K3SAV NS SAVANNAH

[D.J.J. Ring, Jr.]

K3SAV NS SAVANNAH

When America Made a merchant vessel with Nuclear Reactor

NS Savannah’s engine room was designed around a 74 MW pressurized-water reactor built by Babcock & Wilcox, powered by 32 fuel assemblies of low-enriched uranium and surrounded by thick radiation shielding of steel, lead, redwood, and polyethylene. The reactor was enclosed in a cylindrical containment vessel with 4-inch-thick steel walls, padded against collisions and designed with special manholes at the base to equalize pressure in case of sinking. The reactor generated steam for a dual-turbine propulsion system that produced over 20,000 shaft horsepower, enough to push the 600-foot ship to 24 knots. The engine room measured about 55 by 78 feet and included everything from the turbines and electric generators to evaporators and compressors.

Power was distributed through two 1,500 kW steam turbo-generators and backed by two 750 kW auxiliary diesel generators and a 300 kW emergency diesel unit. The nuclear plant alone cost $28.3 million, while the hull cost another $18.6 million. In her early operations, the reactor released thousands of gallons of radioactive water into the ocean, but later upgrades fixed these issues. After 450,000 accident-free miles and global tours to 77 ports, the ship’s reactor was shut down and defueled in 1975. Though decommissioned, the reactor section remained sealed under strict license until 2031, a silent reminder of when atomic power briefly sailed the seas in luxury.