Maybe the perspective is odd but that thing looks huge. Like they are building a fucking star destroyer or something.
its to contain all the juche inside of it
Juchelear Submarine (yes I have no idea how to pronounce Juche)
I think it’s DjuChe like Che Guevara
It is a shipyard, maybe that’s an unrelated ship for something like cargo.
This is guided missile destroyer also being constructed in the same shipyard, sub is there too, look here the first picture
I found a YouTube link in your comment. Here are links to the same video on alternative frontends that protect your privacy:
Nuclear subs are big for sure, but I think here it is the perspective.
fyi for my comrades - hyphenation in Korean names is mostly a south Korean thing, DPR Korean doesn’t hyphenate so it would be Kim Jong Un. Now you know 🌟