Verification of the Comprehensive Nuclear-Test-Ban Treaty
Nuclear weapons have traditionally been tested by detonating a nuclear explosive above ground or high in the atmosphere, or in water, or below ground. Before the long-term effects of nuclear explosions on humans were not known, soldiers carried out drills in the test areas, in real conditions.
When it was learned more about the health effects of the nuclear substances released in the explosion, and how they were carried by wind and sea currents, all tests, except for subterranean tests, were banned in 1963. In 1974 a 150 kiloton (kt) limit was set for the size of the nuclear explosion.
