U.S.S. Nautilus. One of Argonne National Laboratory's early assignments (Dec. 31, 1947) was to design a nuclear power plant for a submarine. The Naval Reactor Division (merged with the Reactor Division in 1952) was formed for this work. The result was the U.S.S. Nautilus, the world's first atomic submarine, launched at Groton, Conn., on January 21, 1954.