The S2G reactor was a

naval reactor Naval Reactors (NR), also known as the Naval Nuclear Propulsion Program, is an umbrella term for the U.S. government office that has comprehensive responsibility for the safe and reliable operation of the United States Navy's nuclear propulsion p ...

used by the

United States Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...

to provide

electricity generation Electricity generation is the process of generating electric power from sources of primary energy. For electric utility, utilities in the electric power industry, it is the stage prior to its Electricity delivery, delivery (Electric power transmi ...

and

propulsion Propulsion is the generation of force by any combination of pushing or pulling to modify the translational motion of an object, which is typically a rigid body (or an articulated rigid body) but may also concern a fluid. The term is derived from ...

warship A warship or combatant ship is a naval ship that is built and primarily intended for naval warfare. Usually they belong to the armed forces of a state. As well as being armed, warships are designed to withstand damage and are usually faster a ...

s, and the only

liquid metal cooled reactor A liquid metal cooled nuclear reactor, liquid metal fast reactor or LMFR is an advanced type of nuclear reactor where the primary coolant is a liquid metal. Liquid metal cooled reactors were first adapted for nuclear submarine use and have been s ...

yet deployed by the US Navy. The S2G designation stands for: * S =

Submarine A submarine (or sub) is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term is also sometimes used historically or colloquially to refer to remotely op ...

platform * 2 = Second generation

core Core or cores may refer to: Science and technology * Core (anatomy), everything except the appendages * Core (manufacturing), used in casting and molding * Core (optical fiber), the signal-carrying portion of an optical fiber * Core, the centra ...

General Electric General Electric Company (GE) is an American multinational conglomerate founded in 1892, and incorporated in New York state and headquartered in Boston. The company operated in sectors including healthcare, aviation, power, renewable energ ...

was the contracted designer

History

An S2G was the initial power plant of USS ''Seawolf'' (SSN-575). This was one of three sodium cooled reactors (the core was moderated) ordered for the ''Seawolf'' program at the same time as three PWR units were ordered to support the USS ''Nautilus'' (SSN-571) program; In each case, one reactor was land-based for training and research, one intended for installation on a submarine, and one spare. The land-based unit corresponding to S2G was

S1G reactor The S1G reactor is a naval reactor used by the United States Navy to provide electricity generation and propulsion on warships. The S1G designation stands for: * S = Submarine platform * 1 = First generation core designed by the contractor * G ...

. Persistent superheater problems on ''Seawolf'' caused the superheaters to be bypassed, resulting in mediocre performance. This and concern for the dangers posed by liquid

sodium Sodium is a chemical element with the symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable iso ...

coolant led to the PWR type being selected instead as the standard US naval reactor type, and the S2G on ''Seawolf'' was replaced by the spare

S2Wa reactor 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: * S = Submarine platform * 2 = Second generation core designed by the contractor * W ...

from the ''Nautilus'' program. The Atomic Energy Commission historians' account of the naval sodium-cooled reactor experience was:

References

{{DEFAULTSORT:S2g Reactor United States naval reactors Liquid metal fast reactors