The simplest method now is probably to use precisely-tunable lasers to selectively ionize one isotope over another. So now all you have to do is invent the tunable laser, in an era where the electrical state of the art was the Leyden jar.
If Leyden jars were good enough for Dr Fronkensteen, they’re good enough for me…
I suggest a completely different approach than any previously mentioned. Someone said upthread that it’s impossible to separate U-235 from U-238 chemically. While for all intents and purposes, that’s probably true, technically it’s not. The reason it’s not is that heavier isotopes are a bit slower to react chemically than lighter ones. This effect shows up in biology: substances (sugars, for example) made biologically from inorganic materials have lower amounts of heavier isotopes (deuterium, C-13, C-14, etc.) than found in those inorganics. It’s not a huge effect, but it is measurable.
So I suggest that our 19th century mad scientist discover a bacteria that incorporates uranium in an organic chemical that precipitates out of solution. Since the desired U-235 is lighter than U-238, it will be preferentially incorporated in the precipitate. Thus: enriched uranium!
OK, there’s lots of problems with this idea (I can think of several myself), but I’ll leave it to the usual pedants to point them out.
I’d go with the Victorian gentleman finding a deposit of U238 during one of his daring expeditions through the deepest, darkest confines of -insert continent here-.
Something like a naturally occurring thermal separation process (over billions of years), within a kimberlite pipe (diamonds as an extra bonus to found the enterprise) that would leave an ore containing nearly pure U238, but not so concentrated that it would kablooey spontaneously.
Yes, it’s not a thing in geology, but you can pull the Oklo natural reactor card to bamboozle your way through the scenario.
Okay, so you’ve got “pure” U238. Now what? You can’t make a bomb out of it. Separating the U238 from raw ore is actually the (relatively) easy part.
[absolute hijack]
I remember reading something about the France-Israel quid-pro-quo in each country’s development of their first nuke–something about the Israelis invented (the first?) relatively quick laser method for isolating the Uranium (can’t remember the French contribution). Sound right?
[/hijack]
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Israeli nuclear weapons are based upon Plutonium rather than Uranium. Israel does have allegedly (per Vannunu, but disputed) a smallish enrichment capability using, using gas centrifuges. A technology it acquired in the 1970’s at the same time as Pakistan and S Africa did suggesting collusion between the three, although the semi offcial Pakistani history (Eating Grass) only says that implicitly.
France supplied Israel with nuclear power plants at Dimona and in any case Israel does not have a large domestic nuclear power industry unlike Pakistan and S Africa so it does not need to have a particularly large setup.
Centrifuges rather than laser were and are the fastest and most practical method IIRC. The laser method was invented by an Australian
Ooops… I meant U235 :smack: