I believe a sufficiently advanced model could provide a layman with actionable step by step instructions for building a nuclear weapon. They're complicated but not (AFAIK) that complicated. The more or less insurmountable barrier there is weapons grade material. Thankfully refinement is prohibitive in cost, expertise, and equipment.

In comparison, basic munitions are incredibly simple given a recipe and shop tooling. But just because something is conceptually simple doesn't mean it's a good idea to go out of the way to disseminate step by step instructions.