> We have this, they just go in ships and submarines.

US shipboard reactors use highly enriched (93%, literally weapons-grade because it was originally produced for warheads) uranium, that's not really desirable to distribute throughout the territory.

Even "low-enriched uranium" in a naval context just below 20% (which is the official boundary between LEU and HEU). By comparison regular "civil" nukes use 3-5% uranium.

Bring the ships to port and hook them up to the grid. Talk about swords to plowshares.

They already can do this.

Hundreds of nuclear ships/submarines annually?

Well, at least their reactors.