Here the KUN-24AP container ship would be a massive departure with its molten salt reactor. Despite this seemingly odd choice, there are a number of reasons for this, including the inherent safety of an MSR, the ability to refuel continuously without shutting down the reactor, and a high burn-up rate, which means very little waste to be filtered out of the molten salt fuel. The roots for the ship’s reactor would appear to be found in China’s TMSR-LF program, with the TMSR-LF1 reactor having received its operating permit earlier in 2023. This is a fast neutron breeder, meaning that it can breed U-233 from thorium (Th-232) via neutron capture, allowing it to primarily run on much cheaper thorium rather than uranium fuel.
An additional benefit is the fuel and waste from such reactors is useless for nuclear weapons.
Another article with interviews: https://gcaptain.com/nuclear-powered-24000-teu-containership-china/
The primary issue with land-based reactors is cooling to prevent it from reacting uncontrollably. If you’re sinking something to the bottom of the ocean there is no cooling problem.
Land reactors pretty much need to be on rivers, and from what i understand severe droughts forceshutdowns in europe a year or two ago.