Wikipedia

HMS Astute. When commissioned, Astute will be one of the most advanced submarines in the world.¹

A nuclear submarine is a submarine powered by nuclear reactor technology. Previously, conventional submarines used diesel engines that required air for combustion while travelling on the surface of the water, but used battery-powered electric motors while diving. The limited lifetime of electric batteries meant that even the most advanced conventional submarine could only remain submerged for a few days at slow speed, and only a few hours at top speed. Nuclear submarines consume a relatively small amount of fuel. Current generations of nuclear submarines never need to be refueled throughout their 25-year lifespans, meaning they can sail around the world 41 times without surfacing.² This ability, combined with advanced weapons technology, makes nuclear submarines some of the most useful warships ever built.³

History

In the 20th century, both the United States (US) and the Soviet Union (USSR) were pursuing technologies to build nuclear submarines to overcome the limitations of conventional submarines. Nuclear-powered submarines are one of the most potent symbols of the bygone U.S.-Soviet arms race.

The US headed the way and launched the USS Nautilus, the first nuclear submarine⁴. USS Nautilus could circle the world underwater for up to four months without refuelling.

Construction of the Nautilus was made possible by the successful development of a nuclear propulsion plant by a group of scientists and engineers at the Naval Reactors Branch of the Atomic Energy Commission. In July 1951, the US Congress authorized construction of the world's first nuclear-powered submarine, under the leadership of Captain Hyman G. Rickover, USN.⁵ Admiral Rickover came up with the idea of nuclear submarines. The Westinghouse Corporation was assigned to build its reactor. After the submarine was completed, President Harry S. Truman broke the traditional bottle of champagne on Nautilus' bow. On January 17, 1955, it began its sea trials after leaving its dock in Groton, Connecticut. The submarine was 320 feet long, and cost about $55 million.

The Soviet Union soon followed the United States in developing nuclear-powered submarines in the 1950s. Stimulated by the US development of the USS Nautilus, Soviet work on nuclear propulsion reactors began in the early 1950s at the Institute of Physics and Power Engineering, in Obninsk, under Anatoliy P. Alexandrov, later to become head of the Kurchatov Institute. In 1956, the first Soviet propulsion reactor designed by his team began operational testing. Meanwhile, a design team under Vladimir N. Peregudov worked on the vessel that would house the reactor. After overcoming many obstacles, including steam generation problems, radiation leaks, and other difficulties, the first nuclear submarine based on these combined efforts entered service in the Soviet Navy in 1958.⁶

At the height of the Cold War, approximately five to ten nuclear submarines were being commissioned from each of the four Soviet submarine yards (Sevmash in Severodvinsk, Admiralteyskiye Verfi in St. Petersburg, Krasnoye Sormovo in Nizhniy Novgorod, and Amurskiy Zavod in Komsomolsk-na-Amure)⁷.

From the late 1950s through the end of 1997, the Soviet Union, and later Russia, built a total of 245 nuclear submarines, more than all other nations combined⁸.

Today, five countries deploy some form of nuclear-powered strategic submarines: the United States, Russia, France, the United Kingdom, and China⁹. Several other countries, including Argentina, India and Brazil¹⁰¹¹, have ongoing projects in different phases to build nuclear-powered submarines.

Technology

The main difference between conventional submarines and nuclear submarines is the power generation system. Nuclear submarines deploy nuclear reactors for this task. They either generate electricity that powers electric motors connected to the propeller shaft or rely on the reactor heat to produce steam that drives steam turbines (cf. nuclear marine propulsion). Reactors used in submarines typically use highly enriched fuel (often greater than 20%) to enable them to deliver a large amount of energy from a smaller reactor.

The nuclear reactor also supplies energy to the submarine's other subsystems, such as for maintenance of air quality, fresh water production by distilling salt water from the ocean, temperature regulation, etc. All underway Navy nuclear reactors are operated with diesel generators as a backup power system. These engines are able to provide emergency electrical power for reactor decay heat removal as well as enough electric power to supply an emergency propulsion mechanism. Submarines may carry nuclear fuel for up to 30 years of operation. The only resource that limits the time underwater is the food supply for the crew.

Accidents

Some accidents related to the nuclear power supply have happened over the years, especially in the Soviet Navy.

• K-19, 1961, reactor almost had a meltdown and explosion, which might have started a nuclear war. Several of the crew died of radiation exposure. It is dramatized by a film.

• K-219, 1986, reactor almost had a meltdown and explosion, which might have contaminated the eastern seaboard of the US. Sergei Preminin died after he manually lowered the control rods, and stopped the explosion.

• Kursk submarine incident.

• USS Thresher (SSN-593) Was lost, and her end is unknown.

• USS Scorpion (SSN-589) Lost

See also

• Submarine
• Ballistic missile submarine

References