Two students built an A-bomb (2003)
theguardian.com
theguardian.com
The crucial detail to buy the story is that Jim Frank told Dobson and Selden the truth:
They were pulled aside by a senior researcher, Jim Frank. "Jim said, 'I bet you guys want to know how it turned out,'" Dobson recalls. "We said yes. And he told us that if it had been constructed, it would have made a pretty impressive bang." How impressive, they wanted to know. "On the same order of magnitude as Hiroshima," Frank replied.
There are now a number of options: 1. Frank disclosed classified information, 2. Frank told them some bullshit, following some instructions, 3. Frank didn't tell them anything, and Dobson and Seldon were instructed what to say if anyone asks them, 4. the whole episode is come corrupted memory: maybe Frank gave them a nice pat on the back and decades later Dobson remembered a much more impressive congratulations, just like hunters remember they shot a bigger game than they did.
From all these options I find the first one the most unlikely. By far.
I believe it's fairly well understood that designing a theoretical atom bomb that probably works isn't "difficult", the difficulty is building it. The logistics, and procuring the materials, that's very very hard.
Also note, they did not cover refining the fissile material as part of their process, it was assumed that they had that. Arguably it's the refining that's by far the most difficult process.
I think a large part of what makes it difficult is not the logistics, or even the refinement process. It's the other states looking over and thinking "these guys are making atom bombs", then putting a stop to it. Much like the Iranian attempt where the US injected a worm into the centrifuges that caused them to spin themselves to death.
On top of that, uranium is naturally 99.3% is non-fissile so you need tons of yellowcake to produce a small amount of weapons grade uranium, which requires crazy amount of power for the centrifuges.
I was making specific reference to Stuxnet, and Operation Merlin. There's been several cases of this happening, so I'd say it's hardly fictional.
Making fissionable material is also conceptually easy, but the process is tricky to do without killing yourself. Still Iran has figured it out from publicly available sources (and a lot of smart people). (as the other reply points out, the process is also leaves signs that other nations are likely to pick up on)
edit: I'm not sure if Iran actually has made a working bomb, but the general consensus is they have the ability. If they don't have one it is only because between diplomatic pressure and sabotage they haven't got that far yet - absent of those two they would.
Like fission WILL happen, the question is yield. Is it going to fizzle or will a large fraction of the fuel be burned up?
They talk about how to encourage the latter in the paper:
“The most important feature of the assembly times calculated in subsection (6) above is that they are more than 10 times the total fission chain reaction time. This means that it is essential for the fissile material to be neutron free during the assembly or the reaction will take place prematurely. If the fissile material is neutron free, then it is necessary to "turn on” neutrons to initiate the chain reaction at the desired time. This is the role of the so-called initiator”
Therefore it was not necessarily in violation of any rules to tell them the outcome after they had finished their project.
But still to this day, all the nuclear weapons stuff is shrouded in mystery and secrecy. How they dispose of the waste … classified, how the bombs work, people have ideas, but all classified. The nuclear policy is also opaque and non-democratic.
Why is everyone in this thread so cagey about revealing information? Is it on a need-to-know basis?
In Israel the topic is under strict military censorship.
What little discussion is allowed has to periodically sprinkled with the incantation "according to foreign sources".
No buy the US keeps all the good secrets.
https://en.wikipedia.org/wiki/Mordechai_Vanunu#Pursuit_and_c...
Let's hope we'll never know for sure because I believe the most likely of those three unlikely possibilities is actual use. And that would be very bad news for the world indeed.
Already happened years ago, see elsewhere in this thread. There's also the Vela incident, for which one of the few plausible explanations is an Israeli-SouthAfrican bomb test.
Also note that we're talking about the present, what happened years ago may or may not be reflective of what the situation was back then, but it definitely won't say much about what the state of affairs is today.
"Many critics argue that Vanunu had no additional information that would pose a real security threat to Israel and that its government's only motivation is to avoid political embarrassment and financial complications for itself and allies such as the United States. By not acknowledging possession of nuclear weapons, Israel avoids a US legal prohibition on funding countries that proliferate weapons of mass destruction. Such an admission would prevent Israel from receiving over $2 billion each year in military and other aid from Washington."
Which is another very high likelihood option with regards to the reason for this policy.
We know they have the bomb, nothing in Middle Eastern geopolitics makes sense except in light of this fact. It's like a black hole that you can observe by how it bends the light of objects behind it. Politicians have to play a silly game of pretend around the whole thing but normal people don't.
I mean, ultimately, we're talking about a device that was built nearly 90 years ago. They've only gotten easier to build since then. Absent international regulation and oversight, a motivated startup and modestly-well-funded startup could put them together today, no problem. Not the deluxe MIRV ICBMs nation states have, but something on par with the ones used in WWII? No problem.
If a country has a bomb, then they have a bomb sitting around somewhere. It is common knowledge that the nuclear superpowers have a lot of trouble, especially these days, around maintenance and infrastructure. You've got to develop and build good missiles or aircraft to send those bombs out somewhere, and you've got to maintain the whole chain in working order for as long as it takes. They've probably got to stay on high alert 24/7, because you never know when you'll need to press the button and send the bomb to the target.
Just building a nuclear bomb without its concomitant delivery system means you'll have to get creative to deliver it. Good luck putting it on on a truck and driving it to the target or something. At that point, you'd rather just have a dirty bomb instead: a lot easier to make, and just deliver it to a convenient highly-populated spot where it'll make a big stink.
> Today, the fear is back: with al-Qaida resurgent, North Korea out of control, and nuclear rumours emanating from any number of "rogue states", we cling, at least, to the belief that not just anyone could figure out how to make an atom bomb. The trouble is that, 40 years ago, anyone did.
Achieving it with household items would be very special.
Uranium isotope separation can be done with lasers, for example, instead of the masses of Zippe centrifuges that used to be required (or the absolutely enormous air diffusion plants and calutrons the Manhattan Project used).
If that's true, then the question becomes "how to produce a compact, cheap plutonium breeding reactor" + "how to separate out the plutonium". Both without dying, of course.
The conventional explosion can be simulated quite well on laptops now + small models can be tested. Exploding bridgewires are an off the shelf item now and not something Alvarez has to invent first. Do we need a big "beach ball" of large exploding lenses? Probably not. Not if we can simulate the explosion well enough (and we can add reflectors).
So how does The Serious Hacker get access to the explosives? Maybe make them in the garage with an upscale chemistry set?
The neutron generator is probably the easiest part to build these days.
So... the reactor and plutonium extraction are likely the limiting steps for a small but determined group of people. I bet lots and lots of cooling is necessary while the reactor operates. That'll be hard to hide!
The British Royal Navy did secretly run a reactor in the middle of London for decades without anyone really noticing though, but obviously they didn't really have to hide it from the security services which might be harder.
(Only the Swedes and the Finns do the ':' thing when they add an inflection to an abbreviation.)
that's not energy efficient and takes a long time, but it's relatively easy access.
https://www.epj-n.org/articles/epjn/pdf/2016/01/epjn150059.p...
~100g uranium / 117kg adsorbent material / month
a warhead needs about 25kg (enriched) uranium.
so 2,5 months with ~11,2tons of adsorbent material spread over a few square miles of sea should give you the needed 25kg. That still needs to be enriched, but once in operation a system like this generates about 125kg uranium/year. (if you need more or faster just scale the system, plenty of space within the 12 mile zone)
North Korea indeed got the bomb three years after the article was written - the interesting question is what kept Iran? They didn't manage that feat in 20 years (thankfully, to add).
After all many other countries in area have nuclear weapons.
IMHO being connected to the internet or not doesn't play a role here.
Unless you have some plutonium.
Stuxnet (which caused Iran's ultra-centrifuges to self destruct), the deal to not further their nuclear ambitions (JCPOA) which bought a lot of time, the fairly credible threat that Israel will commit a first strike against any Iranian facility if they feel like it is imminent.
The funny thing is that 99% of public domain info regarding nuclear weapons design comes from US released documents.
For Russia/China warheads we basically have no documents, and even exterior pictures are extremely rare.
In case of Russia there's a new factor in that those weapons might not even be operable anymore.
All the jawboning about efficiency and engineering is nice, but irrelevant given the above problem.
But the Teller Ulam designs are never complete, always redacted, obviously. You still gotta reverse engineer it.
Examples.
- initiators in fission devices
- explosive lenses in fission devices (what’s the exact mix/shape/required explosive payload?
- large scale manufacture of high grade plutonium. What’s the exact effect of plutonium purity on yield/function?
- how effective of a reflector is required for the teller ullman design? What’s the effect of manufacturing error on the ellipses?
There are more, but any one of these questions would require time, money, and expertise to resolve.
1. Using a much larger fission yield then necessary
2. Using a much larger/denser elispes than necessary to avoid manufacturing errors becoming problematic.
3. Using a much more massive reflector than necessary.
The goal of the Ivy Mike test was to validate the concept of the design - not necessarily to validate that it could be made into a practical bomb. I'm not sure if its ever been revealed wether the filler for the shell has any significance towards the final device.
And then there's the theoretical possibility of designing a thermonuclear device without the A-bomb part. I remember skimming through a paper from someone from CERN about it; https://arxiv.org/pdf/physics/0510071.pdf is the guy, but I'm not sure that's the exact paper.
The amount of HEU needed for a device of this type with a yield comparable to Little Boy could fit in a shoebox. Seal it in some lead pipe, stick it in a shipping container and no one would know. The above documentary illustrates this powerfully with animations and expert testimony. Strongly recommended, especially as a companion to "Command and Control" (2016): https://www.imdb.com/title/tt5598206/