the United States.

    • retrac an hour ago

      India has shown some of the most interest to date, due to their lack of domestic uranium reserves. But it's been slow going their fast breeder reactor plans were delayed by like two decades. But it is built and it was loaded with fuel last month [0]

      The French interest in breeder reactors and nuclear reprocessing also originates from a similar concern about lack of domestic access to raw uranium. Though Super-phoenix [0] was a more traditional uranium -> plutonium approach and not thorium. They gave up because just using uranium is way, way cheaper than synthesizing your own fissile materials.

      [0] https://www.world-nuclear-news.org/articles/indias-prototype...

      [1] https://en.wikipedia.org/wiki/Superph%C3%A9nix

    • datadrivenangel an hour ago

      Thorium can be used to make weapons via the breeding cycle. It's much less convenient and straightforward than uranium/plutonium, but it is possible.

      • lunar-whitey an hour ago

        Theoretically, perhaps, but I don’t think anyone with a serious interest in weapons would pursue it. From a nonproliferation perspective, I’d guess the infrastructure necessary to remove contaminants from uranium bred through the thorium cycle would be costly and difficult to conceal.

        • datadrivenangel 38 minutes ago

          Multiple countries have detonated nuclear bombs using U-233 derived from thorium reactors! [0] Practically I agree with you that thorium is proliferation resistant and if someone is bomb hungry they won't prioritize it, but if you want to set up the bomb and all you have is thorium... The infrastructure wouldn't necessarily be significantly larger or worse than conventional enrichment.

          0 - https://en.wikipedia.org/wiki/Uranium-233

    • lazide an hour ago

      Also, it’s only energy positive under some specific carefully managed conditions, and is a real pain to make work.

      If you have easy access to uranium, you just use it directly instead.

  • jbverschoor 2 hours ago

    Well, fible energy is trying to do lots. Gates invested in MSTR (molten salt thorium reactor).

    But regulation, while it has its purposes, stifles many things. At the same time time it’s not even doing what they were meant for.

    There are a number of countries being run far better than the US or the EU

    • dmix an hour ago

      > There are a number of countries being run far better than the US or the EU

      It will be funny if China is what convinces the US to be more open to free industry. Opposite day vs the 1970s

      • bilbo0s 44 minutes ago

        To be fair, these advances are not being made in China due to "free industry". They have something of a command economy for their critical sectors. So it's unfair not to point out that it's easy to make advances if a nation as a whole points to a hill and says, "take that hill". Of course you can do it under those circumstances.

        If it's just your company or some trifling consortium trying to develop nuclear energy advances in a "free industry" environment, the guy who is just slapping up windmills, [T Boone Pickens RIP], is just gonna mop the floor with you. There's just no way to compete on moonshots like that.

  • impossiblefork an hour ago

    Historical experiments with alternative fuel cycles, not serious development attempts. A serious development attempt happened in India though.

hit8run an hour ago

Meanwhile Germany just decommissioned its last nuclear reactors. Given the challenges of baseload renewable generation, it's frustrating to watch working infrastructure being dismantled while we're still heavily dependent on fossil fuels.

  • littlecranky67 39 minutes ago

    Comparing those old conventional reactors to MSR is not suitable at all. And they were not fully functional past their expiry date.

  • BoredPositron 42 minutes ago

    By all the doomerism about German and nuclear there is at least Wendelstein 7-x doing frontier work. It's fine to get rid of legacy nuclear if there is a feasible bridge ahead.

SilverElfin an hour ago

This type of progress shows China is capable of moving from an economy that’s build on labor arbitrage or copying others to genuine innovation. It’s also further evidence of the extreme competence of the CCP in governance, which I feel should be acknowledged despite their authoritarian negatives.

  • inglor_cz 44 minutes ago

    "extreme competence of the CCP in governance"

    I don't think it makes sense to extrapolate from one particular technical field to governance in general.

    The US managed to defeat both Nazi Germany and Japan plus develop nuclear weapons, all in 1941-5. Was it a proof of extreme competence of the US government in general? The some government tolerated abuse of blacks and forced segregation in the South, I would call it a serious governance failure.

DeathArrow an hour ago

I wonder if people would think China copied this from the West.

deadbabe an hour ago

China is far better at long term societal planning. Ultimately, I expect they will be the ones who can solve the climate crisis, after being one of the biggest contributors to the problem.

  • lossolo 11 minutes ago

    > after being one of the biggest contributors to the problem.

    How many "Made in China" products do you have at home right now? Who is contributing to the problem?

  • cubefox 28 minutes ago

    Actually by far the biggest, in terms of total greenhouse emissions (30% of the world). Though other countries emit a lot more per capita.

api 2 hours ago

We have basically limitless carbon free energy with the tech we have now: solar, wind, batteries, fission breeders, large power grids that can move power around cheaply, etc. Put all those together and we have incredible energy abundance.

We also have the ability to electrify most transport except maybe long haul trucking and long haul aviation. Aviation (ALL aviation) accounts for less than 5% of global CO2 emissions, which means we could leave that alone and cut elsewhere until we have batteries and other infrastructure good enough for that.

Build all this out and it'll be cheaper and more scalable than what we currently have.

We in the USA choose to stick with ancient technology because we have a sunk cost and an existing political power structure built around it. Meanwhile China is eating our lunch. Make America Great Again! By... pretending it's 1945 and trying to LARP the previous century.

Classic innovators' dilemma at the national level.

  • nickserv an hour ago

    > We in the USA choose to stick with ancient technology because we have a sunk cost and an existing political power structure built around it.

    Yes, and also vast oil and gas reserves China doesn't have.

    Also there is strong public fear and dislike of nuclear power.

    In countries where there are no or little fossil fuels it is mainly this public opinion which has crippled the nuclear industry. Germany is a prime example.

    Public opinion is obviously much less important in China.

    • seanmcdirmid an hour ago

      > Public opinion is obviously much less important in China.

      That really isn’t true. The reason Shanghai didn’t expand their maglev to Hangzhou is because residents were worried about electrical magnetic radiation, which I don’t think is really a thing. Nuclear took a long time to get started in China because people thought the government to be inept and corrupt, an image that has only recently faded away in the last decade. Without free elections, public opinion is actually much more important if you want to avoid economically destructive riots.

      But this all happens in back rooms, the legal system isn’t very relevant, so if you have an issue but it isn’t a very popular one, you don’t really have any recourse. For example, niche environmental issues, or ones that aren’t widely recognized yet as dangerous…

  • HPsquared an hour ago

    If grid energy was cheap enough, synthetic fuel for aircraft and trucks would be competitive.

  • fragmede 39 minutes ago

    > We in the USA choose to stick with ancient technology because we have a sunk cost and an existing political power structure built around it.

    You don't want to discount the cultural attachment people have to what their parents did and their childhood.

SoftTalker 2 hours ago

China has distracted the USA energy focus by dumping cheap solar panels here while continuing to develop advanced nuclear generation capabilities at home.

  • ragebol an hour ago

    China is simply betting on all horses: solar, wind, thorium, batteries, coal even, anything to not buy foreign oil and be as independent, self-sufficient as possible. Seems like it's working too

    • DougN7 an hour ago

      Seems like a wise thing to do too.

      • ragebol 41 minutes ago

        Yup.. Happens to align somewhat with climate goals too, luckily for the rest of us. Once solar+batteries becomes the cheapest form of generation, the coal usage should also drop, if that isn't already the case

        • JumpCrisscross 24 minutes ago

          > Once solar+batteries becomes the cheapest form of generation, the coal usage should also drop

          Marginal versus bulk. It can make sense, economically, to keep building coal plants even if solar is cheaper if you’re building solar as fast as you can and still need more power.

  • lordofgibbons an hour ago

    How exactly has it distracted the U.S?

    I don't see the U.S rushing to adopt either renewables or nuclear. We're just increasing our fossil fuel burning (natural gas).