This article needs additional citations for verification . (July 2011) (Learn how and when to remove this template message)
The United States Navy Nuclear Propulsion community consists of Naval Officers and Enlisted members who are specially trained to run and maintain the nuclear reactors that power the submarines and aircraft carriers of the United States Navy. Operating more than 80 nuclear-powered ships, the United States Navy is currently the largest naval force in the world.
The United States Navy first began research into the applications of nuclear power in 1946 at the Manhattan Project's nuclear power-focused laboratory to develop a nuclear power plant. Eight men were assigned to the project. One of these men was Admiral Hyman G. Rickover, who is known as the "Father of the Nuclear Navy.”
The first nuclear-powered submarine, the USS Nautilus (SSN-571), was launched and commissioned in 1954. The development of the nuclear-powered submarine greatly increased capabilities; the duration a sub could remain underwater was now limited only by food supply. By using power generated from the reactor, air was able to be continually recycled and water was able to be distilled from seawater. The nuclear-powered sub could also reach and maintain much higher speeds than its predecessors.
Shortly after the USS Nautilus, the USS Seawolf was commissioned. The reactor engine in the USS Seawolf was a liquid metal-cooled (sodium) reactor. This proved to be a more difficult reactor to maintain and was eventually replaced with a pressurized-water reactor, the same design used in the USS Nautilus.
The first production run of nuclear submarines was the Skateclass, which was followed by the Skipjackclass. The Skipjack was designed with a more advanced teardrop hull that provided greater hydrodynamics, which allowed the submarines to achieve higher speeds while producing less noise.
Today, the United States Navy operates four different classes of submarine: the Los Angeles, Ohio, Seawolf and Virginia-classes.
The United States has a total of 70 submarines on active duty as of 2018. All are nuclear-powered. There are 18 Ohio class, 14 Virginia class, 3 Seawolf class and 35 Los Angeles class.
Shortly to follow in utilizing nuclear technology was the aircraft carrier. Commissioned in 1961, the USS Enterprise was the first nuclear-powered aircraft carrier.
The first production class of nuclear-powered aircraft carrier is the Nimitzclass. Ten Nimitz-class aircraft carriers in total were produced with all remaining in active duty. This class of aircraft carrier is currently intended to be replaced with the Gerald R. Fordclass. The Gerald R. Ford-class aircraft carriers are still in production, with three currently being produced. There are plans to produce an additional seven vessels.
The United States to this day has a total of 11 nuclear-powered aircraft carriers and controls the largest carrier fleet in the world.
For almost 40 years, the US Navy had nuclear powered cruisers as a part of its fleet, beginning in 1961 with the commissioning of USS Long Beach (CGN-9) and ending in 1998 with the decommissioning of USS Arkansas (CGN-41). The Navy had a total nine nuclear cruisers spread across five different classes. The Navy found they were too costly to maintain and eventually stopped producing them. Long Beach was equipped with a C1W cruiser reactor while the other eight ships were equipped with D2G destroyer reactors.
All of the Navy's submarines and aircraft carriers are propelled by nuclear power. In order for this to happen, each ship essentially contains a small nuclear power plant. The power generated by this reactor is created through nuclear fission. During the process of nuclear fission, there are two products of significant importance in the reactor: heat and radiation. The heat is generated from the breaking down of the fuel source (uranium). Uranium creates heat through a self-sustaining reaction as it is bombarded by free neutrons created during fission and then reabsorbed to continue the reaction. The heat generated from the reaction heats water in the steam generator. Due to the pressurization of the system, the water that cools the reactor does not boil, but creates a media to transfer the heat to the steam plants to create steam. As steam is produced, it is forced through a series of pipes and past different turbines, causing the turbine to spin and generate electrical power or propel the ship. The steam is then cooled and converted back to water, which is then sent back to the steam generator and the process is repeated.
Nuclear reactors create energy through fission, as opposed to burning fuel. Because of this, no greenhouse gases are produced in the energy creation process. Nuclear energy is completely self-contained and produces no airborne by-products.[ citation needed ] The waste created through nuclear power is contained in the reactor and is disposed of when the vessel is decommissioned or the reactor is replaced.
Unlike nuclear power plants that have to have spent fuel rods removed from their reactors every 18 to 24 months, the nuclear reactors powering the submarines and aircraft carriers of the United States Navy remain fully operational until they are decommissioned. When the reactors powering the ships of the Navy are decommissioned, all the nuclear waste is disposed of at once.
As of 2019 [update] , and since the first US nuclear-powered submarine (USS Nautilus), the United States Navy had logged over 6,200 "reactor years" with no radiological accidents. [ needs update ]
However, on 22 May 1978 on USS Puffer, a valve was mistakenly opened releasing up to 100 US gallons of radioactive water into a drydock at Puget Sound naval base. The leak was fully contained and there was no personnel irradiation.
In order to safely operate the fleet of nuclear-powered vessels, the U.S. Navy recruits and trains the men and women who serve in the Navy Nuclear Propulsion community. There are careers for Officers, requiring a minimum of a college degree, and there are Enlisted careers requiring a minimum of a high school diploma or equivalent.
Because of the rigorous training that Navy Nuclear Officers undergo, only a select group of individuals are given the opportunity to lead a crew and command this technologically advanced equipment. Careers as an Officer in Navy Nuclear Propulsion include:
They oversee the day-to-day operations on board a submarine. They ensure that all systems run smoothly, including the nuclear reactor and nuclear propulsion system, weapons systems, and atmosphere control and fire control systems. They are also responsible for driving the vessel and charting its position and operating communications and intelligence equipment.
Nuclear Surface Warfare Officers oversee the day-to-day operations of a nuclear-powered aircraft carrier and conventional war ships, managing everything from communications and navigation to armament capabilities and tactical deployment. Nuclear Surface Warfare Officers are in charge of numerous shipboard operations and activities, from the engineering plant to the bridge. They have the responsibility of ensuring that Sailors in their division maintain and operate the ship's complex systems.
Naval Reactors (NR) is a government office that has responsibility for all shipboard nuclear power plants, shore-based prototypes and nuclear propulsion support facilities for the Navy. Naval Reactors Engineers assume responsibility for key technical work in a variety of facilities, including:
Naval Nuclear Power School Instructors train the future Navy Nuclear community through a technologically advanced curriculum that is taught with a sole purpose in mind: to prepare Navy Enlisted Sailors and Officers attending Nuclear Power School in Goose Creek, SC, for their work in the nuclear power field. They provide detailed knowledge of how to work the key aspects of a pressurized-water Navy nuclear power plant, which include:
For current undergraduate students who meet the high academic standards and prerequisite background, especially those pursuing majors such as mathematics, engineering, physics or chemistry, the NUPOC program provides money to eligible candidates to complete their undergraduate or graduate degree as well as a regular monthly income while in school. The pay amount varies based on location, but is usually in the range of $4000–5500 per month. There is also a one-time $15,000 bonus for getting accepted for Submarine, Surface, and Naval Reactors Engineer positions. After obtaining their degree, individuals earn a commission in the Navy and pursue one of the Officer career paths in Navy Nuclear Propulsion.
While in NUPOC, students have no special uniforms, classes, or obligations day-to-day. They must, however, refrain from drug use and pass a physical fitness test every six months. Students in NUPOC are considered "Active Duty" and paid at the E-6 or E-7 paygrade. As such, time spent completing a degree accrues for purposes of Naval Retirement and VA benefits such as the Post-9/11 GI Bill.
The NUPOC program is open to both men and women. Depending on career focus, the eligibility requirements have minor variances. There are criteria that one must meet regardless of the focus. Candidates must:
Education: Candidates must be graduates or students of an accredited college or university in the United States or a United States territory holding or pursuing a BA, BS or MS (preferably majoring in mathematics, engineering, physics, chemistry or another technical area) and must have:
Members of the Navy Nuclear community operate, control and maintain the components that power Navy aircraft carriers and submarines. This could involve doing anything from operating nuclear propulsion plant machinery to controlling auxiliary equipment that supports Naval reactors to maintaining the electronic equipment used to send and receive messages, detect enemy planes and ships, and determine target distances.
Machinist's Mates (MM) operate and maintain steam turbines and reduction gears used for ship propulsion and auxiliary machinery such as turbogenerators, pumps and oil purifiers. They also maintain auxiliary machinery outside of main machinery spaces, such as electrohydraulic steering engines and elevators, refrigeration plants, air conditioning systems and desalinization plants. They may also operate and maintain compressed gas-producing plants. Nuclear-trained Enlisted Sailors perform duties in nuclear propulsion plants operating reactor controls and propulsion and power generation systems.
Electrician's Mates (EM) are responsible for the operation of a ship's electrical power generation systems, lighting systems, electrical equipment and electrical appliances. The duties include installation, operation, adjustment, routine maintenance, inspection, test and repair of electrical equipment. EMs also perform maintenance and repair of related electronic equipment.
Electronics Technicians (ET) in the nuclear field are normally assigned to Reactor Control division. They are responsible for maintenance, repair and operation of equipment that is closely related to the nuclear reactor and reactor safety.
To be eligible for any Nuclear Operations career, a candidate must first be selected for nuclear training by scoring above the minimum requirements on the Armed Services Vocational Aptitude Battery (ASVAB) and must:
United States naval reactors are nuclear reactors used by the United States Navy aboard certain ships to generate the steam used to produce power for propulsion, electric power, catapulting airplanes in aircraft carriers, and a few more minor uses. Such naval nuclear reactors have a complete power plant associated with them. All U.S. Navy submarines and supercarriers built since 1975 are nuclear-powered by such reactors. There are no commissioned conventional (non-nuclear) submarines or aircraft carriers left in the U.S. Navy, since the last conventional carrier, USS Kitty Hawk, was decommissioned in May 2009. The U.S. Navy had nine nuclear-powered cruisers with such reactors also, but they have since been decommissioned. Reactors are designed by a variety of contractors, then developed and tested at one of several government -owned and prime contractor-operated facilities. These facilities include Bettis Atomic Power Laboratory in West Mifflin, Pennsylvania and its associated Naval Reactors Facility in Idaho, and Knolls Atomic Power Laboratory in Niskayuna, New York and its associated Kesselring site in West Milton, New York, all under the management of the office of Naval Reactors. Sometimes there were full-scale nuclear-powered prototype plants built at the Naval Reactors Facility, Kesselring, and Windsor to test the nuclear plants, which were operated for years to train nuclear-qualified sailors.
Pressurized water reactors (PWRs) constitute the large majority of the world's nuclear power plants and are one of three types of light-water reactor (LWR), the other types being boiling water reactors (BWRs) and supercritical water reactors (SCWRs). In a PWR, the primary coolant (water) is pumped under high pressure to the reactor core where it is heated by the energy released by the fission of atoms. The heated water then flows to a steam generator where it transfers its thermal energy to a secondary system where steam is generated and flows to turbines which, in turn, spin an electric generator. In contrast to a boiling water reactor, pressure in the primary coolant loop prevents the water from boiling within the reactor. All LWRs use ordinary water as both coolant and neutron moderator.
The Nimitz class is a class of ten nuclear-powered aircraft carriers in service with the United States Navy. The lead ship of the class is named after World War II United States Pacific Fleet commander Fleet Admiral Chester W. Nimitz, who was the U.S. Navy's last living fleet admiral. With an overall length of 1,092 ft (333 m) and full-load displacement of over 100,000 long tons (100,000 t), the Nimitz-class ships were the largest warships built and in service until USS Gerald R. Ford entered the fleet in 2017.
USS Seawolf (SSN-575), a unique submarine, was the third ship of the United States Navy to be named for the seawolf, the second nuclear submarine, and the only US submarine built with a liquid metal cooled (sodium) nuclear reactor known as the Submarine Intermediate Reactor (SIR) or Liquid Metal Fast Reactor (LMFR), later designated S2G. Her overall design was a variant of Nautilus, but with numerous detail changes, such as a conning tower, stepped sail, and the AN/SQS-51 active sonar mounted in the top portion of the bow instead of further below. This sonar arrangement resulted in an unusual bow shape above the water for a U.S. submarine. Her distinctive reactor was later replaced with a standard pressurized water reactor, the replacement process lasting from 12 December 1958 to 30 September 1960.
The A2W reactor is a naval nuclear reactor used by the United States Navy to provide electricity generation and propulsion on warships. The A2W designation stands for:
USS Nautilus (SSN-571) was the world's first operational nuclear-powered submarine and the first submarine to complete a submerged transit of the North Pole on 3 August 1958. Her initial commanding officer was "Dennis" Wilkinson, a widely respected naval officer who set the stage for many of the protocols of today's Nuclear Navy, and had a storied career during military service and afterwards.
The A4W reactor is a naval reactor used by the United States Navy to propel warships and generate onboard electricity.
A nuclear submarine is a submarine powered by a nuclear reactor. The performance advantages of nuclear submarines over "conventional" submarines are considerable. Nuclear propulsion, being completely independent of air, frees the submarine from the need to surface frequently, as is necessary for conventional submarines. The large amount of power generated by a nuclear reactor allows nuclear submarines to operate at high speed for long periods of time; and the long interval between refuelings grants a range virtually unlimited, making the only limits on voyage times being imposed by such factors as the need to restock food or other consumables.
The S1W reactor was the first prototype naval reactor used by the United States Navy to prove that the technology could be used for electricity generation and propulsion on submarines. The S1W designation stands for
Nuclear marine propulsion is propulsion of a ship or submarine with heat provided by a nuclear power plant. The power plant heats water to produce steam for a turbine used to turn the ship's propeller through a gearbox or through an electric generator and motor. Naval nuclear propulsion is used specifically within naval warships such as supercarriers. A small number of experimental civil nuclear ships have been built.
A nuclear navy, or nuclear-powered navy, refers to the portion of a navy consisting of naval ships powered by nuclear marine propulsion. The concept was revolutionary for naval warfare when first proposed. Prior to nuclear power, submarines were powered by diesel engines and could only submerge through the use of batteries. In order for these submarines to run their diesel engines and charge their batteries they would have to surface or snorkel. The use of nuclear power allowed these submarines to become true submersibles and unlike their conventional counterparts, they became limited only by crew endurance and supplies.
The A1B reactor plant is an aircraft carrier nuclear reactor developed by the United States Navy. It is used in Gerald R. Ford-class aircraft carriers to provide electrical and propulsion energy. The A1B is the first naval reactor produced by Bechtel Corporation, which has "performed engineering and/or construction services on more than 80 percent of [land-based] nuclear plants in the United States".
The S5W reactor is a nuclear reactor used by the United States Navy to provide electricity generation and propulsion on warships. The S5W designation stands for:
Machinist's mate is a rating in the United States Navy's engineering community.
The S2G reactor was a naval reactor used by the United States Navy to provide electricity generation and propulsion on warships, and the only liquid metal cooled reactor yet deployed by the US Navy. The S2G designation stands for:
The S2W reactor was a naval reactor used by the United States Navy to provide electricity generation and propulsion on warships. The S2W designation stands for:
In the United States Navy, Refueling and Overhaul (ROH) refers to a lengthy process or procedure performed on nuclear-powered naval ships, which involves replacement of expended nuclear fuel with new fuel and a general maintenance fix-up, renovation, and often modernization of the entire ship. In theory, such a process could simply involve only refueling or only an overhaul, but nuclear refueling is usually combined with an overhaul. An ROH usually takes one to two years for submarines and up to almost three years for an aircraft carrier, performed at a naval shipyard. Time periods between ROHs on a ship have varied historically from about 5–20 years to up to 25 years. For modern submarines and aircraft carriers, ROHs are typically carried out about midway through their operating lifespan. There are also shorter maintenance fix-ups called availabilities for ships periodically at shipyards. A particularly lengthy refueling, maintenance, and modernization process for a nuclear aircraft carrier can last up to almost three years and be referred to as a Refueling Complex Overhaul (RCOH).
Nuclear Power School is a technical school operated by the U.S. Navy in Goose Creek, South Carolina to train enlisted sailors, officers, KAPL civilians and Bettis civilians for shipboard nuclear power plant operation and maintenance of surface ships and submarines in the U.S. nuclear navy. The United States Navy currently operates 95 total nuclear power plants including 71 submarines, 11 aircraft carriers, and 4 training/research prototype plants.
The United States Navy job rating of electronics technician (ET) is a designation given by the Bureau of Naval Personnel (BUPERS) to enlisted members who satisfactorily complete initial Electronics Technician "A" school training.