The office was originally a joint activity of the U.S. Atomic Energy Commission (AEC) and the U.S. Navy's Bureau of Ships. When the AEC was abolished, Naval Reactors became a joint effort of the Navy and the Energy Research and Development Administration, which partly replaced the AEC. In 1977, ERDA was combined with the Federal Energy Administration to form the U.S. Department of Energy. On the Navy side of the organization, the Bureau of Ships has transitioned since the 1950s to become the Naval Sea Systems Command (NAVSEA), within which NR is Code 08, usually abbreviated NAVSEA 08 or SEA 08.