The systems and methods generally include a nuclear power plant unit assembled in a shipyard from a plurality of structural modules, each of the structural modules having manufactured components for use in power production when moored or fixed to a floor at least one of in and proximal to at least one of an offshore marine environment, a river environment and a coastal marine environment. The nuclear power plant unit is subdivided into at least one arrangement of structural modules that includes an electrical interface for one of transmitting electrical power generated by the nuclear unit and powering a system of the unit, a communications interface for communications internal or external to the unit, a user interface that is configured to permit a user to access a system of the unit, and a network interface for data communications to or from the unit.