The S5W reactor is a nuclear reactor

United States Naval reactor

United States Naval reactor refers to nuclear reactors used by the United States Navy aboard certain ships 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...

 used by the United States Navy

United States Navy

The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...

 to provide electricity generation

Electricity generation

Electricity generation is the process of generating electric energy from other forms of energy.The fundamental principles of electricity generation were discovered during the 1820s and early 1830s by the British scientist Michael Faraday...

 and propulsion

Nuclear marine propulsion

Nuclear marine propulsion is propulsion of a ship by a nuclear reactor. Naval nuclear propulsion is propulsion that specifically refers to naval warships...

 on warship

Warship

A warship is a ship that is built and primarily intended for combat. Warships are usually built in a completely different way from merchant ships. As well as being armed, warships are designed to withstand damage and are usually faster and more maneuvrable than merchant ships...

s. The S5W designation stands for:

• S = Submarine
  Submarine
  A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...
  
   platform
• 5 = Fifth generation core
  Nuclear reactor core
  A nuclear reactor core is the portion of a nuclear reactor containing the nuclear fuel components where the nuclear reactions take place.- Description :...
  
   designed by the contractor
• W = Westinghouse
  Westinghouse Electric (1886)
  Westinghouse Electric was an American manufacturing company. It was founded in 1886 as Westinghouse Electric Company and later renamed Westinghouse Electric Corporation by George Westinghouse. The company purchased CBS in 1995 and became CBS Corporation in 1997...
  
   was the contracted designer

This pressurized water reactor

Pressurized water reactor

Pressurized water reactors constitute a large majority of all western nuclear power plants and are one of three types of light water reactor , the other types being boiling water reactors and supercritical water reactors...

's simplicity, overdesign, and redundancy was intended for ease of operation and tolerance of battle damage. These characteristics contributed greatly to the type's reliability, longevity, and excellent safety record. The S5W was the standard reactor for submarines of the United States Navy from its first use in 1959 on USS Skipjack (SSN-585)

USS Skipjack (SSN-585)

USS Skipjack , the lead ship of her class of nuclear-powered attack submarine, was the third ship of the United States Navy to be named after the Skipjack tuna fish....

 until the introduction of the Los Angeles-class

Los Angeles class submarine

The Los Angeles class, sometimes called the LA class or the 688 class, is a class of nuclear-powered fast attack submarines that forms the backbone of the United States submarine fleet. With 43 submarines on active duty and 19 retired, the Los Angeles class is the most numerous nuclear powered...

 submarines with S6W reactor in the mid-1970s. One S5W plant was also used in the United Kingdom

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

 on the Royal Navy

Royal Navy

The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...

's first nuclear-powered submarine HMS Dreadnought (S101)

HMS Dreadnought (S101)

The seventh HMS Dreadnought was the United Kingdom's first nuclear-powered submarine, built by Vickers Armstrongs at Barrow-in-Furness. Launched by Queen Elizabeth II on Trafalgar Day 1960 and commissioned into service with the Royal Navy in April 1963, she continued in service until 1980...

.

Sometime before 1971, the S5W vessel and core replaced the S1W reactor

S1W reactor

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...

 vessel and core at the S1W prototype facility. Even though operating an S5W reactor core, the facility continued to be called S1W. To use the additional power generated by the S5W reactor at higher power levels, steam dumps were constructed in the same S1W building but outside the original submarine style hull.

, two S5W reactor plants remain in service: ex-USS Daniel Webster (MTS-626) and ex-USS Sam Rayburn (MTS-635). These "moored training ships" are used to train U.S. naval nuclear operators at Naval Weapons Station Charleston.

Later-model S5W reactor plants were often refueled with a S3G core-3

S3G reactor

The S3G reactor is a naval reactor used by the United States Navy to provide electricity generation and propulsion on warships. The S3G designation stands for:* S = Submarine platform* 3 = Third generation core designed by the contractor...

, the third version of the S3G core.

External links

• S5W at the Federation of American Scientists
  Federation of American Scientists
  The Federation of American Scientists is a nonpartisan, 501 organization intent on using science and scientific analysis to attempt make the world more secure. FAS was founded in 1945 by scientists who worked on the Manhattan Project to develop the first atomic bombs...