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The first underground physics experiment near Carlsbad was Project Gnome, December 10, 1961 |
| Totally unrelated (and many years prior) to WIPP, the Project Gnome detonation was
the first U.S. underground nuclear test with the objective of using nuclear explosives for
peaceful applications. Project Gnome was intended to provide a detailed
understanding of the underground environment created when a nuclear
explosion was detonated in thick salt deposits.
The nuclear device was emplaced 1,184 feet underground in bedded salt at the end of a 1,116 ft hooked tunnel designed to be self-sealing. A shaft 1,216 ft deep ended in a station room connected to the tunnel. |
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| The Gnome device was detonated at noon local time with a yield of 3.1 kilotons. Although it had been planned as a contained explosion, the detonation resulted in venting to the atmosphere. Smoke, steam and radioactive material began venting from the top of the access shaft (1100 ft southwest of the underground detonation) 2 to 3 minutes after the detonation. Significant venting continued for about 30 minutes and then began to decrease gradually. The highest measured onsite gamma intensity was 1 R/hr. This intensity was recorded 1,300 meters northwest of the shaft opening at 7:38pm on the day of the shot. The highest offsite reading was 1.4 R/hr, which was briefly encountered along Highway 128 one hour after detonation (about 5 miles to the northwest of the site). The surface radioactivity resulting from the escape of steam decayed rapidly. On the following day, a small flow of steam was still detectable and underground recovery operations were delayed, in part because of the high radiation levels at the shaft opening (for example, 5 R/hr at 9:08am the next morning). Re-entry excavation began six days after the test, and the cavity was entered about 6 months later on May 17, 1962. | There were other goals attempted with Project Gnome. It was the first test as part of the "Plowshare" program. 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 potentially useful radionuclides (for radio-pharmaceutical and therapeutic applications) become entrapped in the molten rock formed by an underground nuclear explosion. Since recovery is difficult when common silicate rock solidifies, a different matrix for the radionuclides was sought. It was hoped that salt, being water soluble, could be processed to easily recover the radionuclides for further testing. |
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Re-entry was through an underground tunnel excavated parallel to the original one. The roughly hemispheric cavity measuring 160-170 feet in diameter (larger than the base of the dome of the U. S. Capitol building) and 60-80 feet high (equivalent to a 7-8 story building) is shown in the photo at left. Temperatures up to 130 degrees were recorded. Although some "hot spots" of radiation were found, the general level was from 0.05-0.06 R/hr. Today's radiation level in the cavity is 0.005-0.015 R/hr (about the same as natural background levels found at the surface). The earlier intense radiation had colored the salt of the cavity wall various shades of blue, green, and violet. The test was conducted for the U.S. Atomic Energy Commission by the Lawrence Radiation Laboratory, Livermore, California. |
Movie
clips available from DOE's Office of Science & Technology Information
From 1965-88, Russia explored a program similar to Plowshare that detonated 128 nuclear explosives for nonmilitary experiments. A common goal to develop peaceful uses for nuclear explosives led to ice-breaking meetings between nuclear scientists in Russia and the United States - meetings that allowed Cold War adversaries to share their knowledge of civilian applications for nuclear explosives.
Beyond the Nevada Test Site (NTS), nuclear testing activities were conducted at eight locations in five different states as part of the Nuclear Weapons Testing, the Vela Uniform, and the Plowshare Programs. As part of the Plowshare Program, nuclear tests were conducted at two sites near Rifle, Colorado (Rulison and Rio Blanco), southwest of Dulce, New Mexico (Project Gasbuggy), and near Carlsbad, New Mexico (Project Gnome-Coach). Projects Rulison, Rio Blanco, and Gasbuggy were designed to stimulate the production of natural gas in tight sandstone formations.
As part of the Vela Uniform Program, nuclear tests were conducted near Fallon, Nevada (Project Shoal), on Amchitka Island, Alaska (Project Long Shot), and near Hattiesburg, Mississippi, (Projects Salmon and Sterling). Projects Shoal and Long Shot were designed to determine the behavior and characteristics of seismic signals generated by nuclear detonations and to differentiate them from seismic signals generated by naturally occurring earthquakes. Projects Salmon and Sterling were designed to evaluate seismic signals from both coupled and decoupled detonations in a salt medium (the Tatum Salt Dome).