Storax Sedan was a shallow underground nuclear test conducted in Area 10 of Yucca Flat at the Nevada National Security Site on July 6, 1962, as part of Operation Plowshare, a program to investigate the use of nuclear weapons for mining, cratering, and other civilian purposes. The radioactive fallout from the test contaminated more US residents than any other nuclear test. The Sedan Crater is the largest human-made crater in the United States and is listed on the National Register of Historic Places.



Project Plowshare was the overall United States program for the development of techniques to use nuclear explosives for peaceful construction purposes. As part of the program, 31 nuclear warheads were detonated in 27 separate tests. Plowshare was the US portion of what are called Peaceful Nuclear Explosions (PNE); a similar Soviet program was carried out under the name Nuclear Explosions for the National Economy.

Successful demonstrations of non-combat uses for nuclear explosives include rock blasting, stimulation of tight gas, chemical element manufacture, unlocking some of the mysteries of the R-process of stellar nucleosynthesis and probing the composition of the Earth's deep crust, creating reflection seismology vibroseis data which has helped geologists and follow-on mining company prospecting.The project's uncharacteristically large and atmospherically vented Sedan nuclear test also led geologists to determine that Barringer crater was formed as a result of a meteor impact and not from a volcanic eruption, as had earlier been assumed. This became the first crater on Earth definitely proven to be from an impact event.Negative impacts from Project Plowshare's tests generated significant public opposition, which eventually led to the program's termination in 1977. These consequences included tritiated water (projected to increase by CER Geonuclear Corporation to a level of 2% of the then-maximum level for drinking water) and the deposition of fallout from radioactive material being injected into the atmosphere before underground testing was mandated by treaty.