Machinist's Mates, Nuclear Power (MMN) operate and maintain Naval Nuclear propulsion plants and associated equipment; supervise and administer naval nuclear propulsion plant operations; thoroughly understand reactor, electrical, and mechanical theory involved in the operation of the nuclear reactor, steam plant, propulsion plant, and auxiliary equipment; operate and repair systems associated with reactor plants, propulsion plants, and auxiliary support systems (e.g. air compressors, distilling plants, propulsion turbines, electric power generation turbines, shaft line components, air conditioning equipment, feed and condensate, steam, hydraulic, seawater systems, air, potable water, lubricating oil and oil purification, reactor auxiliary and support systems pumps, valves, and heat exchangers); perform tests, transfers, and inventories of lubricating oils, fuels, and water; and maintain records and reports on both surface and sub-surface ships.