NS Savannah

NS ''Savannah'' was the first nuclear-powered merchant ship. She was built in the late 1950s at a cost of $46.9 million (including a $28.3 million nuclear reactor and fuel core) and launched on July 21, 1959. She was funded by United States government agencies. ''Savannah'' was a demonstration project for the potential use of nuclear energy. The ship was named after , the first steamship to cross the Atlantic ocean. She was in service between 1962 and 1972 as one of only four nuclear-powered cargo ships ever built. (The Soviet ice-breaker ''Lenin'', launched on December 5, 1957, was the first nuclear-powered civil ship.)

''Savannah'' was deactivated in 1971 and after several moves has been moored at Pier 13 of the Canton Marine Terminal in Baltimore, Maryland, since 2008.

Origin

In 1955, President Dwight Eisenhower proposed building a nuclear-powered merchant ship as a showcase for his "Atoms for Peace" initiative. The next year, Congress authorized ''Savannah'' as a joint project of the Atomic Energy Commission, the Maritime Administration (MARAD), and the Department of Commerce.

She was designed by George G. Sharp, Incorporated, of New York City. Her keel was laid down by the New York Shipbuilding Corporation at Camden, New Jersey. Her nuclear reactor was manufactured by Babcock & Wilcox. She was christened by US First Lady Mamie Eisenhower at the ship's launching on July 21, 1959.

In 1969, ''Savannah'' became the first nuclear-powered ship to dock in New York City. She was a centerpiece for a citywide information festival called "Nuclear Week In New York." Thousands of people toured ''Savannah'' and attended related special events. These included demonstrations of advancements in peaceful uses of atomic energy, such as food products preserved by radiation, new applications for technology and many information and education programs. ''The Tonight Show Starring Johnny Carson'' featured "Nuclear Week In New York" on two programs. Dr. Glenn T. Seaborg, Chairman of the Atomic Energy Commission, was the featured speaker and President Eisenhower was honored for his introduction of the global Atoms for Peace program. The appearance of ''Savannah'' and the Nuclear Week festival program was designed and implemented by Charles Yulish Associates and supported by contributions from leading energy companies.

Concept

Eisenhower desired a "peace ship" that would serve as an ambassador for the peaceful use of atomic power. According to an Eisenhower administration statement to Congress, "The President seeks no return on this vessel except the goodwill of men everywhere ... Neither will the vessel be burdened by proving itself commercially feasible by carrying goods exclusively." and
Although initial proposals used a copy of s power plant, a conscious decision was made to design a propulsion system to commercial design standards with no connection to military programs.

George G. Sharp, Inc., a prominent naval architecture firm in New York City founded in 1920, was responsible for all of ''Savannah''s design but the Babcock & Wilcox nuclear reactor. ''Savannah'' was the sixth large ship to have fin stabilizers, intended to enhance the safety of the reactor and improve passenger comfort. Since the reactor occupied the center of the ship and required clear overhead crane access during refueling, the superstructure was set far back on the hull. The raked, teardrop-shaped superstructure was specifically designed by George G. Sharp's ship design consultant Jack Heaney and Associates of Wilton, Connecticut, for a futuristic appearance, decorated with stylized atom graphics on either side. Heaney was responsible for the interiors, which featured sleek modern "Atomic Age" styling.

Description

''Savannah'' measures in length and in beam, with a loaded draft of , and a loaded displacement of 21,800 tons. ''Savannah'' was built with seven cargo holds, a reactor compartment and a machinery compartment, making nine water-tight compartments. There are three full decks. The reactor compartment is located near the center of the ship, with the superstructure just aft of the reactor top to allow the reactor to be refueled. Holds 1 through 4 are forward of the superstructure, with cargo handling gear between 1 and 2 and between 3 and 4. Cargo hold 5 is served by side ports, as it is located beneath the swimming pool. Holds 6 and 7 are aft of the superstructure.

The topmost deck of the superstructure comprises the pilothouse, radio room, chart room, a battery room and an emergency diesel generator. The next lower deck comprises the officers' accommodations, with an officers' lounge at the tapering rear portion of the superstructure. Below this level is the promenade deck comprising, from forward aft, the elliptical main lounge, the main stair and elevator, and the Veranda Lounge. The bar was provided with enclosed walkways outboard, and a glass wall overlooking the swimming pool and promenade deck aft. A dance floor was provided in the center of the lounge, surrounded by tables with illuminated glass tops. The back bar features a glass and metal sculptural interpretation of the periodic table of the elements.

"A" Deck is the first full deck level, with cargo handling facilities fore and aft. Deck surfaces have been retrofitted with cargo container anchors. The interior of "A" Deck contains the main lobby and purser's office, the infirmary, barber, beautician and steward's facilities, as well as the health physics laboratory intended to monitor the effects of the nuclear reactor. All thirty passenger cabins are located on "A" Deck, each with a private bath and accommodations for one to three passengers.

"B" Deck contains the ship's kitchen and the dining room. The 75-seat dining room features a curved wall sculpture entitled "Fission" by Pierre Bourdelle. At the opposite end of the dining room a metal model of the SS ''Savannah'' is set in a glass panel. The overhead light fixtures are screened with brass bands representing stylized atoms. The kitchen features an early water-cooled Raytheon Radarange microwave oven. "B" Deck also includes crew quarters and the crew mess and lounge.

"C" Deck comprises more crew quarters, the laundry and a butcher's shop. A glassed-in central gallery provides a view of the main engine room. A pressure door provides access to the upper levels of the reactor compartment.

"D" Deck houses the machinery spaces, cargo holds and the nuclear reactor.

Reactor

''Savannah''s reactor was designed to civilian standards using low-enriched uranium with less emphasis on shock resistance and compactness of design than that seen in comparable military propulsion reactors, but with considerable emphasis on safety and reliability.

The reactor was placed to allow for access from above for refueling. The 74 MW reactor is a tall, narrow cylinder, housed in a cylindrical containment vessel with rounded ends and a vertical cylindrical projection housing the control rods and refueling equipment. The containment vessel houses the pressurized-water reactor, the primary coolant loop and the steam generator. The steel vessel has a wall thickness varying from , designed to accommodate the gauge pressure generated by a ruptured primary coolant pipe. There are two manholes in the top of the containment vessel. Two manholes in the bottom of the containment vessel are designed to admit water to the containment vessel if the ship sinks in more than of water to prevent the pressure vessel's collapse. The containment vessel was not occupied under operational conditions, but could be accessed within 30 minutes of reactor shut-down. The lower half of the containment vessel is shielded by a concrete barrier. The upper half is shielded by of lead and of polyethylene. A collision mat shields the sides of the vessel with alternating layers of steel and of redwood in a assembly.

The reactor was de-fueled in 1975, but remains in place. The reactor is high with a core in diameter and high, with 32 fuel elements. Each fuel element was in diameter and housed 164 uranium oxide pellets enriched to an average of 4.4% U-235. The 16 center elements were enriched to 4.2%, and the outer 16 elements to 4.6%. The pellets were in diameter, with pressurized helium gas in the annular space between the pellets and the element walls. Twenty-one control rods were provided, long, across and thick. The rods could be fully inserted in 1.6 seconds by electric drive.

Machinery

The main machinery room measures long by wide and high. The main control room is immediately aft of the machinery room, from which engineers controlled both the reactor and the steam propulsion plant. A window separates the control room from the machinery room. The control room is visible from the viewing gallery on "C" Deck above. The steam plant is a relatively standard steam plant in its general characteristics, with a nine-stage high-pressure turbine and a 7-stage low-pressure turbine driving a single propeller shaft. The steam and water chemistry program was set up and managed by the Bull & Roberts Company to match the systems it provided for US Navy nuclear-powered aircraft carriers and submarines. The turbines were specially adapted to use the saturated steam typically provided by a nuclear power source. It was also unusual in having a electric motor geared to the high-pressure turbine for use in an emergency. The motor was driven by either the ship's steam turbogenerators or the 750 kW emergency diesel generators located in the rear of the pilothouse. These generators could provide basic propulsion to the motor while running the reactor coolant pumps. The motor was upgraded to provide greater torque and reversibility to allow it to move the ship away from a pier in the event of a reactor accident.

The propulsion plant's designed capacity was for a design speed of . Actual performance yielded about and a maximum speed of .

Economics of nuclear propulsion

''Savannah'' was a demonstration of the technical feasibility of nuclear propulsion for merchant ships and was not expected to be commercially competitive. She was designed to be visually impressive, looking more like a luxury yacht than a bulk cargo vessel, and was equipped with thirty air-conditioned staterooms (each with an individual bathroom), a dining facility for 100passengers, a lounge that could double as a movie theater, a veranda, a swimming pool and a library. Even her cargo-handling equipment was designed to look good. By many measures, the ship was a success. She performed well at sea, her safety record was impressive, and her gleaming white paint was never smudged by exhaust smoke (except when running the diesel generator). From 1965 to 1971, the Maritime Administration leased ''Savannah'' to American Export-Isbrandtsen Lines for revenue cargo service.

However, ''Savannah''s cargo space was limited to of freight in . Many of her competitors could accommodate several times as much. Her streamlined hull made loading the forward holds laborious, which became a significant disadvantage as ports became more and more automated. Her crew was a third larger than comparable oil-fired ships and received special training in addition to that required for conventional maritime licenses. Additionally, a labor dispute erupted over a disparity in pay scales between deck officers and nuclear engineering officers. The pay issue continued to be a problem, so the Maritime Administration canceled its contract with States Marine Lines and selected American Export-Isbrandtsen Lines as the new ship operator. A new crew was trained, delaying further use for almost a year.

As a result of her design handicaps, training requirements, and additional crew members, ''Savannah'' cost approximately US$2 million a year more in operating subsidies than a similarly sized Mariner-class ship with a conventional oil-fired steam plant. The Maritime Administration placed her out of service in 1971 to save costs, a decision that made sense when fuel oil cost US$20 per ton. In 1974, however, when fuel oil cost $80 per ton, ''Savannahs operating costs would have been no greater than a conventional cargo ship. This figure does not factor maintenance and eventual disposal of the ship's nuclear power plant. The ship's namesake, SS ''Savannah'', which in 1819 became the first steam powered ship to cross the Atlantic Ocean, was also a commercial failure despite the innovation in marine propulsion technology.

Nuclear refueling, waste disposal and decommissioning

During her initial year of operation, ''Savannah'' released over of very low-level radioactive waste at sea, having substantially exceeded her storage capacity of . The Nuclear Servicing Vessel ''Atomic Servant'' was built to receive waste from ''Savannah.'' The unpowered barge featured a fuel storage pit for a replacement fuel and control rod assembly, lined by of lead. ''Atomic Servant'' was made available to service ''Savannah'' anywhere in the world.

The radioactive primary coolant loop water was removed at the time of shut-down, as were some of the more radioactive components within the reactor system. The secondary loop water was removed at the same time. Residual radioactivity in 1976 was variously estimated as between , mostly iron 55 (2.4-year half life) and cobalt 60 (5.2-year half life). By 2005, the residual radioactivity had declined to . Residual radiation in 2011 was stated to be very low. The reactor and the ship will be regulated until 2031.

Service history

After christening on July 21, 1959, it took another years to complete the reactor installation and initial trials before the ship was moved to Yorktown, Virginia, under temporary oil-fired power, where the reactor was started and tested. Full reactor power was achieved in April 1962. ''Savannah'' was delivered on May 1, 1962, to the Maritime Administration and turned over to her operators, the States Marine Lines. On her maiden voyage beginning on August 20, 1962, ''Savannah'' undertook demonstrations, first sailing to Savannah, her home port. During this trip a faulty instrument initiated a reactor shutdown, which was misreported as a major accident in the press. From there she passed through the Panama Canal and visited Hawaii and ports on the west coast of the United States, becoming a popular exhibit for three weeks at the Century 21 Exposition

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