Recent studies point to a reduction of atmospheric pollution using nuclear energy for merchant ships. This work examines the development of an economically competitive nuclear power solution for merchant ship propulsion. The solution also addresses the requirements of a wider market, like islands, offshore oil platforms, and remote cities. System engineering and analysis at various product breakdown levels also propose architectural options to improve competitiveness of nuclear power in mobile nuclear power plants (MNPPs). Analyses include market research on clients and technical considerations on nuclear energy costs. The results show that an enterprise that delivers electric power to remote clients and dedicates to management of all nuclear aspects seems to be the best organizational and technical choice. Besides, ships should be of modular type and the MNPPs should be easily detachable at sea. Only container ships and remote islands demand enough power to justify the use of nuclear power. Nuclear power has high probability to be economically competitive for large container ships, however, only if public policies impose levels of risks akin to other industries.