In the early 50s, American scientists proposed the idea of using the energy of a nuclear explosion for so-called peaceful purposes. It was assumed that the explosions of atomic bombs of various power can be used to solve a wide variety of production problems. The idea was that with the help of an explosion, huge masses of earth and rocks could be extracted very quickly and cost-effectively, making these tasks easier, for example, when creating water canals or mining quarries. In 1957, the American government launched the so-called Operation Plower, during which, until 1973, 27 nuclear explosions were made. During one of them, the largest "dry" funnel was created, which, unlike the famous Chagan crater, which became a lake, has been preserved in its original form to this day.
The Sedan crater project was carried out during the second nuclear explosion as part of Operation Plowcher. Scientists wanted to create a huge crater by testing the possibility of using the peaceful atom for mining. Like all other tests in the framework of Operation Plow, this project was carried out at a nuclear test site located in the state of Nevada. By the way, from 1951 to 1992, about a thousand atomic bombs were detonated in this place.
Today the terrain of the test site resembles the Moon, which is also dotted with craters of various sizes from fallen asteroids. Nuclear weapons tests are no longer carried out here.
Satellite image of part of the Nevada nuclear test site.
How the largest nuclear crater in the United States was created
To prepare for the explosion, engineers created a well almost 200 meters deep and lowered a nuclear explosive device weighing 212 kilograms and with a capacity of 104 kilotons into it.
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The detonation was carried out on June 6, 1962. The power of the explosion turned out to be such that at first a huge dome of sand, stones and earth rose to a height of 90 meters above the surface, which exploded in three seconds, scattering more than 11 million tons of soil over many kilometers.
A crater with a diameter of 390 meters and a depth of 100 meters appeared at the site of the explosion. Today, it is considered the largest crater in the United States created by a nuclear explosion.
Measurements of the radiation level an hour after the explosion showed a dose of 500 roentgens, which is fatal to humans. Gradually, the radiation level decreased and after 7 months it became completely safe for humans. At the same time, so much that it allowed being near the crater without any protective clothing.
The consequences of a nuclear explosion
The worst thing was that after the explosion, a huge cloud of dust was raised into the air, containing various radioactive particles. Then it split in two. The resulting radioactive clouds rose to a height of 3 and 4.9 kilometers each. Dispersed by the wind, they headed to the north-east of the country, reaching the Atlantic Ocean. As the clouds moved forward, they "crumbled" with radioactive fallout. In total, according to unofficial data, more than 13 million people living in the states of Iowa, Nebraska, Illinois, South Dakota were in the zone of deposition of radioactive particles.
According to official data, among all the nuclear tests carried out, the Sedan project turned out to be the most dangerous in terms of the amount of radioactive fallout. In particular, it is for this reason that Operation Plow was closed in 1973. Strong pressure from the American public, concerned about the health consequences of such trials, also played a role.
Is the Sedan crater dangerous today?
Currently, the Sedan Crater Proving Grounds in Nevada are in high demand for group tours.
More than 10,000 people visit this place a year. An observation deck is installed at the crater itself, allowing you to see the local landmark in all details.
Visiting rules are strict. It is forbidden to bring photo and video equipment, binoculars, telephones and other equipment. It is not allowed to take any souvenirs from the landfill area. Even a stone raised from the ground can cause a tourist to be turned to the exit. The zone is strictly guarded by the military and this place is closed from free visits.
At the end of the 60s, similar experiments with the peaceful atom were carried out in the USSR. They lasted much longer than in the United States, up to the end of the 1980s. The Soviet government was not stopped by the bad experience of the Americans with the Sedan crater in 1962. Therefore, a year later, the Chagan Atomic Lake appeared on the territory of Kazakhstan. But this is a completely different story, which you can read about in the previous article.
Nikolay Khizhnyak