tim333 a minute ago

The US had a similar but not identical reactor in the 60s, the Molten-Salt Reactor Experiment https://en.wikipedia.org/wiki/Molten-Salt_Reactor_Experiment

It had uranium-233 from breeding from thorium in other reactors.

The main problem with these things is they seem very unprofitable. The US reactor ran from 1964 to 1969 and produced a small amount of power but is still running about $10m a year in decommissioning costs. You thing you can run these things a while and think it's over but:

>Sampling in 1994 revealed concentrations of uranium that created a potential for a nuclear criticality accident, as well as a potentially dangerous build-up of fluorine gas: the environment above the solidified salt was approximately one atmosphere of fluorine. The ensuing decontamination and decommissioning project was called "the most technically challenging"...

lunar-whitey 6 hours 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 6 hours 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 6 hours 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 6 hours 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 6 hours 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

  • polski-g 3 hours ago

    You can absolutely make nuclear weapons with U233.

  • lazide 6 hours 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 7 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

  • [removed] 6 hours ago
    [deleted]
  • dmix 6 hours 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 6 hours 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.

      • lunar-whitey 4 hours ago

        China has many capital controls but generally supports industrial activity in the state interest; the US does the opposite.

impossiblefork 7 hours ago

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

preisschild 3 hours ago

Yeah, the US had an experimental Molten Salt Reactor in the 60s