H-bombs for peace: The lasting legacy of Project Plowshare's Nevada, New Mexico & Colorado experiments

On December 10, 1961, a three-to-five-kiloton hydrogen bomb exploded underground approximately 25 miles southeast of Carlsbad. 

Six years later, another subsurface nuclear detonation, this one involving a 29-kiloton bomb, occurred southwest of Dulce in northwestern New Mexico. Yet these separate events were not part of a weapons testing program; they were instead conducted under the auspices of Project Plowshare — experiments for the peaceful use of nuclear devices. 

Project Plowshare was an idea that could only have been conceived during the unique convergence of the nascent Cold War and the unbridled optimism of the 1950s. Could nuclear weapons, which had finished the war with Japan and cemented our status as a superpower, be converted into non-aggressive uses in the industrial, scientific, and civilian sectors? 

Could we excavate our canals, build our dams, drill and stimulate our wells, and power our cities with the unbridled energy of atoms?

The possibilities seemed limitless.

“To kill people, except in self-defense, violates moral law; to enable, on the other hand, more people to live a better life accords with man’s higher spiritual aims. Atomic energy can do either or both,” wrote author Ralph Sanders in his 206-page 1962 book  "Project Plowshare: The Development of the Peaceful Uses of Nuclear Explosions."

Beginning in December 1961 and ending in May 1973, the United States Atomic Energy Commission (AEC), predecessor to the Department of Energy (DOE), conducted 35 nuclear detonations for 27 separate experiments in Nevada, Colorado, and New Mexico. 

All were done with the aim not of destruction, but of scientific and engineering progress. According to the DOE Office of Scientific and Technical Information (OSTI) website, at least 25 additional projects were also planned but never executed. 

While the majority of experiments were carried out in Nevada, New Mexico boasted the first nuclear detonation under the Plowshare program, known as Project Gnome or GnomeCoach, and the first joint government-private industry Plowshare nuclear experiment, known as Project Gasbuggy. 

“There were only the two projects here,” confirmed David Hoover, Curator of the National Museum of Nuclear Science and History in Albuquerque, “though there might have been more if the program had continued.” 

Interestingly, both New Mexico projects involved not construction-related aims, but were focused on improving energy development. Project Gnome would primarily examine the feasibility of trapping the energy released by nuclear explosions and using it to generate power at an aboveground plant. Project Gasbuggy would test the practicality of nuclear devices to “frack” a well and stimulate gas production. 

According to OSTI documents, Project Gnome began in February 1959 with a series of three, non-nuclear, high-explosive seismic experiments that were used to predict “ground shock” levels prior to the actual nuclear explosion. 

Despite these earlier tests, on the day of the detonation in 1961, the nearby potash mines and oilfields in the test area were evacuated as a precaution against mine collapse and/or fallout. At zero hour, 1185 feet below the surface in the Salado Formation, the nuclear device exploded with approximately one-quarter the power of the atomic bomb dropped on Hiroshima. 

The blast created a cavity in the salt bed with a diameter of 160 to 170 feet and a height of 60 to 80 feet, with accounts noting that the ground “jumped” eight feet into the air. Unfortunately, after the initial explosion, the experiment went awry — the cavern failed to seal itself as predicted and radioactive vapor escaped through the shaft. 

“They really didn’t get the results they wanted [thermonuclear power generation],” noted Hoover, “however, it did provide information on radioisotopes, which has later proven valuable for medical research.” 

Six months after the detonation, after drilling a new tunnel, scientists entered the cavern and beheld a bejeweled landscape of blue, green, yellow, and violet colors created by gamma rays, with salts melted into cave-like formations. 

“The geology they saw . . . they got to look at things never seen before,” said Hoover. Project Gasbuggy, unlike Gnome, involved a federal/private partnership between the AEC and the El Paso Natural Gas Company. 

According to a September 1967 Popular Mechanics article, the purpose of this cooperative experiment was to stimulate a low-permeability gas field near three of the company’s wells using a hydrogen bomb approximately seven times more powerful than the one used at Gnome. 

The 4,240-foot borehole ended within the Lewis Shale and Picture Cliffs Sandstone Formations, which they hoped the nuclear device would successfully fracture to increase flow, as well as create a huge cavity that would act as a reservoir to store the released gas. Based upon OSTI records and the American Oil and Gas Historical Society’s website, the detonation created a molten, glass-lined cavern; however, it apparently collapsed within seconds. 

The Gasbuggy experiment did successfully fracture the rock, in some areas more than 200 feet, and natural gas production did significantly increase in the area, with the experimental well producing 295 million cubic feet of gas. 

Unfortunately, the gas was contaminated by tritium, a radioactive form of hydrogen, which the AEC opted to burn off during production tests that lasted through 1973.

While two more nuclear gas stimulation experiments followed Gasbuggy, both in Colorado in 1969 and 1973, at least eight other fracking experiments were canceled, including ones in Wyoming, Utah, Pennsylvania, Colorado, and Canada. 

The age of “uninhibited” nuclear experimentation appeared to be ending. 

“I think they lost their appetite for it,” said Hoover. “Public pressure began mounting against it and other technology was cheaper.” Project Plowshare was officially terminated in 1975, though, according to Hoover, the program was funded up through 1977. 

“The Plowshare program did help with VELA verification [monitoring of nuclear detonations to ensure compliance with the 1963 Partial Test Ban Treaty by the Soviet Union],” explained Hoover. This monitoring was made more difficult by the fact that the Soviet Union also had their own peacetime nuclear program, with over 100 detonations for all types of purposes. 

According to Hoover, “they had a lot of accidents, including one on a tributary of the Volga River that flooded nearby towns.” 

Today, Project Gnome is a DOE Category II Legacy Management Site which undergoes long-term monitoring of groundwater contaminant levels of cesium, strontium, and tritium. 

Project Gasbuggy, located within the Carson National Forest, is also routinely monitored, as are the nearby gas wells. Both sites are denoted by markers and are easily accessible to the casual adventurer.