With steam plasma tubes. We have 2 50x1cm steam plasma tubes at 4 atmospheres. These produce 1.2MW of heat. They boil off water, and super heat it yo 750oC. These propel the craft 4 times quicker than Marine diesels – off regular awter. No disel burn – so no CO2.
These will also run a nuclear submarine,We discharge the steam in the deep, so a stream of bubbles never reach the surface. As today. The Deep sea is full of steam vents. So it just looks like nature.
So we run ships and submariens off regular water – no enriched uranium ever required. Totalyl safe – so we do not get the sudden vanishing of nuclear submarines.