Comment by JumpCrisscross

6 hours ago

> South Korea is capable enough to build nuclear submarines even if the US had denied them the said facilities

Technically, yes. Politically, no.

“To produce fuel for the submarines’ naval propulsion, the ability to enrich uranium was required. However, this plan probably served two goals, since a country with enrichment capability can also enrich uranium to weapons-grade levels without significant difficulty. The fact that [former President Roh Moo-hyun] launched this plan less than five months after North Korea’s [2003] withdrawal from the Non-Proliferation Treaty (NPT) supports the possibility that his ulterior motive was to acquire uranium enrichment capability in part to enable the future development of nuclear weapons. Ultimately, Roh had to abandon this plan in 2004 amid rising suspicion of South Korea’s nuclear ambitions after the International Atomic Energy Agency (IAEA) discovered that South Korean scientists had previously conducted an unauthorized enrichment experiment” [1].

[1] https://www.csis.org/analysis/will-south-koreas-nuclear-ambi...

What am I missing about how hard it is to enrich uranium? We did it in the 40s, having a significantly less solid understanding of all of the physics involved. Material science on containers, motors, energy generation, etc have all been significantly improved in the intervening decades.

Wikipedia says U235 is ~0.7% of earth deposits, and as little as 7kg may be required for a minimal nuclear device. Processing, 700kg of uranium does not sound insurmountable, even with a terribly slow and inefficient process. Just grinding it up and using some kind of mass spectrometer could trivially separate a 3Dalton mass difference.

  • It takes a lot of centrifuges to refine the amount and, more importantly, the purity of fissile material. By the time you need them, it would take a long time to spin up that infrastructure and iron out the kinks.

    It’s not a casual undertaking and other nations will know you’re doing it. The major global powers are not interested in more nuclear weapons, not only to maintain their hegemony but also to limit the number of parties that could cause massive issues. Not to mention the likelihood that a national or political shift could mean nukes in the hands of those less…restrained.

    Plus it raises the surface area of others gaining access to the material or capabilities. Proliferation is bad for the world, generally.

  • > What am I missing about how hard it is to enrich uranium?

    The challenges are primarily geopolitical. There are uranium enrichment operations in a number of countries around the world. Weapons grade enrichment is a lot harder, but nothing that a sufficiently funded and motivated nation state couldn’t achieve if they wanted to and, most importantly, didn’t have any other countries discover it.

    > Processing, 700kg of uranium does not sound insurmountable, even with a terribly slow and inefficient process.

    You have to get enough uranium ore, process that down, then enrich it on a large scale. Uranium ore deposits aren’t very uranium dense except for a few known mines, so pulling rocks out of the ground in another country may produce extremely low yields.

    Enrichment is a very slow process requiring a lot of stages because U235 and U238 are barely different, so they don’t separate much in each stage. Everything has to work together and work well. Like you said it’s not insurmountable, but by the time a country has spent years mining low-yield ore and building complicated many stage centrifuges they’re likely to make a mistake that leads to an intelligence agency catching on.

  • I mean Iran is certainly managing it, so I think it's mostly a political will / will this get you attention and coup'd thing?