The Atomic Energy Commission (AEC) conducted the nuclear excavation experiment "Sedan" on July 6, 1962. The detonation was part of the AEC's Plowshare Program to develop peaceful uses for nuclear explosives.
Sedan was a 104-kiloton nuclear device detonated 635 feet underground to develop the technology to use nuclear energy for earth moving projects.
The explosion displaced about 12 million tons of earth, creating a crater 1,280 feet in diameter and 320 feet deep. The force of the detonation released seismic energy equivalent to an earthquake magnitude of 4.75 on the Richter Scale.
Because the craters at the NTS had features similar to the topography of Moon craters, Astronauts for Apollo 14 visited Sedan in November 1970. Astronauts for Apollo 16 and 17 also trained at the NTS craters in 1971 and 1972.