The Seafloor Power Station is one or more unmanned electric power generating Units (2) sending power to and operated from existing coastal sites by a manned facility (1) by connecting lines and hoses (3) delivering power to a grid by lines (4). Each Unit's hull (11) maintained in a vacuum, contains both nuclear steam and electricity generating systems. The hull functions as overpressure containment and as condenser in the event of a loss of coolant accident or other steam release. The Units operate submerged in very cold water, with depth set by remotely controlled vertical mooring systems, mounted on gravity mats (27). A Unit must be surfaced by its mooring system to refuel the reactor, an action both conspicuous and public, enabling international oversight of the fuel disposition.