Project Gnome

Background

First announced in 1958, Gnome was delayed by the testing moratorium between the United States and the Soviet Union that lasted from November 1958 until September 1961, when the Soviet Union resumed nuclear testing, thus ending the moratorium. The site selected for Gnome is located roughly 40 km (25 mi) southeast of Carlsbad, New Mexico, in an area of salt and potash mines along with oil and gas wells.

Unlike most nuclear tests, which were focused on weapon development, Shot Gnome was designed to focus on scientific experiments:

It was learned during the 1957 Plumbbob-Rainier tests that an underground nuclear detonation created large quantities of heat as well as radioisotopes, but most would quickly become trapped in the molten rock and become unusable as the rock resolidifed. For this reason, it was decided that Gnome would be detonated in bedded rock salt. The plan was to then pipe water through the molten salt and use the generated steam to produce electricity. The hardened salt could be subsequently dissolved in water in order to extract the radioisotopes. Gnome was considered extremely important to the future of nuclear science because it could show that nuclear weapons might be used in peaceful applications. The Atomic Energy Commission invited representatives from various nations, the U.N., the media, interested scientists and some Carlsbad residents.

While Gnome is considered the first test of the Plowshare program, it was also part of the Vela program, which was established in order to improve the ability of the United States to detect underground and high-altitude nuclear detonations. Vela Uniform was the phase of the program concerned with underground testing. Everything from seismic signals, radiation, ground wave patterns, electromagnetic pulse, and acoustic measurements were studied at Gnome under Vela Uniform.

Gnome shot and after-effects

Gnome was placed 361 m (1,184 ft) underground at the end of a 340 m (1,115 ft) tunnel that was supposed to be self-sealing upon detonation. Gnome was detonated on 10 December 1961, with a yield of 3.1 kilotons. Even though the Gnome shot was supposed to seal itself, the plan did not quite work. Two to three minutes after detonation, smoke and steam began to rise from the shaft. Consequently, some radiation was released and detected off site, but it quickly decayed. The cavity volume was calculated to be 28,000 ± 2,800 cubic meters with an average radius of 17.4 m in the lower portion measured.

The Gnome detonation created a cavity about 170 ft (52 m) wide and almost 90 ft (27 m) high with a floor of melted rock and salt. A new shaft was drilled near the original and, on 17 May 1962, crews entered the Gnome Cavity. Even though almost six months had passed since the detonation, the temperature inside the cavity was still around 140 °F (60 °C). Inside, they found stalactites made of melted salt, as well as the walls of the cavity covered in salt. The intense radiation of the detonation colored the salt multiple shades of blue, green, and violet.

Today, all that exists on the surface to show what occurred below is a small concrete monument with two weathered and slightly vandalized plaques.