I think that's one of the easier parts. Even if you have to mine it yourself somewhere in Greenland, Australia, or Northern Sweden (where I presume you are from), it shouldn't be too hard.

(Only the Swedes and the Finns do the ':' thing when they add an inflection to an abbreviation.)

as a national state with sea access, you could filter it from seawater.

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)