Overview

The Project GNOME detonation on December 10, 1961 near Carlsbad, New Mexico was the first nuclear test with the objective of developing nuclear explosives for peaceful applications. Along with expanding the data on an underground nuclear detonation in a salt medium, the primary objectives were to:

• Study the possibility of converting the heat produced by a nuclear explosion into steam for the production of electric power
• Explore the feasibility of recovering radioisotopes for the scientific and industrial applications
• Use the high flux of neutrons produced by the detonation for a variety of measurements that would contribute to scientific knowledge in general and to the reactor development program in particular

Measurements of an earlier underground detonation had indicated that roughly 1/3 of the energy was deposited in the melted rock at temperatures above 2,000 degrees Fahrenheit. This information encouraged hopes that a nuclear detonation in a dry medium might cause heat to be stored long enough to permit efficient recovery. GNOME was developed with the idea that a nuclear detonation in a salt deposit would create a large volume of hot melted salt from which heat might be extracted. The possibilities to be investigated for the production of power were the tapping of the steam created by detonation itself and the generation of high-density, high-pressure steam by the circulation of some heat-absorbing fluid, like water, over the heated salt. This generated steam would be used to drive a steam or hot gas turbine coupled with an electric generator.

Because of the widely increased use of radioisotopes in scientific experiments, medical diagnosis and therapy, agriculture, and industrial production, PLOWSHARE scientists sought to find new means for manufacturing and recovering isotopes. Previous underground nuclear tests had demonstrated that large quantities of radionuclides become entrapped in the molten rock formed by an underground nuclear explosion. Since recovery is difficult when the rock solidifies, a new medium of transport for the radionuclides was sought. It was hoped that salt, being water soluble, could be processed to recover the radionuclides more cheaply and simply than from insoluble, low-grade ore.

The GNOME device was emplaced 1,184 feet underground in bedded rock salt at the end of a 1,116 foot hooked tunnel meant to be self-sealing. A shaft 1,216 feet deep and ten feet wide ended in a station room connected to the tunnel.

GNOME was detonated at noon local time with a yield of 3.1 kilotons. Although it had been planned as a contained explosion, GNOME vented to the atmosphere. A cloud of steam started to appear at the top of the shaft 2 to 3 minutes after the detonation. Gray smoke, steam, and associated radioactivity emanated from the shaft opening about 7 minutes after detonation. Radioactive materials vented to the atmosphere about 340 meters southwest of ground zero. Within 11 minutes after shot-time, both the shaft and the ventilation lines were issuing large quantities of steam. During the next 30 minutes, the large flow continued and then began to decrease gradually. The highest measured onsite gamma intensity was 1 R/h. This intensity was recorded 1,300 meters northwest of the shaft opening at 7:38pm on shot-day. The highest offsite reading was 1.4 R/h, encountered along Highway 128 one hour after detonation.The surface radioactivity resulting from the escape of steam decayed rapidly. On the following day, a small flow of steam was still detectable. Underground recovery operations began six days after the detonation. These operations were delayed, in part because of the high radiation levels at the shaft opening (for example, 5 R/h at 9:08am the next morning).

When workers reentered that cavity on May 17, 1962, they found temperatures around 140 degrees Fahrenheit but only small amounts of residual radiation. The earlier intense radiation had colored the salt of the cavity wall various shades of blue, green, and violet.

What You'll See

A plaque marks ground zero. It read as follows:

A second plaque reads:

Public Tours Dates and Times

The plaque can be seen at anytime, no tours are offered.

How to Get There

From Carlsbad, New Mexico, go south on U.S. Highway 285. Before reaching Loving, New Mexico, go east on Route 31. When you reach the Route 128 Junction, make a right and head east. Proceed for 7.3 miles then make a right on Eddy County Road 795, also called Mobley Ranch Road. After 6/10's of a mile you'll notice 795 makes a dead end fork to the right, ignore it and continue straight ahead. After 4.4 miles a small dirt road appears on the left. Turn there and proceed east about 1/10 - 2/10's of a mile to the marker.

For those with a portable GPS, the exact location of Gnome is 32 degrees 15'46.7"N / 103 degrees 51'57.3"W.

Google Map