In addition to the main propulsion engine there is a separate emerney propulsion system consisting of two 1,250 shaft horsepower ctric propulsion motors and their associated starters. Each motor ives one of the main propulsion shafts through its main reduction ar. The large, standby diesel generator can be used to provide power these two motors.

UNITED NUCLEAR CORP.

The prototype nuclear propulsion plant is an integral design utilizforced circulation, pressurized water in the primary system. The e assembly, steam generator, and pressurizing function are all tained within the reactor vessel thus minimizing space require

nts.

The core conceptual design is a two-zone right cylinder. Cruciform trol rods, of silver-indium-cadmium material clad with inconel, powered by canned magnetic actuators. The overall shielding den permits unrestricted crew access to the outside of the reactor partment when the reactor is operating at full power.

anned rotor centrifugal primary pumps, connected by short runs sleeved piping are utilized to provide forced coolant circulation. e pumps are located slightly above the core to prevent possible core covering and to provide a feasible method of pump replacement. e primary coolant water, maintained at a pressure of 1,050 pounds square inch absolute, flows upward through the core in one pass downward through the steam generator; it is then pumped back the core. The top of the reactor vessel is used as a steam dome for -pressurization. An overpressure of 50 pounds per square inch is ntained through the use of helium.

n the secondary system, the steam generator is located above the in the pressure vessel. It is a once-through type and consists of e identical modules in parallel. Each module can be isolated and oved.

CHAPTER V.-NS "SAVANNAH" EXPERIENCE

PROGRAM GOALS AT INCEPTION

The NS Savannah was built to demonstrate to the world the U.S. interest in peaceful applications of atomic energy while concurrently precipitating solutions to problems that would confront a second generation nuclear-powered merchant vessel. The program was designed to prove a nuclear reactor was a reliable, safe and practical heat source for merchant ship propulsion.

APPROVAL, DESIGN AND TESTING OF THE NS "SAVANNAH"

DESIGN AND CONSTRUCTION

The first nuclear-powered merchant ship was proposed in 1955. The Congress approved construction (Public Law 848, 84th Cong., sec. 716 of Merchant Marine Act, 1936, as amended) on July 30, 1956.

The keel was laid approximately 2 years later in May 1958. The ship was launched in July 1959 and the reactor powerplant achieved initial criticality on December 22, 1961. At this time only three central power stations were critical-Shippingport, Dresden, and Yankee. One unusual feature was the construction and installation of the reactor and reactor support system without benefit of prototype development.

TESTING

A thoroughly comprehensive test program was initiated for this first nuclear reactor powered ship to determine that all systems would perform as required. These included extensive dockside tests at reduced power, followed by incremental power increases at sea until full power (22,000 shaft horsepower) was achieved during sea trials on April 4, 1962, and the ship was accepted as completed by the U.S. Government on May 1, 1962.

DEMONSTRATION

From August 20, 1962, to March 1963, the NS Savannah visited 11 major ports on all three U.S. coasts and Hawaii. She traveled 30,722 miles in this first demonstration series.

In March of 1963 the vessel made her first call to the specially prepared nuclear servicing facility at Galveston, Tex. The maintenance period was to last about 2 months and was intended to permit some general system upgrading and repair work, in addition to completion of testing required for annual U.S. Coast Guard and American Bureau of Shipping certifications.

At the completion of the maintenance period, labor troubles with the crew developed and the general agency agreement with States Marine Lines was terminated. This was to delay the vessel's port visitation itinerary by 1 year.

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