We already have electric oceanic ships. They’re called nuclear submarines.
Allseas is putting the reactors on their vessels as well iirc.
While perhaps not practical for oceanic shipping as is, it's a fun exercise to demonstrate the energy density of nuclear power.
US nuclear submarines consume highly-enriched uranium, that's nearly as (and sometimes more) pure as the weapons-grade version. That doesn't mean oceanic reactors aren't possible, it just means that military subs are a bad example.