Actually, it’s for a REVIEW of a book I’m doing. To elaborate, a character (who’s deliberately vague on the details), manages to process enough Uranium to build a gun-type fission bomb, from Cornwall Pitchblende, in a entirely (albeit well-funded) one-man operation, and an incredibly crude (at best) understanding of nuclear physics. Using circa 1850s technology.
Now, calling this “implausible” is probably being overly generous—I’m personally going to chalk the project’s success up to a revolutionary diffusion process using a membrane of crushed pixie fairies—but just to be thorough, I thought I’d try and find out how “implausible” it was, from people better in the know than me. I’m, after all, but a dabbling amateur in studying nuclear engineering.
Like I said, I don’t need (or particularly want) dangerously precise technical instructions, if that puts anyone’s twitchy conscience at ease (and I’d think anyone who actually did would have better resources than trolling message boards for tips); just a “ballpark” estimate—what would be the simplest, caveman-crude method of enriching said Uranium, even assuming the person(s) doing the enriching somehow knew exactly what they were doing?
There are two separate enrichment steps required to produce weapons grade uranium. The first is to separate purified uranium from uranium ore which is done via chemical leaching using sulfuric acid (plentiful in the 19th century) to produce Yellowcake which is then kiln baked (doable in a coke furnace to produce purified Uranium metal.
At 1850s level technology, it seems somewhat possible, albeit in horrific working conditions and with abysmal efficiency but that’s ok if we’re just trying to make a single bomb.
Now that you have Uranium metal, it’s about 97% U238 and 3% U235 which you need to refine into 90% U235 to produce weapons grade uranium which will be the difficult part. Because they are both isotopes of the same chemical, no chemical reaction will separate the two. Instead, what needs to be done is convert it into Uranium Hexafluoride gas and then use a series of high speed centrifuges gradually refine the product.
Hydrofuoric acid and fluorine gas would have both been available in the 1850s but I think the 100,000 RPM centrifuge would be where you’ll have the most issues. Producing it on an industrial level is incredibly complex but current high end lab benchtop centrifuges manage to hit 100,000 RPM. The problem is that weapons grade uranium leaves very little room for error as it’s a binary process whether your purity is high enough to cause a runaway chain reaction in the time before the entire bomb blows apart.
I think with the finest glassblowers and metalworkers in the land, it’s a plausible stretch that you could produce centrifuges with the appropriate power that you could marginally reach the magical purity required to be weapons grade uranium, again with horrific working conditions and abysmal efficiency.
So I would say, if your character is a Victorian gentleman of ambiguous but ample financial means and if his goal was to produce enough uranium for a single bomb using vastly inefficient processes that are at the limits of technology, it’s barely plausible.
Consider that in 1850 electricity was known only as a laboratory curiosity, with the fundamentals of the theory under active research. Industrial power was steam engines, shafting and belts. And humans.
The centrifuges needed are not small, and take significant power. There simply would not have been any source of power large enough in the 1850’s - indeed the power needed would almost certainly have exceed the entire world’s industrial power capability manyfold.
The lack of any electrical power eliminates calutrons as an enrichment device. Again, the power requirements would have made them unviable anyway.
Other forms of extraction are gaseous diffusion and thermal gradient separation. Of these, you might just might, maybe, stretching credulity well past any reasonable limits, get thermal gradient separation to work.
However the, OP asks that it be done by one person, albeit very well funded. No chance. We are still talking major industrial sized systems by 20th century standards. Even if you only want to create just the one device, and had decades to wait for the plant to yield the needed fuel, by 19’th century standards, you are still going to need a massive industrial complex.
Another problem for the protagonist is going to be staying alive long enough to perform the task. UF[sub]6[/sub] is horridly corrosive, in all sorts of bad ways, and anyone working for Fluorine and its acids on an industrial scale, is not going to do well. Let alone the constant radiation that will get you if the chemicals don’t first.
Unless you have access to magic, there’s no way it can be done. Even if the the UK devoted it’s entire industrial output, it wouldn’t even scratch the surface.
In three years, 75,000 people made enough U-235 for one bomb.
If you wanted to do it in a book though, you’d start with giant distillation columns, hundreds of feet high built from gleaming columns of purest copper using a secret process known only to alchemists in the Hindu Kush and sailed secretly to England buried in the cargo holds of Tea Clippers (thermal diffusion).
Then your inventor might need some help from the Royal Mint - they’d ramp up the production of ha’pennies and send them to Cornwall to produce the Imperial Voltaic Pile (electromagnetic separation)
Luckily, the last past is easy. It’s straight forward to scale up some of Arkwright’s Spinning Jennies to give you a nuclear centrifuge.
On the other hand, in a scifi book, you can just say that he discovered a way to filter the dissolved ore through a special zeolite, a molecular sieve that he dug out of the ground. Of course, it required very high pressure, which he obtained using a grape press.
If you need more explanation, the pores in this particular zeolite are exceptionally selective, rejecting any ions unless they have precisely the correct atomic mass. Fantastic Voyage was far more implausible, but a great story.
I read the original post over again and now realize that I missed the point. I thought you were in the process of writing a book, not reviewing one already written. My post was an attempt to flesh out your pixie-fairy process.
This is a problem that has eluded the best minds of industrialised and technologically advanced countries. Indeed more nations have failed at this project than have succeeded. Yet you somehow think that some guy in 1850 can do it. No he cannot.
I think a lot of people are underestimating just how far sheer bloody mindedness will get you. If you don’t care about doing it the most efficient way possible, the safety of your workers or the environmental impact, there’s a lot of things that magically become easier.
Power requirements for a centrifuge aren’t really that great. You can get lab centrifuges that spin at 100,000 RPM that can be powered off a single wall socket so generating enough power would have been well within the reach of 19th century industry. Even without electricity, steam powered turbines attached to sufficiently intricate gearing could potentially power such a centrifuge. The main constraint seems to me whether you can get the required engineering on parts such that a centrifuge doesn’t blow itself to bits as it spins up to speed. Metallurgy by the 19th century was already pretty good and getting the right alloys of steel at the right tolerances seems within the grasp of 19th century artisans. A lot of people are under the mistaken impression that modern techniques across the board produce higher quality parts that previous generations. In a lot of cases, automated manufacturing is actually worse in quality that hand crafted parts, especially for things like gears and valves and a lot of the highest end parts are made by hand in ways that would not be unfamiliar to a 19th century artisan.
If someone like AQ Khan were magically transported back to 1850 with the goal of producing a single nuclear device, damn all the consequences, I would not be hugely surprised if he managed to accomplish it.
Also, it would be easier to make a plutonium bomb than a uranium one. You would need to refine uranium to fuel grade, build a breeder reactor, then separate out the plutonium from the spent fuel. But you would get to avoid the high purity extraction of U235 which seems to be the most difficult step.
The backing of an industrial base that was 120 years more modern than anything you could find in the UK of 1850, with things like and electric grid, computers.
The resources of a nation state, which said that money was essentially no object.
Tens of thousand of trained scientists and engineers supporting him.
How will you replicate that in 1850 Oxfordshire?
*AQ Khan is also a strange choice, considering the man was notoriously difficult to work under.
While I agree with the plutonium version, why bother with complexity? Simply say that the man found a meteorite of extra-solar origin in which the uranium was largely U-235. The man may not have realised that it was meteorite and simply considered it a lode.
The least hardware intensive way might be similar to a mass spectrograph;you’d still need a lot of electricity and have to refine out uranium metal. It would be slow but wouldn’t need the extra chemistry and centrifuges.
Fluorine gas wasn’t isolated until 1886. Even if the Victorian gentleman manages to create metallic uranium, he has no way to synthesize a chemical compound of uranium that can be separated with either gas diffusion or centrifuge.
In any case, centrifuge technology in the 1850s was certainly not up to the task. It was a big deal in 1864 when someone invented a centrifuge that spun fast enough to separate milk from cream. Separating isotopes of uranium requires a device several orders of magnitude faster.
There’s no way someone in the mid-19th Century could create enough U-235 to make a bomb. There are too many precursor technologies that don’t exist yet.
“Sheer bloody mindedness” is a good description of the original Manhattan project. Building an atom bomb in 1945 was right at the edge of what was possible given the technology of the time. It was only possible because the U.S. government was willing to build an entire industrial infrastructure from scratch. Turn back the clock 100 years and it becomes an impossible task. It would be like someone in the 1860’s building a rocket to go to the moon.
If you are willing to make the bomb the size of large house/sailing vessel you have other options.
You make your bomb out of regular uranium ore purified.
You use a buttload of heavy water as moderator.
Basically, you are trying to make a CANDU reactor optimized to blow the fuck up.
Maybe throw in large crap load of neutron reflective natural elements surrounding the reactor/bomb thingy to increase yield.
On the outside of that, heavy shit like lead or more uranium ore to act as a inerterial mass tamper to slow the explosion down a bit to increase yield.
Add a horse cart or two of stuff like cobalt or other elements that will be turned radioactive by the neutron flux to make it a nasty dirty bomb.
You might even first make a CANDU reactor first to make some plutonium (or thorium to make XYZ) to add the mix to make blowupable reactor 2 have more punch.
All this approach requires is a good bit of knowledge/luck and a buttload of heavy water.
Making heavy water is really just a matter of how much work/energy you are willing to commit to get X amount. Nothing high tech or dangerous about it.
You can’t make a gun type device with plutonium. It won’t work. Only uranium is useful for gun assembly.
Centrifuge speed is not the only issue - centrifuge diameter also matters. You need a very large centrifuge that is rotating at silly speed. And you need a lot of them. A single centrifuge gets you a minuscule increase in concentration. Again, the power and scale of process needed is immense. A single person working with a single 1850’s capable centrifuge might be able to generate a few micrograms of concentrate over a period of years. This would remain nothing but a laboratory curiosity.
Crushed pixie faries is a much more likely path to success.
Problem being, there was exactly no electricity in 1850. You need to wait another 16 years for a useful generator to be invented. Calutrons (essentially the mass spec concentration device) need huge amounts of power, and are either huge, or you need lots of them.
If Spock could build a computer capable of predicting the future out of a wall of vacuum tubes (who paid the electrical bill and what did they use for air conditioning?) then why can’t our Victorian gentleman make an atomic bomb by refining “isotopes”, something nobody knew existed at the time?
The trouble with an atomic bomb is that the chain reaction has to happen fast. Draining a reactor gets you a slow meltdown. If you are (un)lucky, you get a water dissosciation and hydrogen explosion like Chernobyl, followed by a general fire; the worst damage was the plume of fallout smoke, not explosion. People stood on a bridge a half a mile away and watched the whole thing (may they rest in peace - bad location)
So simply purifying a critical mass is not enough. One of the other important things if I recall rom the pre-invasion hype about Iraq was the need for specific capacitors and electrical blasting caps. I suppose a gun-type bomb eliminates the need for that, but even then doesn’t the fit need to be precisely machined to ensure no misfire? (Heinlein in one of his stories describes a bomb that is two polished hemispheres to make the critical instant as complete as possible.)
So add explosives/blasting cap technology and machining highly radioactive materials to the list of interesting tech.
