Career path

Bowman Scholar Program

Bowman Scholars



Nuke Power






Description of a Typical Naval Nuclear Propulsion Plant

In Naval nuclear propulsion plants, fissioning of uranium atoms in the reactor core produces heat. Since the fission process also produces radiation, shielding is placed around the reactor to protect the crew. During a typical submerged patrol, a typical crew member receives less exposure to radiation than he would if he remained ashore and worked in an office building.

U. S. Naval nuclear propulsion plants use a pressurized water reactor design which has two basic systems: the primary and the secondary system. The primary system circulates ordinary water in an all-welded, closed loop consisting of the reactor vessel, piping, pumps, and steam generators. The heat produced in the reactor core is transferred to the water, which is kept under pressure to prevent boiling. The heated water passes through the steam generators where it gives up its energy. The primary water is then pumped back to the reactor to be heated again.

Inside the steam generators, the heat from the primary system is transferred across a water-tight boundary to the water in the secondary system, also a closed loop. The secondary water, which is at a relatively low pressure, boils, creating steam. Isolation of the secondary system from the primary system prevents water in the two systems from intermixing, keeping radioactivity out of the secondary water.

In the secondary system, steam flows from the steam generators to drive the main propulsion turbines, which turn the ship's propeller, and the turbine generators, which supply the ship with electricity. After passing through the turbines, the steam is condensed back into water and feed pumps return it to the steam generators for reuse. Thus, the primary and secondary systems are separate, closed systems in which constantly circulating water transforms energy produced by the nuclear reaction into useful work.

There is no step in this process that requires the presence of air or oxygen. This, combined with the ship's capability to produce oxygen and purified water from seawater, enables the ship to operate completely independent of the earth's atmosphere for extended periods of time. In fact, the length of a submerged submarine patrol is limited primarily by the amount of food the ship can carry for the crew.

The Nuclear Power Pipeline

All submariners are required to attend the Navy Nuclear Power School in Charleston, SC. This is a six month course of instruction which includes instruction in Chemistry, Mathematics, Materials, Reactor Operations, Thermodynamics, and Reactor Theory and Design. This course of instruction can be considered education on the graduate level and in some instances can be used as graduate level credit later in your career. After completion of Nuclear Power School the student has all of the theoretical tools needed to operate a Naval Nuclear Propulsion Plant.
The next step in the training program is the application of the fundamentals learned in power school at one of the Navy's Nuclear Propulsion Training Units (NPTU). NPTU's are located in Ballston Spa, NY and Charleston, SC. Here the student has the opportunity to get hands on training on an actual nuclear propulsion plant. The NPTU program includes a six week classroom session for the specific plant followed by the "in-hull" phase where students are divided into crews that maintain continuous 24-hour watches at the prototypes. Instruction includes Plant Design, Reactor Operations including startup, shutdown, and casualty simulations, Plant Chemistry Control, and Radiological Controls. Upon completion of Prototype, the student is qualified as an Engineering Officer of the Watch (EOOW) and is allowed to stand watch without an instructor in the maneuvering area. Some students who have shown outstanding initiative, leadership, and technical proficiency may be offered to become a staff instructor for a year following graduation.
After completion of the following year's studies the student is then assigned to Submarine School located in Groton, CT. This beautiful setting located a short distance from Newport, RI, New York, NY, and Boston, MA allows the student to concentrate on his future profession, a SUBMARINE DRIVER. At submarine school the student will lean about Submarine Construction, Weapon Systems, Sonar Systems, Target Motion Analysis, Tactics, and Special Operations. The three month course of instruction, prepares the junior officer for reporting to his first submarine command and provides him the tools for successful integration in the submarine wardroom.

From: The United States Naval Nuclear Propulsion Program Over 100 Million Miles Safely Steamed on Nuclear Power Printed by the US Departments of Defense and Energy

- This page last updated 10/22/2003 -

Send your questions or comments to the Webmaster