It is my understanding, and 'tis a very limited understanding at that, that everything the UK govt does eventually becomes declassified - in extremis, because it has been X years since it did whatever.
Even if my understanding is correct in the general sense, it may well not be a complete understanding. And I’m especially talking about nukes and so on here.
So - is any country at the moment obliged to reveal everything anyone needs about how to make a nuke - not just the basics but all the technical issues - and if so, who and when?
And what about even more exciting stuff like taking discrete logarithms…
Pretty much all the information needed is already available.
The main difficulty is obtaining the needed fissile raw material.
Even the USA had the most difficulty with this – the entire Oak Ridge, TN & Hanford, WA sites were huge complexes built to refine enough uranium. There was never any test done of the Hiroshima bomb, because the design was so accepted.
You can go to libraries and look up the designs for nuclear bombs. But try buying uranium, or even parts needed to refine it – you will promptly be visited by police!
Indeed. It’s quite “easy” to build a working nuclear bomb if you can get your hands on the refined uranium or plutonium. I remember some big hubub when I was in college or high school about how some teenager did exactly that. All the other parts/components are relatively simple and easy to obtain.
Of course, obtaining the needed fissile material is not easy at all. Nor is the refining process even if you got your hands on some uranium ore.
Now, as far as fusion bombs go, I have no idea how much more sophisticated the technology is, but even for those you still need fissile materials to get the fusion reaction started. And Tritium is probably not that easy to create either.
A college student in the 60s (possibly early 70s) produced a paper on how to make a fission bomb. One detail I remember from an interview was that he was given plenty of information from suppliers to the US government. He called a company that produced explosive detonators, made up a story about some type of non-weapon device he was building, and they bragged that they could help him because they made the detonators used in US nuclear weapons.
There are 2 main types listed here in wikipedia. The ‘gun’ type I don’t think requires much refinement. You basically just need to propel one chunk of fissile material to a high enough velocity such that it impacts the other with enough force to reach critical mass. If you happen to overshoot, I don’t think it matters. The only tricky part would be getting the tolerances close enough so that it impacts properly and not off center.
The implosion type requires more sophistication since the entire sphere has to be compressed evenly until you get detonation. But I think these can be made much more compact.
The last time I was talking to someone about this I said I was amazed that there weren’t more countries with the bomb since it was really 1940’s technology. But as others have noted, it’s the refinement process that’s really difficult. The gas you create to put into the centrifuges (uranium hexaflouride?) is highly corrosive. In addition, it has to go through many centrifuge steps before it’s sufficiently enriched to be bomb grade. That requires significant infrastructure so I suspect that’s the main obstacle.
The question of how easy it would be to design a bomb now was discussed a bit in an earlier thread. IMHO there is a lot that isn’t revealed, even with blueprints of the main assemblies.
To address the OP’s question. I would suspect that the various nuclear non-proliferation treaties that the UK, and most other nations are signatories to would trump any declassification laws. The UK may well have been in breech of the treaties when the information cited in the above Telegraph article was made available. I would imagine that the information was rather swiftly removed, and a few more careful processes put in place.
