Underground nuclear weapons testing

Underground Nuclear Weapons Testing

Test preparation at the Nevada Test Site

Underground nuclear weapons testing refers to the detonation of nuclear weapons below the Earth's surface. This method of testing is used to evaluate the performance, yield, and effects of nuclear weapons while minimizing the release of radioactive material into the atmosphere. Underground testing became the preferred method after the Partial Test Ban Treaty of 1963, which prohibited atmospheric, outer space, and underwater nuclear tests.

History

The first underground nuclear test was conducted by the United States on September 19, 1957, at the Nevada Test Site. This test, known as "Rainier," was part of Operation Plumbbob. The success of this test demonstrated the feasibility of underground testing as a means to contain radioactive fallout.

Plumbbob Rainier test

Following the Partial Test Ban Treaty, underground testing became the primary method for nuclear weapons development. The United States, the Soviet Union, and other nuclear powers conducted numerous underground tests throughout the Cold War.

Testing Techniques

Underground nuclear tests are typically conducted in deep shafts or tunnels. The depth and geology of the test site are critical factors in containing the explosion and preventing the escape of radioactive material.

Shaft Testing

In shaft testing, a vertical hole is drilled into the ground, and the nuclear device is lowered to the bottom. The shaft is then backfilled with materials designed to contain the explosion.

Tunnel Testing

Tunnel testing involves detonating a nuclear device in a horizontal tunnel. This method is often used in mountainous regions where deep shafts are impractical.

Effects and Containment

Diagram of nuclear explosion craters

The primary goal of underground testing is to contain the explosion and prevent the release of radioactive material. The explosion creates a cavity and a rubble chimney, and the surrounding rock absorbs much of the energy.

Notable Tests

"Uncle" nuclear test, 1951

• Operation Plumbbob: Conducted in 1957, this series included the first fully contained underground test, "Rainier."
• Operation Teapot: A series of tests in 1955 that included both atmospheric and underground detonations.

Operation Teapot

• Whetstone Sulky: A test conducted in 1964, notable for its use of a large underground cavity to contain the explosion.

Whetstone Sulky test

Environmental and Health Concerns

While underground testing reduces atmospheric fallout, it can still pose environmental and health risks. Seismic activity, groundwater contamination, and the potential for accidental release of radioactive material are significant concerns.

International Treaties and Moratoriums

The Comprehensive Nuclear-Test-Ban Treaty (CTBT), adopted by the United Nations General Assembly in 1996, aims to ban all nuclear explosions, including underground tests. Although the treaty has not yet entered into force, many countries have observed a voluntary moratorium on nuclear testing.

Related Pages

• Nuclear weapons testing
• Nevada Test Site
• Comprehensive Nuclear-Test-Ban Treaty
• Operation Plumbbob